Heathkit AV 3-U Millivoltmeter

[Yorkie]

Here are some pics of the nice little Heathkit AV3-U AC millivoltmeter I bought at Rufforth Autojumble last Saturday - not that I needed one, but at a fiver, I couldn't pass it by. The three valves (2 x AT7 and a 6C4), are worth more than that! It's a nice little bit of kit and works a treat, despite some of the caps being questionable purely on age grounds, (dated 1965), (spots the Hunts!), so I'll probably replace those. A handy bit of kit as an audio output meter for peaking up IFTs etc, or seeing what effect a new output valve makes. Goes up to 400kHz and from 0.01 Volt FSD to 300V in ten ranges. I found the circuit at www.vintage-radio.info but I've been unable to trace the full manual despite a jolly good furtle around on internet. In the unlikely event that anyone has a copy of the manual which they could e-mail to me, I'd be most grateful.

The 'U' on Heathkit equipment denotes 'UK', suitable for UK mains, and such kits or ready built equipment came from the Gloucester factory, which in its heyday was quite sizeable I believe. Despite the higher UK mains voltage, Heathkit equipment (invariably not earthed, which for test gear that might be used on live chassis is not bad thing), used flimsy two core mains flex restrained by tying two knots in the flex either side of the entry point in the back panel. That can be seen in the pics. Safe enough I guess, but not ideal by today's standards.

This one looks as though it was factory built - not constructed at home from a kit, and the label tied on it suggested it had been used in a school or college science lab.

On reflection, if only for stripdown value, I should have bought the second one on sale for £3.00, which had a smashed dial glass.

[Skywave]

Yes, a useful piece of kit. If you find that the meter pointer tends to stick at about the centre of the scale, my memory tells me that that is a known fault. It is apparently caused by static charge between the pointer and the meter front 'glass' - which is some form of plastic. I can't recall what the 'standard fix' for that was though - sorry.

Al.

[Yorkie]

Yes, a useful piece of kit. If you find that the meter pointer tends to stick at about the centre of the scale, my memory tells me that that is a known fault. It is apparently caused by static charge between the pointer and the meter front 'glass' - which is some form of plastic. I can't recall what the 'standard fix' for that was though - sorry.

Al.

Yes that's right Al.

It happened on all Heathkit meters - the Valve Voltmeter for example. All you need to do is to wet the end of your finger and touch the plastic 'glass' front of the meter which discharges the static and returns the needle back to normal. A useful bargaining tool to tell the seller that the needle sticks so maybe the meter is faulty. I didn't haggle over the price - I thought £5.00 was fair and I think it's a bit unseemly to be haggling over a couple of pounds.

I have a friend who is now well into his late 80s who I often used to take to Radio Rallies with me when we were both active radio amateurs. He always haggled as a matter of principle (his principle that is). His opening gambit was "What would you take off a pensioner for this?" presumably meant to make the seller feel guilty and akin to a pickpocket if asking for anything but rock bottom price.

It seemed to work like a charm.

However, I recall one occasion when he went into this routine and the stallholder said "what price is on it?" My chum replied "£8.00". The stallholder said 'Well give us £8.00 then or eff off'. My friend wasn't the least bit taken aback and said "I was thinking that a fiver would be about right" and started walking away. When he was almost out of earshot, the trader shouted after him "Go on then - a fiver". A fiver changed hands and neither party seemed the least bit put out by this exchange of words, which I thought was more in keeping with the Grand Bazaar in Istanbul. But then I was new to Yorkshire back then, and didn't know the ropes!

[martiR2R]

A copy of the manual was requested, successfully, on the UKVRRR forum a couple of years ago, they may still be members?
Martin

[Joe]

See: http://www.vintage-radio.net/forum/showthread.php?t=58863

[Yorkie]

Thanks for pointing that out guys.

I'm not hopeful though - the UKVRF member who had the manual ('Harrybedlebaum') has only posted 34 messages in seven years on that forum, and last visited it on 16 December 2012.

However, the recipient on the manual 'Barrie' was on the forum as recently as 2 July, so I might do better sending him a PM him, which I'll do - nothing ventured nothing gained!