02-03-2013, 09:47 AM
(This post was last modified: 02-03-2013, 10:21 AM by Radio Fixer.)
The Avo Mk1 and 2 testers use a 440 micro A meter.
Yep! 13 years ago that I wrote the article for Radiophile on repairing MK1 amd MK2 valve testers. Since then other people, often as small teams, have written excellent material. See Radio Bygones No 134, Dec 2011 that gives detail for extensive component replacement . This one didnt touch one of the most likely problems of replacing a duff meter, although it may have mentioned getting it repaired (cant remember). Another article is in RB No 141, Feb/March 2013 that does. This uses a Simpson meter that I think will have to be imported from the US, probable all up cost maybe £140.
Unfortunately, the Maplin meter used by me is no longer available but there is another, in the UK, from Anders.Com, Model CV-20X 100uA for £21 including UK shipping that looks very similar mechanically. (http://www.andersmeters.com/Analogue_Pan...--109.html). Note a blank scale has to be bought separately, for a couple of pounds.
There was an update to the AVO Radiophile article written by me that never got published, send me an e-mail Kevin if you would like it.
The Mullard High Speed Tester to me has many disadvantages. The boxes of cards takes up a lot of space and then the very one you need is often missing from sets containing 100s. Also, I would prefer to make my own judgement, from meter readings, on a valve being good or bad and not discard on a go / no go light. Speed of testing for a hobbyist isnt an issue.
cheers Gary
Yep! 13 years ago that I wrote the article for Radiophile on repairing MK1 amd MK2 valve testers. Since then other people, often as small teams, have written excellent material. See Radio Bygones No 134, Dec 2011 that gives detail for extensive component replacement . This one didnt touch one of the most likely problems of replacing a duff meter, although it may have mentioned getting it repaired (cant remember). Another article is in RB No 141, Feb/March 2013 that does. This uses a Simpson meter that I think will have to be imported from the US, probable all up cost maybe £140.
Unfortunately, the Maplin meter used by me is no longer available but there is another, in the UK, from Anders.Com, Model CV-20X 100uA for £21 including UK shipping that looks very similar mechanically. (http://www.andersmeters.com/Analogue_Pan...--109.html). Note a blank scale has to be bought separately, for a couple of pounds.
There was an update to the AVO Radiophile article written by me that never got published, send me an e-mail Kevin if you would like it.
The Mullard High Speed Tester to me has many disadvantages. The boxes of cards takes up a lot of space and then the very one you need is often missing from sets containing 100s. Also, I would prefer to make my own judgement, from meter readings, on a valve being good or bad and not discard on a go / no go light. Speed of testing for a hobbyist isnt an issue.
cheers Gary
