Does anyone remember the formula for matching 50 to 75 Ohms with 2 very short lengths of coax? If I remember it used a 75 Ohm section at the output of the amp, and a 50 Ohm section to the CATV hardli
Thats the one guys, thanks. Carl KM1H _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
Author: Pete Michaelis - N8TR <pete.n8tr@gmail.com>
Date: Fri, 31 Jul 2009 23:20:19 -0400
A very nice Windows program that calculates the needed lengths is available at: http://www.seed-solutions.com/gregordy/Software/SMC.htm 73 Pete - N8TR _______________________________________________
http://www.tuc.nrao.edu/~demerson/twelfth/twelfth.htm By paralleling two lengths of 50 or 75 ohm line, it can also match to 25 or 37.5 ohms; or to even lower impedances by paralleling three lengths o
That is a good program but it doesnt cover the non synchronous procedure as described by K1XX back in 1978. Thanks for posting it. Carl KM1H _______________________________________________ Amps maili
Thanks Ian Carl KM1H _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
Hi Ian & Carl, Actually given only 50 ohm and 75 ohm coax and not paralleling any coax you can match all resistive impedances between 50 and 112.5 (75*75/50) ohms. e.g. 50 ohms -- 29.3 deg. 75 ohm co
Hi all,in addition to the examples Larry offered, the scheme will also match impedances less than 50 ohms, down to 22.2 ohms if I remember correctly. A two way power divider where two 50 ohm loads ar
Thanks to Larry and Gerald for pointing out that the series method is much more versatile than I had imagined. Greg Ordy's program takes care of that, and also says when a match is not possible. Conn
It depends on the type of connector. UHF connectors are often closer to 35 Ohms if I recall correctly. N connectors can be either 50 or 75 Ohms ... if using a barrel for splicing, it is probably bet
UHF connectors have varying effects but for all pratical purposes show a 20dB or better return loss thru 222 mHz before climbing. Many versions do show RF heating due to poor quality insulation, even
20 db? I've strung a whole series of connectors together and didn't get half a db. 275 feet of coax (LMR 400) with connectors at the rig to grounding panel/Polyphaser(2), cable to base of tower (2),
Roger, You are confusing insertion loss with return loss. A return loss of 20dB is the same as an SWR of 1.22:1 which is also equal to a reflection coefficient of 0.1. Insertion loss is a combination
Arent network analyzers wonderful tools Larry? I too was confused by the competing arguments long before the Internet got up to speed and let a VNA talk to me. My "varying effects" comment was due to
Would someone please fill me in with the distinction between synchronous and asynchronous? David G3UNA Thanks to Larry and Gerald for pointing out that the series method is much more versatile than I
Ive always taken it that the traditional 1/4 wave, along with even and odd multiples, is the classic synchronous version. Results are repeatable. Carl KM1H ___________________________________________
Carl, I asked myself what a mated PL-259/SO-239 connector "really" looked like RF wise many times after hearing all kinds of horror stories. Finally after procuring a couple network analyzers and the