KA8KPN's Web Home

Yesterday, I got the ladder out of the garage and connected the ends of my suspect feedline to my NanoVNA, and observed that there were many, many, fine dB of loss on this 20 or so feet of LMR-400. A quick check with an ohmmeter showed that the braid was shorted to the center conductor. Well, that's not good! So, I cut one end off and observed that when I put that one on, I didn't get the center conductor all the way in to the connector. Now that that's fixed and the SWRs are reasonable, communications has been achieved.

I've spent many months, er, years messing around with keyers and keys and radios and, well, ancillary appliances and appurtenances in my shack. In all that time, I haven't done much operating. Why not? Well, because I haven't had even a marginally useful antenna. I've been building a helically-wound vertical that I intend to make multiband by feeding it through an automatic tuner, but my attempt to raise it was a pretty spectacular failure and I've been discouraged since then, although I still intend to see if I can make it work I just haven't had the time or the energy.

I don't know what possessed me. I mean, how many keys does one need?

I've heard that N3ZN keys were excellent keys and I heard that Begali keys were excellent keys and I decided that (despite the cost) that I'd get one of each and compare them.

This is my Begali key. And it's just....gorgeous.

Now that I have certain, um, financial transactions completed, I now have a little bit of spending money. I've sworn to not buy any new radios until the HF antenna is finished, which is a promise I have (mostly) kept. (I just couldn't pass up the Wouxun KG-UV8E that I found at the swapmeet a couple of months ago. Honestly, I didn't even try.) The antenna is mostly done, by the way. I'll talk about it when it's been used.

Lots of things have happened with the keyer. I bought rotary encoders and had boards made and populated one and it works like a champ. Only one small error on the board, and it's in the silkscreen so I'm going to ignore it, although you can see it in the photo above. So, if you have an interest, how can you get your own keyer?

Well, start at OSHPark and get yourself some of the boards:

The source for the firmware is on Github

Well, I finally went and did it. I built the 6-meter quadrifilar helix I've been talking about for years. Okay, it's not quite done, I'm waiting for a decent pair of wire strippers to arrive, but a week ago I took a four-inch PVC pipe, some 3/8 inch dowels, some Romex, and adhesive and fabricated a QFH antenna. I used a short Python program I wrote to determine the dimensions and, well, I did it wrong. The short wire in what I built should be the long wire at the operating frequency, so the whole thing is too long for the 52 MHz design frequency.

The problem was that the emitter of Q16 wasn't grounded in the schematic, so it didn't get grounded in the board layout, so pin 2 of Q16 wasn't grounded in the boards I got from OSHPark, so the LED didn't turn on.
A little yellow wire fixed the problem.

I've been working toward this for a while. Since I last visited the keyer project, I rearranged my workbench so my work area is larger. My computer, which used to share half the table of the workbench now covers the entire table, and I got my microscope out and went a little nuts with the surface-mount parts. Having finished that, there was no reason not to put the through-hole parts on the board, either. And now, well, a picture is worth 1000 words, right? One of the red LED's doesn't light, and I don't know why, but there will be time to figure that out later.

With the arrival of the 0805 LED's, all the keyer parts that I have been waiting for have arrived. A couple of weeks ago, I started to populate one of the boards that I had with the parts on hand, which were the MMBT3904 transistors. So, work can now begin in earnest. More events as they happen.