RF Grounding Options for HF Mobile Magnetic Mount

I am using MFJ Mini-Sticks for 20m and 40m on a 5-inch NMO magnetic mobile mount. The 20m stick works quite well, as I had good contacts to Hawaii, Canada, and the US east coast from here in Santa Barbara, California.

I believe the performance can improve if I had a good RF ground. I understand that capacitance offers some grounding between the mount and car, but it is not very efficient for 14 MHz and below.

I have a 2005 Toyota Matrix, which offers no ability to have a lip mount. I want to avoid drilling holes, which is why I am using a magnetic mount. What would be some effective ways to get a better RF ground without permanently altering the car?

---Michael

asked Jan 26 '10 at 23:00

NO6O
371●1●1●11

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Michael, like you I have a magnetic mount antenna to preclude the necessity of drilling a hole in the car body, to provide a direct ground for the antenna. I use a number 10 AWG wire hooked to the base by using a electrical eyelet connector which is placed over the threads before screwing the antenna to the mount. The 10 AWG has a small electrical eyelet attached to the other end and this is attaced under a screw inside the drivers side door. Before I attached the wire below the screw I removed the paint around the screw hole. After replacing the screw, I used liquid tape to cover the screw and wire connection to help prevent corrosion.

Regards Larry

answered Jan 26 '10 at 23:11

K4RFE
914●1●1●6

edited Jan 26 '10 at 23:38

Thank you, Larry. I wondered about running a wire to an existing screw, but wanted another opinion first. The whip screws into a 3/8-24-to-NMO adapator, so I could put the eyelet on the antenna's threads before screwing it into the mount. What is "liquid tape"? I assume it's used as a sealer, but I have not heard of that term until now. Also, did you have any trouble removing the screw near the door, without breaking off the head? --- Michael

(Jan 26 '10 at 23:23) NO6O

I answered my question about Liquid Tape. For others, here is a link to it: http://www.plastidip.com/industrial_solutions/Liquid_Tape_-_Electrical_Insulation ---Michael

(Jan 26 '10 at 23:30) NO6O

Michael, I first scraped the paint of the screw with an razor blade knife and around the screw head to make it easier to remove. Larry

(Jan 26 '10 at 23:48) K4RFE

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Tags:

ground ×6
hf ×5
mobile ×4
magnetic ×1
mount ×1

Asked: Jan 26 '10 at 23:00

Seen: 1,228 times

Last updated: Jan 26 '10 at 23:38