model 49-602 - Printable Version
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model 49-602 - truePhilco - 03-28-2020
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
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!
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!
RE: model 49-602 - RodB - 03-28-2020
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 The one with the resistor may have already been replaced by someone before you.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
RE: model 49-602 - RodB - 03-28-2020
That would be a 1N4007 silicon diode.
RE: model 49-602 - rfeenstra - 03-28-2020
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!
RE: model 49-602 - Radioroslyn - 03-28-2020
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.
RE: model 49-602 - truePhilco - 03-29-2020
Thanks all, to work I go. 