Quite right, Mike. A Pi-L will match a wide range of impedances. What I was saying was that, IIRC, the Pi-L provided the spurious signal rejection required by the FCC over only a narrow range of impedances.
Ron AC7AC -----Original Message----- Quite a few years ago I was running the comm's on one of the British Antarctic Survey bases (Adelaide Is). My main TX used a Racal amp with 3 x 4-400 in parallel (if I remember correctly). It used a Pi-L network. That network quite happily matched 20:1 SWR if necessary. The tuning was rather critical but in other respects all was normal as far as the tubes were concerned. The coax (RG-8 type) from the TX to the balun would run very warm in those circumstances and sag from the ceiling. Not desirable I admit but necessary to broadcast safety critical WX forecasts to remote sledging teams on a frequency in the 2MHz range that the antenna was never designed for and seldom used. Regards, Mike VP8NO On 21/02/2012 04:14, Ron D'Eau Claire wrote: > Well, Don, it's been a number of years since I homebrewed an amp, but from > what I recall a pi-net wouldn't meet the later FCC regs and a Pi-L network > only sufficed over a fairly narrow matching range. > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
