[R-390] flying R390A

[ToddRoberts2001 at aol.com]

In a message dated 8/3/2006 9:30:31 PM Eastern Standard Time, 
kgordon2006 at verizon.net writes:
While they are a good little receiver, they have their share of problems, 
among others, the mechanical filter center frequency is somewhat odd.

Ken W7EKB

Ken, I found the 500KHz filters from the 51J-4 work nicely in the 
R-648/ARR-41. The stock filters of 1.4KHz and 6.0KHz are not the best choices. The 6.0KHz 
is fine for AM but the 1.4KHz seems too wide for CW and really too narrow for 
SSB or AM. The F500J31 is a good substitute for the 1.4 - just about right 
for SSB and narrow AM.   I removed the 2 original filters and installed HC6-U 
size crystal sockets in the I.F. module chassis where the original filter pins 
would go. The ends of the solder-type filter terminals on the original 
hard-wired F500F14 and F500F60 can be snipped off and the filters will then plug into 
the crystal sockets just like the filters do in the 51J-4. I subbed a F500J31 
for the 1.4 and plugged in the F500F60 for wider BW and the radio really works 
well with those 2 selectivity choices. And it is easy to just plug in the 
slightly-modified F500F14 back into the radio if that filter is wanted again 
instead of the 3.1.   73 Todd WD4NGG