I need a little help from the antenna guys once again...

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btritch

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I need a little help the antenna specilaists once again...I have noticed that the antenna on top of my ford f150 receives well, But not as well as most mag mounts do...Therefore I need a better mag mount that is the MOST suited for 150-170 MHZ, I do a little 400 and 800 but not very often, MOSTLY 150-170...And it can't be but maybe an inch or two longer than the current one to get in the shop.. Here is a link to the one that's on there now.. http://www.radioreference.com/forums/attachment.php?attachmentid=15413&d=1210644398
It needs to be at or around the same size, I only have a few inches longer to work with, Shorter'd be ok.. I really need mag mount if possible.. Any suggestions anyone, I have looked at some of the former posts on this topic and have saw some good suggestions and ideas but they've all looked to long, although I could be mistaken, Does anyone know of any this sort? Suggestions open..

Thanks Again TEAM!
 

DPD1

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Your picture shows a 1/4 wave. You would do better with a VHF 5/8 wave. If you hear different stuff between 150 and 170, tune it to 160 and split the difference. Otherwise, tune it to whatever part of that area you are most interested in. 800 should still come in fine if it's just the local system.

Dave
www.DPDProductions.com
Antennas & Accessories for the RF Professional & Radio Hobbyist
 

KC0QNB

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Well you can buy a 150 mHz 1/4 wave (about 18 inches long) and you can buy a 5/8 wave base load(about 54 inches long) and you can buy a nmo type magnetic mount that will work with both if you buy the right antennas, get commercial grade. Larsen, Antenex, Maxrad, and of course A/S, Maxrad and A/S are owned by the same company but are definitely two different antenna designs.
If you are thinking about your ham ticket one antenna will do it all. What year is your truck?
 

N1BHH

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A VHF quarter wave does extremely well for 400 and 800. I have one right now hooked to my Pro-2055 and it does what I want it to do. I hear everything that's programmed in, all 1000 channels. The Larsen NMO-150/450/800 does very well and I have one on the van. Both antennas do work very well. A 5/8 wave which is 48-49 inches will have narrow bandwidth characteristics. Another thing about 5/8 wave antennas, I have found the quarter wave outperforms the 5/8 since the 5/8 is concentrated at the horizon, where the quarter wave has a radiation pattern similar to a doughnut.
 

btritch

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Wncy237

I have asked about all of these ideas and they have told me that they'd rather have a mag mount on the top such as the one now, However I have done some measuring.. The one in place now is a 16".. Now according to measurments, I am allowed to go up to 21 1/2 inches long from the top of the truck,, That's including the base..What is one that actually cut to size for VHF Hi, 150-170? 1/4 inch?

I have no idea why I put that for a title, Troy TN. named off their license about the time I typed it.. lol sorry...
 

KC0QNB

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Take 234 and divide it by the frequency so for say 160MHz (band center) 234/160=1.4625 feet multiply that by 12 to get 17.55 inches at 160MHz. This only applies to a quarter wave antenna.
To show the frequency to wave length relationship try this on,
30MHz 1/4 wave antenna would be calculated thusly 234/30=7.8 7.8x12=93.6 inches
now to go up to 800 MHz 234/800=.02925x12=.348" about 3/8 of an inch
So with this data a full waveength for 30 is 31.2 feet, 160- 5.85 feet and at 800 it would be 1.392 inches just over 1-3/8 inches.
 

btritch

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Take 234 and divide it by the frequency so for say 160MHz (band center) 234/160=1.4625 feet multiply that by 12 to get 17.55 inches at 160MHz. This only applies to a quarter wave antenna.
To show the frequency to wave length relationship try this on,
30MHz 1/4 wave antenna would be calculated thusly 234/30=7.8 7.8x12=93.6 inches
now to go up to 800 MHz 234/800=.02925x12=.348" about 3/8 of an inch
So with this data a full waveength for 30 is 31.2 feet, 160- 5.85 feet and at 800 it would be 1.392 inches just over 1-3/8 inches.
so for the 150 mhz, I'd need a 5.85 foot antenna...wow!
 

KC0QNB

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quarter wave is only 18- 3/4" read the whole post.
I believe a 5/8 wave base load mounted on a bracket in the hood groove would blow away the 1/4 wave on a magnet on the roof performance wise, and the truck would easily fit in the garage with no antenna clanging, provided the truck is not jacked up.
Do I need to explain why? simply put. capture area, you will have nearly three times the capture area with the 5/8 base load.
 

btritch

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quarter wave is only 18- 3/4" read the whole post.
I believe a 5/8 wave base load mounted on a bracket in the hood groove would blow away the 1/4 wave on a magnet on the roof performance wise, and the truck would easily fit in the garage with no antenna clanging, provided the truck is not jacked up.
Do I need to explain why? simply put. capture area, you will have nearly three times the capture area with the 5/8 base load.
yeah, i see what you're saying, makes sense..
 
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