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-   -   Heathkit IT-12 Signal Tracer (https://www.vintage-radio.net/forum/showthread.php?t=155711)

tim.norris 14th Apr 2019 12:37 pm

Heathkit IT-12 Signal Tracer
 
5 Attachment(s)
I purchased this from across the pond last year as they seem to be somewhat rare over here and therefore tend to command high prices . The only problem being that it is 110v this was negated by the purchase of a 240/110 converter from the Maplins closure sale for a bargain price. On arrival it was found to be in reasonable condition cosmetically apart from the grille cloth had turned to dust . a wrong knob and the probes red tip was in a poor state . Internally it was very clean and someone had made a good job of wiring /assembly . I swopped out various out of tolerance resistors and the capacitor to the output tube a.12ca5 was replaced. I intended to restuff the smoothing capacitor but i ended up having to leave off the alloy cover due to a miscalculation on my part ! I didn`t like the idea of the probe lead traioling over the bench so swopped this out for a bnc connector .easily reversible. Forum member David G4EBT kindly turned a new probe end cap from a piece of Acetal rod i provided . The probe was rebuilt with a new ceramic capacitor installed and the diode tested ok and a new length of 50ohm rg58 coax terminated with a bnc connector. a new power cable fitted and two similair knobs from Cricklewood electronics which were a good fit on the imperial shafts .While shopping in Aldi (other supermarkets are available) i spotted some Aida cloth used for cross stich embroidary that looked perfect for the speaker grille cloth .Its quite stiff and perfect for sticking to the remaining grille frame. On power up the unit worked well apart from the magic eye a 1629 valve was like me not very bright ! and some strange intermittent rustling/crackling noises when the volume was increased. A replacement 1629 was obtained and after a lot of head scratching the noise fault turned out to be a badly microphonic 12Ax7 dual triode valve which was replaced with a nos russian equivelant .These are used in guitar amps and are getting somewhat expensive. Reasembled and cleaned it not only looks well but works well . Next up is a Heathkit capacitor tester . Regards Tim

LyntonP 14th Apr 2019 7:00 pm

Re: Heathkit IT-12 Signal Tracer
 
Excellent job. Well done.
Lynton

MrBungle 14th Apr 2019 9:44 pm

Re: Heathkit IT-12 Signal Tracer
 
Indeed. Nice to see a good heathkit restoration.

David G4EBT 15th Apr 2019 9:12 am

Re: Heathkit IT-12 Signal Tracer
 
3 Attachment(s)
Excellent end result Tim - well worth the effort.

I was pleased to have been able to play a small part in the restoration by making a small part for the probe! Knowing that the dimensions of the tip would have been imperial, initially when I sketched the tip I started measuring in imperial but soon gave that up. (13/16, 7/8", 1/4", 11/16" etc). Made me realise how convenient it is to work in metric.

Can't help wondering how the original tip met its fate - it looked like it had been 'fried'!

Always a joy to restore Heathkit equipment - I won't be alone in saying that back in its heyday, I often longed to buy several of the kits, but they were always just out of reach price-wise. Now that they aren't, we get the pleasure of restoring, owning and using the equipment. I often wonder what proportion were built from kits or were bought ready made. The build quality can be variable, which might be a clue.

MrBungle 15th Apr 2019 9:23 am

Re: Heathkit IT-12 Signal Tracer
 
Nice job with the probes.

Totally agree. I was young and broke. The moment I got money I spent it on hedonism. Next thing I know Heathkit were gone. Bummer! I have restored an RF-1U, IM-13U, IB-1100, IP-2817, GD-1U, V7-AU in the last year or two. I will do a post or two about these when I get a few minutes. I've been lucky - all mine were well constructed so far (apart from the IB-1100 which was initially well constructed but someone committed a few crimes in it when the crystal stopped working): https://www.vintage-radio.net/forum/...d.php?t=136242


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