RAT Valve Tester? - UK Vintage Radio Repair and Restoration Discussion Forum

Boom · 7th Oct 2008, 2:34 pm

Has anyone here built one of these? What results did you get? Would I be likely to run into any major problems sourcing parts? Can anyone supply ready cut PCBs?

TIA

Brian R Pateman · 7th Oct 2008, 5:49 pm

Some information about this in an archived thread in "Vintage Test Gear" here;

https://www.vintage-radio.net/forum/...ead.php?t=3486

Regards,

daviddeakin · 21st Oct 2008, 2:25 pm

I decided the RAT looked like more trouble than it's worth, so I built a curve tracer, which isn't hard, if you only want to test small (low current) valves and you have an oscilloscope. (Oscilloscopes are much cheaper than valve testers!)
http://i81.photobucket.com/albums/j2...e/CIMG2767.jpg

http://i81.photobucket.com/albums/j2...er/Tracer2.jpg
Rough schemtic, I actually need to update this but you get the idea: http://i81.photobucket.com/albums/j2...racerSweep.jpg

retailer · 26th Oct 2008, 12:31 am

I built the RAT valve tester some years ago and have found that it is my tester of choice. The project was no more difficult than scratch building an amp. It is more difficult and a lot more time consuming than building a kit amp. It does what it was designed to do very well, it is both quick and accurate, it does not test for shorts or gas although with its protected current limited anode and screen supplies a shorted valve is quickly spotted. Its short commings are its inability to test a wide range of valves due to the simplified socket setup, I have added an plugin box with extra sockets and switches to increase the range of valves that can be tested. I am building a new version with a full ranged of switched sockets, a shorts test and possibly a gas test. If you are a vintage instrument collector then the RAT test is probably not for you, but if you need to match pre and power amp audio valves quickly then the RAT tester does the job very well.

7th Oct 2008, 2:34 pm	#1
Boom Retired Dormant Member Join Date: Jan 2007 Location: Westbury, Wiltshire, UK. Posts: 2,451	RAT Valve Tester? Has anyone here built one of these? What results did you get? Would I be likely to run into any major problems sourcing parts? Can anyone supply ready cut PCBs? TIA

7th Oct 2008, 5:49 pm	#2
Brian R Pateman Nonode Join Date: Jun 2005 Location: Western Lake District, Cumbria (CA20) - UK Posts: 2,136	Re: RAT Valve Tester? Some information about this in an archived thread in "Vintage Test Gear" here; https://www.vintage-radio.net/forum/...ead.php?t=3486 Regards, __________________ Brian

21st Oct 2008, 2:25 pm	#3
daviddeakin Hexode Join Date: Apr 2007 Location: W Yorks, UK. Posts: 407	Re: RAT Valve Tester? I decided the RAT looked like more trouble than it's worth, so I built a curve tracer, which isn't hard, if you only want to test small (low current) valves and you have an oscilloscope. (Oscilloscopes are much cheaper than valve testers!) http://i81.photobucket.com/albums/j2...e/CIMG2767.jpg http://i81.photobucket.com/albums/j2...er/Tracer2.jpg Rough schemtic, I actually need to update this but you get the idea: http://i81.photobucket.com/albums/j2...racerSweep.jpg

26th Oct 2008, 12:31 am	#4
retailer Heptode Join Date: May 2005 Location: Adelaide, South Australia Posts: 541	Re: RAT Valve Tester? I built the RAT valve tester some years ago and have found that it is my tester of choice. The project was no more difficult than scratch building an amp. It is more difficult and a lot more time consuming than building a kit amp. It does what it was designed to do very well, it is both quick and accurate, it does not test for shorts or gas although with its protected current limited anode and screen supplies a shorted valve is quickly spotted. Its short commings are its inability to test a wide range of valves due to the simplified socket setup, I have added an plugin box with extra sockets and switches to increase the range of valves that can be tested. I am building a new version with a full ranged of switched sockets, a shorts test and possibly a gas test. If you are a vintage instrument collector then the RAT test is probably not for you, but if you need to match pre and power amp audio valves quickly then the RAT tester does the job very well.