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Post by libslayer on Nov 13, 2013 23:56:32 GMT -5
My buddy 'Thumped323' has been having a lot of issues with his antenna and had tried almost every style of antenna to try to correct the tuning issue. Well this home made ground plane was his fix.....and holy cow it worked wonders. Check out the pics. KATO808 #DeepInTheHeartOfTexas Attachments:
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Post by libslayer on Nov 13, 2013 23:57:16 GMT -5
Another shot. Attachments:
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Post by libslayer on Nov 13, 2013 23:58:00 GMT -5
#3 Attachments:
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Post by libslayer on Nov 13, 2013 23:58:39 GMT -5
This is what I call....'educated southern engineering'
What do yall think? ;D
KATO808 #DeepInTheHeartOfTexas
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Sandbagger
Administrator/The Boss 
Posts: 6,247 
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Post by Sandbagger on Nov 14, 2013 7:14:38 GMT -5
This is what I call....'educated southern engineering' What do yall think? ;D KATO808 #DeepInTheHeartOfTexas A "ground plane kit" should not be necessary on a mobile setup, if the vehicle body is metal. The "ground plane" is provided by the vehicle body. If there is a problem getting an antenna to match up (assuming the antenna is good), there is usually either a connection issue, or the antenna is mounted too close (vertically) to a mass of body metal. Also, to provide an effective ground plane at 27 MHz, requires radials 1/4 wavelength (9') long. 6" radials would be fine at 450 Mhz, but would offer very little (if anything) at 27 Mhz. I would venture to guess that he had a ground connection problem which was inadvertently fixed when this "kit" was installed, and that is what fixed the matching issue. |
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Post by libslayer on Nov 14, 2013 8:46:21 GMT -5
He said it had something to do with reflection not really SWR. All I know is we got a line of sight at 26 miles the other night, so whatever he did worked. ;D
KATO808 #DeepInTheHeartOfTexas
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Post by cbrown on Nov 14, 2013 9:59:23 GMT -5
I would venture to guess that he had a ground connection problem which was inadvertently fixed when this "kit" was installed, and that is what fixed the matching issue. I'd have to agree. |
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Post by libslayer on Nov 14, 2013 14:20:07 GMT -5
I'll pass this info on to thumper. Thanks.
KATO808 #DeepInTheHeartOfTexas
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Post by cbrown on Nov 15, 2013 10:08:05 GMT -5
He'd be better off getting it off the rack and mounting it directly on the roof of the truck.
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Nov 15, 2013 10:15:27 GMT -5
He'd be better off getting it off the rack and mounting it directly on the roof of the truck. Well that's certainly true, but a lot of people (myself included) are hesitant to drill holes in the roof, or attempt to figure out how to remove and replace the interior roof liner, without destroying it in the process.  |
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Post by THUMPER on Nov 15, 2013 20:18:20 GMT -5
What you doin in the back of my truck! Nice pics though.
I did spent a few hours on a Saturday at a local cb shop trying many different antennas, mainly to use a better meter than mine from radioshack. Whips, fiberglass, truckers in existing mount on rack. Tried magnet mount wilsons on center of roof, and previous mentioned antennas on a magnet mount. Even different coax and tested a new radio they tuned out of box with all the antenna setups again a second time(minus drilling through roof). All tuned about the same, average swr about 1.5-1.8 from 1-40 and about 30-50% reflection.
Tech thought it was lack of ground plane. So I checked everything with my meter, everything on truck was grounded well and all bolted on accessories as well. So decided to make a ground plane to fit between what was already mounted. Nothing changed from original setup before adding ground plane, except for grounding light bar since it covered part of ground plane, but didn't see any real change. Extra screws are just to keep cooling fins from whistling while I drive since it faces rear of truck.
Tune is great now, no more than 1.1 swr on ch 1-40 and only about 5% reflection. Whatever issue may have worked itself out it was worth the short term headache!
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Post by libslayer on Nov 16, 2013 1:37:51 GMT -5
Hey there's thumper......can you guys give him a hearty hello? This is the guy that really sparked my interest in CB radio. And one day soon I will be a licensed operator. ;D
KATO808 #DeepInTheHeartOfTexas
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Post by cbrown on Nov 18, 2013 9:55:18 GMT -5
Well that's certainly true, but a lot of people (myself included) are hesitant to drill holes in the roof, or attempt to figure out how to remove and replace the interior roof liner, without destroying it in the process. Ya, I know its tough. The worst time for me was someone I knew wanted to put his two meter setup into his car, and wanted me to do the install. No problem, until I saw the car. He wanted me to drill a hole in a rear fender for the NMO mount. His car - a 1980 Rolls Royce Silver Shadow II. If I screwed up, I couldn't afford the paint for a touch-up, let alone a new fender. Luckily the install went off without a problem, but I was darn nervous drilling that 3/4" hole. |
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Post by libslayer on Nov 18, 2013 10:08:37 GMT -5
Kinda hard to drill a hole in a classic. How'd it turn out?
KATO808 #DeepInTheHeartOfTexas
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Post by cbrown on Nov 19, 2013 9:28:24 GMT -5
Fine, actually. This was back in 1984, so at the time it was a four year old car. But still, I made sure I took my time.
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