Mobile HF HAM Radio - Vehicle Bonding and Reducing Ignition RFI

An overview of my attempts at bonding my mobile HF setup for greater antenna efficiency, and other attempts at reducing ignition noise in my RX.

HF Mobile Install Overview video:

MFJ 20 Meter Hamstick unboxing and setup:

MFJ-929 Tuner Unboxing and Setup:

MFJ-929 Operation Video:

MFJ-909 Coupler: Unboxing, Setup, and Installation

[littlerhino]

Hey man, an ASE certified mechanic here, I wouldn't recommend adding a choke on the ignition wires, it's just a bandaid to the problem that you acknowledged in the conclusion of the video. Low impedance is what you're after. More power transmitted to the spark plug means less radiated into your antennas. The choke might also lower the efficiency of the plugs, leading to ignition issues, though if that were the case you'd certainly notice this many years later.

[NebukedNezzer]

I have a chevrolet silverado 2500 4x4 truck and had to rf bond lots of stuff on it and replace the packard wires with MSD to get the ignition noise down. when I had 80s toyotas I put coaxial rf capacitors on the fan wires near the fans. On a 2000 echo I had to add a coaxial rf capacitor near the in tank fuel pump. on one car I needed coaxial caps on heater fan and windshield wiper motor. lots of stuff can make noise. Yes, ground the tail pipe to body and frame. You can use a portable radio on am to sniff for noise or a coax on the am ham radio with a sniffer loop on the end( cut back the shield a couple inches and bring the center wire out in a loop that connects its end to the shield). Used that on cb radios when I worked at a radio shop in the 70s. I never became a CBer but love the movie "Citizens Band".

[WJFRadio]

I used a similar mount for HF on my Honda Pilot and I also used a ground strap, but I cut off the painted caulking and scraped off some of the paint to get a better ground.

[ricardocalles]

As a novel approach, how about replacing the spark plug and coil wires with a high quality HV coax (with100% shield/braiding) and then ground both ends of the cable shield to a good ground. The only tricky part is carefully removing the old plug boot connectors and re-attaching them to the HV coax. HV Coax is available in ratings from around 5kV up to 150kV dielectric. For auto applications, a 25 -30kV rating should be fine. This will also improve spark plug energy since most spark plug wires have around 10k - 20Kohms of resistance so you'll get more power to the plugs which can help improve fuel combustion which will improve MPG. Also, most HV coax I've seen is rated to 200 degrees C (392F) so it will easily withstand the heat under the hood.

[MegaJunebug]

Find all your engine grounds and clean them up, when you bolt them back on use copper never seize. It helped with mine

[adriandrenalin]

Just FYI on bonding straps on the exhaust pipe, you need to grind that rust off before you bond the wire. rust acts like an insulation to the good metal under the rust so grind the rust and bond that wire to clean bare metal.

[James_Bowie]

So the RFI you show at the beginning of your video: is that the before or after RFI? Ferrite beads on spark plug leads are a complete waste of time. Grounding the exhaust pipe properly at 3 or more places is usually quite effective at HF.

[alexwade]

Around 2:30 you saying you can barely hear the noise, but your noise blanker is on.

[Littlelewie]

One thing that could be causing this is your electronic injection system. One other thing I have found is any device creating interference can easily cause it through its power feed wires. Example, led lights pull amperage in fast pulses causing the voltage in the feed wires to fluctuate and become antennas. Put capacitors on as close to the noisy device as possible. Values are hard to suggest I'd say about 1uf. You almost can't go too big.

[NNDF]

I had a similar situation. I had to use chokes on the alternator wires. At the alternator and at the battery. And at the fuse box

[patrickwelch]

cool. Thx for the reply. Nice setup. I am just getting on mobile hf and I am operating in a restored m37 truck that is completely bonded and shielded as it was a radio truck in its army days. hf is useless in my other vehicles bc of noise 73 N2XEV

[joeddejohn]

Quite an effort. Going through something similar right now.

[NAVYABHAN]

I appreciate your effort’s, but the grounding strap’s are picking up a lot of static from the surrounding areas and weakening your transmit and receive. What I have done on my vehicle is used “shielded cable’s “ for my ground’s. This improved outside noise rejection dramatically. A lot of people use 10 gauge wire, but I don’t and never will again. My SWR is .25 on all channels. My radios are all Galaxies!

[jwnagy]

Not antenna wires....you mean ignition wires...right?

[Q_]

Really wish I could find the solution to this...

I've Grounded and Bonded everything.

Cleaned all Previous Grounds.

Replaced Battery.

Replaced Alternator.

Replaced Ignition Coils and Sparkplugs with NGK Resitive ones.

Replaced Fuel Pump.


Radio is connected straight to the battery.

Does anyone have a solution???

[jameskua]

What was the mix of the ferrites? If they were not either mix 31 or mix 43 (more likely to help on higher frequencys) then they may not do much good. Those white ferrites look like the cheap "no mix specified" ones you get off of ebay or Amazon from china. Good Ferrites can cost several dollars each. I would get 6 Mix 31 ferrites made by fair rite themselves. Mouser is a distributer for fair rite and has the best prices. If you don't know the mix of your ferrites, then you have nothing. There is MUCH to learn about ferrites. de James K0UA

[TheFlyingSquerill]

search eBay "new old stock cb cornell-dublier" you should locate an ignition noise damper has a long red tube with wire coming out of it...should eliminate your ignition noise...

[bktk]

ground engine block to battery with wide short straps

[norcalstimpy]

Great video! K0BG.com is the best website I have found for all things mobile ham radio including a great section on grounding. Take care!

[joerowland]

Good start first ground radio to tuner like daisy chane to groung muffler pipe
Shoud b grounded every secshin but 3 miname
You need a v.o.m. meter check for 0 omes exspeshle at antten
Put a ground strap on the alternator to frame n battery
Forgit the bead on the spark plug wire's Jegs has thare brand wire cheap but thare good for rfi
Bound all the body panels together
N ground body to frame in 4 place at least thare rubber for vibration in body mounts the bounding dos not help whith rfi as much as lower your take off angel but just on hf
All this is in the arrl mobilelering hand book mobile hf something i really like bin doing it for 30 YEARS n 706 mark 2 n mfj m500
N outbacker antten
Hope this helps 73 n9prf