[Elecraft] KX1 Recvr nearly deaf (Was KX1 receiver alignment)

[Vin Cortina]

Some additional data.

Voltages at U4, U5 and U6 check out OK.  However, the base voltages at Q7
and Q9 are out of spec.

Base at Q7 should be about .7V, but is about .37V  and base at Q9 should be
about .3V but is about .15V.

I am continuing my troubleshooting, but welcome any and all advice.

Thanks again.


Vin Cortina  KR2F

K1-4 s/n:1977
KX1  s/n:1476



-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Vin Cortina
Sent: Thursday, July 06, 2006 11:06 AM
To: Elecraft at mailman.qth.net
Subject: [Elecraft] KX1 Recvr nearly deaf (Was KX1 receiver alignment)

Hi folks,

I have resolved the "signals getting loud when I touch the board" mystery
with help, but there is still something amiss.  Upon further testing, the
receiver appears to be profoundly deaf. It does hear some signals on 40, and
even some on 20, but not nearly as well as it should. However, I have some
clues here. Attaching the antenna does affect the signal level, so the
receiver is, to some degree at least, seeing the antenna. Also, the receiver
is detecting signals and is on frequency.  It hears my signal source OK, and
even the few strong external signals are perceptible, but again not nearly
as strong as on other receivers here. Another point of note, the background
hiss really doesn't sound like what I would expect. No static crashes, not
the background noise I would expect. Just a dull hiss like you would hear
when raising the volume on a PA system with no input.
Another point, although seemingly unrelated, is the AF gain control gives me
basically no audio until I get to about 3 o'clock. Then it gets loud very
quickly. (This could be a combination of not very sensitive headphones and
the audio taper characteristics of the pot, if in fact it is an audio
taper.). And then just before it hits maximum clockwise position, I hear a
slight "pop" and it gets noticeably louder.  I do realize that I probably
need more sensitive headphones/ear buds, but this would not explain all of
these symptoms.