Pye Component Analyzer

[Skywave]

In that case, Andrew, seems to me that the wire to the grid connection has fallen off or has been removed. As you imply, a closer 'eye-ball' exam. hopefully will throw some light on this. And who knows? You might see the problem - if you are endowed, that is, with a pair of Magic Eyes! Heaven only knows, I wish I was!

Al.

[Andrewausfa]

Al,

I've just been looking at the pin connections for the TV4 and EM1 valve and the pin outs per the data on the National Valve museum site differ to what you've offered above which is maybe what's causing confusion. They say;

1. -
2.h
3.h
4.k
5.-
6.g1
7.t
8.a

This ties up with the connections on 'my valve, whatever it may be! I've taken the valve out and there's absolutely no markings on it. I've done a nice close up of the valve base. Which ever valve it is I'm wondering if I could pay my mortgage off with it.

Andrew

[pwdrive]

Al,

I've just been looking at the pin connections for the TV4 and EM1 valve and the pin outs per the data on the National Valve museum site differ to what you've offered above which is maybe what's causing confusion. They say;

1. -
2.h
3.h
4.k
5.-
6.g1
7.t
8.a

This ties up with the connections on 'my valve, whatever it may be! I've taken the valve out and there's absolutely no markings on it. I've done a nice close up of the valve base. Which ever valve it is I'm wondering if I could pay my mortgage off with it.

Andrew

Hi Andrew, looking at that picture it looks like an EM1 type connections ie:

Target at ht, pin7.
Anode to ht via a high value resistor (2 or 3 meg), pin 8.
Cathode to deck, pin4.
Grid to grid leak (10 meg) and SW, pin6.
pin 5 n/c, pin 1 n/c (?)
Heaters, pins 2 & 3.

Lawrence.

[Andrewausfa]

Thanks Lawrence,

Yes I believe the valve is a TV4 (I've just put my name down for a Ferrari), which is why I was looking at that valves data Pin 1 in my photo is not connected.

Dinner, then some wiring changes, then some power.

Andrew

[pwdrive]

Looking good then, if the heaters light up as norm and the HT and anode load is ok then you should get a green display if the indicator is ok, if not the indicator might be (usually) shot.
Good luck at switch on Andrew.

Lawrence.

[Andrewausfa]

Scampi, chips and peas did the job.

I've replaced two wires and fitted a temporary length of three-core mains lead. The unit was then connected through a lamp limiter. Photos are with the limiter switched in, I've not switched it out of circuit yet. No nasty noises or smells.

The range lighting seems to work which is good news as the five bulbs look painful to replace. I should add for clarity, that the bulbs shine through holes in the main front plate from the rear. Behind the dial plate are five circular, differently coloured pieces of acetate. The light shines through these and then through rectangular slots in the brass dial plate.

Andrew

[pwdrive]

Ooh...greeness, looking good Andrew.

Lawrence.

[Skywave]

Al,
I've just been looking at the pin connections for the TV4 and EM1 valve and the pin outs per the data on the National Valve museum site differ to what you've offered above, which is maybe what's causing confusion. They say . . . etc., etc.
Andrew

Interesting: compared to what I listed, not only does that scheme start from a different pin, it goes round the circle anti-clockwise! However, your questions about the 'Eye' have now been answered: any more input from me about pin-outs, type of valve, etc. is now irrelevant. But I remain a bit puzzled about the pin-out issue, since the sources of my data are the Radio Valve Data books (published by Iliffe, originally published by Wireless World), and I've never known them to be incorrect with critical data - yet. Fortunately, it is very rare for me work on bits of kit with side-contact valves. I don't like them anyway: I'm always fearful that I will rip the glass envelope out of the Bakelite base when trying to remove the valve from the socket! Aaargh! [deleted expletive]

Al.

[pwdrive]

Hi Al, I have the same valve data book (Iliffe) it seems none of the valve pinout diagrams show pin numbers, my repair techs. brain would normally say number and read clockwise but as you say in the case of the EM1 etc it is opposite to the normal convention, maybe that's why the data book does not give actual pin numbers, to avoid possible confusion etc.
The purely pictorial representation of the pinout showing the electrode connections is correct. Must admit it's a new one on me also.

Lawrence.

[Andrewausfa]

I've never had anything with side contact valves in before, all new to me.

This morning I've given it full mains to no apparent ill effect. On the leakage terminals, the neon briefly flashed as I switched ranges, I'm getting less than half the selected voltages. The 100v setting was showing circa 42 volts at the terminals and so on up the range.

Despite cleaning off the existing oil, the large 4uF paper and oil capacitor in the centre of the photos is still weeping. The other large capacitor, is giving some odd readings despite me taking it out of circuit. It was reading over 36uF (it's nominally 4uF) in circuit and 11uF out of circuit on my Peak meter.

I'm not a big fan of changing things dramatically but with this rather prototypical meter I think I'm going to remove these two capacitors and replace them with electrolytics. Firstly, they're clearly not what they were and secondly, I understand the oil they contain isn't too nice and they shouldn't be weeping anyway.

Andrew