Initial impressions

2/21/98
After over a year of haggling with the owner, I finally decided to purchase the Philco 70. This set is in very sorry shape. It had apparently been stored in a damp location for a long Time. The cabinet is delaminated, virtually all of the glue has let go. The arch support is missing as well as the knobs. The vertical plywood braces on the back sides of the arch now are a stack of loose cards. Staples which fastened them to the sides have rusted away so that the heads now are all that remain. The result is a sagging that makes the set look "fat"

The front is coming away from the rest and the scrollwork on front of the speaker is broken and missing chunks of wood. Grille cloth is torn, plywood is separating, veneer is split, and some is missing.
The chassis appears complete, all tubes are there and the frayed power cord is as well.

There is a lot of surface rust on the chassis as well as the speaker basket. In addition to the rust is a substantial accumulation of dust and cobwebs.

A closer Look

2/22/98
After taking a few "before" pictures, I pulled out the chassis. It is the early version without AVC. There have been some repairs in the past, notably the 2 electrolytic filters had been replaced by a single multi-section can at higher capacitance. The tone switch is now a variable control, and 2 mica capacitors were long ago replaced. All of the tubes are quite old, but only one (the globe 27) is a Philco brand. A quick check showed 10 ohms DC resistance across the primary of the power transformer. The on/off switch appears not to disconnect.

Power up

2/23/98
A visual check revealed no obvious loose wires or shorts so I hooked up the Variac and brought up the voltage about half way. The tubes all lit up. After bringing the voltage up gradually, I checked for overheating components. The only one was the already replaced electrolytic capacitor. I then connected the speaker and powered it up again. There was a slight hum which was lessened with the tone control. No stations were received, but the audio amplifier responded to my signal injector when placed near the 1st audio tube

Initial troubleshooting

2/25/98
I jumped in a pair of NOS filter capacitors of higher than necessary value. This removed all vestiges of the hum. I checked the B+ which was at nearly 300 volts with the Variac briefly turned all the way up. I made a quick check to determine if the oscillator was radiating a signal and heard none. I then checked the plate voltages of all the tubes. Only the R. F. tube had none. This indicates an open in the " detector transformer". I used a capacitor checker to check for leakage. EVERY ONE tested bad including a few that had been replaced previously.

Cabinet disassembly

3/1/98
I started to dust off the cabinet with a paintbrush. The cabinet was so shaky that I decided to take it down to pieces to avoid further damage. I carefully removed the side moldings and then the nails that hold the sides to the base. This was very easy as the rusty nails were already very loose. The front had already pulled away from the arch on it's own, I then removed the speaker and discovered that it had been reconed previously, apparently a professional job. Next I removed the central front section by removing about a half dozen screws. Now only the base and outer front sections were attached. I decided to leave them attached.

I noticed that the area surrounding the exposed face had perfectly preserved unstained veneer. I then realized that I could use some of that to replace the missing pieces from in front of the speaker. This veneer, like most of this radio, was already separating from it's underlayment. This will make the removal easy.

glue

Using a plastic card to push some carpenters glue under the veneer and between the layers of the plywood and clamps to keep it in place, I glued various pieces. The very fragile front panel quickly gained rigidity. I became more confident that it could be restored.

coil

3/8/98
I removed the open coil from the chassis. The thin primary winding was moldy and had the telltale green color of copper oxide. Sure enough, the wire was nearly reduced to powder. The secondary winding, on the other hand, looked fine. The bad winding had about 64 turns of what appears to be 36 gauge cotton covered wire. I knew that replacing that would be difficult, so I decided to seek an alternative. I found in the junk pile an I.f. transformer from an AA5. This used a type of cotton covered litz wire that had been wound with a wax coating. This proved to be very easy to wind as the wax was still sticky enough to keep the wire from raveling.

3/12/98
Looking closer at the on/off switch. I see that it had been neatly jumped with a piece of bare wire. The mechanism clicked, albeit sluggishly. I sprayed it with contact cleaner. It tested OK with the ohm meter. I got some wood at a craft store to use on the front panel. Continued gluing and clamping. Also found a suitable vintage piece of plywood to replace the missing rear brace. A friend supplied a tracing from his model 70 to use as a pattern.

3/15/98
Replaced the repaired R.F. coil and powered it up again. I was able to pick up some squeals. After twiddling a few trimmers, I was able to hear a few stations crowded at the top of the band. By placing the tube shield on the set, all reception ceased. Both R. F. and IF alignment seem way off. Alignment will not be done until much later. More gluing and clamping....

3/16/98
Wiggling a few wires and the set began to play, IN SPANISH at the low end of the band? I quickly determined it was receiving SHORT-WAVE. a good trick for a broadcast band only set. Tuning around I received stations from Canada and Europe Probably the 49 meter band around 6 megahertz.

3/20/98

It plays!

3/28/98
I received the parts from AES along with alignment instructions and toning lacquer. I am continuing the gluing and clamping of the wood parts. I have almost used up a large bottle of brown Elmer's carpenters glue at this point with plenty more to glue.

4/4/98
As I continue to glue and clamp, I have been playing the set for an hour or so at a time. There do not seem to be any problems with the set, so I will finish repairing the rusty tuning capacitor and contemplate how best to clean up the rusty chassis. (Originally, the chassis was painted gray). The cabinet repairs will continue for at least another month.

5/25/98
Due to various other obligations I have been only able to make time for small progress. Some have been minor disappointments. Nearly every day I went into the shop and glued a different section or two of separating veneer. While working in the shop, I played the Philco each day. Recently, I noticed that the sound would vary and sometimes is distorted. I suppose that many of the capacitors will need replacement after all. I mounted the new grille cloth on it's cardboard frame. Due to a miscalculation, I had to quickly remove it, wash the (white Elmers') glue out, dry and iron the cloth. The second attempt was successful with no damage to the cloth.

I have begun to fill small cracks and chips in the edges of the veneer with plastic wood, I used Parks refinisher to remove some of the crazed lacquer on the plywood arch. I haven't yet decided what to do about the one large area of missing veneer on the bottom rear of the arch. I did decide to remove the veneer from the top half of the front of the set. I will replace that with brand new veneer that will be ordered from a mail order catalog.

The rear arch support that I made from the template sent me by a friend does not appear to fit. I am not sure at this point if it is wrong, or I am not forming the shape of the arch correctly. I will check again after the side braces are glued in place.

5/31/98
I had pressed the central front panel to remove a slight bow. The panel had become nearly flat, but a few areas of veneer had developed bubbles. I was able to walk the bubbles to an edge and reglue. I began to fabricate the wood pieces to replace the missing areas of fretwork. I rough cut with a coping saw and glued in place, leaving some excess to be trimmed later with a Dremel tool. There was still some of the original finish in the recesses of the "columns" on the sides of the front arch. I used a pen-like tool with fiberglass fibers to remove that without scratching the wood.

6/7/98
Today I was looking around the shop and found the top of a junk RCA radio that had similar walnut veneer to that of the Philco. I decided to try to remove the veneer to use to patch the large area on the side of the Philco that was missing. Using an Xacto knife, I was able to pull off large sections of this veneer fairly easily.

6/25/98
Recently, I now suspect that the chassis was not painted gray originally, but simply galvanized. I used some Naval Jelly and 600 grit sandpaper to remove some rust and coated the speaker basket with Rustoleum cold galvanizing compound. the finish is very nice, appearing lighter than before. I suspect that it will darken with age or dirt. I have started to patch the veneer on the arch and fill gaps with plastic wood filler. I stained a small patch and applied some toning lacquer. The result looks promising

7/4/98
Mostly I have been experimenting with stains and repairing veneer. I won't go into details here as I basically have no idea what I am doing. I have very little artistic talent, and the results are less than mediocre.

7/19/98
I obtained a large piece of walnut veneer from a friend. It is .040" thick, much thicker than what was on the radio. (.018). The thickness will not be a problem as I will be replacing complete pieces. I carefully chose sections based on the patterns of the grain to produce a symmetrical effect. I have glued and pressed the veneer in place and begun to rough trim with an Xacto knife. I have taken some more pictures of the progress, but unfortunately they did not come out well enough to publish here.

8/24/98
I have stained the new veneer and applied a few coats of toning lacquer. I have also redone the fretwork with the veneer scraps removed earlier. the overall result has been good. The radio looks better than I expected ,but not as nice as most restorations I have seen. I have placed the back brace into the set temporarily. It is indeed off from the intended shape, but not nearly as far as I had feared. I will probably do a little filling with wood filler and then stain the whole piece. As soon as the brace is done I will return to the chassis restoration.

11/27/98
During the past few months, I have completed the cabinet's restoration to my satisfaction. Far from perfect, but a good looking radio. I started to repair the electronics. So far I have rebuilt 3 of the bakelite blocks. I did this by heating the tar like material inside the blocks with a soldering gun, and carefully prying out the contents. This is a rather smelly and dirty method, but it works. I put modern capacitors inside the old blocks and secured them with a small amount of hot glue. I saw no need to fill the entire cavity, as it is hidden from view anyway. The set is still playing , but so far I have not found the cause of the whistles and squeals.
Today, I decided due to a good weather forecast, to paint the chassis with the galvanizing compound. This necessitated the removal of the variable tuning capacitor. Once removed, I see that it will require more time than estimated to disassemble and restore the tuning cap. More Naval Jelly and sandpaper treatments will be needed on and under the capacitor.

12/8/98
After the galvanizing paint and rebuilding of the tuning capacitor and trimmers . I added rubber washers to the mounting to take up extra space and remounted the assembly. I found some old style electrolytic cans, and put them on the chassis for show. The power transformer was only slightly rusty, so I sanded the rough spots and covered them with a black Magic Marker. Using Philco's alignment instructions I attempted an alignment. the adjustments went smoothly, but this did not help the problem with whistles. The reception on the high end of the band improved and stations from 1300 to 1500+ were received well without whistles.

12/24/98
Christmas eve, not much for a non - Christian to do exept work on radios. I replaced another capacitor, then turned to the alignment again. I am convinced something is off causing the whistles. After a complete "by the book" alignment I peaked the IF's again, this time by ear. Lo and behold it worked! The whistles disappeared. I suppose the original IF frequency no longer is correct for the proper tracking of the other components. Just as I was celebrating this victory, the set deteriorated. Stations suddenly got lower in volume and were no longer in the correct place on the dial. I checked the oscillator frequency. It was running properly.

12/26/98
I made some checks and found that the tuning capacitor rotor shaft had shifted due to a loose hold down spring. I repaired that and did yet another alignment. The set plays well now. I received old time music on WJZ (actually WWJZ 640) now in Mount Holly, southern New Jersey.

1/1/99
Today I put in a few odds and ends such as the new power cord and one last capacitor .I mounted the chassis using new thick rubber washers. I added a 1 1/2 amp line fuse for added protection. Now after nearly a year I declare the model 70 restored.

MARTY AND THE PHILCO

I Thank you for reading this diary and hope It was interesting and informative. Please e- mail any comments to: radiomf@comcast.net

Thanks,

MARTY

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