[R-390] A vs non A

[Jim Green]

I don't post very often, but this topic intrigued me. I have a good  
example of a Motorola R-390 and a EAC R-390A. I have gone through the  
R-390A using the Y2K manual and replaced all the old caps and out of  
spec resistors. I have solidified the rectifiers in the PS, but it is  
reversible should I come across a couple of good original tubes. That  
was last winters project. It was time consuming, but quite enjoyable.  
I'm planning to do the same with the Motorola R-390, but the build of  
the circuits in some of the modules look much more difficult to work  
on. However, I believe the effort will be worth it.

As it stands, I think the R-390 is a better performer than the R-390A.  
However, your milage may differ. A good question to ask yourself is do  
I plan to listen to SSB and CW most of the time? Or am I going to  
listen to AM signals?

I listen to AM signal more often. I prefer the Xtal filters in the  
R-390 for this reason. I find the Mechanical filters in the R-390A are  
a bit harsh, and ringy compared the the xtal filters. That being said,  
The S/N ratio is the big thing, and they both kick A in that department.

I also have a very nice R-392. Not a real competitor in the R-390  
race, but it has the advantage of being dust-proof & it works well in  
my woodworking shop.

Jim