[
attachment=23522]I hope you don’t mind my lack of knowledge. I have just taken up this hobby but with Covid there are no vintage radio meetings in my area for me to join and learn how to diagnose and repair vintage radios.
My Model 610 has three electrolytic caps but the one marked #41 unlike the #56 and #54 on the schematic is not grounded to chassis. I know from reading the Rider changes note, that these caps were mislabelled on the schematic and that’s not the issue. I know #41 is really #56.
I don’t know how to wire this insulated electrolytic cap properly.
Everything I read says to insure that you replace the fibre insulation ring on these aluminum caps when replacing but I will be cutting the red and black coming from this cap and reinstalling the new cap under the chassis. Where and how do I ground it?
I realize this is simple question for all of the Phorum readers but I don’t want to mess it up and would appreciate any assistance.
Under the insulatingcardboard sleeve there is a metal insert touching the can, it is connected to the wire going to the transformer centertap (rectifier negative).
If installing caps under chassis, use the wire that was described above for the negatove and the wire that was going to the cacitor's center contact for the positive.
This is for the 56 cap as on the sch.
The other two have their cans grounded to the chassis.
Those capacitors are not original to the radio. The original cans used the outside of the can as a contact either to ground or to the center tap on the transformer depending on which one you are wiring. As Mike points out the insulating sleeve keeps the can (and metal tab that was on the side of the can used to connect a wire to) away from the chassis. In your case, the new caps may have the negative lead as a wire rather than the can itself.
schematic (
http://www.nostalgiaair.org/pagesbymodel797/M0013797.pdf ) #41 and #54 connect to chassis ground and # 56 connects to the center tap of the transformer secondary. See where the leads are connected now as a guide but check with the schematic as well. There's a picture of some original caps in the post
https://www.philcoradio.com/phorum/showt...#pid148593 so you can get an idea of what they looked like. The upper photo one has been cut open and gutted to place a modern cap inside it. The lower photo is after it was put back together and is what the original look would be.
Bob
I though those Aerovoxes were the nut-held type with the central positive, no?
In them olden times they'd be better off using the screw type as then the central would act as a solder post; else the wire would have to be stretched to the centertap and it might not be long enough.
Thanks and please don’t take offence but I still am confused.
I can’t see any metal insert touching the can. There’s only the collar holding it in place and two wires from this cap. A red wire going to tube 80, not sure the pin# and a black wire that terminates at the B.C. Wire wound resistor part no. 33-3037. Photo of that wire enclosed. It is the black wire with a partial sleeve on it. If that goes to the transformer centertap I don’t know how to determine that. I am studying schematics but haven’t advanced enough to follow where everything goes.
I still am confused and would like to know where to connect the + and - of my cap and how to ground it.
Sorry but my previous post was posted before I saw Klondike’s reply. I will check out the picture in his post and see if that helps
What you've got is a red wire (+) and a black wire (-) existing the bottom of you caps. The there is no - connection made internally so there is no need for the insulating sleeves.
So to answer the pending question let's pull up the diagram.
https://philcoradio.com/library/download...l.%201.pdf What we have is # 56 the - side goes to the ct of the high voltage winding and 57&58. + side of 56 goes to pin 1 or 4 of the #80 tube. Next #54 - side goes the chassis ground and + side goes to pin 3 of the # 42 tube and some other stuff that all connected to pin 3. Finally #41 goes to the junction of #'s 40&42. - side goes to chassis ground. Would use a pair of 10mf @450v for the 8's and a 22mf @ 450v for the 16.
It can be confusing until you’ve done several chassis and become familiar with how Philco did things.
Radiorosyln, Thanks for the information.
Before I solder anything I will study the schematic connections you indicated as a good learning experience. I do want to confirm that these connections reflect the changes in the schematic that I had read about before in the Riders manual. I enclose them below.
“Changes page 9-3 Philco Model 610”
“We’ve been advised by the manufacturer that the following changes should be made in the schematic numbers of this model found on pages 6-19 of Riders Volumn VI. The schematic number 54 should be changed to #41; #41 to #56; #56 to #54.”
Thanks and sorry to keep asking questions but want to do it correctly.
Bob
The numbering is not that important. What is, is that you look at the connections and see that they go to a part described. Of course correct numbering makes it a bit easier, especially if there is a drawing of the chassis and the parts list.
But you do know that a cap of a certain parameters goes between the rect. negative (xfmr centertap) and it is usually a black wires, and the positive (the rect tube's cathode or filament, depending on the tube) which would be the red wire, and you check against that. Then you go about other capacitors. And other parts if you question the connections. Typically the factory connections or 1940-s - 1950-s repairs do not have to be questioned, so you simply re-use the connections.
When you see a today's repair with not so neatly soldered connections, you question it. But then there are sometimes mistakes in the schematics so ask questions or else it just might not work (many Philcos schematics, for instance, miss a tie-dot between the second filter cap and the B+ voltage; a known problem, but for a newby it is not something that he knows so if trying to follow that you will render the radio inoperative).
And so on.