18th Apr 2020, 2:23 pm | #101 |
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Re: Kolster Brandes 666 Valve radio restoration.
Hi Graham ,
Quote Personally I'd replace C1 before proceeding, but I do have capacitors in stock. Not sure what mean ? Do you mean you do have capacistors required including C1 ? |
18th Apr 2020, 2:30 pm | #102 |
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Re: Kolster Brandes 666 Valve radio restoration.
What I meant was that if I were repairing this set I'd replace C1 at this stage and wouldn't need to order one in as I have drawers full of 0.0047uF capacitors. I'm not offering capacitors if that's what you're thinking. If I didn't have a capacitor available I might test C1 and proceed cautiously if it were OK.
You can test C1 if you wish. With V6 inserted and power applied measure the DC voltage between chassis and each end of C1 (two readings). One reading should be hundreds of volts and the other ZERO. Unfortunately just because an old capacitor tests good now it doesn't mean that it won't fail in a few minutes or a few hours destroying other difficult to obtain parts. Replace C1. It's a no brainer.
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18th Apr 2020, 2:49 pm | #103 |
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Re: Kolster Brandes 666 Valve radio restoration.
Hi Graham
Hope you not mind me asking Do you sell capacitors you have as i would be interested in buying one off you if was to proceed to replace the existing capacitor As new to repairing Radios , wondering how easy or difficult it would to replace this capacitor , as see its bedded right in corner side and not easy to get at , have attached picture of , wondering what would be the best procedure to fit new one if was to replace, would you need to cut out the old one with wire snips and tag onto old electrodes , or need to unsolder and remove the hole board side to do it, |
18th Apr 2020, 2:57 pm | #104 |
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Re: Kolster Brandes 666 Valve radio restoration.
may proceed to check capacitor C1 and see if passes this Test
|
18th Apr 2020, 3:06 pm | #105 |
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Re: Kolster Brandes 666 Valve radio restoration.
Sorry, but I'm not venturing out of the house to post stuff during the Covid 19 pandemic. That's a personal descision and not open to discussion.
You'll need to replace many capacitors in this set, so you might as well order the lot from one of the big suppliers. It is acceptable to cut out an old cap, leaving the leads as long as possible, and then solder an new component to the leads.
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18th Apr 2020, 3:45 pm | #106 |
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Re: Kolster Brandes 666 Valve radio restoration.
Hi Graham
Thank you for letting me know , possibiy be able to order off Ebay Just done a C1 capacitor test With V6 inserted and power applied measure the DC voltage between chassis and each end of C1 With the meter set at 600V one end of the C1 getting a reading of approx 500V and the other end reading of 002V Any thoughts on these readings |
18th Apr 2020, 3:52 pm | #107 |
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Re: Kolster Brandes 666 Valve radio restoration.
Switch down to the 2VDC range to check the low voltage end of C1. Typical voltage with a good capacitor is 0.1VDC or less.
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18th Apr 2020, 4:10 pm | #108 |
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Re: Kolster Brandes 666 Valve radio restoration.
Switch down to the 2VDC range to check the low voltage end of C1 Typical voltage with a good capacitor is 0.1VDC or less
Just tested Getting a reading of 1.235 |
18th Apr 2020, 4:15 pm | #109 |
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Re: Kolster Brandes 666 Valve radio restoration.
Don't do anything else until you've replaced C1.
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18th Apr 2020, 4:20 pm | #110 |
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Re: Kolster Brandes 666 Valve radio restoration.
o.k
Will wait and order new 0.0047uF capacitor and replace I have just Looked on Ebay and did a search there seems several different types of this type of capacitor available not sure which would be modern equivilant |
18th Apr 2020, 4:26 pm | #111 |
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Re: Kolster Brandes 666 Valve radio restoration.
This thread may help:-
https://www.vintage-radio.net/forum/...ad.php?t=88767 My personal preference is yellow polypropylene types. Other member's preferences may be different. Some might argue that you should restuff the existing capacitors.
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18th Apr 2020, 4:45 pm | #112 |
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Re: Kolster Brandes 666 Valve radio restoration.
Hi Graham
Some interesting info but bit bewildering Have found some yellow ones on ebay described as :- 10x Capacitor 0.0047uF 4.7nF 5% 630V DC Polypropylene Axial Valve Metal Film Have to buy a job lot of 10 but if correct type could order |
18th Apr 2020, 4:50 pm | #113 |
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Re: Kolster Brandes 666 Valve radio restoration.
They'll be fine.
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18th Apr 2020, 5:00 pm | #114 |
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Re: Kolster Brandes 666 Valve radio restoration.
Hi Graham
Thank you for your help ,will order suppose will have to put repair on hold until they arrive and fitted new one will try cleaning the chassis up little more while awaiting Clive |
18th Apr 2020, 5:05 pm | #115 |
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Re: Kolster Brandes 666 Valve radio restoration.
You're going to have to replace a lot more capacitors before this repair is complete.
If you want to do some more testing:- SNIP OUT C1. Remember where it came from or leave one end connected. Plug in the speaker. Plug in the valves making sure they're in their correct sockets. Switch to GRAM or Pick Up (PU) and turn up the volume. Apply power via the test lamp. Check that all the valves light up. A loud hum from the speaker indicates that the smoothing capacitors have failed. Take DC voltage readings with respect to chassis on all the pins and the top cap of V4 and V5 except the heater pins (pins 4 and 5). Report back with results.
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18th Apr 2020, 6:00 pm | #116 |
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Re: Kolster Brandes 666 Valve radio restoration.
Hi Graham
Stages taken so far Have snipped Through C1 capisitor Powered up the set using the lamp limiter Results all 6 tube/valves are lighting up slightly have attached pictures of 5 (max can upload) Not hearing anything from the speaker!!! the final test as noted below i will do tomorrow as getting bit late this evening and as need to mount set upside down and sturdy as the valves protruding and not want to damage Take DC voltage readings with respect to chassis on all the pins and the top cap of V4 and V5 except the heater pins (pins 4 and 5). Report back with results |
19th Apr 2020, 10:50 am | #117 |
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Re: Kolster Brandes 666 Valve radio restoration.
Hi Graham
Bit stuck at moment as not 100% sure looking at set layout which valve is which do know rectifier valve is V6 which i have marked v6 but the description of adjasent / next to valve says (IF VALVE IN SCREEN ) but on valve listings has diagram different descriptions for valves as to schemetic layout , so not 100% which valve is which as looking at set ,can see layout by aerial view drawing but but doesnt say which valve numbers are, attached picture of set showing valves ,as i look at set know far right hand valve is V6 is v5 next one along ? Last edited by real0real; 19th Apr 2020 at 11:09 am. Reason: additional info |
19th Apr 2020, 11:06 am | #118 |
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Re: Kolster Brandes 666 Valve radio restoration.
V5 is the output pentode and is adjacent to V6.
V4 is second detector and first LF valve.
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19th Apr 2020, 11:13 am | #119 |
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Re: Kolster Brandes 666 Valve radio restoration.
o.k can see now on aerial view which corresponds
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19th Apr 2020, 11:14 am | #120 |
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Re: Kolster Brandes 666 Valve radio restoration.
This may help.
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