F1 Radio issue

3twinridges

3twinridges

Well-known member
We have an original 6v hi-fidelity radio in our 52 F1 build. It has been restored and has the fm board added to it. It’s still 6v positive ground. It plays great in the garage with no issues. When you get it out on the road, the volume comes in and out.

I read the troubleshooting section in the manual, and it seemed to indicate that the fuel gauge sender may be sending interference. I have the noise reducer condenser for the fuel gauge sender and oil pressure sender but not installed. Should I install those? Do you think that is the problem or a tube going bad? It seems like if it was a tube it would do it in the garage. Thoughts?

JB
 
JB

Since the radio works while stationary in the garage, I would check the antenna lead for a possible loose connection caused by the trucks movement. Have adjusted the “trimmer” on the side of the radio. Page 285 4a. Antenna trimmer adjustments.

Hope this helps,

Tom
 
I play tube guitar amps....if its tube related it might be because of the jostling around when your moving, or a tube just going bad on it's own. Might try some contact cleaner on the tube pins and push them in and out of the sockets to clean them
 
Mmeader said:
I play tube guitar amps....if its tube related it might be because of the jostling around when your moving, or a tube just going bad on it's own. Might try some contact cleaner on the tube pins and push them in and out of the sockets to clean them
Click to expand...

So do I and have a number of old Fender amps.

The fact that it plays well in the garage and comes and goes in the truck, leads me to believe it's a connection or interference issue.

Curious if it plays well in the truck before you start it?
 
I put NOS noise suppressors on the fuel sender and oil sender, we will see if that solves it. It could be a grounding issue, layers of primer and paint. I will keep troubleshooting it.

JB
 
Its been a so long time since I was into radios. Many had condensers all over, ground straps
on hood, those springs in front wheel bearings behind the dust cap. Then most if not
all went to transited power supply like 1957 or 58 and all those suppressors went away.
Sounds almost like a voltage spike? Buffer caps? we use to snap tubes with your finger
any noise or static bad or weak tube. Capacitors have a life span as many nos in the
box on ebay but they are 75 yrs old no good. I have no idea what was done to your
receiver like probably had a transistor ******** installed which I have no luck with or maybe the power supply was changed > no clue.... so in the shop its fine but on the
road its not but on the road generator is putting out more amps and volts: All I can say it with no money spent do a red neck test - a 6volt battery on your floor jumper wires
remember pos ground. now go for a ride that will eliminate most or all interference, generator noise plug wires suppressors worth a try first.......sam
 
Did some troubleshooting today. We have 6 bolts at the radio with the switch on and engine off. Start it and run for a minute, we have 7.5 bolts at the radio, and it’s cutting on and off. Think our voltage regulator is the problem? It’s NOS but could be stuck I guess.

JB
 
Don't know. The 7.5 V may be normal after starting. My 40 with radio has a capacitor attached to the volt reg. FWIW
Paul in CT
 
I changed out the voltage regulator with another NOS one I had. Everything works fine. I guess the voltage cut out needs a little adjusting on the first one. I need to research that so I can adjust as a good spare.

JB
 
Radio is still cutting in and out. Sent it back to the shop and they tested it, found no issues! Makes me think I have a bad ground. If I have a bad ground, would that cause me to pull more amps, possibly overheating the power supply or blow a fuse?

JB
 
Check the easy stuff first, like ground wires. Don't rely on the radio case or box mounting screws for a ground. Run a wire from a screw on the case to the frame of the car as short as possible. You can check this easily for testing with a simple clip lead.

Does the fading in and out follow throttle position? If so, the problem could be ignition noise.
Flatheads put out a lot of ignition noise. Carbon wire or resistor plugs will usually cure this.

You need a COAXIAL capacitor on the output terminal of the alternator or generator.
These connect in SERIES with the output lead, NOT to ground like most RFI caps. Only the case is grounded with these.
A standard cap to ground right at the voltage regulator armature terminal. NO CAP ON THE FIELD TERMINAL.

The various caps can be had at most commercial 2 way radio shops.
While you are there ask questions about your problem but talk to a tech, NOT a salesman.
 
I don’t think it’s a bad breaker Ross, the heater works fine. Pete will try the ground first, I think that is the issue. I laid some thick epoxy primer under the dash so I don’t think it’s making good metal to metal contact.

JB
 
So have you checked your antenna connections as in the center connection and also the ground for the antenna ?? Lots of things mentioned here but the antenna would be the first thing to test. Connect another antenna for a trial. The voltage of your charging system should be 7.5 volts with some revs up so you did not have a problem there with your original regulator. Power supply and ground on radio case should be tested also when driving along. Regards, Kevin.
 
I was told the FM board is very sensitive to low voltage when you are using it on a 6V system.
 
Definitely a noise problem. Radio works fine with clutch pushed in rolling and idling, but under power comes in and out. I picked up noise suppressors for the generator, coil, and voltage regulator. On the voltage regulator does the connector go to the arm screw?

JB
 
I added the generator suppressor and voltage regulator suppressor this morning and still had the issue. Then I added the coil noise suppressor and changed out the ******** to a new solid state unit and issue is solved. Not sure if it was the coil or the ******** but it sounds awesome! Going to enjoy the rest of the day with my victory!

JB
 
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