UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Test Gear and Workshop Equipment

Notices

Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders.

Closed Thread
 
Thread Tools
Old 29th Sep 2017, 9:03 pm   #1
1980s_john
Tetrode
 
Join Date: Apr 2005
Location: Ipswich, Suffolk, UK.
Posts: 59
Default Coutant bench PSU - thanks and fixed a factory fault

Thanks to this forum for the schematics from 2011, I have a LQT100 which I recently fixed. The schematics clearly show there is only one variable resistor per channel, this is to calibrate the PSU ammeter. On one channel it was OK, but the other was way out. A quick twiddle cleaned the pot and both sides are now fine. On one channel I found that the voltage dropped by about 1V when drawing 1A. I took the unit apart for a look, the boards for each channel swing out - need to remove the front panel (pain to undo 6 knobs each with 2 grub screws), then unbolt the top front-to-back rods, and loosen the bottom bolts so the rod can swivel. When I retested I found there was no voltage on the output, but the meter showed normal. With help of the schematic I could trace from the output sockets to the meter and found the negative output socket was not connected. A look underneath showed that a wire was loose from its tag, and there was no sign of any solder. After rehooking the wire a quick dab from the iron and all was well again. It must have left the factory in the 70s with the wire just hooked on, amazing it took 40 odd years before it was fixed!
Regards,
John
Attached Thumbnails
Click image for larger version

Name:	foldout.jpg
Views:	130
Size:	66.5 KB
ID:	150081   Click image for larger version

Name:	solderless.jpg
Views:	132
Size:	68.4 KB
ID:	150082  
1980s_john is offline  
Old 29th Sep 2017, 9:17 pm   #2
kalee20
Dekatron
 
Join Date: Feb 2007
Location: Lynton, N. Devon, UK.
Posts: 7,059
Default Re: Coutant bench psu - thanks and fixed a factory fault

The LQT100 (and the LQT200) are good power supplies. The circuitry is somewhat dated, even for the time they were made, being largely discrete rather than IC's. And there's a lot of hand-wiring (such as the unsoldered wire you found). But that's a reflection of the design and construction, not the performance, which is really good!

The styling and appearance is clean, neat, functional. They are dead easy to use, and look good.

Look forward to many hours of happy experimenting with your LQT!

Last edited by kalee20; 29th Sep 2017 at 9:18 pm. Reason: Spelling
kalee20 is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 2:29 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.