Looking over a 37-61.
http://www.nostalgiaair.org/PagesByModel...013208.pdf
It originally had one of those volume controls with the long shaft and the control itself over on the back side of the chassis.
This one has been replaced with a "regular" VC mounted to the front side of the chassis with the other controls. The original assembly is gone.
Two questions:
Why did Philco use this strange long shaft VC in the first place?
Should I expect issues from a VC mounted to the front on the chassis?
Thanks
Bill
It may have to do with the layout if the chassis. You don't want to mount a VC near a magnetic field like a power transformer as it may cause undue hum pickup.
Terry
Im wondering about it being a layout/size issue myself, but just from a size of the VC itself standpoint.
Ive only seen the "long shaft" types of VC's on the 37 Philco models with the center, separate RF deck.
On this particular radio, the vc was replaced with a rather large body VC that was actually jammed up on the edge of the RF deck.
I had a modern small body vc so I went ahead and swapped it in. RF deck has room to move now.
Im only doing preliminary testing, but the radio works very well after dim bulbing and powering up on variac. It has a low level hum (electrolytic), but the vc doesnt seem to be adding any to it.
So, who knows? SInce the original "long shaft" assembly is missing, I will move forward with recapping and use the more common, front of chassis mounted VC and see if I end up with any issues.
This is a great thread. My 37-650 has the same long shaft VC. Someone had previously replaced the VC and they had used tape to connect the shaft to the new VC. Since being restored, I guess the tape gave out because the shaft becomes disconnected on mine about once a week. I can fish around by moving the knob and get it hooked back up, but it's annoying. I need to tear my down and fix it properly, so I will await your results. I like the idea of using a regular control mounted up front.
PuhPow, have you tried a 1/4" shaft coupling? This is a metal sleeve with setscrews which fits over both shafts to connect them together.
http://www.ebay.com/itm/Pair-of-1-4-shaf..._177wt_917
You are much better off leaving the pot in its current position with short leads to the audio circuitry.
Thanks Mondial. I would have never thought of that. I just purchased those. That's a great solution.
Or a piece 1/4 rubber hose a two tie wraps works fine in my hands. The hose will give you a little bit of flexibility that the solid coupler won't. Both are good ideas.
Terry