Sunday, 26 February 2017

Telequipment D65

Some time ago I acquired an old 1976 vintage Telequipment D65 - 15MHz, all solid state dual-trace scope.  Unfortunately it had a couple of faults which is why it was being thrown away.

Telequipment D65

The scope basically worked but.
  1. It wouldn't turn on as the scale illumination / power switch knob was cracked and therefore kept slipping
  2. The trigger was intermittent, when powered on the triggered sweep may decide to a) start halfway across the screen, b) in the correct position and then fade or c) work as advertised.
Well the first thing I did was fix the broken knob, nothing a bit of superglue didn’t solve. This was only a temporary fix until I obtained a replacement second hand knob.  Now I could move onto fixing the annoying intermittent trigger fault. 

After a bit of digging around on the net I stumbled across this post on the UK Vintage Radio Repair and Restoration forum. Somebody else was having the same issue which could be fixed by tapping the trigger knob or the side of the case for that matter. 

Trigger, Timebase X amp & blanking PCB
Troublesome PCB

The fault was on the trigger, time base x-amp and blanking PCB.  It would seem that these scopes use doubled sided PCB's with naff though hole links which go bad with age. I re-flowed the solder on all the little links and this fixed the problem. 

Overall I'm pleased with this little scope which weighs 11.5Kg, it has made a  great addition to the workshop.  I should recap the power supply board at some stage.

Some more pictures of this scope can be found on my Flickr page.