Technical Rf capacitors

Gathering ignition schtuff for the flatty and it got me to thinkin (rare) have any of you used an RF capacitor for sound system needs while running the vintage plug wires? I ran one in my bracket racer to clean up electronics for the delay box and MSD, gained a 10th plus in 60' time, but it was big, like a pop can, and free. I know they can work but what's our fellow HAMB folk using? Thanks...

 

What kind of sound system? what kind of ignition system?

OEM stuff....there was usually a small capacitor on the power side of the coil, to filter ignition noise for an AM radio. Corvettes used shields over the plug wires and distributors, because they had no metal firewall to block ignition noise. If you have a bad diode in an alternator, you're likely to hear a whining in the radio, frequency depends on rpm. Chokes are used to filter noise from power wires on many modern electronic things, you might have seen lumps on computer cables, that contain a ferrite ring.

Big capacitors filter low frequency noise, small ones filter high frequency noise.

 

Have you checked with auto audio installation parts companies or installers?

 

I'll be running a semi-hidden modern bluetooth CD player and a 600W amp with a couple subs. I sort of figured the metal tubes for the plug wires will ground out some of it, but with modern electronics I'm not sure what's best which I why I thought to start a topic. Ignition is a Mallory dual point and the coil is the the old Holthouse. Wires are solid core. No ignition amps or the like, charging is a Powergen alternator. There's 2 condensors (capacitors really) involved in the coil get up. 1 is on the coil power lead, 1 on the distributor, and I figured those were for points life/control.

 

Try it and see how it works.

Sent from my Trimline

 

How about something like this ? And made by Champion Sparkplug

 

If you're running with no hood then RF radiated getting to the antenna. If you have a hood run ground strap from hood to body and make sue you have a good body ground. Running RF plugs will also help. The capacitors are for ripple noise on 12 volt power lines which if large enough you can also hear it on the radio.

 

We used to tie an overhand knot in the coil wire ..

 

NGK still sells these in various ohm values... 5K ohms is a popular size. The only trick is you need a plug that has the 'old style' threaded top.