[Elecraft] Freq probe

Mon Mar 3 15:29:01 2003

That's an excellent question, John! 

The issue of putting the cover on to run PLL came up a couple of years
ago before the KPA100 was released. The KPA100 might well cause a
different shift. I haven't heard from the Ele-guys about it. Maybe Wayne
or Eric will chip in. 

I got in the habit of dropping the top cover in place when running CAL
PLL, and so I didn't even think about it. I did that in order to get the
best "dial calibration". I was not aware that running CAL PLL could also
cause the "5 kHz artifacts" until the recent posts on the subject, but
it makes sense since putting the cover on after doing the CAL PLL shifts
the oscillator frequency.

BTW, a number of posts refer to the instruction to remove the probe
before operating the K2 to avoid slightly greater spurious signals in
transmit. That's true, but that caution refers specifically to removing
the probe from the BFO test point. In the past, we often left the probe
in the BFO test point so we could re-run CAL FIL to adjust the filters
at any time the mood stuck without opening up the K2 again. I believe
the earlier assembly instructions even suggested doing this. 

But that's not what we are doing here. We are talking about the PLL
Reference Oscillator test point for CAL PLL, not the BFO test point for
CAL FIL. I don't know what the impact would be, if any, of leaving the
probe in the Reference Oscillator test point when operating.  I still
remove it because things are really crowded in there anyway with the
KPA100 lid on it, and I found that the KPA100 squashed the cable down if
I left it connected. 

Ron AC7AC
K2 # 1289

-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of John Huffman
Sent: Monday, March 03, 2003 9:45 AM
To: [email protected]; 'Elecraft'
Subject: Re: [Elecraft] Freq probe

Ron -

Is this also necessary it the top cover is the KPA100?

73 de NA8M
John