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I have a L8 coil should read 1500 Ohms reads 496K Ohms. This is causing pin 8 of 6X5 to read about 90v low. This is a trans former looking coil. Must I re-wire it? Or does any one know a good place to get one?
http://www.nostalgiaair.org/Resources/596/M0008596.htm
Schematic:
L8 is the coil between C18 B and C18 C
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There is no L8 in this document.
There is L5 which is 1500 Ohm.
It is the field coil of your speaker.
If it reads 500K, you should re-wind it.
If it is not the field coil, look at the sch again and make sure you show the correct reference designator before we go and search at it again.
L8 is not in the parts list either.
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L5 is the field coil of the speaker, if it was open I don't know why pin 8, which is the cathode, would would have a lower voltage, if anything it would read high since there is a filter cap there and there is no load. Check the voltage on pin 4 of the 6V6 tube, it should read 230 vdc, if it reads zero then the field coil on the speaker is open. Now the speaker field may be burned out or it may be because one of the leads has broken off internally. If it has burned out then it's very likley that C18B or C16 is shorted or near shorted.
Regards
Arran
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http://www.flickr.com/photos/trog8/72891...hotostream
pic of the coil being used number name on it is as follows:
control corp
7c210
the item read 465K ohms
once removed the voltage at pin 8 6X5 went to 422vdc
I have checked and replaced both c18 B & C
All tubes check good none are weak
I will post schematics show show notes how in certain ver have this coil dis-attached from the speaker.
Its location was next to the power transformer on the bottom.
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Trog,
I honestly do not understand the purpose of so many posts, and confused ones at that.
First you give a ref des L8 that does not exist, then you repeatedly ask what to do with an open choke when you've got more than one answer that it should be rewound / replaced.
Cank you decide what you want? Whatever it is, wherever it is on the sch, it is open and needs to be repaired or replaced.
Why are we going in circles here?
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Sorry about posting the schematics that list it as L5. Their are three different sets of schematics. The parts listing That I have does not list a L5 or L8.
We are talking about the same part.
The coil between c18 B & C
I am very thankful for your help. I'm trying to find the part being sold. I'm not really set up to rewind a coil at this point.
(This post was last modified: 05-29-2012, 12:32 AM by
Bradley Rush.)
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Found coil at
http://www.tubesandmore.com/
P-C194A
Thx again all.
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I replaced L5 with the new coil.
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So, how are the voltages, good now?
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instead of 60vdc high they are 40vdc. T3 that drives the speaker appears to be bad.
#1 6SK7 pin 6: 98vdc Pin 8: 263vdc
#2 6SA7 pin 3: 264vdc pin4: 98 vdc pin 8: -.8
#3 6SK7 pin 6: 95.5vdc Pin 8: 262vdc
#4 6SO7 pin 6 111vdc
#5 6V6 pin3 261vdc pin4: 261vdc pin8: 31.5
#6 6X5 pin3 341vac pin 5: 341vac pin 8: 270vdc
I have injected audio into 6V6 sounds good
I have injected audio into 6QS7 sounds good higher than 6V6
I have tuned the radio as per description.
Tone control seems sensitive.
I have to turn the volume up to max to get any radio station.
Lots of noise on the high end of the dial from mid range. Radio appears to be over driven.
ANNOYING 60Hz HUM gone
I'll be removing T3 from the circuit to be sure next.
I put the voltages i thought would be of interest. The others are about -.2 to -.6 volts high. I will provide complete voltage and resistance sometime this week.
(This post was last modified: 06-03-2012, 10:50 PM by
Bradley Rush.)