Jon Teske wrote:
I used to manage operations for the military that used R-390s in vast
quantities. It was not uncommon to have over a hundred of them at a
facility and thousands in our overall inventory. For what they were
designed to do they did a great job. As is mentioned they did not have
a product detector. I once saw a prototype sideband adapter, but
before it was adopted in any number, we went to newer solid state
receivers (none in the ham price category... 10K each and up.]

There was a military sideband adaptor available using sheet-beam tubes,
although I forget the nomenclature. There also were a lot of civilian
models that will work as well.

There were a couple problems we had with R-390's. The main one was
maintenance. The tuning scheme was so complicated you practically had
to be a mechanical engineer to fix one. The gear trains to control the
permeability tuning are a wonder to behold. They were cumbersome to
tune and military intercept operators who used them all day long
complained of "R-390" wrist because it took so much arm torque to
change the megahertz dial. It was time consuming to get from one end
of the spectrum to a different end. Some guys, particularly HF search
operators got carpal tunnel from tuning them day in and day out. They
consumed a lot of energy, particularly if you had a bunch of them
operating at the same time. We usually had air handlers to cool the
rooms they were in. The only reason they didn't drift is because ours
were on all the time.

They are phenomenally stable by the standards of the day, and the short
term stability is actually better than some PLL receivers today.

The audio quality is pretty bad, though, and the mechanical filters
on the 390A that are a godsend for pulling signals out of the noise floor
also contribute to severe ear fatigue because of the enormous group
delay. I get a headache listening day in and day out.

Of course a ham restorer dealing with unit quantities doesn't have the
maintenance management problems we had because a ham trying to fix up
one or two can probably scrounge up the parts or cannibalize another
like units, but we had to look at the R-390 and almost any other piece
of gear the military used in terms of life cycle support, personnel
costs, training tails, depot stockpiling and a host of other issues.
It was a good receiver that just wasn't supportable anymore. The same
could be said for the SP-600 series which was actually obsolete when I
entered the profession 43 years ago, but that hasn't stopped dedicated
hams from making them work in unit quantities.

The good news is that Chuck Rippel's shop down in Chesapeake looks like
the Ft. Devens radio refit facility did thirty years back. He has racks
and racks of 390s in for repair, and he has all the special tooling and
jigs for module testing. So you still have the depot level support that
the military provided, it's just that Chuck is providing it now.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

The good news is that Chuck Rippel's shop down in Chesapeake looks like
the Ft. Devens radio refit facility did thirty years back. He has racks
and racks of 390s in for repair, and he has all the special tooling and
jigs for module testing. So you still have the depot level support that
the military provided, it's just that Chuck is providing it now.

I remember hearing about the Ft. Deven facility. I was never there,
but most of the Army GI's who worked for me trained there. As I worked
with all of the services, I got guys who came from all the schools,
Devens, Pensacola, Goodfellow and others. They seemed to have
different syllabi for training, often contradictory. I was the Program
Manager for the overall project and I didn't have specific
responsibility for the guys who actually worked in the maintenance
shops. My job was really to see that there WAS a maintenance shop and
that someone had responsibilty to train the folks and staff the
facilities, so it was far more political than practical. Since I had a
ham ticket and the guys in the shop knew that I knew which end of a
soldering iron was hot, they cut me a lot more slack than they would
with the average "suit" who came in from Washington. I tried not to
say "We're from HQs, we're here to help you."

Is Chuck Rippel in Chesapeake VA????

Jon W3JT
--scott

Jon Teske wrote:

Is Chuck Rippel in Chesapeake VA????

Yes. It's like a 1960s military supply depot in his backyard. It's wonderful.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On Mar 24, 8:01 pm, Rick wrote:
Well, I am beginning to have some doubts about the likelihood of finding
an excellent-quality Hammarlund HQ-180 at a price I can afford.

Certainly I am going to keep looking, but meanwhile I guess I need to come
up with a few alternatives that I can "settle" for if, as seems likely,
the HQ-180's have priced themselves out of my reach.

I need something that is all tubes, and works well on SSB. I plan to use
it mostly on CW but I need decent SSB performance. AM is relatively less
important (it should work on AM but doesn't need to be a spectacular
performer).

It does need to be general coverage 500 KHz to 30 MHz.

R390's and 51J4's would be good (but of course, more expensive than the
HQ-180) but none comes with a product detector and so performance on SSB
is likely to be marginal at best, right?

I have looked at a few Hallicrafters SX-100's (that is to say, looked at
their pictures on eBay... haven't actually seen one up close in at least
30 years). How does that model and other comparable models from
Hallicrafters and National stack up?

Did Heathkit ever make a general-coverage communications receiver that was
worthy of the name "communications receiver"? I know they had one, I
think the model was AR-3. I had one when I was a kid and it wasn't much.
Everything else I've seen from them seems to be ham bands only, and mostly
80-10 (no 160).

Any suggestions, places where I should start looking?

I would love to have an HQ-180 also but they are just too pricey. I
did find a nice HQ-170 on Ebay and restored it. The HQ-170 is not
general coverage but I really like mine for general boat anchor Ham
use. You can check out my HQ-170 and Ranger on my Flickr site.
http://www.flickr.com/photos/wb5kcm/...7594523189590/
It's not the greatest AM fidelity wise receiver due to the narrow IF
bandwidth but still does a nice job. You can pick up a nice HQ-170 at
hamfests for around $100 to $200 depending how pretty it is.
73, Randy