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

Philco 37-610 Thump*No 7 Volts to pilot lamp
#16

Hi Ralph,

Other experts please chime in if I am wrong here. Most restorers will accept up to a 20% error in the resistor value for older radios because most of the resistors have a tolerance of 20%. Replacing the 2 resistors with the lower values that you described would still put you in about a 10% error. since they are oth 10% lower, in theory, the voltage would be no different than the theoretical design voltage.

Much has been said by others responding to your post, all very good info. do consider reheating solder connections, ohming coils, and verifying circuit continuity through the band switch. Definitely verify grounds. Consider bonding ground points to each other if the chassis is rusty.

If you have a signal generator, it would be a useful tool in troubleshooting this issue.

"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
Best Regards, 

MrFixr55
#17

I agree with MrFixr regarding resistor replacement tolerances.

Joe

Matthew 16:26 "For what does it profit a man if he gain the whole world, yet lose his own soul?"
#18

20% seems to be the commonly accepted tolerance. Keeep in mind, this is +/-20% which makes it 40% (counting from the center value) range.
It's possible there are some places where one might want a tighter tolerance, but most will be OK with 20%.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#19

Keep in mind we don't really know what values the engineers came up with. All we see is what is on the drawing and what is inside the chassis. They used the closest component value to what the calculated one was, plus the parts manufacturers couldn't get much closer than 20% for standard parts. It's evident that cost often determined the final parts placement (what do you mean I can't add fidelity?). So this is why I use 10 percent tolerance. Plus, it's easy to calculate.
#20

Mr Fixr,

I have replaced resistors #22,23 and 47                                                                                              All voltages are with in 20% except 6K7 plate voltage is 63v not 175v
With power off 0 ohms between pin 5 and ground.
No stations when touching grid cap of 6A8. When testing with another radio I did not get any squealing. When moving the radio outside I did get 3 stations fainty with a .1 cap on screw #1 of the antenna with screws 2 and 3 jumped and me touching the cap. No stations when using wire for a antenna.
2 things did happen while trying to get it to play. playing with grid cap of 6K7 I got some motor boating also when wiggling the center chassis I could get the motor boating to come and go. Do I need to replace the grommet's on the center chassis?
The antenna lead going to the band switch needs to be resoldered, the radio shows its not a good connection when wiggling the wire. Looks very hard to get at the soldering point of the band switch.

Ralph




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
trying to identify this wire type
Thanks to all for the feedback. As Arran said, it is probably an older replacement and yes it has a grid cap so I will ...georgetownjohn — 09:32 PM
trying to identify this wire type
It's possible that the red wire, actually a grid cap lead, is a very old replacement, I can't remember seeing a pre 1939...Arran — 09:18 PM
Gilfillan Brothers Car Radio?
Hi everyone,  Special thanks to Joe Rossi for tracking down this obscure radio and thanks to others who took up the hun...Antipodal — 08:15 PM
trying to identify this wire type
Here's one source for your wire of many. Take care and BE HEALTHY! Gary P.S. Can't get the right color you need? I ...GarySP — 06:40 PM
trying to identify this wire type
...and modern wire of the appropriate gauges and insulation V-rating (300V minimum, usually shown right on the wire) is ...morzh — 05:47 PM
1930s Stromberg-Carlson Tombstone Radio need help identifying model number
I have a question about this radio, is there anyone that has access to this radio that has an intact unmolested speaker ...captainclock1988 — 04:28 PM
1930s Stromberg-Carlson Tombstone Radio need help identifying model number
Well what makes me confuse all of those companies is that all three of those companies (Setchell-Carlson, Stromberg-Carl...captainclock1988 — 04:21 PM
trying to identify this wire type
The red wire is rubber covered wire. The others are cotton braid over rubber often in colors or a tracer, also strand...Chas — 02:43 PM
trying to identify this wire type
Greetings Phorum members, Hope you can help me identify this type of wire in the photo I have attached.  I am not sure ...georgetownjohn — 01:53 PM
Philco 60 Squealing
All correct shields must be in place, all tubes correct no subs of any kind. Check any soldered, riveted ground conne...Chas — 01:24 PM

[-]
Who's Online
There are currently no members online.

>