[Elecraft] K2 BFO problem

[Don Wilhelm]

Snowy,

I am glad to hear that it is now working for you.  It sounds like you 
had a soldering problem somewhere.
A surplus of solder usually means that the lead and solder pad were not 
heated sufficiently.
If you have other areas where you find excess solder, just reheat and if 
necessary, wick away the excess - you may have a fully functional K2 
sooner than you think.

It sounds as though some (or perhaps all) of the K2 A to B mods were 
installed in an attempt to get it working.
Which of the group of mods is installed is important to keeping track of 
the level of the K2.
You may want to download the K2ATOB instructions and all the other mod 
instructions to do a physical check of the installed components.  
Knowing the level of mods installed is important when chasing problems.  
Make a log of the A to B mods installed for future reference.  The  
level of the IF crystals  on the RF board and the KSB2 option is also 
important to having a good filter response - those crystals should be 
marked with a "-S" suffix.K2s above SN 2560 have the new crystals.

If the wiring mod for the sidetone source with firmware 2.04 has not 
been installed, do it.  It is required for the
KIO2 or the KPA100 (see the instructions for those options) .  If you 
have MCU 2.04r firmware it is mandatory  - you will not have sidetone 
without it.  If your firmware is 2.04P or earlier set the menu sidetone 
to U4-8.

73 - Merry Christmas and Happy New Year,
Don W3FPR

On 12/19/2021 5:36 PM, snowy howell via Elecraft wrote:
> Good Evening Don Sorry for the late reply, not used to the format of  > the reflector and stumbled onto your suggestions to solve my BFO > 
problem. I am please to say that I have now got it working > correctly. 
Getting nowhere with the test I decided to dismantle the > radio down to 
just the RF board, removed a surplus of solder from the > D36/37 area, 
re-flowed the pins of U10, lifted the leg of the 5.1meg > resistor and 
L33, didn’t know about the rubber bung being conductive > however once 
again removed a surplus of solder from that area, I also > added a small 
cut of insulation tape to form a bed for the resistor > on L33, thinking 
that turns may be shorted, at this point I ought to > explain I 
purchased this as a built but non worker, it is an early > radio as it 
has a Rev A mother-board with a small pot for R60 and an > early control 
board with the 12v switch rather than the berg > connectors, I have 
built 5 or 6 of these for people and never had a > problem certainly not 
as many faults as this one appears to have had, > there is no serial 
number on the radio, but it has had the PLL > thermistor conversion as 
well as the D36 done. Have to thank Dave for > sticking with me on this 
one, without his guidance I would still be > trying to sort the PLL 
problem. > > Have a good Christmas and New Year 2022 > > 73 > > Snowy 
G0HZE > > Sent from Mail for Windows > > 
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ere