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 Post subject: Re: Replacing seleniums in a Perma Power
PostPosted: Jun Tue 18, 2019 10:03 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 9986
Location: Toledo, Ohio
OK, I am reading 116K ohms from B+ to B- on the radio. Since I have done no work on the radio itself I am looking for suggestions to substitute a load to place on the Perma Power to figure out an appropriate dropping resistor for the B+ supply.

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Jim
KE8GMW
------------------------
"AC volts and DC volts and little lamps and lities..."


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 Post subject: Re: Replacing seleniums in a Perma Power
PostPosted: Jun Wed 19, 2019 1:16 am 
Member

Joined: Sep Thu 23, 2010 6:37 am
Posts: 11410
Location: Powell River BC Canada
If the radio isn't playing, the 116 K may be leakage or
a bias divider.

Why would you need to drop the voltage ? It already has
a voltage divider, with , if custom holds, 10 % of the expected
load flowing with nothing connected

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de
VE7ASO VE7ZSO
Amateur Radio Literacy Club. May we help you read better.
Steve Dow
ve7aso@rac.ca


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 Post subject: Re: Replacing seleniums in a Perma Power
PostPosted: Jun Wed 19, 2019 9:22 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 9986
Location: Toledo, Ohio
The radio is still all original underneath and some of the dogbone resistors have cracks in them. I also replaced the original selenium with a silicon diode which has a lower forward voltage drop along with newer capacitors. That is why I am asking the question .

As it stands now without an extra dropping resistor, the no load readings are 135,125,114 and 101 volts for a 92 VAC input. I am looking for readings of 135,112,90, and 67 volts under load with a 120 VAC input.

_________________
Jim
KE8GMW
------------------------
"AC volts and DC volts and little lamps and lities..."


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