26th May 2020, 4:18 pm | #241 |
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Re: Kolster Brandes 666 Valve radio restoration.
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26th May 2020, 5:51 pm | #242 | |
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Re: Kolster Brandes 666 Valve radio restoration.
Quote:
Do the positive (red) ends of the capacitors go to the same end of the resistor, or opposite ends of the resistor? What's the resistor's value?
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27th May 2020, 8:46 am | #243 |
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Re: Kolster Brandes 666 Valve radio restoration.
Will have a look and check bit later today , have noticed from picture taken ,possibily marked on outer case with red band on capacitors if correct positive ends going to a resistor ,
(plus uploaded a pcture of old capacitors / resistors replaced) Clive |
27th May 2020, 9:36 am | #244 |
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Re: Kolster Brandes 666 Valve radio restoration.
The positive ends of those two capacitors are going to either end of a 3.3k resistor. One end of that resistor is terminated on a tag, or perhaps a valve holder pin. Various wires lead from that tag or pin.
Which valve and pin is it and where do the wires lead to?
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27th May 2020, 10:04 am | #245 |
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Re: Kolster Brandes 666 Valve radio restoration.
That 3k3 resistor and the caps look like a later addition to the set. Most of the resistors are body tip spot types and the soldering around the 3k3 and capacitor is a bit grotty. There aren't any 2uF capacitors in the service data either.
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27th May 2020, 10:12 am | #246 |
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Re: Kolster Brandes 666 Valve radio restoration.
Yes on all counts. I was trying to work out what the mod, which may have been incorrectly applied, was intended to do. Given the capacitance and voltage of the capacitors, additional smoothing seems likely.
I'd be amazed if the smoothing caps within the cardboard container have survived. It may be necessary to restuff it or fit new caps on tag strips, or suspended in the wiring.
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27th May 2020, 7:18 pm | #247 |
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Re: Kolster Brandes 666 Valve radio restoration.
Which valve and pin is it and where do the wires lead to?
have not had chance to look at today ,will have look at tomorrow Clive |
28th May 2020, 10:02 am | #248 |
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Re: Kolster Brandes 666 Valve radio restoration.
Ref, 2nd photo in Post#231: That decoupled 3.3k resistor looks to be connected in series with the HT side of the 1st IFT's primary winding, you can see that they have removed the HT supply feed (in & out) wires to that transformer from tag H and connected them to the end of the resistor, the other end of the resistor is shown heading towards tag H of the IFT, you can see the small hole that's used as a reference point to identify the tag letters, immediately to the left of it is tag G with the two wires that are connected to it which connect to the transformers primary tuning capacitor and the anode of V2, next tag clockwise from that (but out of sight under the capacitor) is tag H.
If that's any help. Lawrence. Last edited by ms660; 28th May 2020 at 10:27 am. Reason: additional info |
28th May 2020, 11:05 am | #249 |
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Re: Kolster Brandes 666 Valve radio restoration.
Thanks Lawrence.
I wonder have that interacts with R20, C8 and C18 then?
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28th May 2020, 11:27 am | #250 |
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Re: Kolster Brandes 666 Valve radio restoration.
It doesn't, it's in series with the primary of the 1st IF transformer only, one of those de-coupler capacitors is connected to C18, the other's connected to tag H of the transformer.
You can see from the various photo's that the feed ultimately comes from R13 on the main tag board, it makes its way across to the 2nd IF transformer and then to the input to that 3.3k decoupling network then it makes its way across via the RF transformers E tag to the small tag board on the side of the chassis where it connects to R20, from there it connects to C18. The original route can be seen in a photo on Mikes' website. Lawrence. Last edited by ms660; 28th May 2020 at 11:39 am. Reason: additional info |
28th May 2020, 11:33 am | #251 |
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Re: Kolster Brandes 666 Valve radio restoration.
So one of the new caps is in parallel with C18 then?
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28th May 2020, 11:45 am | #252 |
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Re: Kolster Brandes 666 Valve radio restoration.
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28th May 2020, 12:05 pm | #253 |
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Re: Kolster Brandes 666 Valve radio restoration.
I have tried tracing where wire from capacitors and where goes to appears connected to IF L12/13 as far as i can make out attached sketch
Clive |
28th May 2020, 2:31 pm | #254 |
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Re: Kolster Brandes 666 Valve radio restoration.
According to the valve data, pin 5 is one of the heater connections.
Lawrence. |
28th May 2020, 4:19 pm | #255 |
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Re: Kolster Brandes 666 Valve radio restoration.
Lawrence must have found section A of the KB service manual which has notes on the coils and other issues. It's available up top under KB Introduction. Sometimes the small hole is very difficult to find as it can be under a component.
but here is the bit on the coils. Last edited by crackle; 28th May 2020 at 4:30 pm. |
28th May 2020, 4:30 pm | #256 | |
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Re: Kolster Brandes 666 Valve radio restoration.
Quote:
Regarding the 3.3k resistor etc I just figured it out from the photo's, hopefully I got it right. Lawrence. |
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30th May 2020, 8:17 am | #257 |
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Re: Kolster Brandes 666 Valve radio restoration.
Thank you to everyone thats helped on getting this radio to work
clive |
30th May 2020, 9:04 am | #258 |
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Re: Kolster Brandes 666 Valve radio restoration.
Well done for a good job of preserving the radio, I bet it sounds good. A special well done to all those who talked you through the process.
Mike |
4th Jun 2020, 8:07 pm | #259 |
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Re: Kolster Brandes 666 Valve radio restoration.
Hi Mike ,
Sound quality is very good well built/made speaker Clive |
21st Apr 2023, 8:02 pm | #260 |
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Kolster Brandes 666 Valve radio Fault
Hi.
Can anyone help? Previously restored a Kolster Brands 666 Radio through forums, but this week has developed a fault., Radio sound when switched on has gone. It started making a loudish buzzing and crackling noise when switched on few days ago . switched off tried switching back on there was a crackling for few seconds, then no volume or sound. I can still hear slight crackling if I the rotate bass / tone switch ). When switched on now can here crackling for few seconds then nothing, any thoughts what maybe causing problem? Regards Clive Last edited by real0real; 21st Apr 2023 at 8:13 pm. |