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Silvertone Powr Shiftr Output Voltage Too High
7/19/2005 11:31:03 PMThomas
My Silvertone Powr Shiftr (chassis 139.151) calls for two 40 MFD 150V input capacitors and two 1500 MFD 3V filter capacitors. I have replaced them with two 47 uF 160V and two 1500 uF 10v electrolytic capacitors respectively. It has original rectifiers.

I tested unit with a multimeter it is shows 3.586V for the A side 136.4V for the B side. What is causing the unit to have these high output voltages? I understand that I can replace the rectifiers with diodes. What type of diodes would work and in what manner should they be installed?

7/20/2005 12:42:35 AMNorm Leal
Hi Thomas

Your power shifter doesn't have regulation. With no load voltage will be high. Once connected to a radio voltage will drop.

You could test the unit using resistors for a load. For a 250 ma load @ 1.5 volts you can use 6 ohms across the "A" supply. Might try 5K wire wound across the "B" supply. This will give a load around 20 ma.

Norm


:My Silvertone Powr Shiftr (chassis 139.151) calls for two 40 MFD 150V input capacitors and two 1500 MFD 3V filter capacitors. I have replaced them with two 47 uF 160V and two 1500 uF 10v electrolytic capacitors respectively. It has original rectifiers.
:
:I tested unit with a multimeter it is shows 3.586V for the A side 136.4V for the B side. What is causing the unit to have these high output voltages? I understand that I can replace the rectifiers with diodes. What type of diodes would work and in what manner should they be installed?

7/20/2005 1:39:06 PMRadiodoc
:My Silvertone Powr Shiftr (chassis 139.151) calls for two 40 MFD 150V input capacitors and two 1500 MFD 3V filter capacitors. I have replaced them with two 47 uF 160V and two 1500 uF 10v electrolytic capacitors respectively. It has original rectifiers.
:
:I tested unit with a multimeter it is shows 3.586V for the A side 136.4V for the B side. What is causing the unit to have these high output voltages? I understand that I can replace the rectifiers with diodes. What type of diodes would work and in what manner should they be installed?

Thomas,

I have the same power shifter that came with a 4-tube RCA Victor battery set (RC1037A). The voltages with the radio not plugged into it are FIL. 3.75 VDC and B+ 131.7 VDC. With the radio plugged into it the voltages are FIL. 1.23V HI/1.025 LO and B+ 85 volts. My unit has the original rectifiers and new caps.

Radiodoc



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