07-21-2021, 08:57 PM
I finished electronic restoration of a 48-1270 this month. This is my second project and could not have completed without the resources at Philco radio.com. I really appreciate y’all.
I bought this console at a flea market in March. It looked challenging to me in terms of electronics but the cabinet was in good shape and I got it for $ 50.
I spent a lot of time studying the Philco service manual and testing tubes, and transformers. All of the tubes except the 5U4 were good. The output transformer was bad and I replaced with a Hammond 125D. Speaker looked good and the field coil was good too. I treated it with Thompson’s water seal (spray can).
I started recap about end of May. I replaced the electrolytics, all the paper caps, and quite a few resistors. I was surprised at having to replace so many resistors but maybe my desoldering work put too much heat to them. Seems like caps were tied to lugs at lowest layer with resistors and wire leads on top - pretty tedious for a nearsighted old man. Maybe a desoldering station would be a good investment. I finished the recap along with a new line cord and fuse around End of June.
She worked pretty good on first test after replacing rectifier. I had a small problem with some high pitched tones when volume was low and treble high. After finding the VC, bass, and treble pots were pretty much in spec. I remembered the inverse feedback implemented in the output transformer secondary coupled to the VC through a resistor network. The high side of the secondary is supposed to connect to the R203/204 network but since I used the Hammond 125D it was easy to connect the wrong lead. It was an easy fix once I discovered my error.
The record changer work was pretty much just cleaning, lubrication, and minor adjustments all per service manual. I am amazed at how good radio and record player sound. The scratch eliminator circuit actually works pretty well.
Cabinet work consisted of thorough cleaning, and sealing of all interior surfaces with shellac. I used Howard’s Restore-A-Finish and followed up with Howard’s Wax. I cleaned the door pulls with a vinegar/water solution (1:9). It’s not perfect but looks really good in my man cave.
I’ll attach pictures and post anything else pertinent as it comes to mind. I’ve done AM alignment but not FM and will likely have a post on that subject when I have time to work on it. Again, thanks for all the help.
I bought this console at a flea market in March. It looked challenging to me in terms of electronics but the cabinet was in good shape and I got it for $ 50.
I spent a lot of time studying the Philco service manual and testing tubes, and transformers. All of the tubes except the 5U4 were good. The output transformer was bad and I replaced with a Hammond 125D. Speaker looked good and the field coil was good too. I treated it with Thompson’s water seal (spray can).
I started recap about end of May. I replaced the electrolytics, all the paper caps, and quite a few resistors. I was surprised at having to replace so many resistors but maybe my desoldering work put too much heat to them. Seems like caps were tied to lugs at lowest layer with resistors and wire leads on top - pretty tedious for a nearsighted old man. Maybe a desoldering station would be a good investment. I finished the recap along with a new line cord and fuse around End of June.
She worked pretty good on first test after replacing rectifier. I had a small problem with some high pitched tones when volume was low and treble high. After finding the VC, bass, and treble pots were pretty much in spec. I remembered the inverse feedback implemented in the output transformer secondary coupled to the VC through a resistor network. The high side of the secondary is supposed to connect to the R203/204 network but since I used the Hammond 125D it was easy to connect the wrong lead. It was an easy fix once I discovered my error.
The record changer work was pretty much just cleaning, lubrication, and minor adjustments all per service manual. I am amazed at how good radio and record player sound. The scratch eliminator circuit actually works pretty well.
Cabinet work consisted of thorough cleaning, and sealing of all interior surfaces with shellac. I used Howard’s Restore-A-Finish and followed up with Howard’s Wax. I cleaned the door pulls with a vinegar/water solution (1:9). It’s not perfect but looks really good in my man cave.
I’ll attach pictures and post anything else pertinent as it comes to mind. I’ve done AM alignment but not FM and will likely have a post on that subject when I have time to work on it. Again, thanks for all the help.
