1985 GE BC-A Color TV

[Findm-Keepm]

Originally Posted by Jon A.

....Take care of the griplet issue and you'll have quite the showpiece...

This. Ain't. A. Griplet. Set.

The BC-A chassis is probably the most reliable of the late GE's - you are thinking of the AA/AB and AC chassis from the 80s. Those and the EC/EM chassis made $$ for servicers.

The later PC and PM (cousins in time with the BC-A chassis of the OP's set) also were prone to problems - with a Vertical cap (100uf/50V, C621) and a few flybacks. Nothing major like the griplet sets, and once you replaced the vertical cap (use a 100/100V), they were great sets. One 19" PC chassis set was my daily watcher for 3 years until I got a curb-crawl 20" Sony. I couldn't sell the GE - it had a pre-UL testing "red label" CRT, and was a mock-up set with no model number. It was a test bed for GE's Engineering Dept at the Portsmouth plant. I still have some of the Engineering Dept. "junque" from that haul/auction.

[Findm-Keepm]

Here's a peek inside the 112 Channel Tuner - my 112/130 channel tuner (on the left...) is an engineering sample and probably doesn't work.

[Jon A.]

Originally Posted by Findm-Keepm

This. Ain't. A. Griplet. Set.

Thanks for the reprimand. I wasn't the source of the information, look at this:

Originally Posted by zeno

Uses GE tuner complete with intermitant griplets.

73 Zeno
LFOD !

[Findm-Keepm]

My sincerest apologies - the tuner in these doesn't have the griplets either. The white wires you see? Jumpers that solved the problem in the 112 and 130 channel tuners. (EP93X442 and EP93X590) - the earlier 108 channel ones did - they were used in the AB/AC remote/random access sets.

The BC-A chassis tuners used a Siemens design, straight from their datasheets, minus changes made for North American use. Grundig also used the same design/chipset for the prescaler and band-switching chips.

108 Channel tuners used a Toshiba or NEC chip set that was rock solid. Some folks modified them for use as tracking generators for their homebuilt spectrum analyzers. The local oscillator in the tuner was shifted, filtered and tapped for use.

One of these days, when I get a new all-in-one printer (my Canon Pixma died...) I'll scan all of the GE Engineering notes found with all of the Engineering Dept stuff. Some of it is boring - small value changes in resistors, caps and the like for performance improvement over the datasheet designs, and outright breakdowns of competitors stuff, like Sony tuners, RCA (pre-GE) tuner control modules. Other stuff is insightful - like what CRT brands and types had the best resolution with their chassis (EC and AB/AC only, nothing later...).

I think I've posted pix of bare PC-A chassis boards I have where they were checking out temperature effects on different Phenolic materials used in the boards. I've also got modules with no markings on the board, extra holes, and "ENG SAMPLE" stamped in ink on the boards. I thinned them out some - and salvaged CRT sockets, power resistors and hardware, keeping only the best 4 or 5 boards - some date back to the JA/MA/MB sets of the 70s.