[Elecraft] Fwd: Re: K3 signal at 28004

[Mike Harris]

-------- Forwarded Message --------
Subject: Re: [Elecraft] K3 signal at 28004
Date: Sun, 11 Dec 2016 10:23:38 -0300
From: Mike Harris <mike.harris at horizon.co.fk>
To: James Bennett <w6jhb at me.com>

I have that signal on my K3 without any other Elecraft peripherals 
wrapped around it, internally it is pretty well stuffed with options. 
However, I have installed the K3s KIO3B and KXV3B and observe the following:

With the antenna connected and using the 500Hz 5 pole CW filter if I 
tune off 1kHz and set the dBV metering to 0dBV+/- on the noise floor 
when re tuning to the signal I see 3dB+/- increase.

Enabling PRE 1 and re zeroing the dBV reading on tune increases to 
+11dBV+/-.

Enabling Pre 2 and re zeroing the dBV reading on tune the signal has 
vanished.

Pre 1 and Pre 2 are not co located and it is possible that layout is 
determining what is being picked up internally.

Maybe a K3s owner would like to report the presence or not of this 
signal. The K3s RF board has apparently been redesigned making it quieter.

Cycling the preamps on an weak external signal coming in off the 
antenna, results in the expected changes in signal and noise, that is 
when Pre 2 is enabled the external signal doesn't vanish.

This will need to be re visited using my XG3 on 1uV to eliminate QSB 
effects.

Regards,

Mike VP8NO

On 11/12/2016 02:51, James Bennett wrote:
> Hank - I had that same signal at 28.004 and it was caused by my KAT500, as I recall. Elecraft has a fix for that - simple mod to the KAT500, if I recall correctly. Do you have a KAT500 and have you possibly removed power from it? If so, that's probably where your signal has gone. Just a guess....
>
> Jim Bennett / W6JHB
> Folsom, CA
>
>> On Dec 10, 2016, at 5:30 PM, HankP <pfizenmayer at q.com> wrote:
>>
>> Ok I give up - I always have a strong signal about 28004 on my K3 and it was there this morning just like always and most all day - now its GONE and the rx seems like its still working normally -107 dBm on the P3 for the 1 uv in . TX ok too. Just no 28004 ??? What is the magic ?? Hank K7HP