ham ham-archived

The pf0a/pa3gyf pa-144-1kW

[20210215] Rediscovering Personal HAM History

Today, as part of my larger objective to archive my past (HAM) projects, I scanned various documents related to a project Frank van Vliet, pf0a nowadays, and I undertook around early 1999. I actually think more people were involved (like Vincent and Jurgen), so I hope I’m not failing on the credits here…

The idea was simple: We would build a 1 kW (or 400W legal-limit, if you prefer) Power Amplifier for 144 Mhz around “The Russian Tube” that became available in rather large quantities around that time. In those days, I had the ability, financial means, interest, and willpower to deploy a serious 2-meter station…

As far as I can recall, we managed to design and order the HV transformer (I still have one!) and the custom-made combi-transformer for auxiliary (screen/control grid and heater). My job was to order the latter transformer and design the screen-grid power supply. So I designed the circuit, with quite some safety measures, and the PCB, and built (at least) one prototype.

Unfortunately, due to personal issues later in 1999, I had to abandon the project (and HAM as a whole for several years), but I think I managed to hand over the results to Frank and others, and I think Frank managed to complete the build for the (pe0mar) Lighthouse Contest Group. The combi-transformers (I’m pretty sure I had to order 10 of them) and the screen-supply prototype I built seem to have gone lost after 1999, but I still have to HV transformer waiting for a new destiny…

Current Status and Future of this Project

Well, I’m no longer that active as a HAM anymore, and I no longer have the antenna options I used to have. So finishing this project would only serve as a rehabilitation of my ego for bailing out in 1999. Hence, for now, the project is archived as unfinished.