11-02-2024, 09:19 PM
How about putting a choke in the power supply?
The big cap was likely an attempt to stabilize the DC. Kids who create "Boom Cars" (cars with ridiculously high powered subwoofers) do this at the amp to compensate for the long run of power cable. Without the cap, you can even see the headlights dim with each "boom".
I have not dealt with a vibrator powered radio for a really long time. The last time was in the late 70s. I was in my early 20s working on a 1957 Lincoln. The owner just wanted the car running. The radio worked the way it was. I distinctly remember the vibrator whine of a mechanical vibrator Very "spiky" similar to noise induced by brushes. I can't remember if Mom and Dad's '56 Ford made the same noise, the car rusted away in 1966 after well over 100K miles but still ran. I had worked for a guy who restored Mustangs and Lincolns, as well as selling whatever he could find and we could fix. Lincoln went to "transistor powered" by 1958, and all transistor by 1960. Ford was all-transistor by 1963.
I did fool around with a lot of car radios collected from cars discarded at the town dump. I ran the 6V ones directly from an AC transformer without modification. Sadly, I can't remember if the vibrator was noisy or not. I think so, at least on the Automatic glommed from a 57 VW (they did not go 12V till much later than American cars did, and did not convert to Alternators till much later.
I had earlier suggested replacing the 0Z4 with a 6X5, but come to think of it, Ford products in the mid 50sused typical heater type rectifier tubes, not the 0Z4, which was popular in GM sets. I still think that it would help, though.
I like the "divide and conquer" method but in addition to testing by pulling the detector / AF tube, I would reinstall and pull the IF tube. However, considering that the noise is most prevalent with the volume control full down, I think that it is carrying through the power supply to the output stage. This is why I wonder if an LC or RC filter added post-rectifier would be helpful.
Is the output push-pull? I had a radio from a 57 Chevy that was.
The big cap was likely an attempt to stabilize the DC. Kids who create "Boom Cars" (cars with ridiculously high powered subwoofers) do this at the amp to compensate for the long run of power cable. Without the cap, you can even see the headlights dim with each "boom".
I have not dealt with a vibrator powered radio for a really long time. The last time was in the late 70s. I was in my early 20s working on a 1957 Lincoln. The owner just wanted the car running. The radio worked the way it was. I distinctly remember the vibrator whine of a mechanical vibrator Very "spiky" similar to noise induced by brushes. I can't remember if Mom and Dad's '56 Ford made the same noise, the car rusted away in 1966 after well over 100K miles but still ran. I had worked for a guy who restored Mustangs and Lincolns, as well as selling whatever he could find and we could fix. Lincoln went to "transistor powered" by 1958, and all transistor by 1960. Ford was all-transistor by 1963.
I did fool around with a lot of car radios collected from cars discarded at the town dump. I ran the 6V ones directly from an AC transformer without modification. Sadly, I can't remember if the vibrator was noisy or not. I think so, at least on the Automatic glommed from a 57 VW (they did not go 12V till much later than American cars did, and did not convert to Alternators till much later.
I had earlier suggested replacing the 0Z4 with a 6X5, but come to think of it, Ford products in the mid 50sused typical heater type rectifier tubes, not the 0Z4, which was popular in GM sets. I still think that it would help, though.
I like the "divide and conquer" method but in addition to testing by pulling the detector / AF tube, I would reinstall and pull the IF tube. However, considering that the noise is most prevalent with the volume control full down, I think that it is carrying through the power supply to the output stage. This is why I wonder if an LC or RC filter added post-rectifier would be helpful.
Is the output push-pull? I had a radio from a 57 Chevy that was.
"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
Best Regards,
MrFixr55
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