[Hammarlund] Favorite Hammarlund Radio

[Kenneth G. Gordon]

On 11 Dec 2011 at 9:17, Carl wrote:

> ** But it had fairly steep IF skirts plus the filter. I find the RBB
> enjoyable on 80CW even on a crowded band and the RBC is fine on the
> higher bands.

I found my RBB to be a very enjoyable and useful receiver in its 
range. I was not as impressed by my RBC. However, that may be because 
it wasn't up to snuff.

I STILL wish I had the pair in my shack. (sniff...) :-(

> ** Look at the front ends again Ken; circuit design and the tubes
> used. The RCA's used the latest and quietest while the SP's used the
> noisest and most obsolete they could find.

Well, I don't know that that is quite true: at the time the SPs were 
designed, the tube and circuits used were the most common. But you 
are certainly correct in your assessment of those circuits and tubes: 
they were NOT the best by any means.

> While most anything will
> work well where the antenna noise predominates the SP's wisely stopped
> at 20mc in most models. My SP-400 is deef on 15/10M considering its
> other qualities and its just a rebadged SP-200. The RBx's are almost
> too sharp for AM quality and were mainly used for CW and RTTY. AM was
> for short haul such as entering port.

Yes. As I said, I found my RBB to be just about perfect for CW and 
RTTY at the time I was using them, which was back in the 1960s.

> ** Having spent several years aboard ships with the RBx's and the
> RAK/RAL as emergency backups I can say without a doubt the RBx's were
> completely immune to overload. Dont forget that the CW nets were full
> break-in with seperate RX/TX antennas only seperated by a short
> distance.

Like **I** did it. :-)

BTW, in my talking about the RBB/RBC, I had momentarily forgotten 
that you were a Navy Chief and spent years in the Navy using those 
receivers, so you know more about them than I ever could.

> ** The audio limiter/AGC in the RAK/RAL is equally effective. They are
> arguably the best regens ever built....another RCA great.

I consider the RAL quite simply the finest HF TRF receiver ever 
built, bar none. I used one for something like 12 years as my main 
station receiver and absolutely loved it. I have two today.

When I read that stupid statement in the CQ magazines Surplus 
Conversion Manual about it being a "hopeless antique" I got highly 
incensed. Obviously whoever wrote that never used one. :-(

> Too bad they
> blew it with the POS SRR series.

Well, the SRR series had some pretty good points, and some innovative 
ideas. However, after working on those for a considerable period of 
time, it became painfully obvious to me in very short order that RCA 
must have had some new and inexperienced design-engineers working on 
that project.

For one thing, they had all the tubes in that thing with the screens 
operating at the exact same voltage as the plates! Talk about heat 
and wasted power and noise! Geeze!

I fixed quite a number of the SRR-11/12 and 13 one of my early 
employers was using by removing every module, and installing a 56K 
resistor in the screen feeds, bypassed where necessary.

That simple process reduced the heat produced by at least one 
magnitude, and thereby increased their reliability. It ALSO 
dramatically reduced the internally generated noise! 

After doing that, I was impressed, overall, by the receiver.

One thing I did like about the SRR was that projection dial readout 
system: as far as I am concerned, it is the only analog dial readout 
that had enough accuracy. It ALMOST equaled a digital readout. The 
"dial scale" was something like 12 feet long.

And the SRR had a real product detector too. I don't know of any 
other receiver of the period which did.

Lastly, I really, really like those subminature tubes used in it. 
Those things are amazingly reliable....when they aren't being cooked 
to death by some stupid kid designer right out of school.

A couple of other things I didn't like about the SRR were the cranks 
in the bandswitching mechanism, especially the early ones, which were 
always breaking, and secondly, the damned coils would go bad on you 
and had to be rewound. But even those two things, if one was careful, 
didn't happen very often...and today, both can be fairly easily 
fixed.

I have several examples of the SRR-11/11A and the SRR-13/13A in the 
queue to be restored, but I have only one SRR-12.

Ken W7EKB