[Premium-Rx] Old Receiver NF and ACL

[Jeff Kruth]

Well, once again Terry is on the mark. The "Steel Box" tuner design can be seen in the legendary UT-1000 frequency extender, 235-1000 MHz, used in many intercept systems.
 
As a corollary: ACL was an interesting spin-off from WJ. Founded in 1964, when germanium transistor would just cut the mustard as a high frequency amplifier, the tuners were touchy. The first stage intermodded more easily than the nuvistor/GE planar triode designs that CEI stuck with at the time (ACL used a Ge 2N2996, as well as some custom Ferranti transistors in those tuners).  I used to eat lunch with Ed Turos, the #6 guy at ACL.  ACL was very proud of the fact that they built the first Modular, All Solid State (except the crt in the SDU and the HV reg tube), plug-in printed circuit board design (could un-plug and change IF filter BW cards easily!). They sold the design,the SR-209, repackaged as the GLR-9, to the Army for the ASA.  Sold over 300 systems!  Ed was the salesman and very proud of that. The SR-212 which was a 2u, all solid state version of the 3u CEI RS-111A (hybrid design, 30-1000 MHz Rx with built in SDU) was used in the P2 and P3 aircraft (subchasers) as their VHF-UHF intercept radio.  He was quite proud of that. General Mills (the cereal people) bought ACL in the late sixties (probably when they had the money bump as Terry says), when they were in College park, MD.  This became Norlin and and later AIken Industries. (I think there was another name change in there as well, maybe a division of Aero-Geo-Astro). ACL as Aiken, lasted until the early 1990's.
 
I knew several of the engineers ho worked there and they knew what a junk man I was (or "nut case"). When they moved to Florida as REI, I got a call about the "leftover" stuff: I was allowed to go though their old digs at Edsall Road in Alexandris VA and clean it out. Got a lot of "stuff" (including a Ficus tree from the Mahogany Row offices that I kept going for about 10 years. I called it my "55 mile an hour tree" as in bringing it home in the back of my stake-bed truck with all the other stuff, all the leaves blew off! My secretary nursed it back to health and it lasted quite a while).  What is not generally known about them is that they re-did all the "Huf-Duf" "elephant cage" antenna sites around the world (FLR-9??getting old...) that the intelligence agencies used to keep track of the machinations of the "away team". I got a lot of printed material about these sites and learned one of their biggest product lines was AUDIO switch boxes! Elmensdorff, Augsberg, 11 sites in total.
Fun stuff and a real trip down memory lane!
 
73
Jeff Kruth
WA3ZKR
 
 

Jeff is correct about the old CEI receivers.  Two of the engineers who designed these radios told me they optimized the designs for noise figure because there was no other measurable indicator of performance in those days.  The customers demanded measurable performance.  One told me their optimization extended all the way to the audio stages.  I pointed out how the math stacks up to favor optimization starting at the front end.  He responded by telling me about a design where in the field, the noise in the audio stage interfered with a particular application of a radio.  I was still skeptical, but he wouldn't reveal the details (Finding out how these radios were used is the hardest part of the research I am doing). A retired WJ test tech told me about some of the factory alignment and optimization procedures used on the old UHF tuner designs they called the "steel box tuner."  They involve a number of things that were never in the manuals.  Some were straightforward, like testing all the 7077 planar triodes and selecting for lowest noise.  Others were obscure, such as their use of two narrow brass straps where a thin copper wire would have handled the current with ease.  Part of the factory tuner alignment procedure involves prying these strips apart slightly or squeezing them together. ACL was founded because the lead tuner designer for WJ/CEI kept insisting transistors were up to snuff for use in tuners but was rebuffed by CEI President Ralph Grimm.   So he recruited a handful of other engineers and left to found ACL.  ACL receivers were very good but the company foundered when one of the partners insisted on an expensive expansion into the UK.  A more restrained partner who was a superb engineer and the best manager resigned and returned to WJ (he retired as a vice-president).  This was not the only incidence of a revolving door in this industry.  This is why there is a significant resemblance between radios from different companies. This brings me around to one thing I dislike about the concept of premium receivers.  The early companies Jeff listed, CEI, ACL, Nems, DEI... all made premium receivers.  The performance of their radios were head and shoulders above the consumer market at the time and they certainly commanded a premium price.  I don't agree with the definition that a premium receiver must have a microprocessor or some digital circuitry.  Until DSP left its infancy, the digital stuff was for operational convenience and was sometimes included at a cost in performance. Terry O'