Wierd SSB problem on my K2 on 20M

[Tom Althoff]

I know the BFO filter settings are saved with each mode and filter width...is there anything band specific that would cause the following symptoms...

While listening to SSB signals:
160/80/40 LSB SSB OK
20M USB Rig seems to be stuck in LSB though the dial says "u".   Signals are unintelligable and appear to be wrong sideband or badly adjusted BFO setting
17/15/12/10 USB SSB OK

I just checked it out on 20M SSB for the first time a few hours ago so it looks like #1117 is not quite ready to play full-time yet.

Tom K2TA
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[Ron D'Eau Claire-2]

My guess is that the BFO is misaligned, Tom. The BFO frequency changes
according to the Upper or Lower sideband, and I'll bet that if you check the
CAL FIL function with the counter probe in the BFO test point, you'll see
the SAME frequency for either Upper or Lower sideband. Ham bands below 20
meters normally use the lower sideband, and that's probably okay. But when
the upper sideband was aligned, the BFO was set on the wrong side of the
signal and so USB on 20 meters and up (all the way through 10 meters) will
not work on USB.

Ron AC7AC

-----Original Message-----

I know the BFO filter settings are saved with each mode and filter
width...is there anything band specific that would cause the following
symptoms...

While listening to SSB signals:
160/80/40 LSB SSB OK
20M USB Rig seems to be stuck in LSB though the dial says "u".   Signals are
unintelligable and appear to be wrong sideband or badly adjusted BFO setting
17/15/12/10 USB SSB OK

I just checked it out on 20M SSB for the first time a few hours ago so it
looks like #1117 is not quite ready to play full-time yet.

Tom K2TA
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[Tom Althoff]

I agree...definitely the BFO is off...but dramatically.

The "listen for the zero beat of the noise" test which worked before I
removed old L33 and replaced it with the torroid version.  I could tune
through either side of the passband with the BFO.   Then I changed all the
crystals using the matched set and did the BFO temp stablilty mod.   I need
to recheck that to be sure I didn't yank a crystal that I wasn't supposed
to.

Initially the BFO High Freq was only 4915.52.    I took 2 turns off of each
side of the torroid (boy...that wire is friggin' thin!!!) and got the range
up to 4915.99.

But then I decided to do a practical test and listen in the headphones as I
adjusted the BFO.   Instead of getting the noise zero beat around 4913, the
noise continued to drop until I ran hit 4915.99.

So something is not right.   I wonder if there was something that needed to
be changed or adjusted when I replaced the stock crystals with the matched
set?

I'm going to leave the torroid winding alone at this point.   I've been
going for 24 hours without sleep and I think I'm getting slap happy with
this.  Maybe a fresh start in the morning will bring a new perspective.

Tom K2TA

----- Original Message -----
From: "Ron D'Eau Claire" <[hidden email]>
To: "'Tom Althoff'" <[hidden email]>; <[hidden email]>
Sent: Saturday, October 30, 2004 6:13 PM
Subject: RE: [Elecraft] Wierd SSB problem on my K2 on 20M


My guess is that the BFO is misaligned, Tom. The BFO frequency changes
according to the Upper or Lower sideband, and I'll bet that if you check the
CAL FIL function with the counter probe in the BFO test point, you'll see
the SAME frequency for either Upper or Lower sideband. Ham bands below 20
meters normally use the lower sideband, and that's probably okay. But when
the upper sideband was aligned, the BFO was set on the wrong side of the
signal and so USB on 20 meters and up (all the way through 10 meters) will
not work on USB.

Ron AC7AC

-----Original Message-----

I know the BFO filter settings are saved with each mode and filter
width...is there anything band specific that would cause the following
symptoms...

While listening to SSB signals:
160/80/40 LSB SSB OK
20M USB Rig seems to be stuck in LSB though the dial says "u".   Signals are
unintelligable and appear to be wrong sideband or badly adjusted BFO setting
17/15/12/10 USB SSB OK

I just checked it out on 20M SSB for the first time a few hours ago so it
looks like #1117 is not quite ready to play full-time yet.

Tom K2TA
_______________________________________________


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[Tom Althoff]

Gosh darn it!

I found out what I screwed up.   I put 5 of the matched crystals in X7-X11,
and instead of putting the other two in X5 and X6 I put them in X3 and X4,
the BFO crystals!

Sorry to waste bandwidth on the reflector with my wiring errors.

I have a pile of crystals here that I pulled from the garbage.   How do I
identify the BFO crystals?   Some say 4.91-S, some say 4.91-0195 etc etc.

This is what happens when you try to do too much in one day!

Any help on how to figure out which 2 of the 14 pullouts are the BFO
crystals for X3 and X4?

Thanks!

Tom K2TA

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