Tektronix 1720/1730 vectorscope/WFM
 

Just got a pair of Tek video scopes, a 1720 vectorscope, and the 1730 waveform
monitor. Both were DOA, but brought back with a couple new caps and resistors in
the switching supply. Both have nice bright unburned CRTs, and seem to even be
reasonably well calibrated when viewing a set of SMPTE bars from a generator.

My question is concerning the graticule lights, all of which are out due to
failed bulbs.

What type of bulbs are these, and what is replacement procedure? Looks like you
almost need to remove the CRT (which doesn't strike me as typical of Tek
engineering) to get at the bulbs, which appear to be wire lead bulbs soldered
onto the main PCB?

The only manuals I have been able to find are the ones Tek has on their website,
and there are differences in the number of bulbs (3 vs 2) as well as the power
supply that drives them.

Anyone have a manual appropriate for the early ones?

Anyone have a lead on a cheap rackmount case for these? Mine came naked...

You can download a manual here. Is this the right one? Bulb replacement is on page 6-17

http://www.testequipmentdepot.com/te...FUjZQgodV0sALQ

Unfortunately, that's the same one I found. It covers serial numbers over 60,000, and mine is around 23,000. Apparently there was a MAJOR redesign at some point, as circuits and PC board layouts are quite different to my unit.

UPDATE:

FWIW, I found some information buried on the Tektronix webpage regarding this issue:

http://www.tek.com/support/faqs/what...nd-vectorscope

The older units use a bulb type OL-381 or BPR-022. This is a VERY strange little bulb, with 2 recessed socket contacts on the base. The "socket" soldered onto the PCB is just 2 little pins that the bulb plugs onto.

I found a couple places that could get these bulbs, but prices ranged from 8-10 dollars EACH. :( Not wanting to spend $40 for 4 tiny bulbs, I retrofitted the unit for type 7381 bulbs (same voltage/current, but readily available and about 40 cents apiece). I replaced the original sockets with contacts removed from right angle DIP sockets, to provide a place to plug the new bulbs in. Everything works great, and future bulb changes will be a lot cheaper.

Still would love to have a copy of the service manual/schematics for these scopes if anyone has a lead on them.

I worked on the wfm products at tek

I repaired and calibrated them