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)