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 VTVM
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 Return to top of page · Post #: 1 · Written at 9:44:22 PM on 24 October 2017.
BringBackTheValve's avatar
 Location: Linton, VIC
 Member since 30 December 2016
 Member #: 2028
 Postcount: 67

Good evening,

Could someone with a passion for historical test gear history comment on this old beauty please.

The meter itself has University printed on it.

Does this mean the whole device is manufactured by University, or just the meter?

There is nothing else printed anywhere on the case. I hope to have a look inside the case soon for more clues.

The VTVM is part of my vintage test gear museum. My problem is identification of manufacturers. I understand formal electronics courses of years gone by would include building your own test gear, the latter forming part of your final exams.

Is some of this gear home-built, military, Do It Yourself hobby kit, or a mixture of all mentioned?

Any comments greatly appreciated.

Thank you, pictures on the way.

G.

University Meter
University Meter
University Meter


 
 Return to top of page · Post #: 2 · Written at 3:02:25 AM on 25 October 2017.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 4013

May be a project from Radio Television and Hobbies.


 
 Return to top of page · Post #: 3 · Written at 7:48:44 PM on 1 November 2017.
BringBackTheValve's avatar
 Location: Linton, VIC
 Member since 30 December 2016
 Member #: 2028
 Postcount: 67

I have taken off the cover from the VTVM and have found it in excellent condition. Very clean, beautiful workmanship.

I also found something totally unexpected (to me at least, because I have never seen inside a VTVM before)-----Batteries!

It is mains operated, but a pair (fixed together) of Size E cells are clamped onto the chassis. Type 701.

One of the battery terminals is grounded to chassis via the battery clamp, while the other terminal is connected to the Range Selector, a rotary switch. The terminals are brass strips, much like the flat 4.5V batteries you would see in the early 60's.

Why have a battery when there is a hard working 6V4 on board? A stable bias source? Resistance measuring? I'm out of my depth here.

But back to the construction; there is no obvious name of a manufacturer. The rectifier is made in Holland. The rest of the valves, two 12AU7's and a 6AL5, are British.

The power transformer is quality plus. It reminds me of those model train tranys you used to see as a kid, solid chunky instruments free standing in their own right, cotton covered flex, humming away sweetly while those miniature locos would throw out blue sparks -----and the motor smells, burning carbon brushes, man, those were the days. Enough of that, for now.

Other clues; The two electros also reek of quality. No bursting or leaking, bright fresh looking rubber seals. Made in Australia, UCC United Capacitor Company, Enfield, NSW.

The resistors are serious no nonsense items, lab quality, no doubt. This instrument screams out "broadcast quality", or perhaps military, but if a hobbyist constructed it then it shames me greatly for the slop-hazard items I have assembled in the past.

Under-chassis picture reveals a well planned layout with appropriate sleeving (looks like Fred designed and assembled it)

Pictures on the way.

Any clues anybody?


 
 Return to top of page · Post #: 4 · Written at 8:57:21 PM on 1 November 2017.
Gandhn's avatar
 Location: Windella, NSW
 Member since 5 November 2010
 Member #: 770
 Postcount: 267

University Graham Instruments were made in Sydney, with a few locations, one in Broadway, near City Road, also in York Street.
They made both the meters and the complete instruments. A 1948 price list shows a model EVA Vacuum Tube Voltmeter priced at £ 25-5-0 and I suspect this is yours.
They were known to be good quality devices as yours appears to be.
Harold


 
 Return to top of page · Post #: 5 · Written at 10:11:03 PM on 1 November 2017.
BringBackTheValve's avatar
 Location: Linton, VIC
 Member since 30 December 2016
 Member #: 2028
 Postcount: 67

Thank you Harold,

The pictures should appear soon. I forgot to mention the array of trimmer pots across the back of the chassis.

These can only be accessed with the cover removed, so obviously a no-go area for the user. You can see them in the under-chassis picture.

Another thing that impressed me, the cotton covered mains flex conductors are rubber insulated. The rubber, however,is as flexible as any other rubber item made today. No sign of perishing, plenty of flexibility.

I suppose the old saying is true, "----you pays your money and you gets your quality----"

VTVM
VTVM
VTVM
VTVM
VTVM
VTVM


 
 Return to top of page · Post #: 6 · Written at 11:09:54 PM on 1 November 2017.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 4398

Photos uploaded to Post 5.


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
Brad.

A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 7 · Written at 1:11:16 AM on 2 November 2017.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 4013

It's been quite a while since I saw one of those cycle batteries in the flesh. You are lucky that it hasn't corroded all over the place.

Why have a battery when there is a hard working 6V4 on board?

Yes, the battery is for measuring resistance. I have an AWA VTVM in which I eliminated the need for dry cell by using a low voltage regulator off the filament supply.

The University Graham model EVA is pictured on Radiomuseum and is a potable meter rather than a bench type meter:

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

The workmanship is very good in yours, but the front panel and case still suggest 'project' to me. Perhaps a trade course assignment.

Meters branded University could be bought over the counter and they also sold kits for test equipment back in their heyday.

It would be good to positively identify that VTVM.


 
 Return to top of page · Post #: 8 · Written at 8:39:37 AM on 2 November 2017.
BringBackTheValve's avatar
 Location: Linton, VIC
 Member since 30 December 2016
 Member #: 2028
 Postcount: 67

Some good leads for me to follow up and hopefully find out more about this historical beauty.

Thank you gentlemen.

G.


 
 Return to top of page · Post #: 9 · Written at 1:07:15 PM on 2 November 2017.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 4013

I fixed up my wee hours post. I meant to say filament supply, not DC rail. Simple circuit comprising a diode and a LM317L regulator.


 
 Return to top of page · Post #: 10 · Written at 1:52:56 PM on 2 November 2017.
BringBackTheValve's avatar
 Location: Linton, VIC
 Member since 30 December 2016
 Member #: 2028
 Postcount: 67

No worries,

I would have worked it out when the regulator when bang,ha ha.


 
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