[Joeztech]

Herb;

Thanks for the Christmas wishes. Yes I was born somewhat earlier. My HS graduation was in 1961.

After I finished the IF alignment, I tried the various bands and the radio is working with signals on each band. You can't keep a good radio down! 73 years old and still going!

Joe
KC5LY

[Radioroslyn]

Hey Joe
Very nice work!!! Chassis looks super! I know it take a lot of time and resolve to replace the rubber wire and get everything wired back up again. If you wanted to listen in on some 80 or 40mtr action you could add a little feedback to the IF amp to act as a bfo. It's much easier with tubes with a grid cap. With those you can just slip a little wire under the cap and wrap it around the tube. This will give so feedback between the grid and plate.
Great job and Merry Christmas!!!
Terry N3GTE

[Joeztech]

Radioroslyn;

Thanks for the compliments! Yes a nice BFO would be nice for alternate modulation type signals. I might do something along those lines. I have a few single gang variable air capacitors that I could use to create something for that purpose.

I discovered a minor problem earlier today. If I had the volume set at a certain level, and turned the tone control from end to end it killed the sound completely at anything past 1/2 way toward the plate circuit of the 1st. audio tube. It was not the control, verified with power off and using the ohm meter. It turned out to be another one of the .01mFd capacitors that had shorted (part item 52) which someone had installed years ago. It should have been a .006mFd in order for the tone control to work properly. I was out of .01 capacitors but had a few that I had removed from the set. I found two that were not shorted or leaky and put them in series which makes a .005mFd. I also had a 1000pFd silver mica capacitor and added that across the two in series to make a .006mFd. I took the offending shorted capacitor out of the set and installed the cludged capacitor in its place. I turned the radio back on and Presto! No more loss of audio as the tone control is turned end to end. An added plus is that it also now really does change the tone like it should.

I notice an odd popping sound as the set is warming up. It may be due to one of the audio tubes, but it goes away after the sound comes up and does not return until I turn it on from a cold start again. I hope it is not some problem developing with the field core of the speaker.

The radio sounds so good right now that I may just let it go until I find it becomes a real problem that is obvious to find. I might monitor the B+ to see if there is any fluctuation there as the radio is warming up from a cold start. That would probably show up easiest at C77 if there is an intermittent short or open happening during warm-up.

I went ahead and installed the new push-buttons on the front that I had ordered. They were loose and popped off when pushing adjacent push-buttons, so single folded layer of Scotch magic tape over the button shaft was enough material added to make the push-buttons stay on their shafts.

Joe
KC5LY

[BrendaAnnD]

If you still have any old caps in there, you really should replace them before powering the set up again. That tone control should be your ultimate clue that all the caps are bad. This is likely what is causing your start-up crackling. This could also be caused by a noisy resistor.

[Joeztech]

Yes I still have some more that will be replaced, just have not all the necessary parts on hand right now. So far two of the old type capacitors have turned out to be shorted. They will be replaced once I get all the parts on hand. There are a few in the RF circuit not replaced yet and there are a few resistors that have not been replaced either. I think I have most of those on hand and will concentrate on getting those taken care of too. So many resistors in the set have turned out to be significantly over value already. I am using 5% tolerance resistors to replace them. The film capacitors are either Mylar metalized film types or Polypropylene metalized film types. The only exception were the capacitors in the AC input circuit which I replaced using some ceramic disc Y2 types made for such service. They are far safer than the OEM types that were contained in the bakelite enclosed OEM units. If one of the caps yet to be replaced stops the noise, I will indeed be happy.

Joe
KC5LY

[Joeztech]

It turned out that the popping sound I heard was the second electrolytic capacitor in the B+ string which I had already replaced. This one follows the field core of the speaker. It is intermittently shorting during warm-up, so I will be ordering another one. This time I will get one that significantly exceeds the voltage rating of the original unit. The 80 rectifier puts out voltage before the rest of the tubes begin to conduct. It would be even worse if the power supply had solid state rectifiers instead of a tube rectifier. It is time to send a new order to Mouser Electronics. I will not be turning the radio on again until I have this problem solved.

Joe

[hsusmann]

Joeztech,

Do you have a variac in line with the line cord? I find
that very useful for these situations

Herb S.

[Joeztech]

Herb;

No, I do not currently have a variac. I may get one eventually if I find one with a reasonable price. I have used an incandescent lamp in series with power before to evaluate whether a unit has serious problems in its power supply. I will be looking for a variac at local swap meets. I ordered some replacement caps from www.tubesandmore.com including coupling caps and another electrolytic with a higher voltage rating. Tubes and more seems to have more electrolytics for tube circuits at a reasonable price than others including Digikey and Mouser. Their prices for coupling caps with a 630V rating are quite decent too.

They have a Hammond 125E push-pull audio transformer for $40.77 with multiple speaker output taps that I believe is closer to the OEM Philco transformer, so after I get all the other issues taken care of I may order one of those to replace the Stancor replacement transformer that is in the radio now.

I might build up an AC input voltage bucking adapter to reduce the nominal 120-125VAC power seen at our house these days. These older radios were not designed for modern higher voltage situations. I found a good chassis mount AC input fuse holder available at Radio Shack. Since I already have an existing hole in the rear of the chassis where I removed the phono input, I may just add a fuse holder there for the AC input circuit. I definitely want to protect all the hard work that has gone into this radio. IMO lack of an AC input fuse is a serious design error.

Joe
KC5LY

[hsusmann]

Joeztech,

OK on the variac. I know they can be pricey. I didn't
pay much for mine, forget where I got it, I think a hamfest
many years ago. Definitely a good thing to have for
this hobby!

OK also on tubesandmore.com I have ordered things from
them in the past. Another option is Mark Oppat in Michigan
(oldradioparts.net). Don't know if you know about him or
not.

OK also on the high modern line voltages. This is definitely
a problem. I have not come up with a good solution
besides running my radios on my variac

You are right also about the fuses. Years ago I remember
having a special wall plug that had two 3AG type fuses
built into the plug. I don't know if these are still available
or not but I should look again. I've been mounting inline
fuses under the chassis lately.

Herb S.

[BrendaAnnD]

Joe,

I think I may have a small variac, suitable for at least table radios and small chassis consoles (not sure about more than that). If I run across it in that great recycling site that is my shop, I'll pack it up for you.

[Eric Adams]

Joe, check out http://www.justradios.com/ Great prices on any capacitor you'll need. Great quality also. I've been using them for a while now.

[Joeztech]

Thank you all for the information you are providing and Brenda, thank you for the offer of the variac. Somewhere around here I have the article on how to build the bucking transformer I think. It was written by an amateur radio operator and he did not do a schematic of his design, just verbal and some drawings of parts and connections that way. I would have to study it a while and draw up a schematic for posterity. I think he used a RS filament transformer in the design. Of course such an item has its limits on power handling just like a variac. This particular radio is supposed to consume 110 watts of power from a 110-115VAC line.

Ah yes, the All-American-Five. They graced many a home in years past. Nearly every home had one, which was often combined with an electric alarm clock. We had a Westinghouse unit. I listened to The Lone Ranger, The Shadow, The Hornet, Fibber McGee and Molly and several other shows including The Eddie Cantor Show. We used to live near San Antonio and there were lots of country and western shows that I enjoyed on WOAI. WOAI is still on the air, but I have not been able to pick up that station here on other radios I have. Perhaps this one will do it.

I adjusted the push buttons for good stations in this area and plan to use the call sign inserts that Ron provided on this site. The escutcheon panel needs new felt on the backside and repainting of the front. At first I thought it just needed cleaning, but it actually has some rust that has managed to work its way up through the pain in several spots.

I received a confirmation that tubesandmore received my order and they will probably get it in the shipping process today. I really want to finish all the parts replacements in the chassis so I can start on the cabinet. Yesterday I cut a piece of pine to fit on the left side base area that brought it back up to the correct height and I managed to put some plastic feet on the bottom of the radio so that if I bring it inside the house it will not scratch the floors. My wife would not be happy with scratches! It has also made the radio much easier to move around in the barn.

Cheers!

Joe

[Joeztech]

Today I continued some work on the chassis by replacing items 16 and 15, 47K ohm resistors, and item 37 a 33K ohm resistor. In the process I found an added resistor, a 27 ohm between the grid of the 7J7 Mixer/Oscillator tube and the band switch which is not on the parts list or the under-chassis parts illustration. This is likely a modification to reduce the possibility of spurious high frequency oscillation. Neither the Ryder information nor the Philco Service Bulletin 321 show that added resistor. I need to do some further checking to see if I can find information on this. It would be interesting to see if my suspicions are correct.

I hope to get the remaining capacitors I ordered so I can finish up the chassis work.

[Joeztech]

As things developed today, I received my order of a new electrolytic and other capacitors to finish the restoration of the electronic circuitry. The electrolytic I used the first time around was intermittently shorting. I could actually hear it popping inside during the warm-up of the tubes. You could also feel the pops coming through the can shield. Instead of a capacitor with the same voltage rating, this time I went for a 450VDC rated 20mFd capacitor. It should last for a long time. The other polypropylene capacitors from tubesandmore allowed me to finish replacing all the capacitors except for the mica capacitors and they are working fine with no signs of leakage or problems of any kind.

I notice that the 16 ohm resistor in the filament circuit going to the power pilot lamp drops the current low enough when an 1847 dial lamp is used that a person can easily hold the lamp in their fingers without getting uncomfortable holding it. This should help extend the life of the lamp and also the life of the plastic jewel that covers it on the front of the cabinet.

I will start on the electrostatic shield rebuild soon. I had already determined that the old paper arrangement is too far gone to repair, so that part will get soaked in water until the paper is ready to fall apart. It probably won't take too long as brittle and crumbling as it is now. I have some nice brown Kraft paper to use in re-creating the assembly. I plan to make a construction jig out of some thin plywood to hold the copper wires straight with the first layer of paper underneath them and the copper tape strip to one side. Once I get things lined up, I can solder the wires to the copper tape, then spray over the wires and paper with spray adhesive. Then another piece of Kraft paper will be laid on top of that and smoothed out until the wires are held securely enough. Adequate drying time should be good to keep the wires in place while the whole is wrapped around the wooden oval supports for each end and then stapled. I will take some pictures as I go and post them on the Phorum.

Sure is nice to have the radio working and see the glow of the tubes! Thanks everyone for your help.

Joe

[codefox1]

Just be careful when operating sets on their side as some tubes, notibly aging rectifiers that do not have cathodes, and some old triodes can have a sagging filament which will take them out if they short. However most everything will work nicely upside down.