[Elecraft] P3 Misbehaving?

[Bob Cunnings]

Is the noise floor on the P3 stuck at -140 dBm or so all the time, no
matter what?  I experienced a similar problem after 2 weeks of use,
and replacement of the P3 RF board was required. Apparently, I was
informed, another cause can be handling damage to transformers T100 or
T101 on the P3 Front Panel board, so you might take a look at them.  I
sure wish the P3 schematic was available at the time, it would have
made troubleshooting a little easier (it's still not published
AFAICS). As usual, Elecraft support was prompt and efficient, I'd
contact them if there's no change.

Bob NW8L

On Sat, Sep 11, 2010 at 4:34 PM, Sanger, Joseph <Joseph.Sanger at nyumc.org> wrote:
> Just assembled P3 a few days ago.  Having a problem that I can't seem to solve.
>
> Background:  Haven't done K3 OUT mod yet (SN 113 ---- fairly old) ... really am apprehensive about opening up K3 again ... but I know I'm just being neurotic ... will face any weekend now).
>
> The P3 was pretty much performing as expected ... given that I haven't done the above mode yet, and I live in manhattan with a mediocre hamstick hung outside my window .. I could generally see strongest stations above a lot of noise on P3.  That was good.
>
> But over past few days, it seems that the sensitivity of the device was diminishing .. started to have trouble seeing the few stations that I could actually hear above the noise on my K3 ... and then today, it now appears that the P3 is basically deaf to the K3 ... I see some low ampitude noise, which doesn't vary in appearance with or without the coax cable to the IF OUT of the K3 plugged in.  I am listening to a fairly strong Italian CW station now on 20 meters now, sticking his head above the omnipresent S5-6 noise ... armchair copy, if you will, but all I see is noise at the bottom of the P3 screen.  The center frequency tracks my K3 nicely ... but no matter how I adjust the REF, SCALE and SPAN, all I see is noise.
>
> Any thoughts would be welcome.  Yes, I will dive in and do the IF OUT mod, but am trying to understand the curious behavior, and to see if it sounds familiar to anyone.
>
> Thanks in advance
>
> -- WB2SSB
>
> Joseph J. Sanger, M.D.
> Associate Professor of Radiology
> Director, Radiology Informatics