Philco Canada 39 or 41-722 Tropic

Philco Canada 39 or 41-722 Tropic - Printable Version

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RE: Philco Canada 39 or 41-722 Tropic - Kekoa - 11-09-2014

You got them, Ron. Send me a PM with your address, and I'll drop them in the mail. You want the bumblebee's, too?

RE: Philco Canada 39 or 41-722 Tropic - radiohenry - 11-09-2014

Ron,
I appreciate the help.
Thanks,
Henry

RE: Philco Canada 39 or 41-722 Tropic - Ron Ramirez - 11-09-2014

Okay!

A lot of progress has been made today. But first, let me back up to the IF transformers.

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00007.jpg]

The rebuilt 1st IF is on the left. The 2nd IF can is in the middle, followed by the actual 2nd IF transformer, and the hardware for same.

Another photo of the 1st IF transformer:

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00011.jpg]

Notice the J-B Weld on the can. As I mentioned in a previous post, the metal "keepers" (I don't know what the proper term for these would be) dig into the aluminum when they are screwed on. This keeps the IF transformer "guts" in place. It also damages the can, and can cause the can to break where these parts dig into the aluminum. I added the J-B Weld after the upper hole partially broke upon removing the "keeper".

Here's one of the electrolytics:

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00008.jpg]

This is the one which will have the original thick paper cover reinstalled over it...

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00009.jpg]

...and how it looks once the cover is back in place.

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00010.jpg]

Here's the other electrolytic. Yes, the gluing job is sloppy. I'm open to suggestions as to how to better do this.

RE: Philco Canada 39 or 41-722 Tropic - Ron Ramirez - 11-09-2014

Let me show you how to reassemble the 2nd IF transformer. The procedure is the same for any of these types of Philco IF transformers, and disassembly is the reverse:

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00012.jpg]

Having rewired this IF transformer, it is ready for reinstallation in its aluminum can shield. I should mention at this point that the hair-thin wires of each IF winding are usually wrapped around the ends of each lead wire, so be careful when removing the old wires from the transformer unit.

The unit is encased in wax, and includes two fixed mica capacitors; one in parallel with each IF winding (primary and secondary). The transformer is tuned with two iron slugs, connected to threaded brass rods, which move the slugs in and out of the respective windings.

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00013.jpg]

Now that the transformer assembly is back in the can, the next step will be to reinstall the "keepers" to hold the transformer in place inside the can.

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00014.jpg]

The "keepers" and the two adjusters, which screw onto the ends of the threaded brass rods and make the IF transformers easier to tune. 1938 Philco IF transformers do not have the additional adjusters; the brass rods have slots on the ends for a tiny screwdriver to fit into.

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00015.jpg]

One "keeper" is threaded onto one of the brass rods.

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00016.jpg]

Now the other "keeper" is threaded onto the other rod. A tiny screwdriver can be used to get these started.

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00017.jpg]

But to tighten them down, you need to use a pair of small needle-nose pliers. Be careful doing this - watch each rod to make sure they do not screw inward as you tighten the "keepers".

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00018.jpg]

Now the keepers are tight, and the IF transformer will not come loose.

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00019.jpg]

In order to get the innards out of the can, you have to turn the brass rods clockwise enough so that the rods will clear the can for removal. Do not turn these in too far! I turned these in 10 turns which only left a little bit of rod sticking up on each adjuster; this was enough to allow the inner assembly to be removed.

Now that it is reassembled, turn each rod counterclockwise 10 turns. Keep in mind that you will have to realign the radio anyway, but counting the turns allows you to return the adjustment rods to approximately where they were before you started.

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00020.jpg]

The final step is to reinstall the small threaded adjusters over the little brass adjusting rods. Use a pair of needle nose Vise-Grips to hold the rod in place, then gently screw the adjuster onto the end of the rod. Do not tighten! Just screw them on until they are snug; that is enough.

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00021.jpg]

The transformer now has both adjusters in place, and is ready to reinstall on the chassis.

RE: Philco Canada 39 or 41-722 Tropic - Ron Ramirez - 11-09-2014

I reinstalled both IF transformers, both electrolytics, and wired them all up.

I then installed the last four paper capacitors and another resistor, thus wiring the volume and tone controls back into the circuit.

Radiohenry, I took a few photos per your request:

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00022.jpg]

The paper caps and one resistor all connected to the volume and tone controls.

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00023.jpg]

Another angle of the same thing.

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00024.jpg]

Another view, not quite as close.

Henry, if you need larger photos and/or the 41-722 service info, send me a PM.

RE: Philco Canada 39 or 41-722 Tropic - Ron Ramirez - 11-09-2014

Let's review by looking under the chassis again, as it looked when I began:

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00001.jpg]

Here is how things look now:

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00025.jpg]

Things are much neater down here now. Restuffing the original electrolytic cans made a big difference, and opened up some room underneath.

I had to rebuild both dial lamp sockets, also.

I also installed a speaker connector and a new speaker wiring harness made from three new cloth-covered wires (the type sold by Radio Daze).

The chassis was missing four of its six tubes. Of the two that remained, one was a 6D6 in place of the original 78. The other was a 75. I went to my tube stash and found six tubes of the (mostly) proper type, and installed these, removing the 6D6 and the 75 that were in place on the chassis. I did not have a 7A7. I found that a 7B7 could be used as a substitute. I had a few spare 7B7 tubes, so one was installed in the radio.

RE: Philco Canada 39 or 41-722 Tropic - Ron Ramirez - 11-09-2014

I t ' s A l i v e . . . .

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00026.jpg]

Tonight after supper, I found six tubes to install in the radio, as mentioned in my previous post, and fired it up. Within seconds, I could hear my SSTRAN coming in loud and clear! Icon_thumbup

[Image: http://www.philcoradio.com/images/phorum/41-722/Image00027.jpg]

I'm using the speaker from my 42-720 temporarily as a test speaker. Volume is good and tone sounds good as well; this set should sound very good once it is back in the cabinet.

I still need to install a 5 pF capacitor, part (10A) on the 41-722 schematic. I found some on eBay and bought a small quantity so as not to have to spend a lot of $$$ on a big order. But the radio is working on AM, anyway, without it.

I'll give the set a complete alignment, and try out the SW bands, tomorrow.

We're not totally out of the woods yet on this one, though. Besides the missing 5 pF mica cap, the tuning control feels very rough. It is a dual shaft control and appears to be a ball bearing unit; when turning either the inner or outer shaft, it feels like the bearings have badly worn and are more like rough pebbles. I hope that is not the case; I am hoping that a disassembly, thorough cleaning, and new grease will take care of the issue. We shall see.

RE: Philco Canada 39 or 41-722 Tropic - Warren - 11-09-2014

Hey Ron, when I did my electrolytic cans I made a little "trough" around the edge of the bottom part and then the top large part fit down inside the trough fitting inside the wider bottom section. I then put some glue in the trough and slid the two sections together letting the glue dry, It looked like no one ever opened it. Actually I took photos of it and posted on the phorum . Here is the link... http://philcoradio.com/phorum/showthread.php?tid=7533

RE: Philco Canada 39 or 41-722 Tropic - Arran - 11-10-2014

Ron;
The method that Bob Andersen uses is to uncrimp the bottom of the electrolytic can, which I tried on a junk can I had laying around with limited success, then to extract the old innards with a cork screw and a heat gun. Then you replace the old caps with new radial lead jobs and run the leads through small holes drilled in the base, replace the can, recrimp the can. He has had great success with this method, I have not, and it could be a pain should the replacements themselves need replacement in the future. A variation on this is to file the crimp off the bottom so the can can be removed and replaced on the base, but then both the ground ring and the can have to be glued onto the insulated base.
The method Mike "Morzh" uses seems to work well, he cuts the can maybe 1/4-1/2'' higher above the base, this leaves a flange so you can fit the rest of the can over top, I think he uses a pipe cutter for this, the rest of his procedure is the same as the two above as far as I can tell. One method that I have used is to use a pipe cutter to cut the can further up, and to resecure the top with aluminium duct tape, actually I haven't use this on a twist lock can yet, it was on an axial lead type with a cardboard sleeve.
One I have used on electrolytic cans, ones with a threaded base in a mid 30's Rogers set, was to couple the two ends together internally with a plastic pipe fitting, though you could use anything that fits the internal diameter of the cans, and then used hot glue to glue the can sections to the pipe fittings. I did not cut these cans, someone else did very crudely with a hacksaw at a random height, and not even in a straight line, so I had to wrap tap around the top and bottom sections and file them down to the edge of the tape so they would line up square. I lost about 1/4'' to 3/8'' out of the height of each can, they also used epoxy or some sort of rubber cement to glue the cans together, one of which broke apart whilst servicing the chassis, so I really had no choice with how to repair these.
Regards
Arran

RE: Philco Canada 39 or 41-722 Tropic - Ron Ramirez - 11-10-2014

Warren

That sounds great! I moved your thread on restuffing to the Important Restoration Topics > Other Helpful Restoration Topics section, and I also asked a question about your procedure there.

Meanwhile, back at the Radio Ranch...

I could not get the ball bearing drive completely apart, so I tried to apply some lithium grease and put it back in place. The tuning still feels rough, but it looks like I will have to live with it. I also have a similar 41-758 Tropic (eight tubes instead of six) which has the same ball bearing drive; it is smooth, no roughness.

The mica caps I bought online arrived today. That was fast! I installed a 5 pF cap to replace part (10A) so the electronic restoration is complete.

I did align the set and it plays well on all three bands. It is especially sensitive on AM; it picks up several stations with just a two foot piece of wire. I never have erected my planned outdoor longwire, and the weather will turn cold tomorrow with the arrival of our first arctic blast of the season. Maybe next spring?

The cabinet is loose on the sides where they meet the base of the cabinet; I will glue it back together next. Those Canadians put a nice sheet of asbestos under the chassis! Icon_eek

Those crazy Canadians (no offense intended to any actual Canadians including Arran, Dan, or anyone else)...I wonder if Red Green did that as a joke? Icon_lolno

RE: Philco Canada 39 or 41-722 Tropic - radiohenry - 11-10-2014

Hi Ron,
Thanks for the pics. I will try to get the radio back on the bench and refresh myself with the issues.
Henry

RE: Philco Canada 39 or 41-722 Tropic - radiohenry - 11-10-2014

Ron,
I didn't pull the radio out yet but I did look at what notes I made and am really confused now. So I will definately need to look at the radio which by the way did not make a sound.
I do have a question though. To the right of the filter in the middle is a group of 3 wires tied together. Blue, white and green. Are all three spliced together? I do see a greeen wire going over to the tube socket on the right and am not sure if that is part of the group but I do not see the white or blue exit. Please explain that one.
Thanks,
Henry

RE: Philco Canada 39 or 41-722 Tropic - Ron Ramirez - 11-10-2014

Henry

If you are referring to the three cloth-covered wires, those are the speaker leads. No, they are not spliced together. They go through a hole in the chassis at the point where you see the knot.

Again, if you need larger photos and/or the 41-722 service info, send me a PM.

RE: Philco Canada 39 or 41-722 Tropic - NostalgiaRadioTime - 11-10-2014

Really enjoying watching your progress, Ron!

I was surprised to find asbestos under the chassis of my model 59C, too. Then, I was working on an RCA model 34-X at the same time and upon pulling the chassis what did I find? Yep, more asbestos.

I'm still holding my breath. Icon_lol

RE: Philco Canada 39 or 41-722 Tropic - radiohenry - 11-10-2014

Ron,
Thanks for clearing that up. If I had the radio on the bench that would have been clear. I will go check my Riders to see if the 41-722 data is there if not a pm will be coming .
Thanks,
Henry