For you who are new to my problem I am starting a new string. I found the capacitor that blew, it was the 8mf 450 cap. It was the replacement for original can cap that has a paper ring on the top and bottom of the can. When I replaced the new cap under the chassis I hooked the ground to the old ground, which is actually grounded to the can, but not to the chassis. They have a paper ring that does not let the can ground to the chassis. The mystery whie resistor in question when measured read 23600 ohms, so it is not the 9000 ohms resistor as thought earlier. So now I am very confused. It was recomended that I look at the second type schematic, but mine is not a phono model. I think mine is more like the first schematic. It looks like the resistor is #57 23500 ohms on the schematic and the cap is #56 that blew and does not actually have a negative ground and go to the transformer tap #4. OK, that said, all looks right on my chassis....WHAT WENT WRONG!!!!!!
Thanks
David

David: Is this the Philco 610 that uses an 80 rectifier tube? I have the schematic from the Resources on this site and I want to be sure I'm looking at the correct schematic. The one I am following has 57 as a wire wound 260 ohm with tap at 25 ohm, 54 and 56 are 8 mfd elect with 41 16 mfd elect. If I'm wrong, please direct me to the proper schematic. Aside from that is it possible that you are confusing the two 8 mfd caps leads and placing the first (56) to ground and the second (54) to the center tap? PL

:For you who are new to my problem I am starting a new string. I found the capacitor that blew, it was the 8mf 450 cap. It was the replacement for original can cap that has a paper ring on the top and bottom of the can. When I replaced the new cap under the chassis I hooked the ground to the old ground, which is actually grounded to the can, but not to the chassis. They have a paper ring that does not let the can ground to the chassis. The mystery whie resistor in question when measured read 23600 ohms, so it is not the 9000 ohms resistor as thought earlier. So now I am very confused. It was recomended that I look at the second type schematic, but mine is not a phono model. I think mine is more like the first schematic. It looks like the resistor is #57 23500 ohms on the schematic and the cap is #56 that blew and does not actually have a negative ground and go to the transformer tap #4. OK, that said, all looks right on my chassis....WHAT WENT WRONG!!!!!!
:Thanks
:David
:

Yes, you are looking at the correct schematic. Try this link for a picture. http://s128.photobucket.com/albums/p191/dgrizzy68/?action=invite
Have you read my first posting of this?
I blew a cap when I pluged it in, I replaced all the old caps, even thought it was working perfect. I am starting to wonder if I had the negative in the wrong direction. I put them the way they came out.
David

Funny thing, I just realized you wrote this article I am reading on Philco Service hints re-capping Wet Aluminum can electrolytic capacitors.

I think I found the problem. Those pesky negative-filtered power supplies. I read your article and wonder if I am not actually getting a ground to the chassis when it is supposed to be floating ground. The one can that I was telling you about had the cardboard sleeve and that is the capacitor that I replaced and blew. I connected it to the lead that it was hooked up to before, it looks like it is comeing from the can, but probally is tied to the chassis, or the paper is not working as a good insulator any more. The positive of that cap goes to white resistor 25000 ohms, speaker and 80 rectifier the neagative goes to the isolated can and the wire wound multi tap resistor. That is how I have it up.
Thanks
David

David: Thanks for the mention on the article which was possible with Chucks help. I went over the schematic and came up with the following: The positive of 8mfd elect(56)goes to field coil(53),
10,000 ohm resistor(39)and either pin 1 or 4 on the 80 which pin is also connected to the(6)on xfmer(5V).
Negative side of 8mfd elect(56)goes to cntr tap xfmer(4), 260 ohm resistor(57)and 50,000 ohm resistor (58).
The 25,000 ohm resistor(40)does not go to the 8mfd elect(56)although it does connect to the other side of the 10,000 ohm resistor (39).
Check for ground on the 56 cap to chassis, if its grounded thats part or all of your problem. Also check resistor 57 (260 ohm)for value. PL

:I think I found the problem. Those pesky negative-filtered power supplies. I read your article and wonder if I am not actually getting a ground to the chassis when it is supposed to be floating ground. The one can that I was telling you about had the cardboard sleeve and that is the capacitor that I replaced and blew. I connected it to the lead that it was hooked up to before, it looks like it is comeing from the can, but probally is tied to the chassis, or the paper is not working as a good insulator any more. The positive of that cap goes to white resistor 25000 ohms, speaker and 80 rectifier the neagative goes to the isolated can and the wire wound multi tap resistor. That is how I have it up.
:Thanks
:David

Hello, I tried your ideas and still keep blowing that 8mf cap. I tried another sinario of my own and still blew another 8 mf cap. What am I missing?
Thanks
David

David: You have to re-check the wiring. Even if that cap went to ground (chassis)it should not blow the cap unless its voltage rating is too low. The fault you would have is no - bias. Its got to be reverse polarity. The cap, when wired correctly in the circuit is directly across approximately 340VDC (half wave).

:Hello, I tried your ideas and still keep blowing that 8mf cap. I tried another sinario of my own and still blew another 8 mf cap. What am I missing?
:Thanks
:David

Sure sounds like you have to low a voltage cap or its installed with the wrong polarity. Using you meter set to DC volts, connect it to the same points as where this cap is connected following the same polarity, positive to positive and negative to negative. Turn the radio on, does your meter show a positive or negitive reading? What is the reading? Let us know what you find.
Greg

:Hello, I tried your ideas and still keep blowing that 8mf cap. I tried another sinario of my own and still blew another 8 mf cap. What am I missing?
:Thanks
:David

Thats what I thought, but I put them in one at a time just like they came out. Tha radio did work great before I touched it, but the caps did need to be replaced do to there age.

:Thats what I thought, but I put them in one at a time just like they came out. Tha radio did work great before I touched it, but the caps did need to be replaced do to there age.

David: Take out the caps you put in, take a break from the set (you must have some project on hold) then go back and, using the schematic only, wire in the caps with out using any of the old cap terminals. You may have to add a one or two contact terminal strip to the chassis (your in the area of the xfermr mtg bolts and the cap bakelite box mtg screws)for connection points. pl

Thats a great idea. I will work on it this weekend and give you an update.
David

OK David, you going to drop the other shoe or what? PL

:Thats a great idea. I will work on it this weekend and give you an update.
:David

I am not sure what you mean?

David: It means why are you keeping us in suspense as to how the set turned out. Based on the following:
Tenant A in apartment is woken up a couple of nights by Tenant B upstairs, who works nights, takeing his shoes of and dropping each on floor above Tenant A making loud crash. Tenant A talks to Tenant B and tells him how it wakes him up, please dont do it. Next night tenant B comes home, sits on bed and forgeting drops one shoe. He gently places second shoe on floor. Hour later Tenant B wakes up to banging on his front door. Its Tenant A who says to him all right, all right, please drop the other shoe so I can go back to sleep! PL

: OK David, you going to drop the other shoe or what? PL
:
:
::Thats a great idea. I will work on it this weekend and give you an update.
::David

I took your advice and let a sleeping dog lie. I have been pulling my hair out with the detrola 172.