[ICOM] Fixing an IC-251A

[Ron Hashiro]

Hello Icom fans, today I ask about the IC-251A, a 25 year old radio that 
I recently picked up and really like.

http://www.eham.net/reviews/detail/915

Most unfortunately, after about four months of a second life and renewed 
service, the receiver section went very deaf.  It appears to be a 
somewhat frequent with this model.
It suffered tremendous deafness one day, and it takes a very strong 
signal to get it into the radio.  A repeater that was full scale now 
reads S0 and faintly audible.  There are support tips suggesting 
replacing the Q47 RF amp FET with another FET.

When I went to do that, I found out there's a modification board in the 
radio.  Apparently, the previous owner had installed a pre-amp board the 
size of a matchbook, on the solder side, right over the location 
formerly occupied by Q47.

I find that I buy similar boards and was thinking of replacing it.  
Before I do that, I thought I'd ask the Icom readers what has been their 
experience with similar situations.  The pre-amp board I'm thinking of 
is NPN bipolar microwave transistor.

Any thoughts?

Ron Hashiro, AH6RH
http://ronhashiro.htohananet.com/am-radio/in-hawaii.html