Hi Rick, Yes, the 2N5109s are almost un-obtainium now, but a few months ago Mouser stocked them and maybe DigiKey, but now they are out-of-stock. Even the 2N3866 substitute is hard to find. Over the years (2 decades) I have built at least 10 of these amps, and still have a supply of a dozen or so 2N5109 devices, and since these devices are almost indestructible, I’ll likely never run out! You are correct that this is a problem with this design.
Thanks for the E-field amp link….nice…perhaps another project to build! I like KiCad a lot. super easy to learn. I had never use a PC board program, but I was able to learn KiCad from scratch in one evening! de steve ve6wz > > Now I know why you work stuff I can't even hear :-) > > The 2N5109 is just about extinct. Did you secure a > source for it before you laid out your PC board? If > you did, please share it with the rest of us. Most > people are now using substitutes for the 2N5109 with > varying degrees of success. Are you possibly doing > that? Of course those substitutes are not in a > hermetic metal can, so the PC board has to be laid > out for differently for them. > > You might want to look at these references for > so-called "E-field" arrays of whip antennas: > > A military design: > > https://www.dst.defence.gov.au/sites/default/files/publications/documents/DST-Group-TR-3522.pdf > > Various improvements to the above: > > http://home.earthlink.net/~christrask/Complementary%20Push-Pull%20Amplifiers.pdf > > You also find a lot of other good stuff on Chris's site. > > They go beyond the DXE design. > > Good luck with your project. > > BTW, how do you like KICAD? I'm currently using a grandfathered > EAGLE 7.7 perpetual license, but "some day" I might switch to KICAD. > > 73 > Rick N6RK _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
