Is this a War Dept Ammeter?

[Rannsachair]

A Fiend sent me these pics from a local junk shop:

There are two. Anyone recognise what they are, I see the war dept arrow, looks like an ammeter?

 

[Kayos]

Wayne Kerr make high end audio test gear these days

 

[Seadog]

It's a test set for a particular piece of equipment. Yes, the meter is an ammeter, other than that who knows?

 

[The_Yellow_Ardvark]

It is a meter for measuring "Bridges on RADAR gear.

Ex RN

 

[OJCar]

It has my family's crest on it.
(At least that is what my father told me that was what the arrow was ... )

 

[Lewis_RX8]

Wayne Kerr

Say that fast a few times

 

[Ross365]

On the circuit diagram, is the meter labelled as 5-0-5 uA or 5-0-5 mA ? If it's uA, that is incredibly sensitive, but note how the meter is like in a box within a box! Looks very RAF to me.

 

[The_Yellow_Ardvark]

On the circuit diagram, is the meter labelled as 5-0-5 uA or 5-0-5 mA ? If it's uA, that is incredibly sensitive, but note how the meter is like in a box within a box! Looks very RAF to me.

The CRETE colours between the crabs and the RN were similar.
The Pongo's was green

 

[Rannsachair]

On the circuit diagram, is the meter labelled as 5-0-5 uA or 5-0-5 mA ? If it's uA, that is incredibly sensitive, but note how the meter is like in a box within a box! Looks very RAF to me.

When I zoom in looks like microAmps

 

[Ross365]

If microamps (uA) that is an unusual meter and definitely needs saving from the skip.

 

[Rannsachair]

If microamps (uA) that is an unusual meter and definitely needs saving from the skip.

I will ask what they want for them.

 

[awemawson]

Wheatstone Bridge Balance detector I believe, but what the bridge was used for I can't tell you.

 

[Ross365]

May have confused you; it's not something that I'm interested in acquiring, but I suspect others could be. I'd guess the meter is mounted in some kind of suspension system to make it shock-proof, so best left in the box. As in posts 3 & 4, the unit is part of a system, and probably has no secondary use, so I guess it is mainly interesting just for the meter. The most sensitive meter I've heard of previously was 0-30uA. The Wayne Kerr company is still in business.

 

[slim_boy_fat]

The CRETE colours between the crabs and the RN were similar.
The Pongo's was green

You're talking in code now.....

 

[The_Yellow_Ardvark]

You're talking in code now.....

Not at all, Mr Starwberry Mivie.

 

[Ross365]

All moving coil ammeters are basically the same - very sensitive/low current. Virtually all these ammeters that one comes across are the same, but with an appropriate shunt fitted to suit the range needed. Older types were mostly re-laced years ago! The amount of damping used, on the movement, is dependent on the environmement it is used in.

No. If you said that the typical baseline meter is 1mA FSD, and that those models are often shunted to achieve other ranges, that might be reasonable. But when you go down to movements which read uA, to get that response you need very many turns of wire on the coil, so the wire has to be ultra-thin so manufacture becomes much more difficult and failure more prevalent. An excellent example of this are the 50uA meters in the Avo VCM163 valve tester. These testers often sell for £1000, but many are blighted with faulty meters (I've got one with a faulty meter!). Go on ebay and see if you can find meters reading 5uA and come back and tell us.

 

[RWD3M]

FWIW, 10Q is the vocab section and 16088 is the reference number. The Sect/Reference number system was common to both the RN and the RAF. NSN's came along (iirc) sometime in the early 80's and superceded the older Sect/Ref no.

What's really sad is the ammount of them I can still remember. I truly wish I couldn't, it would probably free up some memory space for something useful!!!

 

[Onoff]

Ancient but at the same time still a current meter.

 

[Seadog]

Radio (Wireless and Radar) Indicating Units

Aircraft part number list v8

Aircraft part number list v8 A special thanks to Ewan Cameron who has helped with a number of manufacturers stamps

www.key.aero

 

[Ross365]

There were plenty of 50 micro-amp fsd ammeters for student use at college. All with connectors, for various shunts, to change the range.

As you didn't look on ebay, I did. There are modern 50uA, low-resistance meters on there from China and those meters have become viable due to the immensely strong magnets now available, so the coils need fewer turns. There was one 50uA vintage high-resistance meter.

20uA meters - none
10uA meters - none
5uA meters - none.