Unusual to have two fuses in a radio. Some manufacturers used two holders in order to select input voltage, 110 or 120 volts. These radios would use one fuse or the other, not both.
B+ voltage starts at pin #1 or #4 of the 80 tube. From there it usually goes through a speaker field coil. Is the speaker field coil open? After that pin #2 on each tube should have B+ voltage.
Norm
:Can anyone help me find the schematic for this radio? It says SG-7 and Kemper on it. Made by Gilfillan and uses these tubes; 80, 2-71's, 2-27's, and 2-24's. It is just dead. No B+. Has two fuses. One is missing but blows anything I put in there.
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Thanks for the info. about the fuses. There are two fuse holders side by side and each shares a middle clip in common. I never saw this before but sounds like what you mention. Will check out things further tonight after work. Thanks Again
John
http://www.antiqueradios.org/gazette/kemper.htm
Ken
Well I goofed as usual. I originally saw a 16u @450 someone had added and so measured at the + side for B+ and there was nothing so thought I had no B+. Now after checking further found B+ on all of the tubes. Not sure why someone added the 'lytic which turns out is from pin 4 of one of the 27 tubes to ground. Why 16u to ground there? On pin 3 (grid) of that same tube scope shows nice signal but at pin 2 (plate) no signal. Just a very slight amount at audio frequency but hardly anything. Have continuity to ground from the cathode about 22k and there was 88v dc on the plate but no signal on the plate and the tube checks good. Just for kicks I traded (switched) the two 27s and the radio sprang to life. Not sure why yet. Maybe I disturbed a bad connection or the tube socket is flaky. Don't know yet.
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I do hope you find the correct schematic, which should shed light on the 16uf Cap - if there ever was one originally or someone decided to add it. You probably know that the Type 27 Tube is an AF Preamp. Pin 4 is the cathode. One might expect to find a resistor perhaps for cathode bias and one might guess a 16uf cap might have been put there to get rid of hum. If that is the case, the hum probably had another source. Since you managed to get the set alive, it's none the worse for the 16uf on the #27 cathode but I nonetheless suspect a hack job. Would love to hear other opinions about this.
:::::Hi John
:::::
::::: Unusual to have two fuses in a radio. Some manufacturers used two holders in order to select input voltage, 110 or 120 volts. These radios would use one fuse or the other, not both.
:::::
::::: B+ voltage starts at pin #1 or #4 of the 80 tube. From there it usually goes through a speaker field coil. Is the speaker field coil open? After that pin #2 on each tube should have B+ voltage.
:::::
:::::Norm
:::::
:::::
:::::
::::::Can anyone help me find the schematic for this radio? It says SG-7 and Kemper on it. Made by Gilfillan and uses these tubes; 80, 2-71's, 2-27's, and 2-24's. It is just dead. No B+. Has two fuses. One is missing but blows anything I put in there.
::::::
:::::
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::::
::::Thanks for the info. about the fuses. There are two fuse holders side by side and each shares a middle clip in common. I never saw this before but sounds like what you mention. Will check out things further tonight after work. Thanks Again
::::John
::::
:::Radiomuseum lists an SG-71 by Kemper, but no schematic
:::http://www.radiomuseum.org/r/kemper_sg71.html
:::Does not mention a relationship to Gilfillan.
:::Might try matching it up with a schematic for one of these radios:
:::http://www.grillecloth.com/sylvania/tubelist.php?comp=&mod=&Num=7&tube1=2-24&tube2=2-27&tube3=2-71&tube4=80&ball=&Submit=Submit&db=5
:::Carl T
:::
::Thanks Carl T
::I can use the AK 55 to troubleshoot.
::John
:
:Well I goofed as usual. I originally saw a 16u @450 someone had added and so measured at the + side for B+ and there was nothing so thought I had no B+. Now after checking further found B+ on all of the tubes. Not sure why someone added the 'lytic which turns out is from pin 4 of one of the 27 tubes to ground. Why 16u to ground there? On pin 3 (grid) of that same tube scope shows nice signal but at pin 2 (plate) no signal. Just a very slight amount at audio frequency but hardly anything. Have continuity to ground from the cathode about 22k and there was 88v dc on the plate but no signal on the plate and the tube checks good. Just for kicks I traded (switched) the two 27s and the radio sprang to life. Not sure why yet. Maybe I disturbed a bad connection or the tube socket is flaky. Don't know yet.
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That number usually leads you to a true,/i> Gilfillan model for a schematic