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

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

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 The one with the resistor may have already been replaced by someone before you.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!

Terry
#6

Thanks all, to work I go. Icon_think




Users browsing this thread:
[-]
Recent Posts
Zenith H725
hello Ed, how about that speacial tape used for ducting it's like foil or how about thin piece of aluminum roof flash...radiorich — 12:19 AM
Zenith H725
Ed; One material that I have seen, but never tried for this was material for making exhaust gaskets, it's similar to ...Arran — 11:42 PM
Zenith H725
I just remembered, I have some hi temp silicone rubber material which could do the trick. Or a piece of FR4 laminate. Th...EdHolland — 08:39 PM
Zenith H725
The PSU filter cap arrived today (thank you USPS!) so I will work on that later. Meanwhile, I have the dial, speaker...EdHolland — 06:42 PM
Philco 610B oscillator wiring
Thanks Terry. After checking my notes I think I recorded about -10v at the 6A7 G4/control grid. The screen grid (G3 &...Tubester — 05:59 PM
The list of my radio & TV collection!
Magical chords of forgotten melodies, old nostalgic music on an old radio... Saturday night blues on the Mid-Waves on an...RadioSvit — 12:20 PM
Philco 42-345 Restoration/Repair
Thank you MrFixr55 the issue with this radio is that the internal coil antenna is missing and there was a wire in its pl...osanders0311 — 11:34 AM
Philco 610B oscillator wiring
Regarding the oscillator circuit which is comprised of the 6A7's cathode, control grid, and screen grid. These elements ...Radioroslyn — 10:33 AM
Philco 42-345 Restoration/Repair
Hi OSanders, First off, welcome to the Philco Phorum where Phine Phamily-Phriendly Pholks Phull of Philco Phacts and P...MrFixr55 — 08:41 AM
Philco 42-345 Restoration/Repair
Today I've been reading through the site trying to learn more about this radio. I also soldered the lose power cord cabl...osanders0311 — 08:24 PM

[-]
Who's Online
There are currently 2406 online users. [Complete List]
» 1 Member(s) | 2405 Guest(s)
Avatar

>