Mobile 3-foot mobile antennas

[Beetle]

Yeah, I think RG8x is a better choice, RG9 will be too wide and RG-59 is for a dual antenna setup I think since it's 75-ohms. .

Actually, for plain vanilla half-wave dipoles installed properly*, RG-59 or any other nominal 75-ohm coax will generally be a closer match at the antenna. At HF, I use whatever coax is available, exclusively. And I've never been disappointed in a dipole's performance.

*"Properly" means at least half a wavelength high and horizontal.

 

[Rwb]

Very interesting. My lil wil has swr og ch 1 1:2 20 1:1 40 1:2.i had to cut almost 2 " off the shaft. My bearcat 980 will easily talk 6 miles am and 40 miles lsb. So if i put 1 of my browning coil antennas or my 5 ft wilson silver tip on i should be able to talk to mars???
Oh mars lives north of me 3 miles and i talk to him easily

 

[M0GVZ]

Then why is your SWR going up when you add power?

Insufficient RF ground. Basically from overcoming the capacitive coupling capabilities of that magmount.

 

[M0GVZ]

Very interesting. My lil wil has swr og ch 1 1:2 20 1:1 40 1:2.i had to cut almost 2 " off the shaft.

Are you using a fixed body mount and have you done any bonding? Usually having to get the dremel out and scithe lumps off an antenna is either a sign of a very good RF ground or its too close to adjacent metal.

 

[Tallman]

Insufficient RF ground. Basically from overcoming the capacitive coupling capabilities of that magmount.

I run my 10 meter radio through my Sirio magmount and do not have that problem at all. I set the SWR with my antenna analyzer and when I run the radio it does not change at any power level.

 

[DeedleD]

over the weekend I'll go back to the parking lot 8 miles away from base and conduct the same test with my Wilson 1000 and see if there is any improvement...I wouldn't be surprised if I get the same performance with a mere 10W using my 5-ft Wilson 1000 and if so, I'll test 100W to see what that gets me...

I performed the test last night, the Wilson 1000 yielded a single s-unit increase (6db) over the 3-foot Midland and the SWR remained 1:1 across the entire band. When it's all said and done, I think the 3-foot Midland and the Sirio are great for what they are, especially if one doesn't have a choice regarding the height restriction, so long as the SWR remains within bounds. My next test will be with the 3-foot Wilson short whip made for Wilson 1000 base. Over the summer I might consider letting go of the mag mount and drill the roof for a more permanent solution.

 

[w9cll]

performed the test last night, the Wilson 1000 yielded a single s-unit increase (6db)

Thats doubling the output so one "S" unit is a good upgrade.

 

[hotrod]

I performed the test last night, the Wilson 1000 yielded a single s-unit increase (6db) over the 3-foot Midland and the SWR remained 1:1 across the entire band. When it's all said and done, I think the 3-foot Midland and the Sirio are great for what they are, especially if one doesn't have a choice regarding the height restriction, so long as the SWR remains within bounds. My next test will be with the 3-foot Wilson short whip made for Wilson 1000 base. Over the summer I might consider letting go of the mag mount and drill the roof for a more permanent solution.

id still be interested on putting a 5 foot firestick on where ya 4 footer was ..hard to beat a Wilson 1000 on the roof though

 

[DeedleD]

id still be interested on putting a 5 foot firestick on where ya 4 footer was ..hard to beat a Wilson 1000 on the roof though

You mean on the rear mount? I actually do have a 5-foot firestick antenna but at the time it seemed too tall so I never installed it and went with a 4-footer so it remains in the garage; i'll give it a shot when it gets nicer out. I just don't like the rear mount because of the fuel pump noise and only use it when I have the Yakima roof rack on and have to remove the whip. Also, since it's in the back, the radiation pattern should be less than ideal...but will be a good test nonetheless. Today I received the Wilson short whip in the mail so at least I'll be able to throw that on and see how it works.

 

[Redbeard U812]

Here is a good read about antennas. Pay attention to grounding and ground plane. Bonding the various panels of a vehicle to the frame. Drop the mag mount. 1/2 wave or 5/8 wave top loaded antennas work the best. I run a 102" with HD spring mounted to headache rack. All my panels are bonded, the mount is grounded, neg pwr lead to battery and to frame and cab or truck.

Good luck,

73's
Redbeard

 

[DeedleD]

Here is an older ARRL Antenna book.

Don't see an attachment with this post, and THANK YOU for the previous one, i'm reading it as we speak!

 

[Redbeard U812]

D

Don't see an attachment with this post, and THANK YOU for the previous one, i'm reading it as we speak!

Deleted the post. Dwnld would not take. Look up ARRL Antenna books. There is a Hall, the older, book 19, and book 21, you can download them for free pdf.

 

[338_MtRushmore]

A 4' firestik was the 3rd antenna I tried. I couldn't believe how noisy the receive was. Maybe I got a bad one, I don't know. The time spent spooling wire off of that thing to tune it was pretty ridiculous too.

Fyi, I don't care for firestik

 

[DeedleD]

A 4' firestik was the 3rd antenna I tried. I couldn't believe how noisy the receive was. Maybe I got a bad one, I don't know. The time spent spooling wire off of that thing to tune it was pretty ridiculous too.

Fyi, I don't care for firestik

Oh yea, I wouldn't have the patience nor the finesse to tune it that way! Luckily both mine are Firestik II with tunable tips so i just remove the rubber cap and screw it up or down to tune then put the cap back on to test the result.

 

[DeedleD]

This morning I quickly slapped on the Wilson short whip on Wilson 1000 base without tuning the whip at all. It's sent 39" tall from the factory and probably needs a couple of inches cut to tune for lowest SWR mid-band. Anyway, I just wanted to see how it handled high power, I was able to get it tuned down to 1.2:1 SWR mid-band with everything up to 300W with no issues at all. Very impressive! When I have more time I'll properly tune it and test it from 8 miles away as usual. I also came across someone wanting to get rid of their unused 8-element ground plane kit for Wilson 1000/5000 for $10 so I also bought that, just to experiment with. Will update once I'm able to conduct more tests.