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 Paton Palec Valve Tester VCT
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 Return to top of page · Post #: 1 · Written at 4:01:07 PM on 15 October 2015.
Tinkera123's Gravatar
 Location: Melbourne, VIC
 Member since 5 October 2009
 Member #: 555
 Postcount: 465

Hi all,

I have acquired a Paton Palec Valve Tester VCT Serial number 330 I10 .... very old, very dirty, but seems very original. No accessories, power cord cut off etc..

Have been searching this Forum and the web .... and located several Manuals and circuit diagrams. And therein lies my first problem ..... which Valve Tester is it????

The below link has a couple of photos of Marks' VCT's. Mine looks like the one on Left from the front .... and Upper for internals. Serial no: is 330 I10. Valve is 6X5GT/G.

https://vintage-radio.com.au/default.asp?f=1&th=725

Mine does not have vibrator, shown in middle right of photo.

Do I have a VCT? Or a VCT-2? Or a VCT-V? Or ??

I have a clear VCT-2 circuit diagram, but have found several variants.
No evidence of a battery, but there are two disconnected leads.

I can find 4 caps without pulling it apart. Some markings are difficult to read .... but my guesses are
0.01MFD 600WV 2 of
0.5Mfd 400vDC
2MF 400VDCW PS 176 +20% -10% This is the creamy coloured can in Forum photos, low and to the left of centre. I assume that the MFD, Mfd and MF all mean uF???

I would appreciate any advice as to the Model, a clear circuit diagram and value of caps and resistors.

Thanks,
Ian


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
Cheers, Ian

 
 Return to top of page · Post #: 2 · Written at 10:39:47 PM on 15 October 2015.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

Mine is a VCT-V it has the optional 6V Vibrator PSU and a somewhat messy layout. It uses a 1V single diode as the rectifier. It is similar to 6X5 electrically, but you will note they only use one diode plate as a half wave rectifier. In a stroke of misguided genius, the vibrator & Valve use a UX4 socket?

The sockets are also different on some as is the meter movement & mine has the one where the scews can fall out & short onto the retaining bracket. Any wax paper caps in it will be cactus.

I tested the 2μF oil filled can type on mine and it failed to leak at 400V so Its still in there. Literature I have suggests 1938 for mine.

VCT-V is actually stamped onto the LH side of the front panel. The last one I serviced had the vibrator & 6X5 on a chassis. VCT-V does not. I could kill the genius that wired virtually everything with purple coloured wire. Mine had been used in the field & several had chaffed.

There is no power cord on mine. There is a plug inside the battery / storage box with a five pin plug. Two wires are for a 6V PSU battery the other three mains. I disconnected the mains from it & fitted a separate IEC socket.

One resistor has a note that its value was "specially selected", Read non standard value, & some mug got the prized job of going through buckets full of duds testing for the right value.

Marc


 
 Return to top of page · Post #: 3 · Written at 7:01:00 PM on 17 October 2015.
Tinkera123's Gravatar
 Location: Melbourne, VIC
 Member since 5 October 2009
 Member #: 555
 Postcount: 465

Thanks Marc.

I have a blurry VCT-V circuit diagram and have been tracing the circuit today. I am now confident that my VCT is as per the VCT-V circuit, but without the Vibrator.

If anyone has a clear circuit diagram, I would appreciate a copy.

Secondly, are "adaptors" available for the later 7 and 9 pin valves?? Or can I make up a converter myself??

Cheers,
Ian


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
Cheers, Ian

 
 Return to top of page · Post #: 4 · Written at 9:18:55 PM on 17 October 2015.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

I have a clear circuit, but one was in Lotus I will assume it is on the backup drive In the test equipment file. It would be best if these, when tracked down are sent direct. My concern is site space.

Brad has put a link to the April 2014 photos of the pair & you can see where the ID is and variance.

I have those photo's of mine & another side by side that I put in the Radio Club Newsletter. Those photo's can be emailed to give you something to blow up & get more detail.

I thought I sent some info to Kevin Chant, but on looking I will have to.

I do have info on an adapter that was used on a model used during the War & it fitted into the lid. There were other adapters that I have made copies of, for some valves with non standard pin outs.

Paton VCT-V Valve Tester Circuit Diagram

Marc


 
 Return to top of page · Post #: 5 · Written at 11:37:31 AM on 18 October 2015.
Tinkera123's Gravatar
 Location: Melbourne, VIC
 Member since 5 October 2009
 Member #: 555
 Postcount: 465

My thanks to both Marc and Airzone. I now have what I need.

Almost went 'cross-eyed' yesterday tracing every wire ..... three different colours ..... black, black and black ...... beneath layers of dirt. All wiring and components look 'original' and undamaged. It will take me much longer to clean it than replace caps etc.. Transformer windings are okay.

Some genius has sprayed 'oil??' on the 4 layered rotary switch .... which has collected years of dirt and now very difficult to clean ..... I am not a fan of lubricating moving parts if they are going to collect dust ... the embedded grit does more harm than no lubrication at all.

Thanks again, Marc and Peter,

Cheers,
Ian


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
Cheers, Ian

 
 Return to top of page · Post #: 6 · Written at 10:33:13 PM on 24 October 2015.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

I would consider circuit board cleaner to get rid of oil. WD 40 is not mineral oil. It does pay to have a trail of grease on the track of the detent springs of the switches. One should not get a lot of dust in it. Apparently there are problems with Silicone.

I have actually got a packet of Silica Gel inside mine. I did note on my Wheatstone bridge that it had Verdigris forming, That I reduced by having a porous bag of Bi Carb in it, so that any acid formed, principally by the Formaldehyde is neutralised.

We were always advised at ag college that despite the dirt, many tractor parts were better off lubricated & they often wallow in the stuff.

Marc


 
 Return to top of page · Post #: 7 · Written at 8:17:39 AM on 25 October 2015.
Brad's avatar
 Administrator
 Location: Naremburn, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 7290

I've always found that silicon spray is best and not attracting dust and other particles bit it probably depends on the brand. I've always used Momar silicon spray, though the problem here is that Momar products are generally not available at a retail level because most of them are of an industrial strength, such as their drain cleaners so they usually only sell to hospitals, schools, shopping centres, hotels, supermarkets and the few remaining factories that we have in this country. I've used silicon spray as a substitute to the poor quality graphite we get these days in locks with great success. It not only lubricates but also flushes out the dark gunky build-up that locks get over time.

WD40 (and CRC equivalent) is a big dirt accumulator and it gives off a bit of a smell too.

All that said, last night a mate of mine who is in to riding bikes to keep fit was showing me some of the lubricants he uses on his bike's parts. Most of these are dry lubricants (they spray on wet but the non-lube component evaporates) and work well as dirt is a big enemy of aluminium and carbon fibre. Specialist dry lubricants - the dirt and dust just falls off. It may be worth a visit to an upmarket bike shop.

Yet to try any of these exotic lubricants myself though.


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 8 · Written at 10:14:48 AM on 25 October 2015.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

I do use silicone spray & some of that is food grade. There was mention of it somewhere, where it was not advisable in some radio applications.

I will perhaps track down where it was. Some stuff has a solvent that will evaporate, others seem to be kerosene (paraffin) based & some of that does not evaporate with any haste.

Marc


 
 Return to top of page · Post #: 9 · Written at 5:08:48 PM on 25 October 2015.
Tinkera123's Gravatar
 Location: Melbourne, VIC
 Member since 5 October 2009
 Member #: 555
 Postcount: 465

Regarding the 4.5volt battery in these units .... is there an "fix" that everyone uses??? A built-in power supply or find appropriate batteries??

I am considering utilising the 'unused' transformer taps (probably for the Vibrator in -V models) and using a couple diodes, caps and a 5 volt regulator .... ?? Any advice?? eg what AC voltage feeds the Vibrator, or what is the current draw from original batteries??

Thanks,
Ian


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
Cheers, Ian

 
 Return to top of page · Post #: 10 · Written at 10:44:48 PM on 25 October 2015.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

You do not feed a vibrator with AC. It turns DC into a square wave and basically a regulator is to me a pointless exercise. The transformer has a muti-tapped primary that links to the meter. There is a switch marked line adjustment and that compensates for different mains voltages.

Some did use a PSU for the 4.5V. Measure the voltage on the Vibrator winding if you do not intend fitting one. It is probably under the maximum voltage a 7805 can handle but I would add a fuse to protect things & make sure there is a 1K loading resistor on the OP of the regulator or it will not regulate (needs min 5mA load to work). Note that the vibrator winding is a tapped winding,

The 4.5V cycle battery is apparently being re-made, you can get battery holders that hold three 1.5V batteries. Mine has three "D" cells in a plastic cotton reel tube, in the original holders, in the box where the probes can also be stored: Works, simple, no mods, no hassle & some of the new batteries can last 10 years, so how often are you going to use it on Ohms?


 
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