Bell and Howell TSC 2000  system calibrator manual/info wanted. - Page 1
Forum section: electronics / testgear

author: Dr Wobble
author_rank: Contributor
timestamp: May 22, 2016, 04:44:01 am
content: I've just got a Bell and Howell TSC 2000 system calibrator. What it is as far as I can tell, is a sig gen with a range from near DC to 10mhz either sine or square. A THD meter and volt/ammeter/resistance DMM all in one box. Oh, it has an precision DC source too from +/- 0 - 19.999v . so it's potentially an amazing bit of test gear.AFAIK it might have been made to test tape recorders. All I can find out is that B&H were a US company who made film projector's, and at some point in the 70's had a test gear division in the UK. This thing uses a lot of logic IC's and is stuffed with tantalum's, one of which has burnt out and has a blob of Ali oozing out. This is on the main oscillator card, so all I'm getting is a distorted sine output which can't be altered. This dates it circa mid/late 70's.I've done a video which I'll put on Utube in the near future, am in the process of editing it. As I'm new to this video blogging, it takes me a while.So if any one has any info on this bit of gear, or even better a manual or schematic's, it would be much appreciated. It will be difficult to fix without as I'm a relative electronics novice.TFL.

author: tautech
author_rank: Super Contributor
timestamp: May 22, 2016, 09:46:38 am
content: There's a bit of info on B&H in these threads:https://www.eevblog.com/forum/repair/bell-and-howell-schools-model-10d-4540-oscilloscope-repair-(help!)/https://www.eevblog.com/forum/repair/bell-howell-schools-oscilloscope/There's a few links there that might put you on the right track.

author: Dr Wobble
author_rank: Contributor
timestamp: May 24, 2016, 08:42:55 am
content: Thanks, so they made scopes too. have contacted the calibration lab who calibrated it back in 1997 in the vague hope they have something.I've replaced the burnt out 15u 20v tantalum cap with a 22u 50v electrolytic as a temporary fix, as well as a 150p silver mica cap. Now the sine output has disappeared, but the "FFF " I was getting on the top right display has gone, and show the voltage present at the input BNC, but off spec. The freqency meter now shows a reading and the "dot" moves with each change in frequency range.The main osc board has 5 IC's on it, a quad nand gate, hex inverter, two op amps and a transistor array. I checked if each has power, they have. But I can't find a single signal anywhere on the board with a scope. yesterday before finishing for the day, I checked the reed relay's ( big silver EAC 1A5AHH) to see if they had power. All had but one had no DC on the switch. This is as far as I've got, and apart from knowing a little bit about logic, I'm not sure what to look for next. To get access to the osc board, I had to take out the nearest two to it. These are the levelling filter and analyser board. Could the having the filter board removed, be stopping oscillation? I'm sketchy on oscillators too, but know some IC based oscillators use filter FB.Here's some pics, first is the front panel, 2nd main oscillator board and third top view of inside. Any advice most welcome.

author: radhaz
author_rank: Regular Contributor
timestamp: May 24, 2016, 03:44:02 pm
content: That unit has a kind of Rotek vibe to it.

author: Dr Wobble
author_rank: Contributor
timestamp: May 25, 2016, 05:50:14 am
content: Ehm, had a look on line, see what you mean. the meters are similar as is the DC out jacks. Could be a possible lead, thanks.

author: Dr Wobble
author_rank: Contributor
timestamp: May 27, 2016, 09:40:59 am
content: Still not got this working but have found out these were made by RCA and Datatape too. they seem to have been used by the government a lot in the USA and end up being sold by the big surplus sellers. minus the manual's. Have maybe tracked one down, but it ain't cheap. this info may help someone in a future search.The lengths we go to to get old gear working. : )Thanks for your interest and help.

author: Vgkid
author_rank: Super Contributor
timestamp: May 27, 2016, 04:36:04 pm
content: Foxboro made a similar calibrator, that might be worth looking into. I don't own one, just have seen them.

author: Dr Wobble
author_rank: Contributor
timestamp: May 29, 2016, 10:59:04 am
content: Thanks.

author: radhaz
author_rank: Regular Contributor
timestamp: May 29, 2016, 09:39:32 pm
content: Not sure if you want to spend $75 on a copy:https://www.surplussales.com/Manuals/man_d-misc_test.html