Last time we tuned in I was trouble shooting the tube heaters, all now seems well with the low voltage. Now the hv supply. I powered up the set using a clean bench supply (6.3v) and probed the plate voltage of the 6D6. The schematic calls for 220 volts I measured approx 1 volt. Since there was no sign of vibration from the vibrator, I did the usual things, tap it etc. No vibration. BTW this is a 5 pin, Delco # 5041245, synchronous, integrated buffer cap, 4 contacts, etc. Next step was to open the can to have a look. Inside I found the vibrator covered with a brown tar like substance, I assume this is the decomposed remains of a foam or damping liner material. I cleaned the vibrator using mineral spirits and used fine emory paper to clean the contacts. I then plugged the vibrator, without can cover, back into the radio and powered it up. Still no vibration, however I could see that the contact arm was deflecting when the power was turned on indicating the magnetic circuit was working. Next I measured the buffer cap and got 0.05 and it held about 200 Mohms of resistance. I then disconnected the buffer cap and clip leaded a new ceramic cap in place, powered up and again no joy.
Next I checked out the transformer out of the circuit. On the low voltage side high to low I measured 0.15 ohm, high or low to center tap I measured 0.07 ohm. The high voltage side high to low, 340 ohms, high to center tap, 162 ohms and low to center tap, 177 ohms. Between the high and low side windings was at least several hundred Mohms.
I have checked the AAR website for a replacement solid state vibrator however an exact replacement for the five terminal Delco does not appear to be available, (I have emailed AAR to ask for their help.) but I am sure something can be rigged to work. What I would like to know is given the above transformer measurements is it safe to assume the hv circuit is ok or should more probing be done ? I don't want to buy a solid state vibrator only to have it fail after I install it. Also what could be causing the old vibrator not to run if the transformer and hv is ok ? The contact gaps look ok. I really would like to get the old vibrator running for no other reason then to see it in action before replacing it with the solid state unit.
Thanks, Steve Schreppler
Those vibrators are hard to get adjusted right. I am sure it's point contact. Even particles from your emery paper can cause poor contact.
You can use a standard 4 pin vibrator along with 2 silicon diodes for rectifiers. Don't know of anyone making a 5 pin solid state vibrator.
Be sure your replacement buffer cap is the same value as original. Transformer primary DC resistance will be low.
Norm
: I am back for some more advice and wisdom. Same project, I am restoring a United Motors model 985400. This radio was installed in a 1935 Chevrolet Master Sedan and is powered by a 6 volt battery system.
: Last time we tuned in I was trouble shooting the tube heaters, all now seems well with the low voltage. Now the hv supply. I powered up the set using a clean bench supply (6.3v) and probed the plate voltage of the 6D6. The schematic calls for 220 volts I measured approx 1 volt. Since there was no sign of vibration from the vibrator, I did the usual things, tap it etc. No vibration. BTW this is a 5 pin, Delco # 5041245, synchronous, integrated buffer cap, 4 contacts, etc. Next step was to open the can to have a look. Inside I found the vibrator covered with a brown tar like substance, I assume this is the decomposed remains of a foam or damping liner material. I cleaned the vibrator using mineral spirits and used fine emory paper to clean the contacts. I then plugged the vibrator, without can cover, back into the radio and powered it up. Still no vibration, however I could see that the contact arm was deflecting when the power was turned on indicating the magnetic circuit was working. Next I measured the buffer cap and got 0.05 and it held about 200 Mohms of resistance. I then disconnected the buffer cap and clip leaded a new ceramic cap in place, powered up and again no joy.
: Next I checked out the transformer out of the circuit. On the low voltage side high to low I measured 0.15 ohm, high or low to center tap I measured 0.07 ohm. The high voltage side high to low, 340 ohms, high to center tap, 162 ohms and low to center tap, 177 ohms. Between the high and low side windings was at least several hundred Mohms.
: I have checked the AAR website for a replacement solid state vibrator however an exact replacement for the five terminal Delco does not appear to be available, (I have emailed AAR to ask for their help.) but I am sure something can be rigged to work. What I would like to know is given the above transformer measurements is it safe to assume the hv circuit is ok or should more probing be done ? I don't want to buy a solid state vibrator only to have it fail after I install it. Also what could be causing the old vibrator not to run if the transformer and hv is ok ? The contact gaps look ok. I really would like to get the old vibrator running for no other reason then to see it in action before replacing it with the solid state unit.
: Thanks, Steve Schreppler
Do you know of a website that has a schematic of the 4 pin vibrator and diode circuit ? Also what model AAR
vibrator, type diode, and type cap should be used ? I assume the cap should be at least 1600V ?
Thanks again, Steve
: Those vibrators are hard to get adjusted right. I am sure it's point contact. Even particles from your emery paper can cause poor contact.
: You can use a standard 4 pin vibrator along with 2 silicon diodes for rectifiers. Don't know of anyone making a 5 pin solid state vibrator.
: Be sure your replacement buffer cap is the same value as original. Transformer primary DC resistance will be low.
: Norm
:
: : I am back for some more advice and wisdom. Same project, I am restoring a United Motors model 985400. This radio was installed in a 1935 Chevrolet Master Sedan and is powered by a 6 volt battery system.
: : Last time we tuned in I was trouble shooting the tube heaters, all now seems well with the low voltage. Now the hv supply. I powered up the set using a clean bench supply (6.3v) and probed the plate voltage of the 6D6. The schematic calls for 220 volts I measured approx 1 volt. Since there was no sign of vibration from the vibrator, I did the usual things, tap it etc. No vibration. BTW this is a 5 pin, Delco # 5041245, synchronous, integrated buffer cap, 4 contacts, etc. Next step was to open the can to have a look. Inside I found the vibrator covered with a brown tar like substance, I assume this is the decomposed remains of a foam or damping liner material. I cleaned the vibrator using mineral spirits and used fine emory paper to clean the contacts. I then plugged the vibrator, without can cover, back into the radio and powered it up. Still no vibration, however I could see that the contact arm was deflecting when the power was turned on indicating the magnetic circuit was working. Next I measured the buffer cap and got 0.05 and it held about 200 Mohms of resistance. I then disconnected the buffer cap and clip leaded a new ceramic cap in place, powered up and again no joy.
: : Next I checked out the transformer out of the circuit. On the low voltage side high to low I measured 0.15 ohm, high or low to center tap I measured 0.07 ohm. The high voltage side high to low, 340 ohms, high to center tap, 162 ohms and low to center tap, 177 ohms. Between the high and low side windings was at least several hundred Mohms.
: : I have checked the AAR website for a replacement solid state vibrator however an exact replacement for the five terminal Delco does not appear to be available, (I have emailed AAR to ask for their help.) but I am sure something can be rigged to work. What I would like to know is given the above transformer measurements is it safe to assume the hv circuit is ok or should more probing be done ? I don't want to buy a solid state vibrator only to have it fail after I install it. Also what could be causing the old vibrator not to run if the transformer and hv is ok ? The contact gaps look ok. I really would like to get the old vibrator running for no other reason then to see it in action before replacing it with the solid state unit.
: : Thanks, Steve Schreppler
: Do you know of a website that has a schematic of the 4 pin vibrator and diode circuit ? Also what model AAR
: vibrator, type diode, and type cap should be used ? I assume the cap should be at least 1600V ?
: Thanks again, Steve
: : Those vibrators are hard to get adjusted right. I am sure it's point contact. Even particles from your emery paper can cause poor contact.
: : You can use a standard 4 pin vibrator along with 2 silicon diodes for rectifiers. Don't know of anyone making a 5 pin solid state vibrator.
: : Be sure your replacement buffer cap is the same value as original. Transformer primary DC resistance will be low.
: : Norm
: :
: : : I am back for some more advice and wisdom. Same project, I am restoring a United Motors model 985400. This radio was installed in a 1935 Chevrolet Master Sedan and is powered by a 6 volt battery system.
: : : Last time we tuned in I was trouble shooting the tube heaters, all now seems well with the low voltage. Now the hv supply. I powered up the set using a clean bench supply (6.3v) and probed the plate voltage of the 6D6. The schematic calls for 220 volts I measured approx 1 volt. Since there was no sign of vibration from the vibrator, I did the usual things, tap it etc. No vibration. BTW this is a 5 pin, Delco # 5041245, synchronous, integrated buffer cap, 4 contacts, etc. Next step was to open the can to have a look. Inside I found the vibrator covered with a brown tar like substance, I assume this is the decomposed remains of a foam or damping liner material. I cleaned the vibrator using mineral spirits and used fine emory paper to clean the contacts. I then plugged the vibrator, without can cover, back into the radio and powered it up. Still no vibration, however I could see that the contact arm was deflecting when the power was turned on indicating the magnetic circuit was working. Next I measured the buffer cap and got 0.05 and it held about 200 Mohms of resistance. I then disconnected the buffer cap and clip leaded a new ceramic cap in place, powered up and again no joy.
: : : Next I checked out the transformer out of the circuit. On the low voltage side high to low I measured 0.15 ohm, high or low to center tap I measured 0.07 ohm. The high voltage side high to low, 340 ohms, high to center tap, 162 ohms and low to center tap, 177 ohms. Between the high and low side windings was at least several hundred Mohms.
: : : I have checked the AAR website for a replacement solid state vibrator however an exact replacement for the five terminal Delco does not appear to be available, (I have emailed AAR to ask for their help.) but I am sure something can be rigged to work. What I would like to know is given the above transformer measurements is it safe to assume the hv circuit is ok or should more probing be done ? I don't want to buy a solid state vibrator only to have it fail after I install it. Also what could be causing the old vibrator not to run if the transformer and hv is ok ? The contact gaps look ok. I really would like to get the old vibrator running for no other reason then to see it in action before replacing it with the solid state unit.
: : : Thanks, Steve Schreppler
Next week I will write an update.
Thanks for the help Norm. Steve
Looking at your vibrator circuit in the schematic there will be two sets of points. The set on the primary side, 6 volt, can be replaced with a 4 pin vibrator. There will be secondary points in your original vibrator. They can be replaced with a pair of diodes. 1N4007, 1000 PIV, should be ok.
Use the same value cap @ 1600 volts for buffer. If this cap is bad or missing the vibrator points will be damaged.
Norm
: Norm,
: Do you know of a website that has a schematic of the 4 pin vibrator and diode circuit ? Also what model AAR
: vibrator, type diode, and type cap should be used ? I assume the cap should be at least 1600V ?
: Thanks again, Steve
: : Those vibrators are hard to get adjusted right. I am sure it's point contact. Even particles from your emery paper can cause poor contact.
: : You can use a standard 4 pin vibrator along with 2 silicon diodes for rectifiers. Don't know of anyone making a 5 pin solid state vibrator.
: : Be sure your replacement buffer cap is the same value as original. Transformer primary DC resistance will be low.
: : Norm
: :
: : : I am back for some more advice and wisdom. Same project, I am restoring a United Motors model 985400. This radio was installed in a 1935 Chevrolet Master Sedan and is powered by a 6 volt battery system.
: : : Last time we tuned in I was trouble shooting the tube heaters, all now seems well with the low voltage. Now the hv supply. I powered up the set using a clean bench supply (6.3v) and probed the plate voltage of the 6D6. The schematic calls for 220 volts I measured approx 1 volt. Since there was no sign of vibration from the vibrator, I did the usual things, tap it etc. No vibration. BTW this is a 5 pin, Delco # 5041245, synchronous, integrated buffer cap, 4 contacts, etc. Next step was to open the can to have a look. Inside I found the vibrator covered with a brown tar like substance, I assume this is the decomposed remains of a foam or damping liner material. I cleaned the vibrator using mineral spirits and used fine emory paper to clean the contacts. I then plugged the vibrator, without can cover, back into the radio and powered it up. Still no vibration, however I could see that the contact arm was deflecting when the power was turned on indicating the magnetic circuit was working. Next I measured the buffer cap and got 0.05 and it held about 200 Mohms of resistance. I then disconnected the buffer cap and clip leaded a new ceramic cap in place, powered up and again no joy.
: : : Next I checked out the transformer out of the circuit. On the low voltage side high to low I measured 0.15 ohm, high or low to center tap I measured 0.07 ohm. The high voltage side high to low, 340 ohms, high to center tap, 162 ohms and low to center tap, 177 ohms. Between the high and low side windings was at least several hundred Mohms.
: : : I have checked the AAR website for a replacement solid state vibrator however an exact replacement for the five terminal Delco does not appear to be available, (I have emailed AAR to ask for their help.) but I am sure something can be rigged to work. What I would like to know is given the above transformer measurements is it safe to assume the hv circuit is ok or should more probing be done ? I don't want to buy a solid state vibrator only to have it fail after I install it. Also what could be causing the old vibrator not to run if the transformer and hv is ok ? The contact gaps look ok. I really would like to get the old vibrator running for no other reason then to see it in action before replacing it with the solid state unit.
: : : Thanks, Steve Schreppler