Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

American Bosch 5AC
#16

No hum on pin 3 of 47.

I think the power transformer is bad. Can't get a steady reading on any of it and I don't get any readings on the other tubes.
#17

Ok remove the 80 tube. Set meter to >500ac. Measure voltage from the ungrounded side of R-12 (should be a big resistor, wire comes from the power transformer) to pin 2 of the 80 socket and then pin 3 of the 80 socket. Should see about 300-350vac on pin 2 and then pin 3 should be the same. If that is OK check R-12 it may be open.

Terry
#18

I don't get any voltage readings on pin 2 or 3. Actually, one one of the pins (not sure if it's pin 2 or 3) the meter starts at over 1000v and drops to 0v. The other starts at about 20v and drops to 0v. R12 checks good. It's a 400ohm 5w resistor and it checks at 408ohms. With the set turned off, pins 2 and 3 show 358ohms and 386ohms. Not sure that matters, though.
#19

Try measuring the AC voltage across pins 2 and 3 of the 80 socket with the power on. Should see about 600vac. Be careful. Hope the transformer is good cause the replacement is going to be hard to find.

Terry
#20

Hope springs eternal but this time the fates got to it. Measuring between pins 2 and 3 with the power on shows infinity.
#21

(07-05-2015, 11:07 PM)dseverson Wrote:  Hope springs eternal but this time the fates got to it.  Measuring between pins 2 and 3 with the power on shows infinity.

Autorangning meter? Can it read 600 or 700vac? Some digital meter won't read that high of an AC voltage.

Terry
#22

No, it's not autoranging. I set it to read from 500v to 2000ma.
#23

dseverson, your post on meter reading setting does not make a lot of sense to me. Is it set to max A/C reading and if so is that 500V A/C? The statement of 2000ma is confusing unless your measuring current. If you are at 500V A/C it is understandable as Terry indicated that your meter will not read the voltage present as it is too high.
Go back to Terry's post #17 so you can measure each leg (plate) to the chassis. It should cut the voltage in half and be within the range of your meter.
Best, Jerry

A friend in need is a pest!  Bill Slee ca 1970.
#24

Finally got back to working on this radio. I went back and removed the 80 tube and took voltage readings on pins 2 and 3 fromthe ungrounded side of R12. I get about 380 volts on both. Also checked R12, a 400 ohm power resistor - not sure of the watts. It measures 408 ohms.
#25

OK so plug in the 80 tube and with the set on measure the DC +voltage from pin 1 or 4 to the chassis. Should see a couple of hundred volts. Next measure the DC voltage on pins 2 and 4 of the 47 tube separately to the chassis. Again should see a few hundred volts at both.
If you like I can send you a pm with my fone# Might be easier and quicker that all this typing!
Terry




Users browsing this thread: 6 Guest(s)
[-]
Recent Posts
An attempt to remove the Field Coil from a G speaker
No Mike. Clear plastic from the packaging of items you buy at Home Depot, the ones you can't open without a hack saw or ...RodB — 05:48 PM
Philco 89 indicator light.
Well thankfully that did not happen.Jim Dutridge — 05:21 PM
An attempt to remove the Field Coil from a G speaker
Paul, thanks, Anything can help. Gary Thanks, lemme look! PS. Looked it up. They have kits and parts for mod...morzh — 02:45 PM
An attempt to remove the Field Coil from a G speaker
Paul, thanks, Anything can help. Gary Thanks, lemme look!morzh — 02:39 PM
46-1201 Trip Switch Spring
I deleted the other thread, as it was duplicate and did not have the photo. Please proceed with this one.morzh — 02:37 PM
46-1201 Trip Switch Spring
Hello, first post here, bear with me. I've been electronically refurbishing a 46-1201 that I received from a relative. ...ConcernedFeller — 01:46 PM
An attempt to remove the Field Coil from a G speaker
I am late to this post, amazing amount of work for a speaker Mike. You must like the challenge. I have a speaker from an...Paul Philco322 — 01:04 PM
An attempt to remove the Field Coil from a G speaker
Mike, give this site a look for your spider. Can't hurt. Take care and BE HEALTHY! -GaryGarySP — 12:41 PM
An attempt to remove the Field Coil from a G speaker
Rod, Bubble packaging? The one I know (if you mean the large bubble type) is really thin. I have some at home. Is there...morzh — 12:23 PM
An attempt to remove the Field Coil from a G speaker
Q8. What's the meaning of life? I have read that someone made a spider out of the clear plastic from bubble packagin...RodB — 11:07 AM

[-]
Who's Online
There are currently 8254 online users. [Complete List]
» 2 Member(s) | 8252 Guest(s)
AvatarAvatar

>