Good morning gentlemen.!
I'm working on replacing a ballast resistor on a rogers 6r1031. There were two available for this set, one for 25 hz the other for 60hz.. It's actually for the phonograph motor. Unfortunately the set has the 25hz ballastron. Any ideas on where to purchase or how to construct a replacement? Go easy on me.. Lol.. This is the first time I've seen this...

As nearly as I can tell, the 25 Hz and 60 Hz models used the same phono motor, and used the different ballasts to compensate for the motor's different impedances at the two frequencies.

Since Z= jwL, motor impedance increases with frequency so to get the same current at 60 Hz as at 25 Hz, you will need to reduce the ballast resistance by a proportional amount, e.g. it will need to be 25/60 (roughly half) of the resistance of the 25 Hz ballast.

So, measure your 25 Hz ballast resistance and multiply the value read by 25/60 and that should be the correct resistance for 60 Hz operation.

You will need to estimate current draw of the motor and use that to "size" the power rating of the ballast-replacement resistor. At 60 Hz the replacement resistor will dissipate roughly half the power as the 25 Hz ballast tube, since current is the same but resistance is cut in half (P=I*I*R)

:As nearly as I can tell, the 25 Hz and 60 Hz models used the same phono motor, and used the different ballasts to compensate for the motor's different impedances at the two frequencies.
:
:Since Z= jwL, motor impedance increases with frequency so to get the same current at 60 Hz as at 25 Hz, you will need to reduce the ballast resistance by a proportional amount, e.g. it will need to be 25/60 (roughly half) of the resistance of the 25 Hz ballast.
:
:So, measure your 25 Hz ballast resistance and multiply the value read by 25/60 and that should be the correct resistance for 60 Hz operation.
:
:You will need to estimate current draw of the motor and use that to "size" the power rating of the ballast-replacement resistor. At 60 Hz the replacement resistor will dissipate roughly half the power as the 25 Hz ballast tube, since current is the same but resistance is cut in half (P=I*I*R)
:
:

Thanks for the detailed response Cv. Sounds pretty easy.. Cheers.!

::As nearly as I can tell, the 25 Hz and 60 Hz models used the same phono motor, and used the different ballasts to compensate for the motor's different impedances at the two frequencies.
::
::Since Z= jwL, motor impedance increases with frequency so to get the same current at 60 Hz as at 25 Hz, you will need to reduce the ballast resistance by a proportional amount, e.g. it will need to be 25/60 (roughly half) of the resistance of the 25 Hz ballast.
::
::So, measure your 25 Hz ballast resistance and multiply the value read by 25/60 and that should be the correct resistance for 60 Hz operation.
::
::You will need to estimate current draw of the motor and use that to "size" the power rating of the ballast-replacement resistor. At 60 Hz the replacement resistor will dissipate roughly half the power as the 25 Hz ballast tube, since current is the same but resistance is cut in half (P=I*I*R)
::
::
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