[amsat-bb] Filter out 3rd harmonic of 145MHz

Douglas Tabor dtabor at estesvalley.net
Wed Mar 29 02:19:29 UTC 2017

Thanks for that info Bob. Like Patrick, I also use the MFJ Diplexer (and spellcheck likes duplexer too) and have had good success with it. I will be ordering a terminator to correct my laziness (and maybe get a dB or two).

Appreciate your reply,

Doug, N6UA

> On Mar 28, 2017, at 16:51 , Bob <WB4SON at gmail.com> wrote:
> I actually dug up a Comet CF-4160J Diplexer (both Comet and Diamond call them "Duplexers") and swept its response with my Spectrum Analyzer, using the Low-Frequency and Common Port. I was also curious to find out if it mattered if the High-Frequency Port was terminated or not.
> The bottom line is that this particular Diplexer would reduce the 2-meter 3rd harmonic by 55 dB, and had an insertion loss of 0.12 dB.  And I confirmed that there was a small reduction performance if the High-Frequency Port was not terminated.
> I would expect the performance of Diamond models would be similar and I will test one when I find one.
> The actual report can be found here:  http://wb4son.com/wpblog/?p=2828  (if the link is blocked, try WB4SON dot com and search for CF4160)
> 73, Bob, WB4SON

Douglas Tabor
dtabor at estesvalley.net

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