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Message |
    
Funtimebob
Intermediate Member
Username: Funtimebob
Post Number: 160
Registered: 5-2002
| | Posted on Saturday, May 28, 2005 - 12:05 am: | 
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Just got a ball mount for my van and i'm a little confused. It didnt come with any directions. the ball itself is mounted on a plastic base. comes with a rubber gasket and 2 metal plates. one is just a "C" with mounting holes. The other is almost a complete circle with a small slot running across and hole in the center. dunno if i'm supposed to use both or just 1 of them.
planning on mounting it on the roof. was thinking that I should use the plastic plate/rubber gasket on the outside. and on the inside the full plate?
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Dx431
Senior Member
Username: Dx431
Post Number: 1048
Registered: 2-2002
| | Posted on Saturday, May 28, 2005 - 1:46 am: |
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A word of advise, drill the center hole Larger than the retaining nut. Don't want to ground out the ant. |
Funtimebob
Intermediate Member
Username: Funtimebob
Post Number: 161
Registered: 5-2002
| | Posted on Saturday, May 28, 2005 - 8:17 am: |
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This one has a small ground strap from a so-239? type connector to one of the mounting screws....? |
Hotwire
Intermediate Member
Username: Hotwire
Post Number: 387
Registered: 1-2005
| | Posted on Saturday, May 28, 2005 - 11:51 am: |
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Those ball mounts can be a pain. To much drilling and that center hole!!!! If using the roof why not try the one5/8 hole mount. I use the wilson mount. Large nut to get a strong clamp down and a nice water tight washer. Some call these mounts bee hive type mounts. This thing is solid as a rock too. I diid use a 1/8 inch thick 4x4 piece of sheet metal in with it to give it more stability. Sturdy as heck now. |
Funtimebob
Intermediate Member
Username: Funtimebob
Post Number: 163
Registered: 5-2002
| | Posted on Saturday, May 28, 2005 - 2:14 pm: |
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I'm using the ball mount with a 5ft Firestick. still need to find a piece of metal to reinforce the roof with. But what the hey, I'm posted at a scrap yard at the moment. hopefully the maint crew is working when i get in. some reason I cant find my cordless drill. not gonna hand file it.
ONE BIG Question. do i make the hole big enough not to touch the SO-239 and use the strap to ground or do i make the hole small enough to tighten down the nut on the connector for ground or both?? never used a ball with a SO-239 |
1861
Intermediate Member
Username: 1861
Post Number: 210
Registered: 2-2004
| | Posted on Saturday, May 28, 2005 - 4:52 pm: |
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USE A SKILL Saw CIRCULAR blade to reinforce .THEY WORK PERFECT. |
Crackerjack
Advanced Member
Username: Crackerjack
Post Number: 551
Registered: 7-2004
| | Posted on Saturday, May 28, 2005 - 5:15 pm: |
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I bought a hole punch, it is the only way to go. |
Hollowpoint445
Intermediate Member
Username: Hollowpoint445
Post Number: 318
Registered: 6-2004
| | Posted on Saturday, May 28, 2005 - 5:31 pm: |
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I used a ball mount on the roof of my car and I loved it. Actually, I used two different ball mounts. The first one I got at that national electronics store that's everywhere. It worked okay, but it wasn't very easy to pivot up and down and the rigid plastic base plate flexed under tension. The second I bought at a CB shop and it has a very hard foam plate rather than rigid plastic. It's much heavier and easier to pivot up and down. But If I ever run another ball mount on my roof I'm going to go with the all stainless one that's about $50 with the spring. My brother works for a utility that uses these for their VHF LO antennas and they are NICE!
I wouldn't bother with the ball mount unless you need a VERY STURDY way to mount the antenna AND a way to pivot the antenna to get it vertical OR reduce the height on short notice for clearance.
Neither of the ball mounts I used had an SO-239 so I can't offer any advice with that, but I can tell you that the "C" ring is for mounting it on a surface that isn't very flat, and the circle ring is for a flat surface.
Adding some additional support with another piece of sheet metal is a good idea. I used a square foot piece of fairly heavy sheet metal with the points pointing back to front and side to side.
My car looked like a life-sized remote control car and I got looks everywhere I went - especially from kids who would point. I didn't mind the kids, but sometimes adults who would point and stare got a universally understood hand gesture. |
Funtimebob
Intermediate Member
Username: Funtimebob
Post Number: 164
Registered: 5-2002
| | Posted on Sunday, May 29, 2005 - 1:20 am: |
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Thanks guys. 1st time installing a ball. I made the roof hole big enough to not worry about shorting the little screw end going into the ball.
used the heavy bracket to mount. Since I'm in a scrapyard I was able to get a piece of heavy gage metal off some kinda rack equip that was scrapped.
used a nibbler to get a corner section off the lid. made a center hole just big enough to barely pass the so-239 and tightened the nut along with the 3 mounting holes. mounted it covering the supplied bracket to take up some of the room from the tightening flange on the so-239.
still gotta put the little strap wire on. also still need to drill a hole in each corner of the reinforcement I made. |
Funtimebob
Intermediate Member
Username: Funtimebob
Post Number: 165
Registered: 5-2002
| | Posted on Wednesday, June 01, 2005 - 3:19 pm: |
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Curious, got everything mounted. went to adjust the antenna. got a flat match on 40. almost a flat match on 1. and this was by almost completely removing the adjustment screw. coulda completely removed it without changing the match. the match got higher by turning it in farther. |
Hollowpoint445
Intermediate Member
Username: Hollowpoint445
Post Number: 336
Registered: 6-2004
| | Posted on Wednesday, June 01, 2005 - 7:39 pm: |
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Sounds like you need a longer spring to lengthen the antenna. |
Funtimebob
Intermediate Member
Username: Funtimebob
Post Number: 166
Registered: 5-2002
| | Posted on Thursday, June 02, 2005 - 12:25 am: |
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already has a heavy duty full size spring from radio shack on it. Bought a USA spring and didnt like how loose the screw base was on it. will never buy a USA spring again |
Hollowpoint445
Intermediate Member
Username: Hollowpoint445
Post Number: 337
Registered: 6-2004
| | Posted on Thursday, June 02, 2005 - 6:08 am: |
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Is it the 6" spring that's usually used for 102" whips?
Just to make sure I understand you, the VSWR is slightly higher on 1 than 40?
Out of curiousity, what happens when you remove the spring and try to tune the antenna mounted directly on the ball mount?
You should be getting a match of about 1.5:1. If everything is perfect the impedance at the feed point should be about 36 ohms which is about a 1.5:1 VSWR. |
Funtimebob
Intermediate Member
Username: Funtimebob
Post Number: 167
Registered: 5-2002
| | Posted on Thursday, June 02, 2005 - 2:08 pm: |
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Hollowpoint, I have a FLAT match on 40, the needle just barely moves about a needles width on 1. Yup its the full size heavy duty spring from radio shack.
being mounted on the roof I dont dare run it without the spring because of small branches along the way to work. BUT I could take the spring off for "Testing" purposes |
