of going to Kutztown was a Firestone 4C3 portable (Sam gave it to me). I was really beat after I got back but after a little rest I thought I'd have a look at it. Popped it apart to find a missing 117Z6 (I guess I really didn't find it) and 2 tubes switched places. Checked the filaments two flunked (1A7 and 1H5) so replaced those, restuffed the filter can, and replaced paper caps. Couldn't put my hands on a 117Z6 so used a 1N4007 in it's stead. Powered it up on a variac, I wanted make sure that the 1N4007 wasn't going to deliver too much dc to the filament string (9v@50ma). I found later that my line voltage is about 114v which rendered 8v to the string (too low) so had to juggle some resistors to get about 9.5v. Sorted a few other minor issues and listened to some otr from a local station.
Centered the dial pointer and did a rf and if alignment. Don't really like the circuit, when it's plugged in to the socket it doesn't switch the ac line off. This means that the 117Z6 is on all the time it's plugged in. And it's making hv too which keeps the filters charged. May have to add a little lamp switch to the ac cord to kill off everything. Next time I'll in the bakery department I'll be looking for some tasty treats in a large clear plastic container, the dial cover it missing. http://www.nostalgiaair.org/pagesbymodel...006226.pdf
Looks like this http://www.radiomuseum.org/r/firestone_4c3.html
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!
Yup ur right. The real problem is I didn't have the 117Z6 and the 1n4007 doesn't have a heater. It's on all the time. I know I've got a couple from the 42-*** portables just couldn't find them last night.
Have got it apart now, found some plastic for the dial cover but will snap a few pics when I get it back together.
Got it back together. Boy that escutcheon is a bear to get in and out. #10 escutcheon/#6 cabinet. The camera doesn't like my bakery plastic dial cover looks a little foggy but it it isn't.
Now that I have it back in one piece one more thing to sort. With the volume control all the way down it's playing kinda loud. Have look in to that.
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
(This post was last modified: 05-14-2017, 10:04 PM by Radioroslyn.)
VC showed about 2K when turned all the way CCW and the same when turned all the way CW and measured from the other end. Cleaning didn't help. It took a few tries to find one that didn't advance too much at low levels indicating the wrong taper but found a suitable replacement.
For a portable set it plays really loud, sounds like it has a 50L6 rather than a 3Q5.
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!
Tnx Kman!
Tube came in the other day so I unsolder the diode and installed the 117Z6 and no dice... So measured voltage and found that the filament string was at 7.5v, not good. Portables with low volt/low current tubes need to be pretty close to the proper filament voltage . In this case it require 9-9.5v to operate. Ended up adding a 20K@2w in parallel with the 1700 ohm filament dropping resistor giving me 9.1v.
As an aside my line volt here is fairly low @113vac
On the schematic it shows a dial light (used in ac operation only) but this set shows no sign of having one. I wired up a bulb and it does work just have to fashion a mounting bracket.
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!
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
(This post was last modified: 05-23-2017, 10:18 AM by Radioroslyn.)
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!
