[R-1051] activity

[Ray Fantini]

Being that no one else is writing anything thought I would take the opportunity to use up some bandwidth and talk about the wonder of General Dynamics and the whole family of radios that includes the R-1051, RT-618, T- 827(URT-23) and there evil ground base cousins the AN/GRC-106 I put all these radios in the same class being they all are hybrids,  all of them use a couple tubes in the rotating turret and rely on the turret technology to provide the necessary image rejection and unwanted spurious products that first generation synthesized sets produced. As far as I know that’s the majority of 1 MHz rotary turrets sets that I know of. I have seen similar ideas in ITT Mackey and Sunair but they are a bit newer being all solid state and rely on tons of miniature reed relays to select the 1MHz band pass filters and don’t use the turret. The older and more costly turret wins out in my mind and for that reason those radios are somewhat special to me. Just as a side note let me point out the Harris URC-94 or RF-280 that’s something like all the Sunair and other stuff but instead of a bunch of bandpass filters and relays they have a signal section with a manual tuned bandpass filter that takes the place of the turret or the filter board with all its relays. Great stuff, think the Big heavy Harris is one my favorite sets just because the way they got around this spurious and image problem but wonder how many Navy personal were befuddled by the process of having to push “TUNE” and peak for maximum reading?
The sixties, seventies and eighties were truly a peak of engineering design and implementation of new and sometimes unique concepts, not like that old WW2 crap that was used in the command sets that other reflectors keep going on about.
But enough about all that, is there a point to my email? Well maybe not. Let me say something about the 5 MHz reference oscillator assembly for the GRC-106 that for some unknown reason I have been seeing them fail a lot. For those of you following along at home that’s the 1A3 Frequency Reference Module. The crystal oscillator is a simple two transistor circuit but no matter what I do it is beyond my capability to repair one of those little bastards. Tried changing capacitors, transistors and everything else but find that if I can’t get them to oscillate they just won’t osculate no matter what I do. Gone so far as to gut the oscillator section and build a replacement oscillator or use an sealed 5 MHz time base to replace them. The worst thing of all is that I got a 1A3 assembly that was NOS, never opened and it had the same failure where the oscillator would occasionally not start. That’s the problem is they won’t always start but then if you touch the tuning capacitor or just do a reading with a meter the dam things start up and run again or you will do some changes and testing the assembly outside the radio it will work but when you get it all back together and after seeing it work on the bench a week or so later when you go to use the radio it won’t oscillate! The weird this is I have seen this on a couple RT-662 and RT-834 exciters-receivers but as far as I know have never had an issue with the Navy time base in the R-1051.
Well that’s enough of my rant for now, let’s see if any of you other people can write.

Ray F/KA3EKH