Kolster Brandes 666 Valve radio restoration.

[Station X]

It'll be fine as long as you only handle the base rather than the envelope when removing or reinserting it.

Pins 4 and 5 of this valve are the heaters and can be ignored. The top cap is the control grid and needs to be measured. You may see a negative voltage here. The meter's reading will be prefixed with a minus sign.

[real0real]

o.k will continue to test brb

[real0real]

Tested V4 acquired following results

Pin 6 Reading of 0V

Pin 7 Reading of 84V

Pin 1 with the volt meter set at 2V Reading of 0.074V

Pin 2 Reading of 0V

pIN 3 Reading of 0V

Pins 4/5 not tested

Terminal cap on top of valve with meter set at 2v getting reading of -0.621V

(notice the cap on top of valve is a little bit corroded may effect the results if some appear incorrect may need cleaning up a bit more than is at present)

[Station X]

Pin 1. Diode. 0.074 Volts. OK.
Pin 2. Metallisation. 0 Volts. OK.
Pin 3. Diode. 0 Volts. OK.
Pin 4. Heater.
Pin 5. Heater.
Pin 6 Cathode 0 Volts OK.
Pin 7. Anode 100 Volts. OK.
Top Cap. Control grid. -0.621 Volts OK.

Field winding volts?

You're not going to get any sound out of this radio until you've replaced C1, at which point the audio stages could be tested via the Gram/Pick Up socket.

I suggest you buy all the capacitors needed in one go.

Have you measured the resistance of R19?

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You can check the voltage on the other valves if you wish. I think you're getting the hang of it.

[real0real]

Just checked speaker terminals, looks bit different than to diagram , but at 2 points getting 84v

[Station X]

84 Volts is fine.

[real0real]

Hi Graham
Have ordered the C1 capicitor off Ebay awaiting delivery
can order additional capitors if needed but not sure of types required

[Station X]

It'll take me some time to answer that one. Perhaps another member can assist?

You could usefully measure the resistance of all the resistors (power off of course). Any that are more than 20% off value should be replaced.

[real0real]

Have not checked ristance of R19 as Yet ,
Could continue check rest of valves if required

[real0real]

What do you think be next best step to take

[real0real]

I think i will finish for today as have to get a few things done and continue tomorrow

[HamishBoxer]

Yes,I can make you a list of needed caps as I have the circuit here that I got off Paul.Any caps 350 DC or even 630 DC will be fine .I will look into it later all being well tonight.

[crackle]

The capacitors are listed in the manual. They are ALL wax paper types, except the electrolytics, even the very small value ones..
You may as well get all non electrolytic capacitors as 630v DC axial types.
I have marked the nearest prefered value where the values are no longer available.
The smoothing Electrolytics should be at least 450v, I used 630v polyester types and hid them in the old card box.
Mike

[HamishBoxer]

You have beat me to it!

[Station X]

Thanks for compiling the shopping list.

I suggest that the OP tests all the resistors so that any replacements needed can be added to the order.

Then if voltage readings can be taken on V1, V2 and V3 it'll give some idea as to what problems can be expected later. Of course the voltage readings may be skewed by leaky capacitors etc.

[real0real]

Hi Graham
Yes testing v1 , v2 , v3 be good idea ,
Any particular preference in order to do as can take valve see what types fitted

[Station X]

You can test the valves in any order. Just respond with the valve designation, pin number and voltage.

[real0real]

Taken out V3 Tube valve
found to be fitted with MULLARD VP4A have attached picture of plus what i think maybe correct pin latout of pins , (read centre pin sometimes used as heater pin in some cases)
would all the pins needed to be tested to get voltage readings or just 4 not centre pin ?
plus top can pin connector ?

[Station X]

Read Lawrence's post #128. You don't need to test the heater pins. Don't forget the top caps.

[real0real]

Thanks , Missed this post earlier , having look at