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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 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. I was the program manager for programs which used a bunch of these, and as such I didn't use them day in and day out (I did use them some, but not as a day-to-day operator.) I also didn't have to fix them myself, but I oversaw the programs that made sure there was someone there to fix them. The criticisms I heard were from the military ops and the maintenance guys. We reduced our maintenance overhead in personnel and spare parts considerably when we finally got rid of them. We could afford to buy 10K receivers because we didn't a ten man maintenance shop on site to keep the R-390s (among other gear) going. Of course in the end, we had to get rid of them because there just weren't parts available in the quantities we needed. They were used for long after government contracts for manufacture and for spare parts production ran out. I've been retired now seven years and the last 15 or so years of my career we didn't have any R-390's on my projects (there probably are some still in the government through, if only in depots.) I saw my last operational SP-600 series in the early 70's. The search operators loved it because you could scan a large chunk of spectrum (before automated systems) in far less them than with an R-390 or 51J receiver. The 51Js were all gone by the time I started in 1964. I don't think I ever saw one operational. 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. Jon W3JT On Sat, 24 Mar 2007 21:01:37 -0400, 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? |
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