|
Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
|
Thread Tools |
25th Feb 2019, 8:45 pm | #41 |
Dekatron
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,642
|
Re: Valve Testers
At one time valve boxes could be opened at one end in order to test them, without unwrapping, which could never be disguised.
|
27th Feb 2019, 5:53 pm | #42 |
Triode
Join Date: Jul 2014
Location: Wembley, London, UK
Posts: 14
|
Re: Valve Testers
Argus25 - Offence? Certainly not! Each to his own and we have more in common than you might think. Me? I also prefer devices with recognisable units (like the desirable AVOs) but, lacking either the money or motivation to restore one, might settle for a quick Good/Bad indicator like the Mighty Mite, which can be relied upon to catch about 80% of bad’uns, although requiring intelligence to interpret. A useful serviceman’s tool, no doubt, but the arbitrariness of their scales and the fact that different manufacturers had different ideas about what constituted Good/Bad means emission testers won’t provide much in the way of universally applicable data. Transconductance, on the other hand, relates to a quoted set of values supplied by the manufacturers. Furthermore, since Mr Steinbaugh seems not to be supported elsewhere in his assertion that emission is a good test of a valve’s state of health, I feel the need for a baking tin rapidly coming over me.
Radio Wrangler & TonyDuell – See the attachment for a British scale. |
28th Feb 2019, 7:23 pm | #43 |
Heptode
Join Date: Jul 2010
Location: Wellington, New Zealand.
Posts: 653
|
Re: Valve Testers
Some time ago I bought a whole slew of earlier valves (47, 84, 36 etc) off an elderly gent and when I took them out I found they were all neatly labelled with emission % - ie 75% 67% etc. Sadly I did not notice this at the time I bought them and I rather suspect he is not longer around to answer how he got these figures - but it does argue for an emission tester with figures rather then just Bad ? Good scale.
|