I have an old US Navy scope but I have no idea of the USM model. I bought it at a hamfest back in the mid-1970's when I was a kid for $5. It was made by Dumont no less! The thing weighs a ton. The 5JP1 tube was bad and it needed to be recapped. My maternal grandfather gifted me a new tube that he got at Liberty Electronics in New York City. The capacitors I had to special order at Lafayette Radio and they came in in drips and drabs (thankfully - I did not have a lot of money). I also managed to blow the 991 neon regulator bulb and a good friend of my fathers who worked as a transmitter technician for WVIT-TV in Hartford sent me a replacement. I also managed to track down a user manual at the time as it turned out that Fairchild had bought out what remained of Dumont and had their intellectual property. The original Dumont manual has a Fairchild cover stapled to it. Funny how one could get information and parts without the Internet back then.
I still have it though I have not turned it on in probably 20 years. I would have to hook it up to my variac and slowly power it up again to allow the capacitors to reform. I have not had much use for a scope these days and if I did, I would get a device that interfaced to my PC. On Tuesday, February 22, 2022 at 4:31:09 PM UTC-5 gregebert wrote: > What's even more interesting is that a lot of these old dinosaurs still > work. A friend at work gave me a US Navy scope (USM-117) from the early > 1960's, and at first it was having some problems generating high-enough > anode voltage for the CRT, but letting it run a few hours apparently coaxed > the capacitors into working again. The other neat thing about this scope is > that the only vacuum tube is the CRT; everything else is transistors which > was quite a feat for 1963. > > Many of our beloved nixies and CRTs are approaching, and even exceeding, > 60 years old and I am in awe of the fact the vacuum seals apparently are > still holding. > > On Tuesday, February 22, 2022 at 11:38:28 AM UTC-8 [email protected] > wrote: > >> When RCA was in its heyday, they promoted their "RCA Institutes” >> correspondence courses in electronics. As part of the course in >> >> TV/radio servicing, the students had to assemble their own test gear. >> This was one of those items. It is actually a rebranded Eico >> >> model 430 oscilloscope from the late ‘60s. I know this since I have the >> model 435 which appears similar but has better bandwidth. >> >> I have always liked the looks of this series of test equipment that Eico >> made during this period compared to their earlier designs. >> >> They are simple to use and relatively easy to fix since they don’t have >> sophisticated features like triggered/delayed sweep. It looks >> >> like you’ve scored a nice one. Good luck and enjoy! >> >> Rich >> >> >> >> >> On Feb 22, 2022, at 9:45 AM, martin martin <[email protected]> wrote: >> >> Since we are on the subject of CRTs... I was asked to pickup all kinds >> of vintage items from an "Estate Giveaway" >> >> Here's the first one! More on the way, Heathkit VTVMs too.. >> >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "neonixie-l" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web, visit >> https://groups.google.com/d/msgid/neonixie-l/586a03e4-6f55-4216-a715-6fc80e515c7en%40googlegroups.com >> >> <https://groups.google.com/d/msgid/neonixie-l/586a03e4-6f55-4216-a715-6fc80e515c7en%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> <RCA.jpg> >> >> >> -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/bfb3541f-bf9d-45f8-8f47-1d5a505c20cbn%40googlegroups.com.
