Advice on Admiralty Audio Frequency Generator?

[Crazy_Jane]

I picked this up on Ebay a while back for 20 quid, an old valve audio frequency generator, Admiralty Pattern 104290 Oscillator Audio FRequency Advance JI is what it says on it.

. Seller said it worked fine, i can't say yet that definitely it doesn't, it powers up but i'm not totally sure about what sort of output i should be getting from it, and want to check that before i connect it to my mixer just in case it's wonky or i get something wrong!

Upper right frequency range and big central fine frequency knob plus 'radio' display

Lower left is the on switch/output level, ranging from 0 to 25 volts

The four connectors along the bottom labelled E, 5 ohm, unlabelled and 600ohm i not so sure about, E is the earth?, the unlabelled one is the neutral? And the other two are different impenances of output?

The lower right switch labelled 600ohm attenuator 0 - 20db

I got some tips on this from another forum a while back, though i'm not sure there were any old gearheads there who'd know this sort of kit inside out, best advice i got was to try the E to 5 ohm outputs out on an old speaker, which didn't actually do anything.

Any ideas folks? Am i missing something really obvious.

Pics below if it helps:

http://img.photobucket.com/albums/v233/BlackRiverFalls/SynthHead/Admiralty3-1.jpg

http://img.photobucket.com/albums/v233/BlackRiverFalls/SynthHead/Admiralty1.jpg

http://img.photobucket.com/albums/v233/BlackRiverFalls/SynthHead/Admiralty2.jpg

[Danno Gee Ray]

A few things to take note of right off.

Valve gear has high voltages running through it. Be very careful when dealing with this kit.

E probably does mean Earth.

Use lower output voltage settings first.

When you first power it on, look at all the tubes (valves) and ensure that each one glows inside. If there is no glow, then the tube is likely failed.
Power off the unit and make sure the tube is seated well into the socket. Try it again.

let it come up to temperature (5 minutes or so) then proceed. Always be ready to pull (shut off) power at the first sign of escaping magic smoke.

If you have a pair of headphones that you can use that you don't care much about, set the output voltage for about One Volt, use the 600 ohm output and E (yes, likely EARTH, or un U.S....Ground) to connect to the headphones. The tip of the headphone connector to the 600 ohm output, and the sleeve to E or ground.

Leave the headphones on the table and listen for a tone in the headphones that varies as you change the frequency. Do not wear the headphones for first test as you could cause hearing damage. You can possibly get away with less output voltage, maybe a little more, definitely NOT much more.

If you don't hear any changing tone, or if any of the tubes are dead, you would likely be best advised to enlist the help of someone experienced in Valve amp repair.

Again, Caution...High Voltages are present.