Tuesday, September 22, 2009


I'm on vacation this week so I get to actually listen until the grey line passes over my head. Usually I'm OTD (out the door) before that happens. The low bands have not been in the best of shape, at least at my QTH. Usually by now the static has pretty much subsided and my band noise settles down to -124 dBm or so on 40M and -118 dBm or so on 80M. Last night listening to FT5GA on 80 my band noise was hovering around -95dBm making copy miserable. I could hear him and I could see him on skimmer but it was so iffy that I decided it wasn't worth adding to the QRM to make an ESP contact.

This morning I was up on 40 and my band noise had settled down into the -121dBm range but signals were very weak. JA1NUT a perennial presence on 40 was Q5 but I had to add filtering to copy him.

I saw ZL7/N7OU on Chatham Is. spotted on the cluster on 80M and tuned down there to have a listen. Nothing. I listened for a good hour and heard him start to build I finally worked him about 15 minutes after sunrise and he continued to build for half an hour after that. My band noise was -110dBm plus static on 80 and N7OU was -108dBm Not many were hearing him because there was no pileup at all in fact I spent most of the time listening to him call CQ and making occasional single contacts as the grey line flew west.

I switched down to 160 to hear VK3ZL and the band noise on 160 was -117dBm and he was a good 6dB out of the noise and easy copy. 9M2AX just came up on the cluster, but its a little before 8 am here and that one is a pipe dream, and ZL7/N7OU has finally succumbed to the sun, I can just barely hear coherence when my band noise momentarily drops below -115dBm.

All in all an enjoyable morning in ham radio land


Monday, September 21, 2009


So far my only luck is on 30M. I must confess I have been getting on AFTER their sunrise so I shouldn't really kick. I got on tonight and heard them in the mud on 80M for a couple of hours but the static was way too bad to make the contact.

While I'm sitting here listening to the static hoping they will come up on 40M, I got a note from Toby DH1TW.

He has an interesting web site at DH1TW.de, with a nice powerpoint presentation on SDR in general. Pop on over there and give it a look see.

In the mean time its back to the static for me


Tuesday, September 8, 2009


Heard 4W6AL come up as I was heading out the door with diversity off he was totally uncopiable. With diversity on he was copiable. Apparently NO one else in the states was copying as the only caller beside a lonely AI9 station, was a FM2 and a bunch of JA's My band noise was -112 dBm very noisy even with the filters collapsed down to 25 hz. As I tuned I was thinking how if I had the filters opened up to lets say 250hz or 500 hz this guy would be totally uncopiable, and just how precise click tuning with skimmer and DXlab's Spot Collector really is. To use 25hz filters you have to be exactly on freq. A few hz and the station is out of your passband. Virtually impossible to do with a knob.

When I hear E. Timor its a good sign the bands are returning to those blessed winter time conditions


Saturday, September 5, 2009

45ft Vert

I've written about my diversity setup so I thought it might be interesting to see my setup. This is my 45ft vertical in the front yard. It is a wire up to a eyebolt that I had installed on one of my pine trees. Here is a shot of the waterproofed autotuner at the base of the antenna

The tuner is a MFJ 929 auto tuner in a 50 cal ammo box

The coax connector from the transmitter is connected to a 2 inch barrel connector that feeds through a hole and is bolted to the back of the box that acts to suspend the tuner in the box. The antenna connection is visible in the above picture. I ran the antenna coax out through another hole. It turns out that the input and output coax feeds need to be isolated. My first idea was to use 2 barrel connectors but that failed miserably. By using this method the tuner behaves properly. The toroid was put on the coax in an attempt to get the "RF" out of the circuit when I had both antenna ports connected to the barrel connectors. It probably isn't necessary.

The MFJ-929 has the feature that it can be powered over the coax through a voltage injector so no additional power line is needed.

MFJ sells an injector

or it is simple enough to build if you have the parts laying around.

The feedpoint is thus. The vertical wire goes into a 4 turn 3" loose coil. This has plenty of give so the wire is not taught as the tree sways in the breeze.

For this installation I have only a couple of radials since this was intended to be a RX antenna. However it turns out this antenna is a quite good transmitting antenna especially from 40M to 6M. It is fair on 80 and poor on 160 as a transmitting antenna but it does work as an RX vertical on that band as well.

As you can see the antenna is quite stealthy

And with a more adequate ground plane would be an excellent antenna for people who have to deal with stealth and covenants and home owners associations. This set up is good for 200W transmitted power.

To use this antenna I simply set PowerSDR to ant-3 (the port to which this antenna is connected) and run about 7 watts down the line in a second or less the antenna is matched. I then turn on diversity in powerSDR using my other full size verticals out in back. I have run tests using WEBSDR.org as my remote receiver and 100W. I have made dozens of DX contacts using this antenna on 40M and 30M, and I have made contacts on 6 as well.

My diversity setup has the 2 antennas separated by about 200ft Here is a shot of my other vertical from my website W9OY.painloss.com You can see the tree from which the 45ft wire hangs directly in line through the garage.

I thought it might be interesting to document this little antenna since it works so well. It is not as good as my full size verticals out in the back but if I had to put up one stealth antenna this sucker would fill the bill.