Windsor (Taylor) 45B valves charts.

[Sideband]

Hi Guys.

I've been playing with my new toy today. Never had a valve tester before but I have so many valves in unknown condition in boxes it will be worth spending some time going through these.

I've been sent some valve charts (thanks Station X and PPPenguin) and these are OK to some extent but do not tally with my tester for all valves. I have three 9-way switches on the front (0-9 so 10-way I suppose) but some valves in the charts call for more positions than this. For example I can test a PL38 using the settings 4, 0, 9 which is fine but a PL81 calls for settings 10, 10, 10 which I don't have. I can check an ECL80 using settings 5, 3, 0 OK but the ECL82 asks for settings 2, 0, 17. Again not enough switch positions...or am I being really thick and not reading these numbers correctly?

Does anyone have charts for my version of the tester that I could copy/buy?

Thanks for any info.


Rich

[FRANK.C]

Hi Richard
I have a Taylor 45A it has 3 switches 0 to 9 as yours has. I am not able to test more modern valves on it ( EL84' etc.).

I may be wrong but I believe that the charts that have the numbers above "9" are meant for a different model of tester that is capable of testing these types of valves.

Frank

[AVO_VCM163]

Richard,

The first part is HERE. I'll try and add the rest tomorrow - or rather later today!
It states that it covers the Taylor/Windsor 45B and the Taylor 45A and 47A.

(The pdf covering half the book is 5Mb - hence an offsite file)

Agreed - the testing of modern valves is not always feasible because of the higher gains and frequency capability leading to oscillations - not only on account of bases and data.
R

[igranic]

Later versions of the Taylor Valve Charts cover the Taylor 45A, 45B, and 45C valve testers; the 45C has ABC switches with 18 positions (0 - 17). If a chart entry has a circular symbol enclosing the number '13' then the settings apply only to 45C valve testers.

Unfortunately, unless you make special adapters, you will find that the 45B (and all but the latest 45Cs, unless modified) cannot test later B9A valves such as the ECL86, PY88, UL84, etc.

I know of one brave individual who has converted a 45b into a 45c by removing the 10 position switches, and replacing them (presumably at considerable expense) with 18 position switches. Wiring them up must have been a nightmare.

Edward

[Station X]

Presumably the problem is that the 45B, unlike say an AVO CT160 with its roller switches, does not allow full flexibility in connecting test lines (A, S, G, C etc.) to valve pins (1, 2, 3 ,4 etc.)?

That being so would it not be possible to wire the test lines out to a patch panel? One half of the panel would have sockets labelled A, S, G, C etc. The other half would be connected to a valveholder/holders and labelled 1, 2, 3, 4 etc. This would allow full flexibility.

Were the A, S etc sockets wired out to a plug capable of being plugged into one of the sockets on the 45B there would be no need to modify it.

[Sideband]

Ahh! I'm beginning to understand now! It's probably not worth modding the 45B to test later valves. It might be feasable to make some adaptors though if necessary. Mind you, with valves like EL84 where there are so many about it's simple to substitute when testing a set. On the other hand if you have a PEN4DD or a PM2A and no immediate replacement, then it's a useful piece of kit.


Rich.

[igranic]

Originally Posted by Station X

Presumably the problem is that the 45B, unlike say an AVO CT160 with its roller switches, does not allow full flexibility in connecting test lines (A, S, G, C etc.) to valve pins (1, 2, 3 ,4 etc.)?

That is correct, but the 45B does have the advantage of rapid set up. With the relatively limited range of valves commonly in use when the 45b began production, the three rotary ABC switches allowed rapid setup of the pin connections when compared to the one-switch-for-each-pin approach of the AVO valve testers. As the range of available valves and pin connections increased, the ten positions on each of the 45B switches became a limitation, which was overcome by the introduction of the 45c with 18-way switches. By the 60s this became a limitation when attempting to test some of the more specialist valves and larger base types (compactron, B14E, etc) and the relatively rare 45D was introduced with AVO-style roller switches.

That being so would it not be possible to wire the test lines out to a patch panel? One half of the panel would have sockets labelled A, S, G, C etc. The other half would be connected to a valveholder/holders and labeled 1, 2, 3, 4 etc. This would allow full flexibility.

Were the A, S etc sockets wired out to a plug capable of being plugged into one of the sockets on the 45B there would be no need to modify it.

This is essentially what I meant when I used the term 'special adapter'. I made one that has a ring of 1mm sockets around the valve base allowing any pin to to be 'patched' to any connection (C,G,A,S,F1,F2) on the valve tester. I used this on my 45c until I upgraded the switch wiring to the final production version; I rarely need to use it now.

Originally Posted by AVO_VCM163

- the testing of modern valves is not always feasible because of the higher gains and frequency capability leading to oscillations - not only on account of bases and data.

With the 45b that is certainly the case - there was little if any attempt to suppress parasitic oscillation. The 45c handled this with strategically placed capacitors; the 45d went a step further with ferrite beads on internal wiring.

One thing that the British valve testers had in common was the ability to test the dynamic gM of a valve, whereas the majority of the US 'tube' testers simply tested cathode emission in a simple diode configuration (i.e. all other electrodes connected together). I believe the Taylor testers were a good compromise of price, functionality, and reliability, being somewhat less prone to accidental or abusive damage than their AVO counterparts.

Edward