Trends in Amateur Radio

It’s always been accepted that one of the attractions of amateur radio was that it involved the building of kits; if you needed (or wanted) a better or more specific transmitter, receiver or transceiver but couldn’t afford to purchase one from your local retailer, you bought one in kit form and built it yourself.
Kits were ordered over the phone and posted to you. Some were better than others but all had potential risks involved, such as the odd missing component.

The Elecraft KX1 kit came professionally packed with a great instruction manual.

This kit from Virgil Stamps at http://www.hfprojects.com is a good example of a well-produced kit that involves soldering all the components into place in the PCB.

And it wasn’t only on the electronics front that you could heat up your soldering iron and get busy; making a suitable antenna was also a huge part of the hobby.

My homebrew 6m dipole strung up and ready for action.

Baluns are also popular construction projects with homebrewers.

I wound the entire length of coax on a piece of PVC piping I had in my workshop.

Of course, you didn’t have to stick with kits if you needed to construct a radio; you could always build one from scratch with components you happened to have in your proverbial junk box.

I built this regenerative receiver using what I happened to have on hand at the time.

Test equipment is also easy to build from kits.

QRPometer on the left, Hendricks dummy load/power meter on the right.

I have noticed a trend beginning to appear in the world of amateur radio, and that’s a swing away from ‘melting solder’. I first noticed this with the advent of the Elecraft KX3 a few years ago. For the first time this world leader in kit production began marketing a rig that only required mechanical construction; all the electronics came pre-manufactured and only needed slotting into place in the enclosure, which needed first to be put together by the ham. This was due to the high number of surface mount components present.

And now Virgil Stamps, proprietor of the beautifully designed and manufactured HF linear amplifier that is aimed at the SOTA and WWFF fraternity (http://hfprojects.com/) has gone this route with the launching of his latest offering, the HFPacker Amp MiniHFPA2. By all accounts it looks like this new trend in amateur radio is here to stay, but as long as it helps get more people on air, that’s sure to be a good thing.

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Installing a Long Wire antenna

Today I decided to pull down my 20m dipole and replace it with a long wire antenna. The reason for this was so I could work the 80m band in addition to the normal HF bands I was currently working.

Some time ago I printed out a table by AA8AF which he called the End Fed Antenna Length Study as I was sure it would come in handy one day. Well that day has come. It was based on the work by G3CCB that was published in “The Antenna File”. The aim was to determine the length of an end fed antenna suitable for the 40, 30, 20 and 15m bands, steering clear of the high impedance half wave points.

The table I saved pointed out a few good lengths, and I chose the one that covered all the bands from 80 to 10m. The ideal length, the table said, was 15m or 10m.
I settled for 15m.

Now everything I had read about end fed antennae suggested that a balun is needed at the transceiver end of the wire. Better still, mount the balun outside the shack to keep RF out, most experts said.

Now I happen to have an LDG RBA-4:1 Balun, which is a voltage balun. I also have the spec sheet which says a long wire is basically an elevated wire at least a half-wavelenght long at the lowest frequency to be used. As a general rule, the higher the better and the longer the better, it pointed out.

Performance will also depend in large part on the quality of the ground connection. It should be connected to a counterpoise or ground for best results.

My balun is mounted outside the shack above the front door and just below the antenna mast on the roof. This would be ideal for the long wire, so up it went.

The LDG balun is fed with coax on the input side and the long wire and ground connect to binding posts on the other side.

The LDG balun is fed with coax on the input side and the long wire and ground connect to binding posts on the other side.

I connected the far end of the long wire to a ceramic insulator and a palm tree, then connected a length of wire to a copper ground stake and headed into the shack to see if it would tune up on all bands.

It did and I was delighted.

My first qso was with Sergei DL1DGS in Germany on 20m CW. Then I worked John VK4WID in Toowoomba on 40m.

At least I know the thing works. It is a bit noisier than I am used to but the day was one of the hottest on record for this time of year at 37C. Maybe the bands were just plain noisy. I’ll try another day to be sure.

Curing RFI in the shack

I have been suffering from the dreaded RFI in the shack. I knew this because every time I keyed the transmitter, my digital clock would flash and my computer would play up or even shut down. Something had to be done.

After much talk with locals VK4CBW Wallace and VK4ZW Ray, I decided to get back to basics and start from scratch. I rebuilt the earthing system to ensure the connections were good, I removed the two external speakers I had rigged up and I removed the antenna switch that wasn’t grounded. This didn’t cure the problem.

Then I installed a 4:1 balun (thanks Wallace) and removed my G5RV and replaced it with a 20-10m dipole that I had shipped in from the US. Much better but still some RFI on one or two bands.

I then made a current choke by winding five turns of coax in a circle 8 inches in diameter at the feed point to the balun, which I mounted just outside the window to the shack where the coax enters. This did the trick.

The choke and LDG 4:1 balun outside the window of the shack.