[Elecraft] Weird EMI issue... part deux

[N2TK]

James,
I am getting a much lower level of noise than you. With no antenna and the
preamp off, the first bar on the S-meter barely flickers. When I spin the
dial quickly I can get as high as S3 noise. The noise disappears below 4.930
and above 5.110.

I only hear the noise in the main receiver. I can spin the dial on the
sub-receiver, if turned on and also hear the noise in the main receiver.
There is never noise in the sub-receiver. With a dummy load on ANT 1, ANT 2,
AUX and RCV inputs there is noise in the main receiver when spinning the
dial with any antenna port selected.

Once I have an antenna hooked up and the background noise is at least S3 on
that antenna port I can't hear the noise when spinning the dial.


Yes, you can forward this info to whomever you want.

73,
N2TK/NP2, Tony 



-----Original Message-----
From: James Sarte [mailto:kc2uee at gmail.com] 
Sent: Sunday, March 01, 2009 10:06 PM
To: 'N2TK'
Cc: elecraft at mailman.qth.net
Subject: RE: [Elecraft] Weird EMI issue... part deux

Hi Tony,

Thanks for taking the time to do that test for me.

I do hear the noise with an antenna connected, but the antenna is not tuned
for 5MHz so the noise floor is pretty low.  I do not hear this noise through
the sub receiver if I use the AUX BNC connector, but I will hear it through
the sub receiver if it's using the same antenna as the main receiver.

Otherwise, everything else you've described is what I'm experiencing.  This
noise is around an S5 to maybe S7 on the meter when I move the VFO knob.

As you also discovered, turning the preamp on raises the noise floor masking
most of the EMI.  It's not very noticeable when the preamp is on.

Would it be OK to forward this email to Elecraft tech support?  I've been
maintaining a running dialogue with them regarding this issue, and your
findings may help them to develop a solution.

Thanks again and 73,
James KC2UEE



-----Original Message-----
From: N2TK [mailto:tony.kaz at verizon.net] 
Sent: Sunday, March 01, 2009 8:32 PM
To: 'amstel78'
Cc: elecraft at mailman.qth.net
Subject: RE: [Elecraft] Weird EMI issue... part deux

I was using SSB settings and had an antenna hooked up. I did not hear any
noise

I put a dummy load on the antenna jack and used AM mode. I can hear noise as
I turn the dial. I can just barely hear the noise when I turn on the preamp.
And with any antenna hooked up I do not hear any noise at all as I turn the
dial. 

Jim, do you hear this noise with an antenna hooked up? I do not, so as far
as I am concerned it does not exist. However if you hear this noise when you
have an antenna hooked up you need to talk some more to Elecraft support.

73,
N2TK/NP2, Tony