10-28-2017, 04:28 PM
I have a Philco 46-1226 Code 125 to restore. I began by checking the AC input circuit. The bandswitch has to be in the Am or SW position to get the volume control On-Off switch to close and show continuity. On this particular radio, the switch on the volume control seems to be somewhat flaky. It does not show continuity every time it is turned on. It may help to take the switch off of the control and clean it out. I have seen some of these older switches that have lubrication inside that dries out and makes them act up. This particular unit may be a late production version of the Code 125 as it does not have the typical Philco bathtub housing that contains the two .01 AC input filter capacitors. It appears to have a single capacitor bridged across the AC input instead simply attached to a conventional bakelite terminal strip. This will actually be easier to upgrade to a modern AC input safety capacitor.
With continuity of the AC Input established, I went on to check the power transformer secondary and it shows continuity across the AC HV winding and continuity to chassis ground through its center tap, so it appears to be OK. I wanted to establish that much before diving into the rest of the unit.
The tuning shaft was frozen and would not move. I managed to get it freed up by applying penetrating oil repeatedly and now it does run end to end across the dial.
This is a unit which has Code 125 imprinted on its model number label in the cabinet and it is also samped in ink on the back of the radio chassis. Thanks to some other threads here on this Code 125 version I have enough information to do the restoration. I pulled the chassis out of the cabinet to find the values and voltage ratings of the electrolytic capacitors in the power supply. There are two of them. One is a short large diameter can Philco P/N 30-2556 which is a 25uF@450VC and a 10uF@450VDC with its negative circuit grounded to the chassis. The other is a tall slender diameter can Philco P/N 30-2570 which is a 25uF@450VDC and a 10uF@450VDC with its negative circuit not grounded.
In the process of removing the chassis from the cabinet I discovered that one lead going to the PM speaker was broken open. It appears that it may have gotten caught in the levers associated with the opening and closing of the record changer assembly and those levers may have actually cut the wire apart - it was a clean cut. I will have to carefully look at lead dress when reassembling this unit into its cabinet. The grandson who now owns the radio from an estate said that he remembered it quit playing years ago. An open speaker wire would sure do it.
I looked underneath the chassis and there was a 40uF@450VDC electrolytic that had been bridged across one lead of the 30-2570 capacitor to chassis ground. The connection at the positive terminal was so poorly soldered that it came dangerously close to shorting to the electrolytic can negative twist-lug. Then the positive lead of the added capacitor was not clipped off and was also allowed to come very close to the chassis metal. Someone was living dangerously!!
This will all get cleaned up while rebuilding electrolytics.
I have a lot of the capacitors on hand to take care of most of the coupling and bypass capacitors, but will need to order new electrolytics to restuff the existing electrolytic cans. The 300 ohm resistor coming off of the rectifier cathode shows signs of considerable heat from operation in the past. It may still be OK. I do not intend to turn this set on until I have repaired the electrolytics and verified I have the correct negative bias to the output tube grids. I will check the 6K6 output tubes and also check the output transformer plate to plate to see if the transformer primary is OK.
This unit still has its original 78rpm Philco record changer. The owner wants a modern changer as a replacement so he can play 45s and 33rpm LPs. I can get a changer and cartridge that is made to play stereo LPs and wire it for mono operation and still allow playing of 78rpm records with a flip-over needle. The OEM changer is about 14 5/8 inches wide and 13 1/2 inches deep, so if I look carefully I may be able to find one that will fit without too much adaptation needed.
I will try to get some pictures of the chassis ready for my next post on this unit.
Joe
With continuity of the AC Input established, I went on to check the power transformer secondary and it shows continuity across the AC HV winding and continuity to chassis ground through its center tap, so it appears to be OK. I wanted to establish that much before diving into the rest of the unit.
The tuning shaft was frozen and would not move. I managed to get it freed up by applying penetrating oil repeatedly and now it does run end to end across the dial.
This is a unit which has Code 125 imprinted on its model number label in the cabinet and it is also samped in ink on the back of the radio chassis. Thanks to some other threads here on this Code 125 version I have enough information to do the restoration. I pulled the chassis out of the cabinet to find the values and voltage ratings of the electrolytic capacitors in the power supply. There are two of them. One is a short large diameter can Philco P/N 30-2556 which is a 25uF@450VC and a 10uF@450VDC with its negative circuit grounded to the chassis. The other is a tall slender diameter can Philco P/N 30-2570 which is a 25uF@450VDC and a 10uF@450VDC with its negative circuit not grounded.
In the process of removing the chassis from the cabinet I discovered that one lead going to the PM speaker was broken open. It appears that it may have gotten caught in the levers associated with the opening and closing of the record changer assembly and those levers may have actually cut the wire apart - it was a clean cut. I will have to carefully look at lead dress when reassembling this unit into its cabinet. The grandson who now owns the radio from an estate said that he remembered it quit playing years ago. An open speaker wire would sure do it.
I looked underneath the chassis and there was a 40uF@450VDC electrolytic that had been bridged across one lead of the 30-2570 capacitor to chassis ground. The connection at the positive terminal was so poorly soldered that it came dangerously close to shorting to the electrolytic can negative twist-lug. Then the positive lead of the added capacitor was not clipped off and was also allowed to come very close to the chassis metal. Someone was living dangerously!!
This will all get cleaned up while rebuilding electrolytics. I have a lot of the capacitors on hand to take care of most of the coupling and bypass capacitors, but will need to order new electrolytics to restuff the existing electrolytic cans. The 300 ohm resistor coming off of the rectifier cathode shows signs of considerable heat from operation in the past. It may still be OK. I do not intend to turn this set on until I have repaired the electrolytics and verified I have the correct negative bias to the output tube grids. I will check the 6K6 output tubes and also check the output transformer plate to plate to see if the transformer primary is OK.
This unit still has its original 78rpm Philco record changer. The owner wants a modern changer as a replacement so he can play 45s and 33rpm LPs. I can get a changer and cartridge that is made to play stereo LPs and wire it for mono operation and still allow playing of 78rpm records with a flip-over needle. The OEM changer is about 14 5/8 inches wide and 13 1/2 inches deep, so if I look carefully I may be able to find one that will fit without too much adaptation needed.
I will try to get some pictures of the chassis ready for my next post on this unit.
Joe
