[Elecraft] K2 RX/TX Problem has been localized

[Don Wilhelm]

John,

That sounds like a leaky capacitor on the KNB2 board.  The first ones to 
suspect are the 0.1 uf caps with 0.1 inch lead spacing.  I would suggest 
arbitrarily replacing all of them as the first order of business.

It is strange that both TX and RX are affected because the KNB2 is only 
in the receive path - but then, strange things can happen.

73,
Don W3FPR

JohnK1JD wrote:
> All
> The intermittent (cold rig only) problem cited below completely 
> disappeared upon removal of the NB and SSB boards (replacing them with 
> the requisite jumpers and the capacitor). The KSB2 board was put back 
> first and the rig still behaved perfectly.  However, when the NB board 
> was plugged back in the problem returned (note - the NB function is 
> turned off).  Interesting that both RX and TX are affected. More to 
> follow...
>
> 73,
> John K1JD
> K3/100 #071
> K2/100 #583
>
>> JohnK1JD wrote:
> Trusty K2/100 SN#583 has a problem which is the first significant 
> issue since building the basic K2 in Oct of 1999. The rig has been 
> mostly unused (neglected?) since the K3 arrived last November, but 
> decided to fire it up the other day and discovered that both RX and TX 
> exhibit a broadband 'hash' sound instead of distinct CW when first 
> turned on, both on signals received and on its transmitted signal. 
> This problem lessens as the radio warms up and eventually disappears 
> completely. I have used it quite a bit this weekend and it's been fine 
> - until I turn it off for a few hours.The frequencies for the VCO and 
> BFO seem OK as do the voltages. Cal PLL was performed and completed 
> without any errors.
>
> Has anyone experienced this intermittent problem before?
>
>
>
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