[R-390] The best

[Todd, KA1KAQ]

On Thu, Jan 4, 2018 at 12:16 AM, Stan Gammons <s_gammons at charter.net> wrote:

>
>
> I know we all like our R-390A and it's arguably the best of the tube
> receivers.
>

'Arguably' being the key word here, Stan. "Best" is a pretty broad
definition that means different things to different people.

Best at what? Best how? As a member of this group since last century, I can
assure you the discussion has been had here and elsewhere, many times.

While the R-390 family of receivers definitely excels in several areas, it
falls flat in others. While areas like appearance are more subjective,
aspects like ease of use and fidelity are not.

I think in areas like stability, sensitivity, and selectivity, the R-390
and later, cost-reduced A models are at the front of the pack.

When it comes to ease of use, something like the SP-600 leaves it in the
dust. If you're not already familiar with the term, do a google search for
'R-390 Wrist'.

Same goes for fidelity - the pre-war push-pull audio output Super Pros with
their continuously-variable bandwidth are tough to beat here, and good
receivers in their own right. Or the SX-28 with its P-P audio and flywheel
tuning, or NC-240-D, NC-183, etc etc.

And that's where the slippery slope of 'best' takes over. I think for
balance and aesthetics, the SX-28 is about the nicest looking receiver out
there, for example.

But I'd never be without my R-390 and later A model - they are keepers,
definitely in the top...5 ? keeper sets for me. And yet another reason to
have a few receivers kicking around.

To your question about comparing the numbers - I'm not aware of any
definitive source out there for comparison of all period sets. However, Jay
Rusgrove/W1VD has done some comparisons on sets that he has gone through
and brought up to spec. The R-390A and SP-600 are both in the list. It can
be found at:

http://www.w1vd.com/BAreceivertest.html

I know Jay personally, he is very thorough and professional. And a decent
guy as well. Happy to answer questions, give pointers, explanations, and so
on. You can read a bit more about him here:

http://www.advancedreceiver.com/page11.html

>From personal experience, along with the SP-600 I've also used the RA-17.
Though not a clinical or technical review, I would certainly put it in the
same class as the R-390 series. It's extremely quiet and sensitive, also
quite stable if the Wadley Loop circuitry is performing correctly.
Excellent build quality, but like the SP-600, it suffers from its own
version of COC (Crappy Old Capacitors) syndrome. It is not easy to service,
either. Takes a little getting use to with its tuning arrangement, but when
it's working well, it's a truly wonderful set to use.

Hope this info helps. Happy New Year to you and the list, as well.

de Todd/'Boomer',  KA1KAQ/4