Taylor Electric valave voltmeter model 172A-schematics/service manual

[dorke]

I bought this 1961 VTVM for 5$ at a flee market.
It needs repair and reconstruction.
Couldn't find any docs on the WEB just a few pictures,like this one.
If you have any please post or link to.
Thanks

 

[kellys_eye]

try these:




courtesy Nimrod121 over at the vintage-radio.net forum

 

[dorke]

At first glance it looks similar.
In my meter,there are 3 valves :
one ECC82 and two 6AL5.
they don't heat-up ,looks like there is a problem with the transformer(no voltages on the secondary.
Transformer info?

In general,it looks like there are much more parts(caps?) in the meter.

The "COM" terminal doesn't look "right" in the drawing,
there is no isolation to +B.

There is a C size battery in the meter as well.

But that is a start,
Thanks

 

[dorke]

Nasa we have ignition !
Found one wire open on the front panel on/off switch(switches both phase and neutral).

Now the valves warm-up and there is the ability to zero.
I measured volts(tried only DC for now) reading is not accurate,needs more work.

A question:
The line cord has 3 colors red,black and green,there was no line plug.
Green looks like earth.
Which should the phase and neutral be in 60's Britain?

 

[kellys_eye]

In my meter,there are 3 valves

Hmmmm

Even according to the Radiomuseum, it's a 2-valve unit. Check out the pics in this link to compare the innards and see what's different (note = you have to sign up to the site if you want detailed information)

https://www.radiomuseum.org/r/taylor_vacuum_tube_voltmeter_mod.html

Red is pahse.

 

[dorke]

Hmmmm

Even according to the Radiomuseum, it's a 2-valve unit. Check out the pics in this link to compare the innards and see what's different (note = you have to sign up to the site if you want detailed information)

https://www.radiomuseum.org/r/taylor_vacuum_tube_voltmeter_mod.html

Red is pahse.

It is a 3 valve model,radiomesum site is wrong to say it is a 2 valve one.

The 2nd diagram you have posted agrees with 3:
1X,2X ...

 

[dorke]

My tester has a mechanical meter issue:
I can zero it mechanically while it is horizontal position.
If I put it in it's vertical position the needle hits the lower side as if gravity drags it down.

In horizontal position,it also zeros electrically and measures correctly in ± DCV.

 

[kellys_eye]

It is a 3 valve model,radiomesum site is wrong to say it is a 2 valve one.

Could be they don't acknowledge the voltage regulator as a 'valve' although it looks like one.

Shame you don't have the original operators manual - perhaps it specifies for horizontal use only???? <-- yeah, I know, it sounds silly.....