For What it is worth, during the course of construction on my K2 I
inadvertently scrambled the K2's eprom storage with ESD. (Electrostatic
Discharge) In one instance I had to do a complete reset of the MPU and
memory back to the factory defaults. Only at that time did the receiver come
back to life again. In my opinion, the little K2 is very susceptible to ESD
( I was wearing a wrist strap) and the thunderstorms you speak of could have
definitely jumbled the K2's data storage.
/joe
----- Original Message -----
From: "Don Wilhelm" <[EMAIL PROTECTED]>
To: "john" <[EMAIL PROTECTED]>; <[email protected]>
Sent: Saturday, December 16, 2006 7:30 AM
Subject: RE: [Elecraft] Help-damaged front end?
John,
Yup, thunderstorms can put some big surges on unterminated hunks of coax.
If it receives any signals at all and you can tune the signals, then it is
unlikely that everything between the mixer and the audio output has been
damaged. That leaves only the preamp for active stages - turn the preamp
on
and off to see if it works, you should see about a 14 dB change (2+
S-units).
If the preamp check works out fine, that leaves only the bandpass filters,
lowpass filters and the T/R switch in the base K2 and the KPA100. Since
you
said it transmits fine, the filters are likely not the problem (a filter
problem would have more impact on transmit) - the most likely thing is
one
of the diodes in the T/R switch is damaged.
I would first do the DC voltage measurements on the T/R switch diodes in
both the base K2 and the KPA100.
73,
Don W3FPR
-----Original Message-----
I've got a K2 / 100 that has had a dramatic loss of sensitivity. This
occurred after a thunderstorm, when the antennas were
disconnected outside
the house, but there was still some residual coax feeds (unterminated)
still connected to the K2.
Where to start to look? Appears to have lost sensitivity on all
bands, all
modes. Transmit is still fine (at least CW) .
Thanks
John
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