Kolster 'B' Socket Power Unit HELP

ID: 251341
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? Kolster 'B' Socket Power Unit HELP 
08.Apr.11 04:16
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Mark Skala (USA)
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Recently I purchased an old Kolster "B" Socket Power Unit with the hopes it would work and fit in with my old battery radios. It does not work. The large condenser is blown. I cannot locate a schematic but do have the following information from the condenser:

Mershon Electric Condenser
Cap Total=30 Per Anode=10

Patents range from 1911 - 1927

There are three (3) taps on the top. It is about 6 inches high and 3 inch diameter.

My question is: what is a recommended replacement? How big (this one is rather large)? Where is the ground if the taps on the top are all positive? Can I simply use modern electrolytics?

Any assistance would be helpful.

Thank you,

Mark

 

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 2
. 
09.Apr.11 01:01
53 from 2460

Alan Scott Douglas † 16.11.15 (USA)
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Alan Scott Douglas † 16.11.15

It is a 3-section electrolytic capacitor; the copper can is negative for all 3 sections.  It was liquid-filled. Ordinary "dry" electrolytics will work fine as replacements, but you should probably monitor the voltage with no load to be sure it doesn't exceed 450V.

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 3
 
09.Apr.11 01:34
59 from 2460

Mark Skala (USA)
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Mr Douglas,

Thank you for your information. I did find where the negative lead is attached to the base of the can. Although modern dry electrolytics would work fine, if a wet cap were available would it be better?

As far as the values, I'm not sure if they are in Farads or microfarads. What would be used for a device of this type?

Regards,

 

Mark

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 4
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09.Apr.11 13:12
98 from 2460

Alan Scott Douglas † 16.11.15 (USA)
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Alan Scott Douglas † 16.11.15

10 microFarads is right.

"Wet" electrolytics  were the first ones developed; later (and now) the liquid electrolyte is contained in an absorbent layer between the anode and cathode foils.

 

Wet electrolytics have certain advantages but are physically so large and prone to leakage that they haven't been made since the 1930s.

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 5
Thank you 
09.Apr.11 18:52
127 from 2460

Mark Skala (USA)
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Mr Douglas,

Thank you for the valuable information!

I believe they also used a bleeder cap with these? (there is a small one by the transformer) Guess that won't be needed any longer?

Regards,

Mark

 

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 6
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10.Apr.11 01:23
156 from 2460

Alan Scott Douglas † 16.11.15 (USA)
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Alan Scott Douglas † 16.11.15

"Bleeder" is normally applied to resistors.

 

If there's another capacitor it could be a bypass for one of the lower-voltage outputs, or it could be a power-line bypass to reduce noise.  It would be a paper capacitor, and is almost certain to be leaky.  A B+ bypass would be 1 or 2 µF, and a line bypass would be 0.1µF or less.

 

Incidentally, I am unable to find a Kolster schematic that uses a Mershon capacitor.  Is this a power pack for a particular radio, and is it identified in any way?

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Power supply 
10.Apr.11 02:06
163 from 2460

Mark Skala (USA)
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Mr. Douglas,

This is a power supply for old farm radios. It provides 4 voltages. The taps are labeled for B-, 22, 67, 90 and 135. No other information other than:

Kolster "B" Socket Power Unit

60 cycles 115 Volts 25 Watts
Manufactured Under Patent No. 1,455,141 - May 13, 1923
Other Patents Pending
Serial No __________
Manufactured By Federal Telegraph Co
and
Brandes Products Corp for
Federal - Brandis Inc
Newark New Jersey

Hope this helps,

Mark

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 8
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11.Apr.11 03:37
203 from 2460

Alan Scott Douglas † 16.11.15 (USA)
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Alan Scott Douglas † 16.11.15

The name "Federal-Brandes" dates it before April 1928, and the use of the Mershon capacitor dates it after 1927.  

 

There should be a tapped bleeder resistor to supply those voltages, and I would expect each tap to have a bypass capacitor.  Some B-eliminators used series resistors, so the voltage would only be accurate when a load is being drawn.  

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 9
Will check 
11.Apr.11 04:31
208 from 2460

Mark Skala (USA)
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Mr Douglas,

I did see a large resistor. I will look at it more in depth this week and get back with you. Thanks much for your help!

Kind Regards,

Mark

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 10
Power Supply Update 
12.Apr.11 04:10
260 from 2460

Mark Skala (USA)
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Mr. Douglas,

I tore it apart this evening, installed three new 10mfd/450vdc caps. There is still a smaller .67mfd cap rivited to a non-conductive base. Unfortunately my meter cannot test these caps so I do not know how stable it is. It is encased in a rectangle metal can about 2"x 9/16"x 1 1/4" in size.

The terminals are all part of a large resistor with multiple taps. I measured to ground and had the following results:

TAP 22 VDC = 55-56 Mohms
Tap 67 VDC = 97-117 Mohms
Tap 90 VDC = OFF Scale
Tap 135 VDC = OFF Scale

When powered on voltages are as follows:

22 VDC = 24VDC
67 VDC = 100+ VDC
90 VDC = 314 VDC
135 VDC = 314 VDC

There seems to be a problem with the resistor. I'm not sure I can calculate what the resistor values should be without knowing the proper output voltage of the transformer?

Thanks for your help,

Mark

 

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 11
. 
12.Apr.11 14:02
291 from 2460

Alan Scott Douglas † 16.11.15 (USA)
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Alan Scott Douglas † 16.11.15

The resistors should be in the thousands of ohms.  There are schematics of competitive brands of eliminators in the Rider manuals.  I doubt if there was ever a Kolster schematic published.  I have a Kolster service manual from this period and it's not there.

All the paper capacitors will be leaky by now; it's very rare to find one that is still good.

I would recommend asking on the Forum at antiqueradios.com, which is geared more to back-and-forth discussions of troubleshooting procedures.  You may also find someone there who owns one.

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 12
For discussions about models ... 
12.Apr.11 23:26
328 from 2460

Georg Richter (D)
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Georg Richter

Gentlemen,

please allow me some remarks:

Discussions about a certain model should not start from the manufacturer, but from the model page.

If the model is missing in the databse the model has to be suggested  to the RMorg model database, using "Create a new model" on the "home" page.

If the model is accepted it is fine and helpful to upload pictures. If you are not firm how to proceed please read the FAQ section for details. Later this thread can me moved to the model, to free the manufacturer site from discussions without details about the company.

Please don't leave this thread without updating informations from anywhere and about further progress of troubleshooting.

Thanks and Best Regards,

GR

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 13
New Model 
13.Apr.11 03:14
340 from 2460

Mark Skala (USA)
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Count of Thanks: 4

I have submitted a new model for consideration as suggested. Thanks!

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