11-05-2014, 06:10 PM
While my 42-720 project is on hold, I've started on another Philco.
This time the subject is a Philco (Canada) model 39. This set is identical in appearance to the USA-made 41-722 Tropic.
You can see one here - just scroll down to model 41-722.
There are some chassis differences between the Canadian 39 and the Tropic 41-722. Besides the lack of rubber-covered wiring in the 39 (other than the IF transformer leads), the 39's power supply differs from the 41-722. The 39 uses an 80 rectifier and has the conventional bakelite block with the AC line connected to this block. The 41-722 uses an 84 rectifier, has no AC bypass bakelite block but does use two .003 uF caps between rectifier plates and ground.
So these differences alone make me appreciate the 39 more.
Here's a look under the hood.
[Image: http://www.philcoradio.com/images/phorum...e00001.jpg]
These are the kind of sets I like working on the least - because someone was in here before me, and did a very sloppy job. I intend to get rid of the rat's nest of wires that includes two electrolytics dangling in air, and restuff the original electrolytic cans with new electrolytics. I will also use some old paper capacitors, remove the old guts, and restuff them with new capacitors and install these in place under the chassis.
You can follow along by looking over the following schematics (warning: large files so long downloads on anything less than DSL):
Philco Canada 39 (409.6 kb)
Philco Tropic 41-722 (376.8 kb)
This time the subject is a Philco (Canada) model 39. This set is identical in appearance to the USA-made 41-722 Tropic.
You can see one here - just scroll down to model 41-722.
There are some chassis differences between the Canadian 39 and the Tropic 41-722. Besides the lack of rubber-covered wiring in the 39 (other than the IF transformer leads), the 39's power supply differs from the 41-722. The 39 uses an 80 rectifier and has the conventional bakelite block with the AC line connected to this block. The 41-722 uses an 84 rectifier, has no AC bypass bakelite block but does use two .003 uF caps between rectifier plates and ground.
So these differences alone make me appreciate the 39 more.
Here's a look under the hood.
[Image: http://www.philcoradio.com/images/phorum...e00001.jpg]
These are the kind of sets I like working on the least - because someone was in here before me, and did a very sloppy job. I intend to get rid of the rat's nest of wires that includes two electrolytics dangling in air, and restuff the original electrolytic cans with new electrolytics. I will also use some old paper capacitors, remove the old guts, and restuff them with new capacitors and install these in place under the chassis.
You can follow along by looking over the following schematics (warning: large files so long downloads on anything less than DSL):
Philco Canada 39 (409.6 kb)
Philco Tropic 41-722 (376.8 kb)
--
Ron Ramirez
Ferdinand IN