Hi Guy
The 1955 Chev radio is listed as being in Sam's Photofact #278 and also AR #5 which is a book on auto radios. You may be able to get this information through your local library.
Orange drop caps are of good quality and should not be a problem.
These radios have a vibrator and 0Z4 tube which could be problems. Vibrator points oxidize over time. You can remove the vibrator can by pealing back the metal around the bottom edge if necessary and clean the contacts. Replacements are also available from Antique Electronic Supply, tubesandmore.com.
Norm
Hi Guy,
You should be able to hear a low buzzing sound from the vibrator. Was this the sound you originally heard or was there a humming sound from the speaker? Does the vibrator still buzz and do the tubes light? You might have solved poor power supply filtering that was causing the hum and now have more faults to get the set to work. If it's completely dead check fuses and make sure power is getting to the set. You should be able to measure B+ voltage of about 250 volts at pin 8 of the 0Z4 (cathode), if so the power supply is OK and you'll have to work through the rest of the set. Measure the output tube voltages, probably a 6V6 or 6AQ5, you should have high voltage on the plate and screen grid and about 12 volts on the cathode. 6V6; plate pin 3, screen pin4, cathode pin8, 6AQ5; plate pin5, screen pin6, cathode pin2. Count pins clockwise, pin 1 starts at gap. If this seems OK you'll have to work through the set to find where it stops. If the audio stage is working you should hear some noise, usually the volume control will make some rustling sound as it's turned. I hope these suggestions point you in the right direction, good luck, Don.
: : I have a 1955 AM Delco Radio 987088. I completely recappd (noe reception) the unit with orange drop capacitors.
: : When I bench tested the unit after recapping it was compeltely dead (it was at least making a humming noise before :-)....my question is should I have used any othertype of caps anywhere in the unit?
: : Also I am looking for a schematic for the unit...does anyone have one or know where I can find it.
: : Thanks
: : Guy
: Hi Guy,
: You should be able to hear a low buzzing sound from the vibrator. Was this the sound you originally heard or was there a humming sound from the speaker? Does the vibrator still buzz and do the tubes light? You might have solved poor power supply filtering that was causing the hum and now have more faults to get the set to work. If it's completely dead check fuses and make sure power is getting to the set. You should be able to measure B+ voltage of about 250 volts at pin 8 of the 0Z4 (cathode), if so the power supply is OK and you'll have to work through the rest of the set. Measure the output tube voltages, probably a 6V6 or 6AQ5, you should have high voltage on the plate and screen grid and about 12 volts on the cathode. 6V6; plate pin 3, screen pin4, cathode pin8, 6AQ5; plate pin5, screen pin6, cathode pin2. Count pins clockwise, pin 1 starts at gap. If this seems OK you'll have to work through the set to find where it stops. If the audio stage is working you should hear some noise, usually the volume control will make some rustling sound as it's turned. I hope these suggestions point you in the right direction, good luck, Don.
: Hi, If you still need the info, I have a Chevrolet Radio Service and Shop Manual for 1955 that includes all the info available you might need for this radio.
: This is an original print of this manual so I would hope its probably as good as it gets. Please respond if you need any info!
: Thanks Troy
: : : I have a 1955 AM Delco Radio 987088. I completely recappd (noe reception) the unit with orange drop capacitors.
: : : When I bench tested the unit after recapping it was compeltely dead (it was at least making a humming noise before :-)....my question is should I have used any othertype of caps anywhere in the unit?
: : : Also I am looking for a schematic for the unit...does anyone have one or know where I can find it.
: : : Thanks
: : : Guy
: : Hi Guy,
: : You should be able to hear a low buzzing sound from the vibrator. Was this the sound you originally heard or was there a humming sound from the speaker? Does the vibrator still buzz and do the tubes light? You might have solved poor power supply filtering that was causing the hum and now have more faults to get the set to work. If it's completely dead check fuses and make sure power is getting to the set. You should be able to measure B+ voltage of about 250 volts at pin 8 of the 0Z4 (cathode), if so the power supply is OK and you'll have to work through the rest of the set. Measure the output tube voltages, probably a 6V6 or 6AQ5, you should have high voltage on the plate and screen grid and about 12 volts on the cathode. 6V6; plate pin 3, screen pin4, cathode pin8, 6AQ5; plate pin5, screen pin6, cathode pin2. Count pins clockwise, pin 1 starts at gap. If this seems OK you'll have to work through the set to find where it stops. If the audio stage is working you should hear some noise, usually the volume control will make some rustling sound as it's turned. I hope these suggestions point you in the right direction, good luck, Don.