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

Philco 37-690
#40

Why not separate the 3K and 2.2K resistors so they do not heat the same concentrated location on the chassis? You might leave the 2.2K where it is and relocate the 3K to the right side of the chassis where there is no resistor now. The 3K dissipates the most power and generates the most heat.

In the end a certain amount of heat has to be dissipated, but if it can be distributed more evenly over the surface of the chassis, a lower peak temperature will result.

These resistors form part of a voltage divider for the power supply, providing B+ and bias for the circuits, while at the same time serving as a bleeder. They also provide a load to produce the required field current for one of the tweeters. There is no easy way to redesign it.

In any case, keep in mind that the heat generated now is no more than it was when the set was new, and was then considered acceptable by the designers.


Messages In This Thread
Philco 37-690 - by Ron Ramirez - 05-30-2014, 08:22 PM
RE: Philco 37-690 - by morzh - 05-30-2014, 08:31 PM
RE: Philco 37-690 - by Eliot Ness - 05-30-2014, 08:42 PM
RE: Philco 37-690 - by morzh - 05-30-2014, 09:16 PM
RE: Philco 37-690 - by Ron Ramirez - 05-30-2014, 09:29 PM
RE: Philco 37-690 - by Eliot Ness - 05-30-2014, 09:41 PM
RE: Philco 37-690 - by morzh - 05-30-2014, 10:49 PM
RE: Philco 37-690 - by Arran - 05-31-2014, 02:10 AM
RE: Philco 37-690 - by Eliot Ness - 05-31-2014, 08:14 AM
RE: Philco 37-690 - by Joeztech - 06-01-2014, 08:58 PM
RE: Philco 37-690 - by Ron Ramirez - 06-02-2014, 05:32 AM
RE: Philco 37-690 - by Phlogiston - 06-02-2014, 09:45 AM
RE: Philco 37-690 - by Ron Ramirez - 06-02-2014, 09:53 AM
RE: Philco 37-690 - by Phlogiston - 06-02-2014, 12:04 PM
RE: Philco 37-690 - by morzh - 06-02-2014, 12:28 PM
RE: Philco 37-690 - by Phlogiston - 06-02-2014, 12:34 PM
RE: Philco 37-690 - by bfrohwein - 06-02-2014, 01:03 PM
RE: Philco 37-690 - by Phlogiston - 06-02-2014, 02:09 PM
RE: Philco 37-690 - by Ron Ramirez - 06-02-2014, 05:21 PM
RE: Philco 37-690 - by Phlogiston - 06-02-2014, 09:03 PM
RE: Philco 37-690 - by bfrohwein - 06-03-2014, 12:14 AM
RE: Philco 37-690 - by Eliot Ness - 06-03-2014, 09:10 AM
RE: Philco 37-690 - by Ron Ramirez - 06-13-2014, 08:11 AM
RE: Philco 37-690 - by y2kbruce - 06-13-2014, 03:09 PM
RE: Philco 37-690 - by morzh - 06-13-2014, 03:10 PM
RE: Philco 37-690 - by Ron Ramirez - 06-13-2014, 03:59 PM
RE: Philco 37-690 - by Ron Ramirez - 07-01-2014, 09:28 PM
RE: Philco 37-690 - by Arran - 07-01-2014, 11:44 PM
RE: Philco 37-690 - by Ron Ramirez - 07-02-2014, 05:31 AM
RE: Philco 37-690 - by jerryhawthorne - 07-02-2014, 03:37 PM
RE: Philco 37-690 - by Ron Ramirez - 07-03-2014, 10:58 PM
RE: Philco 37-690 - by morzh - 07-03-2014, 11:19 PM
RE: Philco 37-690 - by Ron Ramirez - 07-04-2014, 11:45 AM
RE: Philco 37-690 - by morzh - 07-04-2014, 12:40 PM
RE: Philco 37-690 - by Ron Ramirez - 07-05-2014, 07:29 AM
RE: Philco 37-690 - by morzh - 07-05-2014, 09:40 AM
RE: Philco 37-690 - by Ron Ramirez - 07-17-2014, 08:55 PM
RE: Philco 37-690 - by Mondial - 07-17-2014, 09:56 PM
RE: Philco 37-690 - by Ron Ramirez - 07-18-2014, 05:51 AM
RE: Philco 37-690 - by Mondial - 07-18-2014, 06:43 AM
RE: Philco 37-690 - by Ron Ramirez - 07-18-2014, 07:26 AM
RE: Philco 37-690 - by Ron Ramirez - 07-18-2014, 07:30 AM
RE: Philco 37-690 - by Mondial - 07-18-2014, 08:02 AM
RE: Philco 37-690 - by morzh - 07-18-2014, 09:10 AM
RE: Philco 37-690 - by Ron Ramirez - 07-18-2014, 10:00 AM
RE: Philco 37-690 - by Phlogiston - 07-18-2014, 10:01 AM
RE: Philco 37-690 - by Mondial - 07-18-2014, 03:12 PM
RE: Philco 37-690 - by morzh - 07-18-2014, 04:03 PM
RE: Philco 37-690 - by y2kbruce - 07-18-2014, 05:37 PM
RE: Philco 37-690 - by Ron Ramirez - 07-18-2014, 05:48 PM
RE: Philco 37-690 - by morzh - 07-18-2014, 06:33 PM
RE: Philco 37-690 - by Ron Ramirez - 07-18-2014, 07:21 PM
RE: Philco 37-690 - by Ron Ramirez - 07-20-2014, 09:16 PM
RE: Philco 37-690 - by Ron Ramirez - 07-21-2014, 07:21 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
HiFi (Chifi) tube amp build - but my own design.
Tim, nice write up and thanks for sharing !! Sincerely Richardradiorich — 02:47 AM
HiFi (Chifi) tube amp build - but my own design.
Well, this was a real "Hum-Dinger" :lol: ! This will be kinda long, but hopefully it will help others having t...TV MAN — 01:55 AM
Shadow Meter Bulb
Phorum members, I am trying to find the bulb # for PHILCO Shadow Meter part number 45-2180 that is from a 37-640 chassis...georgetownjohn — 06:53 PM
Philco 41-608 changer coupler
3D-printing...short of machining, of course. Or molding.morzh — 05:20 PM
Philco 41-608 changer coupler
Thanks, Morzh. That solves the issue of the rubber pieces. Now, I need to find a way to replicate the pot metal piec...alangard — 05:07 PM
12' Philco
If it is 12', either Kareem or Andre would have to jump pretty high to look at the front panel. Kareem would have an e...morzh — 01:48 PM
12' Philco
And here's a story about the tires on the truck. Same "no-stoop" guy must have installed these! Take care a...GarySP — 01:17 PM
Hickok AC51 tube tester
I think they have only shown the secondaries of the transformer. Two of them feed the rectifiers' filaments.morzh — 12:58 PM
IF can wire size and Rubber mounts?
Arran If the wire inside cans is the gauges you mentioned, the sole reason for that would be mechanical, to stiffen t...morzh — 12:56 PM
12' Philco
Rod, Yes, I know, but the Giant Philco is not around anymore either, so I go by whoever was alive fairly recently. H...morzh — 12:54 PM

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

>