P3 Noise band

[Bob McGraw - K4TAX]

I noticed when working the 6M contest today, I observed a band of noise
on my P3.   It always tracks above the frequency about 20kHz at the
lower edge.   The width of the band of noise is about 35 kHz.   As I
tune, the band of noise stays relative to the tuned frequency, thus
moving up or down as I tune.    The amplitude of the band of noise is
about 10 dB above the noise floor or about -125 db as shown on the P3.  
I've noted that it exists on both the yagi and the dummy load.

I've changed the input cable between the P3 and K3S, no change. When I
disconnect the cable from the K3S the band of noise is not evident.  It
doesn't cause me any issues, just noticed it.   Makes my go hummmm?

Any clues?

73

Bob, K4TAX


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[Charlie T, K3ICH]

I've seen that "tracking" type spurious display too, especially when using my old  222 MHz or 432MHz  MicroWave Modules transverters and also the internal 2M Elecraft K3 unit.

73, Charlie k3ICH


-----Original Message-----
From: [hidden email] <[hidden email]> On Behalf Of Bob McGraw K4TAX
Sent: Saturday, June 08, 2019 5:57 PM
To: Elecraft Reflector <[hidden email]>
Subject: [Elecraft] P3 Noise band

I noticed when working the 6M contest today, I observed a band of noise on my P3.   It always tracks above the frequency about 20kHz at the lower edge.   The width of the band of noise is about 35 kHz.   As I tune, the band of noise stays relative to the tuned frequency, thus moving up or down as I tune.    The amplitude of the band of noise is about 10 dB above the noise floor or about -125 db as shown on the P3. I've noted that it exists on both the yagi and the dummy load.

I've changed the input cable between the P3 and K3S, no change. When I disconnect the cable from the K3S the band of noise is not evident.  It doesn't cause me any issues, just noticed it.   Makes my go hummmm?

Any clues?

73

Bob, K4TAX


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Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email]

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Help: http://mailman.qth.net/mmfaq.htm
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