Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12, 2025) x

Thread Closed

model 49-602
#1

I need some help on this model. I wanted to get one of each color
in this model, I thought I
finally got them, the Radio Gallery shows I do.
https://philcoradio.com/gallery2/1949a/#Model_49-602
But seen on the schematic two more other colors
I have not seen (ivory, maroon). Let me know if you have.
https://philcoradio.com/library/download/service%20info/yearbooks/1948-1949/split/Part62-Philco%20Home%20Radio%20Yearbook%201948-1949.pdf

But now, on getting all three working. The green one is working and
looking how I like to see them. I know I will not get the ones on the left or
right to look like this. I have already put some new caps on the one on the left. The question
I have for now is, on the bottom left corner of each (black, orange and blue in color) there is what
I think is a rectifier? Please tell me about them, what they do or for?
The ones on left and on right have a resistor on them (mid. dose not)
do you know why? I want to get the ones on the ends 
up and running and have one in each color!


Attached Files Image(s)
   
#2

Hey True, those are selenium rectifiers in the power supply circuit. You will want to replace them with a silicon diode in series with a 47 ohm resistor. The one with the resistor may have already been replaced by someone before you. Some people just use the terminals of the old one to support the new silicon diode. I usually replace the rectifier with a terminal strip then mount the silicon diode on the strip. The reason for the resistor is to drop the voltage back to the desired level. Selenium rectifiers have a higher internal resistance than a silicon diode. You may have to experiment with the resistor value. BTW be very wary of burning up the selenium rectifier, it will fill the room with a terrible odor.

Rod
#3

That would be a 1N4007 silicon diode.
#4

Selenium rectifier. CR100 on the schematic Looks like the right radio has a silicone diode jumpered across. The schematic shows a 60 ohm resistor in series with the rectifier. Is that the resistor you are referring to?

Selenium rectifiers are problematic and should be replaced with a silicone diode of proper voltage rating. The output voltage will be higher so an additional dropping resistor of appropriate values should be added to bring the voltage down to the correct value. I've never worked on one of these radios but have had to replace selenium rectifiers. I hear they smell pretty bad when they go!
#5

TP
This is what you are looking for.
Replace the selenium rectifier w/a silicon diode. Connect your set thru a variac to the ac power w/the variac turned down. turn it on. Look @ the right side of R101B w/a voltmeter. That voltage needs to be right at 7.5vdc. Turn up the variac till you get to 7.5v note the ac input voltage - your line volt voltage and that's how much of a drop you need across R-100. Adjust the value of R-100 till you get to 7.5vdc @ your line voltage.

If the 7.5v line in the set is too high it will burn out the tube's filament prematurely if it's too low poor performance/local oscillator won't run.
The hv line (90v) isn't particularly critical 10v either way is not got to be an issue.

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got it!

Terry
#6

Thanks all, to work I go. Icon_think




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
54C Complete Teardown/Rebuild
Hello Roy, here is this one sincerely Richardradiorich — 12:45 AM
54C Complete Teardown/Rebuild
Richard, Had grabbed it already but thank you just the same.  I find myself wanting to find some way to block out the...glyphmon — 12:03 AM
54C Complete Teardown/Rebuild
Hello roy, here is a link to the schematic . Sincerely Richardradiorich — 11:54 PM
54C Complete Teardown/Rebuild
Richard, The Silvertone 2014 also is a transformerless set, so I am incorporating a 1:1 600 ohm audio isolation transfo...glyphmon — 11:37 PM
Preliminary work on wife's Silvertone 2014
Did an alignment today which was interesting.  IF alignment went great, almost all was already spot-on.  Adjusting on th...glyphmon — 11:35 PM
54C Complete Teardown/Rebuild
The main problem with adding a Bluetooth input is that this set lacks a traditional power transformer to isolate it from...radiorich — 11:19 PM
54C Cabinet Refinish
I started stripping this cabinet before it got super chilly out because I knew I wasn't going to be able to work on ...glyphmon — 11:18 PM
54C Complete Teardown/Rebuild
While I'm waiting to wrap up the final steps on my wife's Silvertone 2014, I started disassembly on the next project.  O...glyphmon — 11:07 PM
Preliminary work on wife's Silvertone 2014
Hello roy, that great news glad it worked out for you !! Sincerely Richardradiorich — 10:50 PM
Preliminary work on wife's Silvertone 2014
Safety caps arrived today.  Soldered one in and had a successful first power-up.  No magic smoke escaped and it tunes in...glyphmon — 09:53 PM

[-]
Who's Online
There are currently 1903 online users. [Complete List]
» 1 Member(s) | 1902 Guest(s)
Avatar

>