October 2015 – Rob's Blog

I have almost completed the Universal Memory Keyer kit from Kits and Parts. The kit goes together well, is well designed and uses quality components. There are a couple of things are can be confusing, like the 4 different types of keying output or the 2 different power inputs. But once you get past those hurdles it, it does everything you expect.

Programming in the memory’s is not something for the feint hearted. To be honest its an exercise in futility, almost. Firstly after pushing the function button then the memory button you are then able to key in what you want in memory. However, its slow on the upload, so, you have to go one word at a time and pause. cq, wait till the keyer beaps e then cq etc, but when you get to your callsign, mine is 7 letters vk4ffab, you have to triple space the letters. V K 4 etc, which is not something that most of use do, we are so used to keying off our call at whatever speed we normally operate at, that doing this, seems, well unnatural.

Anyway, i am happy with the keyer even with its quirks, and will likley buy a couple more, one to use at home permanently, one in the portable station box and another in the homebrew station im working on. Happy days 🙂

IMG: Assembled Universal Memory Keyer

Ok, so my goal for a long while has been to homebrew a complete station, from antenna to tuner, transmitter and receiver. I have been playing with and experimenting with lots of circuits getting my head around what works and what does not work and coming up with a design that will be usable.

I am by no means reinventing the wheel, just having fun and learning as i go along. This is the first part of my homebrew station completed. Next will be the receiver and finally the transmitter, both of which i have working prototypes for already on my workbench, that just need tiding up and fitting into some instrument cases.

Below are the pictures of the build process of a 3-30mhz antenna tuner.

IMG 1: Every project needs a schematic, here is one I stole off the internet.

IMG 2: Assemble the parts needed, 2x ALPS 400pf air capacitors, 1x T200-6 toriod, 1x 12 position single pole rotary switch and 0.6mm enamelled copper wire.

IMG 3: Inductor wound 12 taps, 6 turns per tap, 78t should yield about 50uH more than enough to do 40-10m and possibly even 80m with luck with an end fed wire.

IMG 4: Placed things out where they will go in the case and bolted them down.

IMG 5: Wiring the switch to the inductor.

IMG 6: Inductor all wired up.

IMG 7: Job almost complete.

I will be adding some sheet aluminium to the inside of the top and bottom cases to give some rf shielding, putting teflon tube over the inductor output wire and putting on some knobs. Does it work? Why yes it does and works very well, and will handle the eventual 50w that I plan to use in my home brew station, quite well.