[R-390] What is the difference between 390 and 390A

[Damon Raphael]

Hello Bob,
I use a HQ-180, R390 and R390a.
The 390 radios have more accurate frequency readout, to start. This is 
not surprising since they cost a fortune in 1950s and 1960s dollars when 
they were manufactured. They have the best freq readout of probably any 
non digital radio ever made.
The 390 and 390a have the ability to listen to "wider" signals which 
means better audio fidelity when you want to listen to broadcast music.
What the HQ-180 has, that the 390s don't, is a tunable notch filter.
I use the Hammarlund mainly for SWL and the 390s for ham radio. The 
mechanical filters in the 390a are more effective for rejecting 
interference than the LC filters in the 390, but may give somewhat 
poorer quality audio fidelity at the same bandpass width.
The R390 may be a little more sensitive than the 390a. It has an extra 
stage of RF amplification but this probably doen't really make much 
difference as both radio are very sensitive; otherwise, the Collins 
engineers wouldn't have removed the extra stage in the redesign to make 
the 390a.
If you get a 390 or 390a, then you will have a considerable expense in 
getting it restored to its original operating specifications. There are 
only a few people who know enough about these radios to properly restore 
them.
Hope thmis helps,
Damon Raphael, W7MD
Tucson, AZ


ROBERT YOUNG wrote:
> Hi,
> 
> I'm new here, I'm a BCB dx'er and plan on buying a Collins within the next 
> year and was recommended to come here for help by a fellow member of the 
> NRC. I'll probably have a lot of questions and my first one is what is the 
> difference between the 390 and the 390A? Which would be better for BCB 
> DXing? Also I use a nice HQ-180 right now, can anyone compare the two for 
> me? thanks,
> 
> Bob Young 
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