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WD5IKX
2nd Jun 2015, 18:47
I guess I will start out the mobile forum. I recently finished a new HF mobile antenna which I call the "Bug Eliminator". I purchased an incomplete coil from a ham on QRZ. I finished the coil by making all the connections and adding the "wander lead". I placed it on the 54" mast with shunt coil that was already on my Durango and I placed a MFJ-1694 72" whip on top. The antenna is right at 13.5' and just clears the 14' max height allowed on the roadways. Using my MFJ-259 antenna analyzer I found the resonant point for each band and I place a coil tap clip for 15m, 17m, 20m, and due to the high Q of the antenna I have 3 tuning points to cover the 40 meter phone band. The antenna will cover 30 meters as well when I decide to run CW or digi modes from the mobile. If I put a 36" whip on top I can tune 10 and 12 meters. Due to the size of the coil it lives up to it's name and eliminates many bugs on each trip out on the highways. (o:

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This picture was made at my favorite high point near the QTH where I go to escape the 9+ QRN level I have at home.

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I do most of my HF operating from the mobile running 100 watts SSB. This antenna makes working mobile DX pretty easy.

OK....Lets see your mobile installs.

John
CCD-Freak

M0LMK
2nd Jun 2015, 20:04
I was wondering when someone would find this section :p

What are you using for the lower mast John?

Also, would you mind sharing the dimensions of the coil and number of turns per inch? Would be interesting to compare with the one I am currently making.

WD5IKX
3rd Jun 2015, 00:57
Hi Matt

The mast is one of the 54" non folding masts made by Hustler. DX Engineering sells them as well as some under their own brand.

The coil is 3" in diameter and 5" long 40 turns. (With the mast and whip I am using the coil could be as little as 25 turns to tune on 40 meters)

John
WD5IKX

M0LMK
4th Jun 2015, 13:40
Thanks John.

My coil is 4 1/2" in diameter and 7 1/2" long with 6 turns per inch giving me 67 turns. My mast and whip are shorter than yours though.

WD5IKX
4th Jun 2015, 14:53
HI Matt

Is that your "Ugly Bug" antenna? It looks like it should work quite well mounted on top of the vehicle. I like to make my antennas as long as possible to make them more efficient. I have used several of my HF mobile antennas on a ground stake mount with radials for portable operation and they have worked quite well. I have not tried the "Bug Eliminator" in a portable configuration but it should work well.

268 This is my "Bug Whacker" 10, 12, 15, 17 and 20 meter mobile antenna set up for portable operation.

73

John
WD5IKX

M0LMK
4th Jun 2015, 15:50
Yes, It's V2 of the "Ugly Bug"!

I do have a 9' whip that I may use for the top section with a small cap hat but I will need to beef up the lower mast first.

The coil id being laser cut next week so I should have it put together soon.

WD5IKX
4th Jun 2015, 16:37
Hi Matt

Please post pictures of your laser cut coil. It sounds very interesting.

John
WD5IKX

M0LMK
6th Jun 2015, 10:44
It's in the queue waiting to be laser cut at the moment. Should get it back some time next week.

Here's the basic file that I sent to be cut. It's cut from 5mm clear acrylic. I'll probably get it done from polycarbonate once I'm happy with the design.

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When I have it working properly, I'll put the laser ready file in the resources section together with the full build plans so anyone can build one. I may also get a bulk lot cut and offer them to members at cost if there is any interest. ;)

WD5IKX
6th Jun 2015, 16:50
I would be interested in one if you decide to make it available. What type of cement or epoxy do you plan to use for assembly?

John
WD5IKX

M0LMK
6th Jun 2015, 20:11
I have some Tensol 12 for the test coils.

Not sure what I'll use if I have it cut from polycarbonate.