Philharmonic B+ voltage divider

[Scott Rhode]

Hello,

This is my first post on the forum. I am restoring my first EH Scott, the 8-knob Philharmonic.  There is an open section on the B+ divider, the divider itself is stamped "523".  In reading a previous thread someone said that there were two versions of this divider with the difference being that the 1200 ohm 250 VDC section was increased to 1700 ohms on later models.  Of course this is the section that is open on this radio.  How can I determine which resistance I should use in replacing the open section?

The serial number on this receiver is KK-25 which I expect is the same on all 25-tube chassis.

Thank you for any help.

Cheers,

Scott

[Scott Seickel]

I strongly recommend replacing the whole candohm resistor with a new Ohmite D50K5K0E resistor.   It is 5k and 50 watts.  Purchase a couple of Ohmite 2121E taps, and a Ohmite 7PS50E mount.   The other candohm resistor sections will open, it is just a matter of time.  

If you really want to replace just that section, then you should use the earlier 1200 ohm value.

The serial numbers are different for each set.  KK-25 puts this as a 1937  built set. 

[David C. Poland]

I agree. Replace the whole B+ divider for sake of reliability.

I have a pointer dial KK-237 with a 1938 date on a part inside. If yours is 8 knobs (plus tuning), I suspect yours was returned to the Scott Lab for repair and was up dated. Your would have an unused chassis hole below the tuning shaft where the push/pull Scratch suppressor switch was.

Philharmonics have a number of alpha prefixes, earlier production in 1937 had a single letter like D, E or F. Soon, Scott changed to double letter prefix like KK, LL, RR ... for the various models of the late 1930's to WW2.

[David C. Poland]

FYI - The Philharmonic is referred to as a 30 tube set, including the two eye tubes. The FM Philharmonic is a 33 tube radio. Both tube counts include the 6 tube power supply.

[Scott Rhode]

Scott and David,

Thank you for your advice and information. I will replace the whole candohm. 

This set has 8 controls but does not have an unused chassis hole. 

I'm sure that I'll be back with more questions once I'm able to power the set up.

Cheers,

Scott

[Scott Seickel]

Don't really know what you mean by "This set has 8 controls but does not have an unused chassis hole"   You have a dial pointer version based on your early serial number.  I normally call them "7 knob" Philharmonics, because you have 7 knobs.  The 8th control is a push-pull control for the scratch suppressor, I don't identify that as a knob because you don't turn it. 

Note that the taps on the new resistor will be bunched up close to the center.  Adjust them for proper voltage output, but be very careful to power down before trying to adjust. 

[David C. Poland]

Suggest you attach a photo of the receiver. Use the "paper clip" icon in this heading.