My long-in-the-tooth amplifier has a severe case of slowing input relays, vacuum relays and just old age. The relays are hard to find and are DIPs so footprint matches make it hard to substitute any newer makes. Consequently, I ended up frying in input relays as they slowed down. Still functioning but not wanting to cause any more damage I just built up a K1EL WKUSB Keyer that allows PTT lines to be exerted prior to key line activating and any RF to the input relay of the amp showing up before expected-hot switching. This is settable both via Lead in times and trailing delay times. The KEY line drives the exciter as any keyer would but the PTT line is separate and programmable. It is a nice feature and almost mandatory for anyone operating a transverter, preamps or amplifiers of any ilk (QSK or none QSK).
The kit was straightforward and an easy build if you take into account old eyes and use magnifying glasses and sufficient light. The only surface mount chip comes installed and the rest is common hardware of the type anyone may encounter. 1/8 W resistors gave me some trouble but my eyesight is poor having suffered a detached retina some years ago. A testimony to the kit and its instructions may be drawn from the fact that it worked the first crack out of the assembly sheets. I am using the keyer in stand alone mode but it does function via a USB cord to a computer. I will attempt that sort of setup after I get used to standalone mode.
All the parts were present and the PC board is silk screened so parts placement is dead easy. The only bits I needed to add as it did not come with the kit was two short hanks of hookup wire to attach the speed pot. All in all a nice kit and a great 4 hour project.
Thanks for reading my Blog. Best, Chas W5PG