02-01-2008, 05:59 PM
Hi everyone this is my first post and my first real restoration attempt. I have many questions but will try to take them a few at a time. I am and
have been in the consumer electronics service business(TV/Radio/Phono.. mostly in early to middle years of my business) all of my life. In spite of that I may have some questions that may seem like "duh" to many so please bear with me.
A friend brought in this 41-608 (console with Beam of Light phono) for me to restore. The radio "works" to some extent on only our local station so am going to try and go thru it fairly thoroughly. Have checked the tubes and have 2-3 questionable ones but can't check the "41" outputs so don't know how to judge them.
Right now I was going to ask about capacitors. I see it is recommended to replace all the paper and lytics. The main filter "can" on this one has a Philco name and number on it but I'm wondering if it were replaced at some time. I got the schematic from the on-line source which is a Ryder publication. On the print it shows a #21 A and 21B yet their negative side which would be a common black wire appear to be seperate and connected to two different points seperated by some resistors... #77 ??
The actual "can" is labeled: Black-Neg, Red-16@400, Green-8@400 plus a seperate section: Blue-12@400 with a Yellow for negative. These last two wires are clipped of right at the base of the can. Also the radio doesn't seem to have any AC hum (typical of bad filter caps) and yet with my ESR capacitor tester, both sections check "open" ??? Soooo can anyone shed some light on this confusing wiring etc where print seems to show the negative sides of the two caps in the can (both use black as their common) connected to seperate points along some resistor chain (#77)?
Then I also see a filter (8@400) marked #21 in the plate supply circuit of the Ist Det and Osc tubes. Is this indeed a seperate axial lead cap under the chassis? Do you suppose the can that is currently in the radio was a sub at some time in a repair and they just clipped off the leads for the third seperate filter ... Blue/Yellow leads?
Now... can I get a replacement dual "can" yet with values near the original ? I note this can has like two threaded studs that go thru the chassis and nuts to hold it down. Is is acceptable to just take two current production caps and "tie" in to replace the original and clip the leads on the original to totally remove from the circuit. I suppose this is a matter of customer preferance regarding keeping everything as near original "look" as possible short of cutting apart the can and trying to insert subs inside and replace the can (cover). I saw this illustrated on a link from some site.
One more area now to ask on this "round" . The Bass control is "open"..
schematic says it is a 6 meg. Removed the pot and confirmed and even took metal cover off to check the carbon surface and there is no end to end measurement (infinate) so it is a goner. Can't find anything close in current products and wondering where this may be found at all as a replacement. Lastly, the Volume control has been replaced with one that has no tap as the original must have (2meg with 1 meg tap) This too is impossible to locate. Anyway with these two messed up pots there was only about 1 point at which to get audio out and that was always maximum (which wasn't all that loud).
Oops.. The chassis is quite rusted in areas and grungy looking with some greenish residue in places including tube bases. Some pilot lamp wires bare and broken and dial stringing busted including that extra dial stringing from band switch that moves a lamp up and down to illuminate which "band" or function you have chosen. Any tips about the chassis? How do you best go about cleaning it up? Do some remove all the parts and clean the chassis or even try to replate it??
I'm done now... sorry for the novel... just my way to be sorta thorough but thanks again for all your help and time to trudge thru this long first post! Best regards to all!
have been in the consumer electronics service business(TV/Radio/Phono.. mostly in early to middle years of my business) all of my life. In spite of that I may have some questions that may seem like "duh" to many so please bear with me.
A friend brought in this 41-608 (console with Beam of Light phono) for me to restore. The radio "works" to some extent on only our local station so am going to try and go thru it fairly thoroughly. Have checked the tubes and have 2-3 questionable ones but can't check the "41" outputs so don't know how to judge them.
Right now I was going to ask about capacitors. I see it is recommended to replace all the paper and lytics. The main filter "can" on this one has a Philco name and number on it but I'm wondering if it were replaced at some time. I got the schematic from the on-line source which is a Ryder publication. On the print it shows a #21 A and 21B yet their negative side which would be a common black wire appear to be seperate and connected to two different points seperated by some resistors... #77 ??
The actual "can" is labeled: Black-Neg, Red-16@400, Green-8@400 plus a seperate section: Blue-12@400 with a Yellow for negative. These last two wires are clipped of right at the base of the can. Also the radio doesn't seem to have any AC hum (typical of bad filter caps) and yet with my ESR capacitor tester, both sections check "open" ??? Soooo can anyone shed some light on this confusing wiring etc where print seems to show the negative sides of the two caps in the can (both use black as their common) connected to seperate points along some resistor chain (#77)?
Then I also see a filter (8@400) marked #21 in the plate supply circuit of the Ist Det and Osc tubes. Is this indeed a seperate axial lead cap under the chassis? Do you suppose the can that is currently in the radio was a sub at some time in a repair and they just clipped off the leads for the third seperate filter ... Blue/Yellow leads?
Now... can I get a replacement dual "can" yet with values near the original ? I note this can has like two threaded studs that go thru the chassis and nuts to hold it down. Is is acceptable to just take two current production caps and "tie" in to replace the original and clip the leads on the original to totally remove from the circuit. I suppose this is a matter of customer preferance regarding keeping everything as near original "look" as possible short of cutting apart the can and trying to insert subs inside and replace the can (cover). I saw this illustrated on a link from some site.
One more area now to ask on this "round" . The Bass control is "open"..
schematic says it is a 6 meg. Removed the pot and confirmed and even took metal cover off to check the carbon surface and there is no end to end measurement (infinate) so it is a goner. Can't find anything close in current products and wondering where this may be found at all as a replacement. Lastly, the Volume control has been replaced with one that has no tap as the original must have (2meg with 1 meg tap) This too is impossible to locate. Anyway with these two messed up pots there was only about 1 point at which to get audio out and that was always maximum (which wasn't all that loud).
Oops.. The chassis is quite rusted in areas and grungy looking with some greenish residue in places including tube bases. Some pilot lamp wires bare and broken and dial stringing busted including that extra dial stringing from band switch that moves a lamp up and down to illuminate which "band" or function you have chosen. Any tips about the chassis? How do you best go about cleaning it up? Do some remove all the parts and clean the chassis or even try to replate it??
I'm done now... sorry for the novel... just my way to be sorta thorough but thanks again for all your help and time to trudge thru this long first post! Best regards to all!