Mouser is going to have over 4600 Central Semiconductor 2N5109 BJTs at the end of this month. :-)
https://www.mouser.com/ProductDetail/Central-Semiconductor/2N5109?qs=sGAEpiMZZMshyDBzk1%2FWiw99kSkYzPxmkl%252BSQJuBJrk%3D 73, Mike W0BTU On Sun, Mar 1, 2020, 5:55 PM Larry <[email protected]> wrote: > RE: 2N5109 replacement > > With my supply of 2N5109's getting low, I looked long and hard at > suitable replacement parts. > > There just isn't anything made in a leaded package that's worth while. > > I did find a rather generic power transistor in a "large" SMD package > that works quite well in my preamps for the MF and LF ranges. > > The DCP68 (and for those who need a PNP DCP69) has proven to be somewhat > better than the 5109 in this application with a measured NF averaging > 4.5 dB vs. the 5.5 dB of the 5109. > > I have, in fact, soldered pigtails on the SMD part and stuck it in place > of the 5109 on existing boards (with suitable heat sink). > > I'm happy with the part but of course YMMV! > > 73, > > Larry - W7IUV > > > On 3/1/2020 3:31 PM, Richard (Rick) Karlquist wrote: > > > > > > On 3/1/2020 2:22 PM, VE6WZ_Steve wrote: > >> Just like some guys enjoy woodworking and making furniture that they > >> may not really need, I like to build radio things just for the fun of > >> the project even though I may not really “need” it. For three years I > >> have been using the original 9 circle RX array kit that I bought from > >> DX-engineering, and it has performed well, but I wanted to build my > >> own and add my own design tweaks. > >> > >> Using KiCad, I have designed and built a 9 circle RX array combiner > >> with a 2N5109 pre-amplifier integrated onto the same board. > >> > > > >> 73, 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 > _________________ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
