'34 ashtray radio noise suppression

R

RobbHelf

Member
Hi All,

I've been reading and reading many threads pertaining to the numerous ways guys out there attend to the problem of alleviating spark /current noises while operating their car radios.

Sooooo many different opinions and products. Guess it largely depends, too, on the types of noise that is present.

I call out to the owners and operators of this particular radio and setup....
a '34 ashtray radio built by Philco (model N) attached to the firewall of a '33 Fordor. What are the secrets of your success involving this installation and operation? (I would imagine having this radio in a '34 would involve the same
skills).

Particular questions... What spark wires work best?
What condensors work best and where? What type of antenna works best?
Any other things I missed?

Thanks much guys!
 
Last edited:
Re: '34 ashtray radio noise supression

RobbHelf said:
Hi All,

I've been reading and reading many threads pertaining to the numerous ways guys out there attend to the problem of alleviating spark /current noises while operating their car radios.

Sooooo many different opinions and products. Guess it largely depends, too, on the types of noise that is present.

I call out to the owners and operators of this particular radio and setup....
a '34 ashtray radio built by Philco (model N) attached to the firewall of a '33 Fordor. What are the secrets of your success involving this installation and operation? (I would imagine having this radio in a '34 would involve the same
skills).


Particular questions... What spark wires work best?
What condensors work best and where? What type of antenna works best?
Any other things I missed?

Thanks much guys!
Click to expand...

1- Carbon wire will probably work best with a stock ignition.
2- Use a COAXIAL capacitor on the generator output lead. Use one rated
slightly higher than the generator output.(amps) This type has a
terminal on each end rather than just one pigtail. Electrically it is in
series with the circuit with the body of the cap grounded.
3- Use bypass type caps (one pigtail with grounded body) at various places
you determine by trial such as wiper motor and temp gauge sender.
If you have a 2 brush generator put a bypass cap on the output
terminal of the regulator. DO NOT put a cap on the field terminal.
4- Most of ignition noise comes in the antenna so mounting it on the back
of the car gets it away from the noise source. Br sure to use the proper
type cable when extending the antenna. It is not low impedance coax.

There are a lot of other things that can be done to suppress RFI. It depends
on how quiet you want the noise and how much money you want to spend on the project.
 
Re: '34 ashtray radio noise supression

Thanks Pete. This sounds like a fairly intense project with many potential areas of remedial work. Are you wiling to share any brand names of these caps, cables and wire?
What auto have you applied these fixes to?
 
OK...I know there are bunches of you out there that own these vintage car radios. Would love to hear more about those successes and failures in attempt to eliminate RFI....specifically the setups in the '33s and '34s.
 
Re: '34 ashtray radio noise supression

RobbHelf said:
Thanks Pete. This sounds like a fairly intense project with many potential areas of remedial work. Are you wiling to share any brand names of these caps, cables and wire?
What auto have you applied these fixes to?
Click to expand...

The coaxial caps we used were Sprague brand.
The bypass caps were the same.
The carbon wire was generic and we got it at a wire supplier but it is available at most auto parts stores.
We did just about every brand of car and truck that was on the road.
I was manager of a 2 way business radio service shop so most all of our work was for business radios but the same methods apply for all RFI.
 
Hi Robb, I have an original 1934 fordor 6 volt system with a glove box radio and it works fine with all its original suppression equipment. First I would suggest you read the ford 1934 service bulletins pages 169 to 192 which you can buy in a reprint form from Macs and other suppliers. This will give you all the info you will need for your original centre control ford radio. Also a small radio fitting instruction book is available as a reprint. You must establish what type of noise is in your radio. Is it coming from the high tension ignition as in spark plugs and leads. Or low tension ignition as in coil primary and distributer contacts circuit. Or from the generator and cutout circuit. The original 1934 ford closed cars had a "chicken wire antenna" fitted into the roof on all cars with the lead in cable coming down the passengers side front pillar to the radio. These work very well. If your car is all original as Henry built it you don't need any modern resistance type high tension spark plug leads, but you do require resistors (right angle type) on each spark plug lead at the plugs. Capacitors on the generator cut out battery terminal and the ignition coil low tension terminal on the distributor are also a standard requirement. The radio power cable connects to the battery supply side of the under dash fuseholder and no other place. Do yourself a favour and buy the publications which explain all. Good luck, Regards, Kevin.
 
First off, thank you Pete, for the detail of brand names and your help and concerns.
Secondly, Kevin- this is great help. I will pick up these booklets immediately. By your description, this doesn't sound as daunting as I thought. I was reading all sorts of threads about what to do, but rarely were the contributors saying what kind of car and radio they had. This is a direct comparison to my car - a '33 deluxe fordor - although I may encounter slightly different issues being I have an ashtray radio. I could be wrong, but I lean on the side of each scenario will be different for every car owner.
Again guys, thanks much. I have a starting point.
 
Robb, Just some info on the original ford "chicken wire" antenna in the roof of 33-34 closed cars. That mesh chicken wire is nailed to the wood roof support bows with tacks. It is clear of and not touching the metal roof panels around its perimeter. The radio lead in cable is soldered to the front corner of the chicken mesh and then runs down the front pillar to the radio and if a radio was never fitted to the car the cable is coiled up behind the top of the kick panel. As I said the mesh antenna must be insulated (not touching) the metal car body otherwise it is useless. You can test this by using an ohm meter and connecting it between the antenna cable and ground on the cars body. There should be no connection here. Good luck with your radio fit up. Regards, Kevin.
 
Hi Kevin,

I will be out in the garage early to check on what you have relayed here. Great info. The car is all original and should have the coiled up cable where you say. I hope!!!???
 
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