K2 RX-degraded by KAF2? VCO voltages at 160m

[Jukka Tarvainen]

Hello!

Very pleasant autumn/winter so far with K2/100 on the Topband.

Yesterday I took my K2 home for re-alignment. I noticed that KAF2 was making
my RX worse. I wonder, if there is some problem with low-pass filter or
other part of KAF? I will check soldering and components later. Audio filter
has been most unused option in my radio. Normally it doesn't help anything.
It doesn't help at all with weak signal RX. I left KAF2 out when I put radio
back together. I used unmodules to replace it.

Otherwise K2 seem to be now in better condition. I re-adjusted IF-amplifier.
Also did all CW filters with spectrogram. Now I set 1.5 k, 700, 450 and 100
Hz bandwidths. Before I had OPT1, 700, 400 and 200 Hz. Now I can hear
signals with 100 Hz setting, before at 200 Hz it was quite useless.

I also checked VCO voltage for 160m, never checked that after K160RX was
installed. I remember that it should be also 1.5 - 7.5 V. Bottom of band is
OK around 3.8 V, but when go up to 2000 kHz it is over 8 volts.It is below
7,5 V on the band segment which is used here (<1900 kHz). Should I make
adjustment?

Waiting for better conditions to make more observations of re-aligned K2.

Jukka Tarvainen, OH4MFA
K2/100 #4293

[hidden email]
http://personal.inet.fi/koti/oh4mfa


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[Jukka Tarvainen]

Reply to my previous posting.

Fault is not in K2, only in person who is not reading ALL instructions
carefully. It is necessary to read manuals more often :)  "K2 RX-degraded by
OH4MFA" should be in subject line.

When I changed my sidetone pitch to 400 Hz about year ago, did I adjust
KAF2? No. So, I believe that was my mistake (I just wonder what I have
missed on the bands during this period :) K2 is quite amazing rig. Still can
hear good DX even rig alignment is done poorly. Today I listened Topband and
heard JA station little bit after my sunset. Not usual here...maybe from now
on more usual. And I can hear him with 100 Hz filter setting too. Had short
QSO too (with kW). I can't wait for morning and go to search for HQ9F (heard
them just readable couple of days ago).

For VCO voltage I found old postings and will check is voltage topping, or
do I need to adjust it.

Sorry for bandwidth.

73 and CUL
Jukka OH4MFA
K2/100 #4293

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