Does anybody know how to take this thing apart? I just picked up one of
these units. It has that dreaded "howling audio with low system gain"
problem for the first 10 minutes of operation.
The 100uF 10V bypass cap that is across the 8V line is bad (why did they use
an electrolytic cap this close to its rated limits in the first place?).
Anyway, I got to compare this receiver with my HF-150 and HF-225.
The 150 is the most sensitive, the 225 is next, and the 250 follows by a
close third place. With the preamplifier engaged, the 250 falls into second
place.
Measurements were made using a Boonton Model 103D RF generator.
If I could figure out how to get the 250 apart, the repair is a ten minute
job. Nice receiver, good build quality.

Pete