05-11-2008, 11:26 AM
Hi JB
Answers inline...
Have you any sort of multimeter? You can measure across the terminals of the one-turn loop to determine continuity; the resistance reading should be very low, on the order of a (very) few ohms or less.
Contact Chuck Schwark and purchase his schematic package for this model. It not only includes an extra large schematic, but also under-chassis diagram showing placement of parts, parts list...every thing available in the original Philco service information, plus any pertinent production changes. A wise investment in servicing your radio.
http://www.philcorepairbench.com/schematics.htm
Very different animal. Model 40 is from 1929, and is a set designed to operate on 110 volts, DC ONLY.
You must learn these in order to service electronic components. Otherwise you will need to have someone repair the radio for you. There are high voltages involved with vintage electronics, and the service of same is not something that someone with no electronics background should tackle unless he or she has some knowledge of what they are doing.
I do not say these things to be condescending...but only to warn you of the potential dangers involved.
If you are unfamiliar with servicing electronic equipment...then, yes, finding someone in your area might be a very good idea. We here can walk you through things...but when it comes down to actually performing the work...you really need to have some knowledge of what you are doing.
Personally, I unsolder one end of each wire (one at a time of course), remove all of the old brittle insulation, slip color-coded heat shrink tubing over the wire cut to the proper length...heat it...resolder the end that I unsoldered...move on to the next wire...and so forth and so on. The end result is very authentic-looking, very much like new rubber insulation in appearance.
The repair person who worked on the set in 1993 should have done this, as well as replacing ALL of the paper and electrolytic capacitors. Had this been done then, I would almost bet your radio would still be playing now. Insist that the next person to work on it does this. I base this on the repair tag you shared, in which you mention NO capacitor replacement save for one 110 pF unit.
If you want a radio to be repaired, it should be done right the first time. I do not subscribe to the "replace just a few parts here and there" school of thought...because more old components WILL fail over time. Paper and electrolytic capacitors are the number one fault in vintage radios, and ALL must be replaced for safety and reliability.
One man's opinion. That's all...
Again...good luck...and keep us posted.
Answers inline...
JB Wrote:thank you, ron, for your reply. the one-turn loop is connected to both the points you mention. from the visible side of the 38-9884 board, there are no breaks nor frayed parts of the wire. i can not see the top of the board to determine if the loop is intact. the soldered joint, where the wire from screw number #3 connects to, appears to be newer. i assume it may have been re-soldered with the 1993 repairs.
Have you any sort of multimeter? You can measure across the terminals of the one-turn loop to determine continuity; the resistance reading should be very low, on the order of a (very) few ohms or less.
JB Wrote:i would like to ask if there is a reference manual, or book, or downloadable diagram to identify the internal components? something in addition to the wiring schematic. since i am new at this, i am not sure how i would clean the band switch.
Contact Chuck Schwark and purchase his schematic package for this model. It not only includes an extra large schematic, but also under-chassis diagram showing placement of parts, parts list...every thing available in the original Philco service information, plus any pertinent production changes. A wise investment in servicing your radio.
http://www.philcorepairbench.com/schematics.htm
JB Wrote:i opened the schematic for the model 40
Very different animal. Model 40 is from 1929, and is a set designed to operate on 110 volts, DC ONLY.
JB Wrote:but i have no electronics background to read the symbols.
You must learn these in order to service electronic components. Otherwise you will need to have someone repair the radio for you. There are high voltages involved with vintage electronics, and the service of same is not something that someone with no electronics background should tackle unless he or she has some knowledge of what they are doing.
I do not say these things to be condescending...but only to warn you of the potential dangers involved.
JB Wrote:the 39-6443 label inside the cabinet listed the tubes, and this radio does have the 6J8G tube. how do i check the tube out to see if it is oscillating at all frequencies, do i take that to a local antique radio club?
If you are unfamiliar with servicing electronic equipment...then, yes, finding someone in your area might be a very good idea. We here can walk you through things...but when it comes down to actually performing the work...you really need to have some knowledge of what you are doing.
JB Wrote:and finally, in another topic area, the insulation on all the wires leading from the antenna terminal board, and on the 1 wire from the small two-screw board inboard of the antenna terminal board, is cracked in places showing exposed bare wire. what is the recommended replacement wire?
Personally, I unsolder one end of each wire (one at a time of course), remove all of the old brittle insulation, slip color-coded heat shrink tubing over the wire cut to the proper length...heat it...resolder the end that I unsoldered...move on to the next wire...and so forth and so on. The end result is very authentic-looking, very much like new rubber insulation in appearance.
The repair person who worked on the set in 1993 should have done this, as well as replacing ALL of the paper and electrolytic capacitors. Had this been done then, I would almost bet your radio would still be playing now. Insist that the next person to work on it does this. I base this on the repair tag you shared, in which you mention NO capacitor replacement save for one 110 pF unit.
If you want a radio to be repaired, it should be done right the first time. I do not subscribe to the "replace just a few parts here and there" school of thought...because more old components WILL fail over time. Paper and electrolytic capacitors are the number one fault in vintage radios, and ALL must be replaced for safety and reliability.
One man's opinion. That's all...
Again...good luck...and keep us posted.
--
Ron Ramirez
Ferdinand IN