In the last few weeks I have tried a number of new things in Ham Radio.

Let’s start with power. I have a good old 12v 12A ATX power supply that I have converted for use with the ham radios, see my previous article for the details. One weakness that I noticed with this setup was that there was not enough current being supplied to my 100 watt HF rig; the lights would dim whenever it was putting out more than 75 watts or so. So this week I checked it over with a multimeter to make sure all of the yellow wires were connected to the same circuit and all the blacks to the same, then I just joined all of them into one big wire per color. After a quick test with the HF rig it was clear that there was enough power after all, it now dims almost imperceptibly indicating it could maybe use a few more amps but I don’t think it is suffering any.

I had previously tried hooking everything up to a 12v marine battery which supplied plenty of amps to the radios. However I didn’t want to deal with two problems related to that. First is keeping the battery topped off. I could pretty easily make a relay circuit that would kick in whenever the voltage dropped below a certain threshold. But the second problem is that the battery charger is loud, really loud. And I can’t stand a lot of loud whirring and beeping. So I reverted to using the computer PSU and I think it will handle the job fine. Here are a few photos of my setup now.

I bought what turned out to be a necessary piece of equipment for HF, an antenna tuner. I also thought it would be worthwhile to buy a nice one that includes a dummy load, an antenna switcher, and a built in power/SWR meter. So I chose the MFJ Deluxe Versatuner II. I have also picked up a VHF SWR/Watt meter that is very handy for my antenna building. My HF rig is an old Icom IC-735 which works very nicely, and my 2 meter/440 dual band radio is a Yaesu FT7800.

Neither of these radios is well supported under Linux for rig control or memory management. I’m hoping to get some time to learn more about this and write some software to allow using these with the computer. In that interest I have bought a Rigblaster PNP which is a device that uses your computer sound card as a TNC to get you on the digital modes. I have used it for some CW work but nothing serious yet since I have to wait for the next testing date to get my General (or if I’m lucky, Extra) class license.

In the antenna department I have constructed a Bobtail Beam. This replaces my Slim Jim 2 meter antenna. It has substantial gain and very tight directionality. I have mounted it atop my antenna mast with another antenna I recently constructed, a 440mhz yagi. The rotator is an old Radio Shack Archerotor that I picked up on ebay wire and all for $41. It works great. The bobtail has a very low SWR curve along 2m which is just great for getting me into some of those fringe stations I had trouble with before.

The same can’t be said for the yagi-uda which has a wildly bouncy SWR curve all across the 440 band. Unfortunately some of the frequencies I like to use are in the higher SWR areas. I’ve picked up an older edition of the ARRL Antenna book on Amazon for $10 and I’m going to study antenna theory as time permits and see if I can’t design a “flatter” yagi. Perhaps I just need to add a half dozen more elements!