Philco 604C Electronic Restoration - Printable Version
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Philco 604C Electronic Restoration - Ron Ramirez - 06-05-2015
Here we go again...
My subject this time is not a Tropic, nor is it a Fisher stereo receiver.
It is a Philco model 604C from mid-1936.
[Image: http://www.philcoradio.com/images/phorum/604C/604_00001.jpg]
The 604 is a five tube AC/DC table model radio.
[Image: http://www.philcoradio.com/images/phorum/604C/604_00002.jpg]
It is unusual in that it has the dial and controls on top, with a Bakelite control panel mounted on a cabinet made of Walnut veneer.
Some chassis shots:
[Image: http://www.philcoradio.com/images/phorum/604C/604_00003.jpg]
[Image: http://www.philcoradio.com/images/phorum/604C/604_00004.jpg]
[Image: http://www.philcoradio.com/images/phorum/604C/604_00005.jpg]
RE: Philco 604C Electronic Restoration - Ron Ramirez - 06-05-2015
I forgot to mention: In case you are wondering the differences between the 604C and the later 37-604C, they are as follows:
* The 604 uses standard base tubes. The 37-604 uses octals.
* The 604 only has a three-screw terminal strip providing connections to a longwire antenna as well as two screws for Philco's High Efficiency Aerial. The 37-604 has five screw terminals - two (RED and BLK) forPhilco's High Efficiency Aerial, one for ground (!), and two more used as "shorting" terminals. See the 37-604 schematic for more info.
Well, a few days ago, I pulled the chassis out of the cabinet and dived in.
[Image: http://www.philcoradio.com/images/phorum/604C/604_00006.jpg]
Removing the screws holding the bottom chassis cover in place...
[Image: http://www.philcoradio.com/images/phorum/604C/604_00007.jpg]
A look underneath. As you can see, someone else was in here before me. I will try to make this look neater than it does now.
[Image: http://www.philcoradio.com/images/phorum/604C/604_00008.jpg]
A closer look at the antenna screw terminals. As you can see, the terminal board is broken.
Now let's take a close look at the dial scale...
[Image: http://www.philcoradio.com/images/phorum/604C/604_00009.jpg]
[Image: http://www.philcoradio.com/images/phorum/604C/604_00010.jpg]
Broken in two places, and part of the numbering is worn off. Fortunately, Radio Daze sells a 37-604 replica dial scale. I guess I will have to purchase one.
RE: Philco 604C Electronic Restoration - Ron Ramirez - 06-05-2015
Last night, I began actually replacing components.
This set has its own unique RF unit which is a metal box that houses the band switch, three paper capacitors, and some wire. Coils are mounted on top of this unit, and there are also a couple coils inside.
You think a 1937 Philco RF unit is difficult to service? Take a look at this:
[Image: http://www.philcoradio.com/images/phorum/604C/604_00011.jpg]
This photo was taken after I had replaced all three paper caps. No, I'm not bothering to restuff the old paper caps in this set. It was difficult enough to get the old caps out and the new ones in without damaging anything. Wow! That was tough!
RE: Philco 604C Electronic Restoration - mikethedruid - 06-05-2015
Nice job on those caps, Ron. Looks like one of those jobs were one uses 2 pairs of long needle nose pliers. Been there enough times myself. Very nicely done.
RE: Philco 604C Electronic Restoration - Radioroslyn - 06-05-2015
Hey Ron,
I've got one of those 604C's too. The dial scale was replaced before I got it and the color of it isn't the greatest. Sort of a pale yellow. Wouldn't mind finding a more amber/orange one. Like the pointer.
Someone replaced the caps in the power supply. Plays rather well and is sensitive on the sw band even picks up strong stations with out an antenna.
The tuning condenser is a bit loose I think there is a rubber affair that hold it steady. Haven't done anything about it ,the tuning knob keeps it pretty well centered.
For what it's worth I did make up the replacement bias cell with a watch cell (old one was dead). Didn't seem to make any difference.
Careful working on the bottom as it is easy to smooch the rf coils.
Good player!
Terry
RE: Philco 604C Electronic Restoration - Ron Ramirez - 06-05-2015
(06-05-2015, 09:10 PM)mikethedruid Wrote:
Thanks!
Radioroslyn Wrote:The dial scale was replaced before I got it and the color of it isn't the greatest. Sort of a pale yellow.
Well, if they are still producing dial scales in pale yellow as they used to...well, what else can I do? I think I'd rather have a pale yellow dial at this point than a broken dial with half of the numbers rubbed off.
Yes, the tuning condenser is a bit loose on mine as well. I will have to take the speaker loose to get to one of the mounting screws for the multi-section electrolytic can, which I intend to restuff with new electrolytics rather than have new ones hanging underneath as they currently are.
This won't be an easy set to repair. I'm just glad it does not have any rubber-covered wire as it is too old for that, fortunately!
RE: Philco 604C Electronic Restoration - Ron Ramirez - 06-14-2015
Since I last posted in this thread nine days ago, I have rebuilt all four of the bakelite block capacitors and have replaced about 2/3 of the under-chassis paper capacitors and resistors.
This weekend, I decided to tackle the job I had been dreading: restuffing the metal can which houses the electrolytic capacitors.
It is underneath the tuning condenser, and is held in place by two bolts. One is easily accessible from behind the tuning condenser at the back of the chassis...
[Image: http://www.philcoradio.com/images/phorum/604C/604_00012.jpg]
[Image: http://www.philcoradio.com/images/phorum/604C/604_00015.jpg]
...and the other bolt is hidden by the speaker. Which meant that the speaker had to be unbolted and pulled out of the way.
[Image: http://www.philcoradio.com/images/phorum/604C/604_00013.jpg]
Once the speaker was moved out of the way, the other bolt holding the electrolytic capacitor can becomes visible - and accessible:
[Image: http://www.philcoradio.com/images/phorum/604C/604_00014.jpg]
Oh, by the way, I removed the tuning shaft, dial assembly, and the pot metal housing for the dial lamps to make access under the chassis easier. The dial is going to have to be replaced anyhow, so the dial assembly needed to be removed.
RE: Philco 604C Electronic Restoration - Ron Ramirez - 06-14-2015
Once the two bolts were removed, it was a matter of carefully pulling the electrolytic capacitor can out and away from the chassis.
Here's how it looked:
[Image: http://www.philcoradio.com/images/phorum/604C/604_00016.jpg]
Someone had cut all but one of the wires, and had wired individual electrolytics under the chassis. I am going to stuff new electrolytics inside the original can, using new wires.
First, the original guts had to be removed. I unfolded two of the four tiny tabs holding the cover in place, and set it aside. Here's what I found inside:
[Image: http://www.philcoradio.com/images/phorum/604C/604_00017.jpg]
I was able to easily pry the old unit out of the can.
Next, I prepared four new electrolytics to go inside the can:
[Image: http://www.philcoradio.com/images/phorum/604C/604_00018.jpg]
I added new wires to the four positive ends. All of the negative ends are connected to B- so all of the negative leads were twisted together and soldered to a black wire.
[Image: http://www.philcoradio.com/images/phorum/604C/604_00019.jpg]
I then used some thick paper to make a new insulator to go inside the can, to help prevent anything from touching the chassis. I also taped up the exposed negative wires with electrical tape, so it should be fine.
The rebuilt can:
[Image: http://www.philcoradio.com/images/phorum/604C/604_00020.jpg]
and how it looks mounted back on the radio - just like it did originally.
[Image: http://www.philcoradio.com/images/phorum/604C/604_00022.jpg]
Edit: This job turned out to be much easier than I thought it would be. It was no big deal to remove the two bolts holding the speaker and to move the speaker aside enough to get to the other bolt holding the electrolytic can in place.
RE: Philco 604C Electronic Restoration - Ron Ramirez - 06-14-2015
I used the same colors for each electrolytic capacitor wire as called for on the 604 schematic.
Here's how the chassis looks underneath now:
[Image: http://www.philcoradio.com/images/phorum/604C/604_00021.jpg]
There are still a few more components to be replaced. I'll also add a new cloth-covered AC cord. It won't be long now, and this one will be ready to try out.
I still have to order a new dial scale. I'll do that this week if I don't forget.
RE: Philco 604C Electronic Restoration - Crist Rigotti - 06-14-2015
Very nice Ron! Thanks for the details.
RE: Philco 604C Electronic Restoration - sam - 06-14-2015
great job ron
RE: Philco 604C Electronic Restoration - Ron Ramirez - 06-15-2015
Thanks, Sam (and Crist, too!).
Tonight, I finished replacing the resistors and capacitors. Now, I have to do some repairs to the dial lamp sockets including rebuilding the contacts...figure out how to glue the three-terminal antenna screw terminal board...add an AC cord and it should be ready to try out later this week.
RE: Philco 604C Electronic Restoration - Arran - 06-17-2015
Hmm; I've never heard of "Richey" brand electrolytic capacitors before, I'm not saying that they are a bad make but a lot of mystery brand ones are. I probably would have restuffed that capacitor can as well, but it's more then likely that I would have used a name brand, rated at 105 C, and with radial leads since they are easier to find and they are going to be stuffed into a can anyhow.
Regards
Arran
RE: Philco 604C Electronic Restoration - Ron Ramirez - 06-17-2015
Arran
I had bought a large quantity of those from Bob's Antique Radios some time back, and I'm certainly not going to throw them away now even though I know Nichicons are better. Once the Richeys have been used up, then I'll restock with Nichicons.
RE: Philco 604C Electronic Restoration - KCMike - 06-17-2015
As usual nice work Ron. That cabinet looks to be in real good shape also, and should look good when all back together.