Re: 3rd harmonic on 2M. Any fixes?
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Usually when doing harmonic test with a spectrum analyzer or spectrum scope in the IC705 if one adds attenuation to the signal and it does not change means one is overloading the scope and the harmonic is being generated inside the scope.
to get a good test keep adding attenuation until if add a xdb then the signal on the scope changes by xdb.? But for the IC705 the scope is not exactly calibrated.
73, ron, n9ee/r Ron Wright, N9EE/R Hernando Co ARES EC
Spring Hill, Florida also n9ee55@...
On Thursday, November 10, 2022 at 04:25:03 PM EST, N1QDQ <n1qdq@...> wrote:
I might have transcribed those number incorrectly. I took some notes and had to leave the project for a few hours. I just got back home and put it on the bench, into a good dummy load, and used my IC705 as the test receiver. Transmitting on 145.950, seeing a clear signal on 437.850 (the calculated third harmonic). Put in a Micro-Circuits BLP-300+ which should have -30dB attenuation at 450MHZ and not much of a difference at all. Certainly not 30dB. I'll keep working on it. Thanks for the reply. N1QDQ
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