Tuesday, March 31, 2009

VK9 and FK8 in the log

Conditions were favorable and the bands were quiet this morning and I had them both in the log in 5 minutes. Skimmer allowed me to figure out a pattern that would get me through. The FK8 was listening at the lower edge of the pile up and the VK8 at the upper.

73

Monday, March 30, 2009

I swear if you can think it someone can do it!!!

Recall I was daydreaming about probe antenna arrays. In my daydream I cooked up a situation where instead of coaxial phasing boxes and delay lines you use SDR receivers and some kind of protocol to time mark each packet of sampled information. With this kind of antenna you would have virtually complete control over where your antenna points, and where your nulls occur. You could even do multi-multi arrays, and for a very wide band width of frequencies. The problem with this idea is accurately giving each packet of I/Q data a time stamp.

Bob N4HY put on the reflector some information about a German ham group who was preparing for interplanetary ham communications. This in itself is an amazing thing to contemplate, especially for an old geezer like me who is stuck on 160M and 80M.

What kind of hardware are the Germans using? Why soft hardware of course!!!! SDR and BIG HONKIN ANTENNAS. They are using the SDR-IQ from RF Space.



I was poking around the RF Space website and lookie what I found!!


Here are some of the specs

PRELIMINARY Frequency Range: 0.01 - 32 MHz * Digital Down Converter: Xilinx XC3S500E PC Interface: Ethernet 100 base-T (UDP/TCP/IP) Filters: 32 bit ,120+ dB 90% Alias Free BW Decimation Rate: Variable 70-2047 Output Sample Rate: 39 KHz to 1.15 MHz @ 24b IQ Flatness: <0.1> Dynamic Range: 105 dB MDS: -132dBm in 500 Hz BW Analog to Digital Converter: 16bit w/ Dither Preselection: 10 Filters Attenuators: 0, -10dB, -20dB, -30dB Sample Rate: 80 MHz Memory: 65536 x 16 bit samples External Radio Control: Built-in RS-232 port Dimensions: 210 x 70 x 180 mm Display: 16 x 2 Character LED LCD Power: 5 Volts DC @ 1.5 Amp ** Connections: 4 x BNC (RF In, Ext Ref, Trigger, IF Out) , RS-232, Pulse Out, Ethernet, Power. Expansion: Internal Downconverter, Internal 10 MHz Phase/Frequency Lock. Price (base configuration): Estimated MSRP $2999.00, EURO 2250
$2999 You might say ARE YOU NUTZ!!! Well I just may be nutz, BUT It proves the concept.

Here is the exciting part:

The SDR-IP can be configured with a ultra low phase noise encode clock option (REF-ULN). This oscillator can be locked to reference clocks like GPS and Cesium standards. A trigger option allows the synchronization of multiple SDR-IP receivers to trigger signals or 1PPS pulses from GPS to within ~50nS. This allows many SDR-IP receivers to be used in radio holography, direction finding, interferometry and radar applications. The ethernet I/Q data is serialized so that streams from multiple receivers can be processed coherently (processing software not supplied). When not externally locked, the optional oscillator has a stability of +/- 1 ppm over temperature. The phase noise at 10 KHz is -170 dBc/Hz typical.

Eventually the cost will come down. This unit uses a very advanced A/D which samples the entire Spectrum all at once. The protocol is TCP/IP, on an intranet. Time Stamp? How about buying a few closed out GPS receivers. You could even use the GPS to accurately mark the location of the probe antennas for software analysis.

You can say " but but but this is so expensive and complicated...." You need 20-30 acres for a bunch of beverages. How much does that cost? With a system like this you could build one big tower in the middle of the property make a 4 square of wire transmitting verticals or 3 el parasitic arays, and have a very elaborate receiving array/s probably on 3 to 5 acres. Cheap in comparison to 30 acres AND more versatile. With this kind of setup you can optimize the TX antenna for best gain, and you can optimize the RX antenna for best pattern, hence best of both worlds.

Hmmm it said RADAR and holographic applications.... I wonder how you call CQ on RADAR or a holographic QRZ? I know what 3 dimensional radio looks like since I own one but how does 3 dimensional holographic radio look?

I wonder if we could use the hologram to generate a virtual KNOB?

73

This is how bad it is


This morning I was listening to VK9LA calling CQ on 3523. He was very weak about 5 dB out of the noise but Q5 most of the time. On 3522 there was a QSO. Here is a shot of one of the stations down the band. This guy was not very strong, only about S-7 but just look at his bandwidth on skimmer! My listening freq is where the little green arrow is on skimmer. You can see the tails of the key clix extend well past my listening freq. If you look you can just see the VK9 start to transmit near the arrow. The VK could be copied but so could the clix and no amount of filtering on my end will solve this problem. Note skimmer uses intensity as the way it displays signal strength. If you look closely you can see the key clix are just about the same intensity as the VK9. Also I can tell you from this picture this guy is transmitting through a 2.7khz crystal filter because that is his bandwidth, and the offest of his CW carrier is about 1000hz. Just by switching in his CW filter on transmit this guy could dramatically improve his click problem. See how easy the fix could be even for a legacy transmitter. In fact there are some manufacturers that do just that. You can tell because they have a crappy signal contained within a 500hz bandwidth. You can pick up this kind of signal from the panadapter alone. When your signal has clicks your signal looks like the Eiffel tower with little bumps going up the sides. The higher the bumps the worse the clicks



For comparison here is a shot of the guy to whom he was talking. This fellow is about the same signal strength. I won't publish the first guy's call but he is a W1 with a fancy schamncy Extra call. I'm sure if I sent him these pics he wouldn't have the first clue how to fix the problem because it probably has been manufactured into his radio. If this signal was on SSB guys would be checking in raising hell about the buckshot in this guys signal, but because its on CW this guy probably will never know how bad his signal is. If this was an SDR, first of all you would never see such a distorted and broad signal, unless you were flat topping a linear. Second if you did have such a signal you would merely adjust the code (as in software, not as in Morse) and clean things up, and in one fell swoop you could cure all the SDR's that you have sold. You can tell this is not a linear flat topping situation since the clicks are finely delimited to 2.7khz. Linear flat topping would extend even farther up and down the band and would tend to be symmetric.

A picture is worth a thousand words. Its amazing how much information you can glean from this system. Why if I was an OO I could run amok writing people up!!!

73

Sunday, March 29, 2009

New Radio


This is the really cool thing about SDR. I checked my mail and voila' a new radio heard from!!

Vic VK1AA sent in a note about the GENESIS G40. Its a 40M 5 W transceiver, and depending on the which sound card is used for the A/D converter can work CW/SSB/FM/Digital (not sure why a 40M rig would do FM). For SSB you would need 6 channels including a mic channel, but for CW only 4, 2 inputs and 2 outputs. The size is bout 7.5" x 6", so you could make a really neat little QRP portable rig out of this, or a dedicated 40M PSK31 rig. The only time I run QRP is when I HAVE to (like during the hurricane when the lights are out. I fired up my K-1 and worked all over EU during one hurricane in the dark) The RX specs are excellent. It works with a variety of SDR back end software. It's great to see the world wide interest, and there is considerable interest down under.

I''ve spent the weekend putting together the Softrock 9.0 lite. I'm almost done so its basically a weekend project for those interested. One of the caps in the filter was cracked so I need to replace that before I fire it up.

I saw a buddy of mine at Orlando and he was showing a lot of interest in SDR. I sent him a note that I was doing this blog. He sent me a note back he was waiting on a F3K. Way Cool

73

Friday, March 27, 2009

Just checked my mail

I just checked my mail and here in part is what one gentle man wrote:

Don't stop that blog on SDR!
Its great and I look forward to reading it ever since I discovered it.
I am 81 years old and been in sdr since the SDR 1000. I don't pretend to be very proficient at either
the electronics or the DSP or the computer part of the systems but it is such a wonderful learning experience that I look forward to any explanations. Yours are especially clean and clear.


To me this is totally cool, and I hope if I make it to 81 I'm still digging my SDR!

He says he like my personal touch even my prejudice against the K-3!! Actually even though I am a little harsh on the K-3, what I actually find distasteful is how quickly the backbone of radio in general is being replaced with SDR on every front and how little most hams have been instructed in this technology. I'm cynical and I think it is conspiratorial between the manufacturers and the magazines especially ARRL. How is it our "national organ" has done such a dismal job of educating us? How is it things like this only get covered in QEX, or by some gun slinger with a blog?

When I read the reviews of SDR in QST the reviewers clearly are novices in the land of SDR. Just the way they couch their criticisms make it clear they really don't quite understand what the hell they are talking about. I'm sure in the analysis of radios like they K-3 they are hip deep in experience but not when it comes to SDR. SDR demonstrates a whole different skill set. (that is what this blog has been devoted to, trying to expose the skill set of the SDR)

If you look at this one pic


It begs the question, if a ham over in Russia can make this pic why is it the ARRL failed to generate this same pic? All they had to do was mover the 2 signals INSIDE the roofing filter. This is the thing that I find disturbing, not whether the K-3 is a good radio or not. The K-3 is clearly a very strong radio BUT.... and the fact that the BUT is treated like the crazy aunt in the attic to me is disturbing. here is another pic:


This is shot of the LP-PAN with and without the K-3's IF connected. Note how the K-3 adds 15dB of phase noise to to the signal, and note how clean the LP-PAN (which when run along with PowerSDR constitutes a complete SDR receiver around the IF frequency) is about 15dB better on its own. Another crazy aunt in the attic? Here is a quote from Larry N8LP's site regarding the quality of his LP-PAN

I wanted to make sure that the K3 was the limiting factor when used with LP-PAN, at least up to the maximum signal level of LP-PAN, which is +2dBm (S9+75dB). Above that level, the combination of the K3 roofing filters and hardware AGC add another 30dB of dynamic range under most conditions, making it the best rig on the market in that regard. Luckily, the user will likely never see a signal that large, and the +2dBm maximum signal handling of LP-PAN will not be taxed unless you are in a multi-multi contest station or in Europe next to a large broadcasting station.

As you can see in the top picture for the standalone LP-PAN, IMD DR is about 90dB, with no extraneous distortion products. Quite amazing for this bandwidth, and comparable to some of the best rigs on the market, including the K3.


Note the user will likely never see a signal that large!! I have a car that will do 155mph. I will likely NEVER see an occasion to go 155mph. I have that car because I wanted that car, not because I NEED that car. The last line tells the story. If you add up a loaded K3 its around 4800 bux. Larry's 200 buck converter box PLUS POWER SDR is comparable. Just let that permeate your old cerebral sauce pan for a second!! Now Larry's radio only receives on the IF frequency so to be sure it is not stand alone, but still the statement is remarkable.

The limiting factor of this system is the K3, not the little "LP-PAN plus PowerSDR" receiver. Note the LP-PAN on its own is nothing with out PowerSDR or another software back end. The new F3K will similarly be this good (actually probably a little better in terms of performance), comparable to the K-3 and the F3K is a full featured 100W radio with built in antenna tuner, FOR 1600 BUX and needs no additional filters or anything else!!!! Hello Hello anybody out there? This is where ham radio is going. It has to go there. There are very few circumstances where you would ever need more radio than this for most hams. Like Larry says, maybe multi multi on a desert island or parked next to a foreign broadcaster in EU. I have corresponded with Flexers over in EU and none of them have complained about the IM response of the RX to me.

So what does this say about prejudice? Here are the facts, and you can draw your own conclusion. If you add up the cost of the K-3 fully loaded with filters, antenna tuner, bandpass filters, I/O board, Second RX, and the LP-PAN plus sound card, it comes to about $4800. I have discussed this with K-3 afficianodos before. People start subtracting things to try and get the price down, like well you don't NEED all the filters, you dont NEED the ant tuner, you dont NEED the high accuracy oscillator, you dont NEED the transverter I/O board. OK I will subtract the ant tuner that leaves $4470. Right now you can buys a F5K for 2520 on sale with second RX for 3220. Why do I include all that other stuff, because that is the apples to apples comparison. ALL THAT OTHER STUFF is already in the F5K. In fact the oscilator in the 5K is 0.5ppm not 1ppm, and the 5K has a more versitile and effective antenna switching setup. So again what does that say about prejudice? Here are the facts you can draw you own conclusion.

This is where ham radio is headed for no other reason than economics. Ham radio went the way of transeivers 40 years ago because of economics. You got a lot more for a lot cheaper from a Kenwood that you could get from owning a seperate TX RX combo. The same thing will drive SDR. You get a heck of a lot more bang for the buck, period. You can buy a heck of a nice beam or the better part of a nice amplifier for $1250. A new AL-80B goes for $1449. So there are the facts. You pays your money and gets your deserts. At some point you have to ask yourself is that extra couple dB dynamic range really worth $1250?

just ask yourself these questions and check the ( ) if they are true:

I don't live next to a SWBC station ( )

I don't plan on running multi multi on a deserted island any time soon ( )

I might like to buy a linear amp or beam, or take the wife on a vacation with the 1250 bux I save ( )

73

Not much today

The bands have been terrible here. We are finally getting some rain activity, and when the storms are present in the Atlantic or the Caribbean I suffer greatly, but its a fate I suffer gladly since when they are absent this QTH is hotrnapistol.

It has been tremendously dry and that leads to wild fire conditions around here, so even though it messes up my radio time, it gives me more comfort that the state won't burn down. I had burned spots in my lawn, and a pumper truck parked next to my house in '98 so this is something I take very seriously.

I have all the surface mount done on the softrock without any lost little bits or solder bridges. If you choose to do this I suggest a flux pen and some of the .015 silver solder from Radio shack. Not much is worth anything at RS anymore but this stuff is good stuff. I haven't built something like this for a while so this is a lot of fun to do. There are a lot of building options where you can do a bunch of testing and step by step as you go, but I am doing the "terse" method where you just stuff the board and then test. I hate winding toroids so that will be the only downer of the deal. I'm exactly at this stage

(from ayoko's site)

73

Thursday, March 26, 2009

Is anybody out there??

Today I received a nice note from a reader. I've received a couple of note of encouragement now and its heartening to think that some are gaining from what I have to write. It is an example of the community and enthusiasm that surrounds the SDR initiative.

I asked Steve for permission to re-print his note because I think its important to share his enthusiasm with the community

Hi Lee

Well, I can guarantee that there are at least two folks who are spending valuable time each on your blog, you and me!

I really enjoy it and here is some info for you about me. I was licensed at age 10 as WN1ZPT and was very active through high school and college. My college, Johns Hopkins University, had a nice station in a dedicated small building. Well, that was a long time ago, and about 6 months ago I was bit by the ham bug again. The web helped me to get caught up and the changes in the hardware, licensing requirements, digital modes, etc were simply amazing. But SDR really caught my eye and I have been educating myself day and night about the benefits of using a fast PC to become the radio with a little help from a nicely designed box by Flex Radio.

My 5000A is due today and a nice Dell box arrived yesterday, so I am pretty well set to plunge into SDR in a big way. Your blog has been very helpful and encouraging. I just don’t see what the Elecraft guys see in the K3. They are living in the dark ages. PCs are a reality of life and the PowerSDR application gets better almost every day. Sure, I was once a knob twister, but my mouse skills are also superb.

Keep up the work on your blog. I learn something everyday and will never look back a dual conversion superhets. The real challenge is now antennas!

73s

Steve Silverman
Newly licensed as KB3SII, a 66 year old white guy still doing satellite communications engineering for a living and loving it

I know a couple other satellite communications guys that find SDR fascinating as well. I am glad to have Steve's support and I know he will love his new radio. When I was at the Orlando hamfest last month, at the SDR talk the tent was full of some old timers who were interested in seeing just what all the hubbub was all about. It was very cool to see the interest.

Right now I am looking into starting to build that Softrock V9.0
I bought last week.



(check out Atsushi's slide show here) The base of my magnifier light failed so I'm spending the afternoon over-engineering its replacement. NO WAY JOSE I can build this thing with out my magnifier----> I'm blind without it when it comes to those little parts!!! Check out this video You see! This stuff isn't that hard!! Get "on" your duff and build one!! (DO NOT ATTEMPT TO BUILD THIS IF YOU ARE OFF YOUR DUFF!!)

73

Tuesday, March 24, 2009

Out On The Perimeter

There are several other SDR initiatives happening. I am certainly NOT a catalog of what is going on.

There is a site called HPSDR that I spent some time with. In the days of the SDR-1000 there was a group that came together to develop what was presumed to be a cheap alternative to the $350 "sound card" that the SDR-1000 required. Note the present day Flex radios do not require any separate gear to perform. The "sound card" has been replaced by an A/D converter which is the function that the sound card performed and for audio duties codecs have been incorporated, so these rigs are stand alone except for the computer of course.

It turned out the "cheaper" sound card would up costing about $400 by the time it was all kitted out including power supplies etc. It was pretty high performance though. It was a monumental task (I just bought a couple of these I did not do the work). The boards were distributed by TAPR and if you go to that site you can still see them listed. It was an interesting experience and it became clear to me just how important having a company like Flex was. It was clear this endeavor would not be sustainable, and that has proven to be true. Because Flex is for profit it gives an ongoing enterprise which the community can rally around, and this symbiosis to me seems absolutely necessary to proceed to the future. If everybody is just a volunteer, its a lot like herding cats. The project is fine until you get bored. Because Flex is open to collaborators, l can collaborate share my data and the fertile ground of ideas gets plowed and fruit of those shared ideas grows. If you look back at the posts I have recently posted you can see this is the case. In this edition I hope to look at some of the other ideas floating around world regarding SDR.

HPSDR resides on its own board. There are a lot of interesting projects going on there, but in some respects it reminds me of the "hobby radio" kind of thing Flex was when it started. To see the projects click the tabs near the top of the page. The dark blue are nearing completion and the Cyan are "proposed" (aka day dreams). Very interesting stuff.

Here is a transceiver project built by Phil Harmon VK6APH, and give a taste of the high quality experimentation happening over there.


Phil is a mover and shaker in the HPSDR world and it is very cool to look at his skill set and see what he does. Go over there and peruse the place. They also have a reflector so you can follow along. If you don't know much about SDR following a reflector is a good way to pick up on concepts. Even if you don't quite get it, you will be exposed to the language and eventually things will start to make some sense.

Another SDR enthusiast has taken his interest into a commercial enterprise N8VB has produced the QS1R which is a high performance SDR receiver.

I love the look of this picture. My ten year old says it looks like a city.

So take a look over there and see N8VB's masterpiece. I think he has a transmitter in the works as well.

There have been a couple of clones of the SDR-1000 built and marketed. The latest is the Wonder Radio which is being marketed by an Indian company. This radio is basically a knock off of Gerald's article and capitalizes on PowerSDR as its brains. It has its faults, but I think one very interesting thing is there are a billion plus people in India, and in that billion people are a lot of kids who are driven to get ahead. I can see this as being a SDR laboratory that a kid could get his hands on and modify the code and modify the code etc and become really smart about SDR therefore assuring himself or herself a future. Ham radio is not just the US but it is a world wide enterprise. Imagine when there is a band grab for some ham frequencies the thing that SAVES us is the fact there are hundreds of thousands of Indian kids running their 1 watt knock offs and therefore there is tremendous usage of those frequencies so they should be preserved. Also just because we in the US are a bunch of old fart white men and we are dying, does not mean the hobby is dying world wide, not by a long shot.

I had some correspondence with some SDR types in Russia and they assure me there is a BIG interest over there. I know also there is interest in the old eastern block Soviet countries. So while your quacking about the weather on your latest Yahoo FT-25000 transceiver there is some kid over in India just itching to eat your lunch. I've been to China a couple times and this is absolutely true. In these developing countries they are leapfrogging over the old technology strait into the new, and those of us demanding things stay the same will be left in antiquity.

There was a company in Europe that started a SDR-1000 knock off but I think they went out of business. Now adays it is not trivial to get something like this off the ground. For example the European Union has adopted certain "standards" that erect effective trade barriers and tariffs, in other words hurdles you need to jump before you can market your radio there and hurdles are expensive to overcome. It takes someone with enough resources to mount these barriers. Even in the US to become type accepted required a number of barriers to be scaled.

A radio like the F5K has great potential to be set up as a frequency hoping kind of radio. In order to attain type acceptance the radio HAD to have a firmware layer inserted that stops the ability to do this. Why is this important? Freq hopping algorithms can be constructed that makes the radio virtually undetectable to someone who might want to listen in like the government. Not all ham radios get used by hams.

Lest I forget there are the softrock projects. Here is an article on the softrock rx/tx combo QRP rig. These Softrock rigs are the "every man rig of SDR" They provide a wonderful look inside of SDR at a ridiculously low price. Their performance is pretty much entirely sound card dependent, but there are plenty of sound card upgrades out there for not a lot of money these days. Included in the last article is a reference to yet another minimalist SDR console program called the "KGKSDR" This is just one of the many hobby type home brew projects out there. All you need is a couple hundred bucks some time and determination. I've built a few of the Softrock rigs. I've taken them on vacation along with my laptop. Its fun to flip a wire out the balcony or take the laptop out to a park and flip a wire into a tree and hear what you can hear. Their performance is totally dependant on the quality of the soundcard and horsepower in your computer. Given the horsepower that abounds these days those limitations are no longer limitations

There are probably a dozen other projects going on out there I don't know about. I have a hard enough time keeping track of the little I keep track of. There certainly are other software enterprises in motion including the GNU radio project and others.

If you search around I'm sure you will find much more to experience. Another goodie JAVA Console you tube JAVA Console blog As you can see much good stuff is out there. Radios are being built that can be distributed across computers so your DSP may be on one machine while your GUI is on another. This will be the case with the new PSDR architecture. It will also be platform independent. It will be as I understand it in ERLANG with I understand a healthy does of XML. ERLANG is interesting. You can replace whole modules in the program while the program is running....take out the right brain, put in Brian 2.0, kind of mind boggling (pun intended)

Above all go forth and have some Ham Radio FUN!!

73

Monday, March 23, 2009

VHF

This is a subject I know very little about. I was hoping some of the fire breathing VHFers that occupy the denizens of SDR land would come forth and write a screed about the virtues of PowerSDR in the land of high performance VHF and satellite. Most of the guys interested in this area are pretty technically savvy so they can probably get the jist by just looking at the pictures (thank God)

My experience is limited to the 60's when I built a screen modulated AM 6 meter rig with a 6146 in the final and talked to all the TV's in the neighborhood. In the 70's I had a double extended zepp beam which was the brain storm of Russ Farnsworth (yes of the Farnsworth method) He was a blind ham that was living down the road from me in Arcola Il. This man was a wonder to behold. He was blind but he worked on his own gear using meters that had audio instead of visual readout. Russ had perfect pitch and he was a musician which was how he made his living. I think he went by "Blind Lemon Farnsworth" or something (just kidding) Russ had a little piece of property and he had a telephone pole for a tower. On the side of the telephone pole he had a rail road track. On the rail road track he made or had made a gzmo that could raise and lower his antennas for measurement. Hazer Schmazer he had a Farnsworth!! He also had a hand held field strength meter that outputted audio. He would run around his property taking measurements on his antenna range.

His beam idea was to use a double extended zepp as the driven element and to use a 1/2 wave element with the current nodes lined up behind each half of the double extended zepp. This means each parasitic element was made up of 2 collinear half waves and the 1/2 waves were separated by a 1/4 wave of insulation. So think double extended zepp with a bunch of 1/2 waves in front and behind each half of the zepp element. The result of this was a 2 meter antenna that looked more like a 6 meter antenna, AND with about 6 of these elements you realized 17 dB of forward gain. Cool idea!!! Russ was smart has hell. His feed also taught me about using open wire line on VHF and I have used it up through 432 with good result.

Anyway here is the transverter set up screen in PowerSDR. I high lighted 3 of the possible 13 VHF bands you could accommodate. As you can see each of these can be set up to run the transverter precisely. You can set that band spread (for example 144 to 146 or 144 to 148 depending on your transverter. You can also reverse the mixing scheme so if your transverter goes down in freq as your IF goes up in freq that can be accommodated. (I once converted an old Motorola mobile tube radio someone gave me to 432 sideband by mixing my Drake TX4's output onto the grid of a multiplier in the Motorola. I tuned the oscillator to 460 and mixed the 28mhz on the grid tuned the final to 432 and voila'. That kludge went in the wrong direction, but it was free and it got me on 432. This idea was cooked up by my old buddy Al Wolf K9SI)

You can set up in the case you have a RX only transverter and the RX gain, and the drive level etc. I have a TT 6 meter transverter and I used my SDR-1000 to drive that little bugger and this setup works like a champ. When I got the TT transverter, I didn't have a 6M antenna set up so I just used my 130ft 80M flat top. I made a quick little open wire tuner out of some wire and a couple of caps and had at it. In 15 minutes I was making contacts. My pattern was all up and down the east coast and down to SA so I made quite a few contacts with my 5 watts on my 80M antenna. I know this is all VHF heresy but like I said I don't know anything about this topic.

6M pattern of my 80M flat top


XVTR set up screen:


Here is a shot of what the radio looks like when you fill in some of those fields. The radio looks just like a 2 meter radio It keeps track of what part of the band you are in etc. You can set up the radio so that you can run full duplex for example like you might want to do for satellite work so you can tune yourself in the transponder etc.


Here is a shot of the antenna screen as you can see under expert mode VHF is fully integrated in automatically steering the signal out the right pipe, and turning on the right amp or preamp keying line.


The radio has built in a system to set up how long it takes between a PTT signal and how soon RF actually shows up on the pipe so you can tailor your preamp switching and all that into the signal flow. No need to burn out that nitrogen cooled FET or what ever!!


Station control is even more intense. In the days of the SDR-1000 there was a board designed by Tony KB9YIG (of softrock fame). It was called the UCB or universal controller board. Here is a pic of the board as implemented by KM0T These are shots from his site








Mike has done a great job of implementing the power of SDR into his shack and I strongly suggest you spend a little time on his web site. You see home brewing is NOT dead not by a long shot. The emphasis has just changed from build a RX to building a station.

The SDR-1000 used a proprietary I/O jack called X2. As such all peripherals for the SDR was a custom deal. Here is a shot of the X2 control panel in PSDR

You could control per band up to 6 things. I built an automatic antenna switch based on this arrangement. Click a band and ready to transmit. I also built a little fan control that slowed down the fan on RX and turned it on full on TX. I used pin 6. So all the pin 6 checks for all the bands were checked on TX if I wanted the fan to run high all the time (like for RTTY) I checked the pin 6's in RX.

The F5K has moved to something called the Flex wire which is actually an Phillips I2C bus



The bus allows for special chips to communicate with each other and can have a bandwidth as high as 3.4mhz. The bus is a master slave or master master arrangement and allows for things like pots and eproms and BCD to be addressed as well as switches and relays. If you can get a pot you can make a rotor or you can make an auto antenna tuner at the base of the antenna for example. There is a LOT you can do with this bus that is well beyond what we normally use in ham radio. The bus is a 3 wire affair but it can also be configured to a 2 wire affair. Ever want a wireless data port out by the tower? Check out this!

The first peripheral based on this bus is on design right now by Steve Nance K5FR and Phil Theis K3TUF. Here is a shot:


Note the LEDS It truly is alive!!!! Steve and Phil collaborated with Eric from Flex and Bob this weekend to allow the flexwire to be accessed form DDUTIL Cool!!! I just read a reflector note that this board is now talking to the UCB so things are heading in the right direction.

Read about this woner HERE This device will connect to the previous UCB as well as has multiple outputs that can control VHF transverters as well as low band stuff, as well as has an output that you can control discrete things like turning on your linear from a remote location, or switching the directions on your 4 square from the keyboard. The program that interfaces is called DDUTIL for which Steve K5FR is the author. Here are a couple shots from DDUTIL



And the Macro screen


It is through this program very complex station control manipulations can occur. For example you could have a macro that turns on your linear sets your band to 20M along with your linear to 20M tunes up your STEPPIR on 20, turns on RX 2 in PSDR and sets the VAC output to Skimmer to RX2 and rotates the beam. The VHFer, EMEer or Satellite enthusiast gets a very clear understanding of the macro idea's utility.

The DDUTIL board also can be controlled from a serial or parallel port on the computer so no need to access the flexwire unless you desire the special features the flex wire offers, for example ALC is being devised as a possibility. Flex wire offers the ability to send audio down the line as well as data. You can access A/D converters....hmmm maybe this is the solution to my daydream

Like I said, I'm sure I didn't do this topic justice. There is a ton of information underlying these notions, but what becomes very clear is how much you can play and experiment with your station with this system. It is all highly integrated and highly plastic. If you think home brewing is dead think again. It is so alive and well and vibrant its amazing. I often read EHAM articles about geezers complaining about the demise of ham radio. For me I was totally bored with ham radio. It was this SDR stuff that revitalized my interest. I think the reason people toll the death knell on ham radio is that they are the ones dying. It is their interest that has wanned, and they are merely projecting that onto ham radio in general. Sure magazines like QST have become brain dead. Who cares. I stopped reading QST 20 years ago (except I gave it one more try a couple years ago). It was like a soap opera, nothing had changed. It was still the same stupidity month after month. You too can make a mic holder out of PVC pipe!!! Hey Mabel did ya see QST has an article on building a 2M vertical??? This one was written buy some guy with a PhD in EE. What crap.

Its all out here if you want it, but nobody gonna spoon feed you. You have to get your hands dirty. The rewards abound.

73

Saturday, March 21, 2009

Other Screens and external programs

Here are a few more screens that show how the "radio" works. This is the Power Amplifier test screen. In order to set up the power amp you need an external wattmeter specifically a Powermaster from Array Solutions. This meter is used to complete the feedback loop to the radio.


When you do all this, you are actually making changes to the hardware. This layer therefore interfaces between the hardware of the F5K and the software of PowerSDR. For example to set up the actual bias voltage on the final transistors and the driver transistors, you can adjust this voltage from PowerSDR. You don't pop off the top of the radio and get out a screwdriver and hook up a meter you let the computer do it.

This screen takes you deep into the radio. You can watch this screen as the radio tunes itself and see the various controls changing for example as the carrier is nulled. In the SDR-1000 all this was done by hand. The other thing is you can change the bias for example according to mode. So if you want to run class A you can run class A just by changing the bias.


This screen takes you even deeper into the hardware.


If we were on the "Enterprise" this is the place where Mr Scott would live.....I cannna geeve ya yani moor capn she's breakin upppp...

The Temp and voltage can be monitored or this data can be exported to another program


Note the temp is revealed in the lower right corner of DDUTIL


I also have readout on VFO-A and the two boxes just above the VFO reading go to my LP-100 wattmeter. When I transmit it shows Power out and SWR. Also you can open and close the Flex Profiler program. More on that in a minute.

You have to be careful with these screens if you decide to fool with them. Screw up and y0u can destroy your radio, but I wanted to show these so you can examine a more intimate view of how the hardware interacts with the software, and to try and remove a little of the "black box" nature of the whole thing.

The Flex profiler is a program written by Bob Tracy K5KDN. Bob takes care of the cat control commands for PowerSDR and if memory serves I think he wrote the CW keyboard/memory keyer program in the radio (CWX). Here is a screen shot of Profiler for a CW profile:




Here is an explaination of what profiler does:

AN INTRODUCTION TO THE FLEXRADIO PROFILER CONFIGURATION MANAGER
The FlexRadio Profiler (FRP) is a configuration management program that permits the FlexRadio user to build, store, and recall radio configurations by name. The only limit on the number of profiles that can be stored is the memory capacity of the computer on which they are stored and some common sense on the part of the user.

FRP is a standalone application. You do not have to have a FlexRadio running in order to use it. The FRP program communicates with a FlexRadio via virtual serial ports, just like a logging or contest program.

You can generate a profile in any of several ways. The easiest way is to setup your radio in a desired configuration and record that to a profile name. Another way is to set the controls on the FRP console and save them as a named profile. You can recall an existing profile, modify it, and save it to a new name. Profiles may also be saved in the same directory as PowerSDR.exe and executed from PowerSDR (SVN 1719 or later) without having FlexProfiler running. My present SVN version is 2828

So there you have it..... your way..... hold the pickle hold the lettuce

73

Enterprise



No I'm not going to write about Kirk, Picard or Janeway. I just needed a pic for this edition.

In Calibration I alluded to how cool it is that the entire F5K fleet of radios has a DDS signal internally that is within 0.1dBm of all the other F5k (3K's also fill this bill) It means you can download new stuff to the radio and not spend half the night recalibrating. With the SDR-1000 you had to do this. The SDR -1000 was not so automatic especially in its early days. All the changes were done in software to be sure but you had to sit there and bring everything in the software into alignment. For that you needed a dummy load and a calibrated signal generator and an external watt meter of good repute. To tune up the Power amp you still need an external wattmeter

With what we have today however as you have seen is you can add new software and if there has been major surgery to the radio's brain requiring realignment, you just plug in the dummy and in 11 minutes your radio is all aligned automatically, and your alignment will be very close to every other radio in the enterprise. Across the F5K universe things will be nearly identical for people running the same version of software no matter if your running a lap top or some fire breathing 16 core behemoth. So what's the big deal? Here is the big deal

This is a quote from a note I got from one of the software designers (n4hy):

"With the recent changes to the RX flowgraph (in the test branch now),
and the total and complete elimination of RX image (in the iqtest
branch), and the upcoming changes to the TX branch, it will hard to
see how anyone can say that even a partially conventional design can
hope to compete. The receiver now has the AGC [AT THE END] of the
processing. This means that none of the nonlinear processes ahead of
it will be modulated by the agc. That is simply NOT POSSIBLE with a
traditional design or hybrid design, not even one where the users,
producers, desperately wanting what we have provided them have figured
out some horrible set of ridiculously complicated and/or expensive
devices to try and get it. The QSD receivers and the high speed A/D
receivers are the only way to get there."

DING DING DING Here is a guy who decided to move the AGC loop to the end of the RX flow diagram after all the rigmarole has been done to the signal so there is NO AGC modulation of those preceding processes. The only thing that controls the AGC therefore is signal, and the ACG does not control the transfer curve of some "stage" ahead of it like the ANL or the NB. All those stages do their duty in a clean way, before the AGC. Why do I keep harping on this?

A friend of mine who is a low band DXer (an Orion owner) one night commented on how sometimes if there is a carrier close to the freq of a DX station you can magically hear the DX. This is due to the AGC becoming fixed and not pumping. It is a big deal. If the AGC pumps just at the instant you want the gain to be highest so you can hear the damn DX, the AGC decreases the signal strength. I've only talked to my friend on the radio, but I wonder if he is bald, because that AGC business is enough to make you pull your hair out! How does this fit into the enterprise idea?

The code was rewritten to eliminate this issue. In any other conventional radio where the AGC shows up in the flow diagram is fixed in stone. In any other hybrid radio like the Orion, even if the AGC is partially firmware, the tentacles of the AGC reaches back into the hardware, and the hardware is hard and can not be moved. So you can goof around at the margins making changes in timing and threshold, but you can't all of a sudden decide to move the AGC to the end of the line. This is true of all roofing filter designs, because you need hardware like amplifiers to send signals through IF's. Amplifiers are what holds up the roof. For the Orion this made a big deal. The Orion had the roofing filter and a subsequent second IF filter (you can never get enough of them filters can ya). The second filter had an amplifier and the gain in the IF when you turned on the second filter caused the dynamic range of the radio to degrade. Add a $200 filter and get a crapier radio. Yep sounds like boys at TT were smoking some of that TARP money when they designed this sucker. You get all the distortion and damn little benefit, but they get to sell you another filter. "Well, just modify the radio" you say? When was the last time you took a soldering iron and the dykes to a $4000 radio and expected to resell it for more than a tenth of what its worth? "Well have the factory send out an upgraded circuit board" Ya right... Why do you think we have the Orion II? There ain't no profit margin in fixing the Orion. Also TT put a microprocessor that ran out of memory in the Orion. No more room at the inn for fancy firmware upgrades. Every time you put in a new feature an old feature breaks. That's why the Orion owners over on the TT reflector are still waiting and waiting and waiting for new firmware... Real soon now real soon...

Here is something I saw over there:

"I am amazed with all these bugs ie Red Screen etc. Didn't TT see these problems during their months of testing? Their loyal customers spotted these problems within 48hrs. Lets hope it's not another 1 1/2 years for a correction. I have not downloaded this firmware as of yet. This reminds me of how the car companys let the buying public be the guinea pig." This quote is for the Orion II. The Orion boys are just sitting there wishing they HAD some new bugs to bitch about Is this any way to run an enterprise???? Remember this radio is billed as the last radio you will ever need. OPPS the update came out the same day you died!!

For the Flex radio however the entire fleet of radios just have to download new software and bingo the AGC is at the end of the flow chart where it belongs. But it is even more fundamental because the AGC has the potential to be written perfectly (in my opinion it is already there) every F5K will respond perfectly (or virtually so) where as the legacy radio will not, and the legacy manufacturer will just bring out a new model.

And this is the power of Enterprise. One change in code results in all the radios enjoying the benefit. The Flex scheme is the ONLY scheme in ham radio today that allows this. And because of this the rest of the designs will be left in the dust. The RX now adapts itself as far as image rejection goes. Recall I wrote this is a phasing radio. This adaption is key. This adaption means your radio is running at best image rejection all the time as you tune around the band, as you are on USB or LSB, or AM or what ever. It takes one part of calibration off the table. Soon the transmitter will be the same. Always best tuned. Always tuned in such a way as to minimize QRM to other stations for example. Always tuned in such a way as to eliminate buckshot. Always tuned in such a way that wide band CW and the damn keyclix are not possible.

Yaesu had a keyclick problem for 15 years in the FT-1000 family of radios, and it was never cured. The entire enterprise of FT-1000 radios D MP FIELD MARK 1 MARK 2 MARK 3 MARK 563 had this problem. To cure the problem took some surgery to the guts of the radio, AND if you cured the problem you screwed up the QSK. That was the solution fo the entire enterprise. Yaesu's solution? Screw 'em. It costs too much to redesign for "that" little problem, and we are not measured on that aspect of type acceptance. Imagine a radio where the fix gets sent out in a download and the entire enterprise of radios is cured. I have that radio on my desk.

Let me quote my friend Bob once again

"That is simply NOT POSSIBLE with a
traditional design or hybrid design, not even one where the users,
producers, desperately wanting what we have provided them have figured
out some horrible set of ridiculously complicated and/or expensive
devices to try and get it. The QSD receivers and the high speed A/D
receivers are the only way to get there."

The only way to get there? Where is he going? THE FUTURE is where he is going

What is a traditional design? Think TS 940 or Omni-6 What is a hybrid design? Think Orion or K-3 What lays in the future I think will simply amaze and no enterprise of traditional radios or hybrids will be left standing except as horribly grotesque kludges (
of course you can always stick in another filter) or an anachronism, (you know like those jokers who wear tights and bucklers and eat hanks of meet off the bone, swill gallons of ale and pretend to be knights of yesteryear and then get into their beemers and drive home, or those jokers who get out the HW-16 twice a year and "make a contact") If you think about it, the K-3 is an anachronism It's basically a 5th generation Omni-5. (green tights, bucklers, hanks of meat,..... imagine a bunch if hams in green tights, mawing hanks of meat, and swilling beer... WHEW what mental picture....... wait a minute..... that kind of sounds like field day)

73

I know this is a very Wayne Greeney thing to say but: Is it just me, or are you starting to also get a clue about how we have been sold a bill of goods by the other manufacturers? I was talking to an Alpha owner the other day and when I asked him about his 87 he said "Oh you mean my light show?" Flat out cracked me up. I know from where he comes. I bought the "other one" and I'm less than overwhelmed myself. Both my old AL-1500 (which I stupidly sold to buy the Acom whirly gig) and my 30 year old LK-800tny are better amps.

Friday, March 20, 2009

Calibration

My friend K3RR inquired how is it that I can speak so confidently when I talk about measuring the behavior of my radio and its filters and MDS etc. Since I bought this radio I have grown used to thinking in dBm and not S units. I still write about S units because that's how most hams think.

The reason I can speak so confidently is because the radio calibrates itself across the spectrum.

There was a recent article that looked at the speech processor in the K3. I marveled at all the equipment needed to analyze that processor. Here is a flow diagram


Sheesh that tens of thousands of bux worth of hardware!!! To analyze your radio much less tune it up!! This was how I always did it before. I would put the rig on the bench and spend half the night trying to null the carrier out of my SSB radio, or trying to calibrate my S meter to 50mv.

Here is what I use today:


and this

and this:



This is Power SDR in scope mode and the recording console. I simply speak into the mic and make a recording as I adjust the various controls.

Here are some OLA's with no processing"

and here are some OLA's with compander at 1

and here are some OLA's with DX at 3


I can make a single recording as I OLA through the various settings, and know immediately what sounds good and what sounds like crap errr contest audio.

3x3 OLA's

Before you even click the audio you can tell DX is going to sound wayyyy processed. This is far more useful than the 50 grand of equipment. If I want to adjust my EQ I use this method, put a nail in it and go work some DX. I may spend a few minutes fooling around with this but no half the night.

But how does that answer Joe's question?

It turns out the F5K has a full time virtually dedicated signal strength generator built right in. The DDS (direct digital synthesizer) can give up one of its channels during calibration. The DDS output is constant across the entire fleet of F5K radios (+- 0.1 dB) so you have a virtually constant well known and well characterized super clean signal source in every F5K (and 3K).

What this means is you can change the software for an entire fleet of radios and NOT have to recalibrate all the time. That my friend is sexy beyond belief if you think about it. Once you have a known signal, the rest is all math. 10dB = ten times increase in signal etc. In addition the signal can be picked off anywhere along the signal chain for analysis, like before the filter or after the filter. The S meter reading is picked off after the filter. so you can see why I can so blithely make comments about how my MDS changes by 2 dBm or how 5H3RK who is presently on 10.108 is coming in at -115dBm while my band noise without the preamp is -121 dBm on 30M (-124 dBm with the preamp on) I can also know if I am talking to another F5K owner that if I compare my band noise with his band noise we are talking apples to apples, not just some relative gobbledygook. This is also why I can use this radio as the basis of a lab quality field strength meter, and make real measurements across antennas that actually make sense.

The radio also calibrates itself if you want or need to. Here are some of the calibration screens. Recall this radio is a phasing radio not a crystal filter kind of radio. Phasing radios have many superior features to crystal radios but one thing you have to do is calibrate them. Once calibrated however you can achieve levels of spectral purity beyond what you can achieve with a crystal radio. In the past using passive components obtain the necessary I/Q, non linearity and distortion caused the result to be less than stellar. However in a sampled software radio it can be brought very close to perfect. It is not just another way of doing things it is now a better way of doing things.

Here is a shot of the radio performing a TX image calibration




And here is the the test nearly completed

You can see the signal is almost nulled out

The calibration scheme runs several general tests like a PLL test and a noise test, and then band sepcific tests both on RX and TX. It is these tests that things like RX filters are tested and the RX S-meter is calibrated for each band, and the TX has the filters tested, image nulled and the carrier nulled for each band. As you can see you can choose any or all tests. The result of each test is then included in the central list and when a series is done the results are stored to the EEPROM for later retrivial for use in PowerSDR.

Here is a shot that includes a filter failure on 40M


Don't freak out!! I don't have to box the sucker up and sent it to Austin. The program automatically cycles through and retests any failures, and voila'



I'm ready to pick off that 5H3. As you can see my radio calibrated itself in 11 minutes.

Here are screen shots of the data

If you look closely you will see image rejection numbers on the order of -90 dBm and carrier null numbers in the -120 dBm range. Also you can see that 40M failure in the 3rd screen, and then the retest at the end

Finally you can view your waveform on the scope simultaneously with your transmitted spectrum.

and see how changing something like compander changes look on the spectrum analyzer.

I'm sick of calibration (actually I think this feature is cool beyond belief. This IS how radio should be done.) Time to work some DX!!!!

73

Thursday, March 19, 2009

NR audio files


I had a few minutes to record a mp3 of some 75M audio

The audio starts at normal 2.7khz filter NR is added then RX-EQ and the audio is tailored with the EQ in the 10 band mode. I switch the NR in and out. When its noisy NR is out. Bin is turned on and it makes a difference in the headphones, but the BIN output does not translate well to the mp3. Its effect is much more dramatic in my brain.

The band is filled with static, s-6 to s-7 with crashes to s-9 +5 and the station is s-7.

75m NR

This clip is of just noise in a clear spot on the band. The s meter is the same with NR in or out

75m Noise

On 40m this morning I was watching the S meter while I switched the filters.

The narrowest filter the radio allows is 11hz and at 11hz I was getting about -128 to -130dBm band noise. At 25 I got -128 to -127 dBm At 50 I got -127 to -125 dBm and at 100hz I got -124 to -122 dBm.

JT1R came up on the Cluster and I switched to 80M. With the filter set at 11 or 25 I could hear him out of the noise. Not good enough to copy. I would get JT or 1 or some part of the callsign, but I could hear a coherent signal bobbing out of the noise. At 100hz there was nothing.

MDS on 80 at 11hz is -120dBm and at 100hz is -114dBm 6dB makes a difference!

73

Flex Radio?


This sucker has muscles

(I found this one while searching for the flex radio group on facebook)

73

Still oogling the VP8

I heard VP8KF on last night and decided to try out Dual Diversity and the tightest filters

here is a shot of the radio setup

He was very weak, and the band was somewhat noisy. The antennas are my two 80M verticals

Here is an an MP3 of the encounter. It starts with DD active and then it is switched on and off several times. The times you hear best are with both RX's active. In really weak situations DD makes a difference. The filters are 25hz and the sample rate is 48K and 4096 in the DSP. To change to 48K you enter setup/audio and switch to 48K, easy! This is the highest performance. At this sample rate the 25hz filters become laser sharp. I was reading the Flex reflector and a ham was talking about revisiting 48khz sampling. I usually run 96khz. The trade off is lag. You get superior performance at 48k but there is more lag. In the old days the lag was considerably more. In the latest iteration it is barely noticeable. Where lag really shows up is in the side tone on TX and I really can't perceive a difference. With the advent of all the recent upgrades in receiver performance, I thought I'd give 48 a whirl. I was amazed. The filters are good at 96k, super good, but the filters at 48 are laser sharp. The VP8 gave me a good chance to put the radio through its paces. You will need headphones to review these clips.

VP8KF

I was using every trick I had to copy. The new code in the RX has improved overall performance. In addition to the now adaptive nature of image rejection (that is the RX maximizes the image rejection on an ongoing basis by an algorithm that is active in the background as you use the radio. It adapts itself to its best performance all the time), the NR and ANF have been much improved. Also BIN which is the binaural audio simulation now works great It works better than advertised. When I have used bin in the past in other receivers and in outboard DSP filters, it has always been ho hum. In this case it really makes the signal stand out. I also had dual diversity turned on, this meant I could change filters in both receivers independently. That also gave an interesting effect. I run through various scenarios in this clip. When you hear the VP8 best I have 25hz in each RX, BIN on in RX1. There is BIN in RX2 but that tends to cancel the BIN effect. With these filters you need to be on frequency, period. 5 hz makes a difference. In this instance skimmer helps. The way Skimmer does frequency, it is always exactly on freq. There is a little circle next to the bit stream and if you click that you are dead on period. It is a great help for tuning these sharp filters.

Here is an example of a QSO on 80M this morning I move 45Hz up on their center freq. I start at 100hz filter and you can hear the filter as I move up. Then I switch to 50hz and then to 25. I am in dual diversity mode. I then open up the filters and move back to the center freq.

80m 3 filters dual diversity

These stations are about S9 on 3520.00 I tune up the band from center freq by 45hz to 3520.045. I am at 100hz in both receivers and you can easily hear the decrease in signal strength as I descend the upper slope of the 100hz filter. Next I switch to 50hz so the edge of my filter are centered at +25 and -25 hz around 3520.045. You can hear the result. Next I switch to 25hz bandwidth. Now the filter is + 13 -12 at 3520.045. You can hear the result. Except for the guy's keyclix he is NOT in the pass band. I could easily work a less than s1 station in this mode, only 45hz from an S9 station.

Here is an Israel station last night, Dual diversity and 3 filters switched in and out

4X4

When the station becomes best audible is when I am perfectly tuned with 25hz filters and dual diversity any reduction in filtering or diversity results in no copy

JA4

Here is a JA4 station from this morning. Again with the kitchen sink thrown at him. He starts about 40 sec into the clip and I slowly bring him out of the noise by narrowing filters and playing with BIN and NR

This performance is ahead of what it was just 6 months ago, in fact it is ahead of what it was last week.

On another note my friend Tim W4TME has decided to chronicle his F3K experience in his own blog. He said he was going to announce his blog today so I will give you a preview

http://flex-3000.blogspot.com/

Where I consider myself a close in outsider in the Flex world, Tim is a true insider, (he has an email address that has @flexradio in it and one of those natty powder blue golf shirts) very hooked in, and should give a really interesting insiders view of the new radio. Tim manages the information systems on the Flex site and the knowledge base. He is one smart cookie. Should be a good read.

73

Wednesday, March 18, 2009

Space radio NR, ANL, and other updates

Here is an article I saw on the Flex reflector, which speaks about using SDR in space

http://gcn.com/articles/2009/03/09/nasa-software-radios.aspx?s=gcndaily_160309

one of the stalwarts on the reflector designs space radios for JPL. His radios do -157dBm MDS

Now that's what I call a radio!!

The band stunk this morning so nothing to report on that front.

Bob N4HY has migrated from his custom beta thread to the main beta thread on the SVN, the code he has been working on regarding the RX image rejection is automatically adapted to the best performance on the frequency you are operating in real time. He has also redone the Noise Reduction and Auto Notch. For the first time NR really does something. I have owned half a dozen radios that claimed NR and half a dozen external DSP filters that claim NR. Usually they just add a lot of beeps and boops to the noise. This one has no boops but there is a clear change in the amount of noise in the pass band. The ANF is great. I was listening to a S-3 SSB signal last night when a s9+10 carrier came on. The ANL took out the carrier, then another S9 carrier came on a couple hundred hz higher and both were eliminated. In the mean time the AGC was left unaffected since the ANL comes before the AGC loop in Bob's scheme. Slicker n blobs of mucopolysaccharides (aka snot)!!

TX adaptation is soon to follow

73

Tuesday, March 17, 2009

SO2R part deux

In the Full duplex article below I broached the topic of SO2R. I wanted to elaborate a little further on this mode since there may be some interest. Its a very cool feature.

The way the radio is set up you have 3 separate processes going on all the time RX1 RX2 and TX. The antennas can be independently assigned as well as amp keying

Here is a shot of the antenna selector in expert mode.



In this case I have RX1 and TX assigned to antenna 3 when the radio is switched to 80M. I also have amp keying set to output 3. What this means is when I have 80M selected TX is directed to output to ant 3, the RX is connected to ant 3, RX2 is connected to ant 1, and if I transmit the amplifier that is in ant 3's line will transmit. So in this screen I control the RX and TX including the amp for my 80M part of the SO2R experience.




This is my 160M screen. In this screen I have ant 1 connected to RX 2. TX is also connected to ant 1. RX1 is still connected to ant 3 and now I can control the amp that is in the ant 1 signal path. If I transmit my signal goes through the ant 1 amp to ant 1. There are 2 totally independent signal paths from the radio to each amp and each antenna.

Here is a shot of the radio with 80M chosen


You can see the red square on VFO -a and the antenna selector out to the side.

Here is how it looks with 160 chosen


Note the red square again. To switch to 160 I simply click that TX spot with my mouse. I can tune 160 while doing a run on 80M Here is a shot of me transmitting on 80 1500W on 3504 while listening on 160. Note the RX2 S meter reading in the above shots and also in this shot.


I chose 80 and 160 in the middle of the day as the examples so you can see there are no spurs or any kind of signals present on the 160M panadapter while I have 1500W pumping out the wire. The antennas are separated by about 100ft. I get this same kind of response between any 2 bands set up like this.

The way the audio is set up I can pan RX 2 across the stereo space, in a single ear or in both ears. RX 1 is in both ears unless I turn on the multiRX receiver. In that case I can also pan the audio from those 2 receivers across the stereo space. By controlling the various volume controls I can also set up the mix of loudness from any one source.

What the heck is a watch receiver? (note the multiRX button is now active)


A MultiRX or watch receiver is a receiver done in software. In the bandwidth of the panadapter, the way the software is presently written you can have theoretically 16 different software receivers. Only one is turned on, beside the main receiver. It would be impossible for someone to listen to 16 receivers and control 16 receivers without some kind of control circuit that is surgically implanted, or that is controlled by a neural network or some form of artificial intelligence. My origional idea for a skimmer like device was to have the 16 receivers scan little 5 khz slices of band width and identify each signal in its bandwidth and then create a cue of signals that were needed by the operator. Alex's approach to skimmer I think is a better concept than my addle minded approach, but still the AI thing has merrit.

You will note that a blue line has been added to panadapter 1. This line represents the watch receiver. I now have 3 active receivers in this radio. RX1, RX2 and Watch. If you look at VFO A you will note there is now a frequency associated with TX. That is the frequency where the watch receiver resides I can use this to work a split pile up while I am doing SO2R. If the DX is transmitting on 3504 and listening on 3507.354, if I hit the key, I will be calling where he is listening. I can also listen to what is on both of those frequencies by adjusting the various audio controls next to the multiRX switch.

In the setup menu I can also control muting.


The first choice mutes RX2 on TX and the second mutes RX1 when switched to work a station using RX2. If you are confused by the cacophony of all the signals in your headset, you can use these muting options to help you sort out things out as you go from one band to the other.

The MultiRX feature is available whether you are SO2R-ing or not. Here is how you tune this beast.

The tuning cursor is changed by right clicking in the panadapter, It toggles between no cursor, yellow cursor and red cursor. No cursor allows you to drag the panadapter with the mouse


In this mode I just left click the screen and the little hand grabs the screen and moves it and that tunes the radio. If I right click again I get the yellow cursor:


If I left click now, wherever the yellow cross hairs are centered, is where my VFO A will go. If I right click again I get the red cursor:



If I click now I will move the watch RX and also the TX freq up and down within the panadapter without changing the RX1 freq.

If I move the yellow cursor down on panadapter 2 while in yellow cursor mode I will tune RX2



It sounds way more complicated that it is. In fact after a short time its all second nature and you don't think about it. If you tried to do this with knobs you would hurt yourself!!!

So that's pretty much the deal. SO2R in a box, right out of the box. All I did was hook up 2 amps, 2 antennas, a mic and a key and some headphones. Stick that in your Sennheiser and smoke it!

See ya in the contests!!! (Actually I gave up contests for Lent)

73