Avo valve tester rotary switches

[Bushbaby]

Hi All
I don't know whether I've been lucky here or not (?) but i have just bought what appears to be a new rotary switch for a typical AVO CT160 and similar valve testers by chance from the internet. Now at some point I shall return to building the valve tester project which I started over 10 years ago from another radio forum. I have to say in over 10 years, I've not seen another one up for sale but could be wrong here??

Best Regards

[Dave Simpson]

Jesus Bushbaby, you've just stepped into some rocking-horse manure !  I'm assuming you mean the 9 section thumbwheel switch assembly ?  If so, an NOS one could be worth nigh-on £200. Mind you, it would make an ideal basis for the valve holder panel for your proposed homebrew valve tester project. I actually use the complete valve holder panel, including the thumbwheel switch assembly, from a duff AVO VCM Mk1, in the DC valve tester I built a few years back. 

                                                          Regards,   Dave

[Bushbaby]

Thanks Dave
I saw this at a internet site call "Mullard Magic" for £60 and couldn't resist buying it. The connectors don't appear to have any solder on them and the copper connect plates look old but untarnished just as it the unit has been siting in a drawer somewhere? I have NEVER seen another up for sale at all.

Best Regards

[Bushbaby]

If you recall its for a certain county named valve tester project..........

[Murphyv310]

Most likely one of very few if not the only one known about.
Even 50 years ago they were unobtainable, BRW had one with a broken switch and it was scrapped as AVO didn't have the parts according to the story floating around at the time.

[Murphyv310]

If you recall its for a certain county named valve tester project..........

Sussex  I believe.

[Bushbaby]

Hi Trevor,
Yes indeed, I wasn't sure whether to say this as its on another forum.

[Radio Fixer]

Denis Tabor, deceased BVWS member, had a large collection of valve testers. I did encourage and help him to write an article about them.

When I restored a MK 1 and a MK 2 he advised never to squirt WD40 or anything else into those long rotary switches used to set the pins of the valve under test. He said they rarely give trouble and doing so ensures that they will. I never did and 20 years later they still work as they should.

Gary

[Kalee20]

I do have a CT160 and on mine the switches are very stiff! I partly stripped it apart (without unsoldering anything) to see if there was any debris clogging it, but no...

Any tips anyone?

[Radio Fixer]

Sorry! as said I never had to do anything with mine even though the testers were very ancient and in a poor state. I would be wary about squirting though as Denis was very experienced with them.

Do you have access to back issues of Radio Bygones which had a couple of articles which may help?

Gary