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Id these antennas?

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dave3825

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#1
I was cleaning out today and ran across 2 nmo mount antennas. Can anyone id these and let me know what range they may be tuned for? They both have the same base. ! has the coil as seen in the pic and is 10 inches (whip, not base). The second one is a straight 17 inch whip.



Thanks

 

dave3825

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Both of them are 800? The one in the pic has a coil and is 10 inches. The second one does not have a coil and is 17 inches. Would you know a brand on these?

Thanks
 

teufler

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#5
The one with a coil, looks like a motorola model. Heavy stiff wire, they make a light skineey wire model that bends, this one can prop up a turned over car. you can look at DPD PRODUCTS, they several antennas for 800 .DPD Productions - Amateur/Ham Radio Base & Mobile Antennas: Indoor & Outdoor Applications
If you just use one for monitoring, they work very good on 700-950 trunking systems. They come out of the box where you tune 800-900 , moving 1/2 inch for the 800-900 range. Motorola RRA4983A, HAS THE ANTENNA, COAX AND MOUNT FOR A NMO DESIGN. .oH THE 17" DESIGN, THATs PROBABLY A VHF 1/4 WAVE . Many police cars had a vhf and an 800 antenna. The 17" antennna, is more flexible . Probably cut for 165,000mhz or pretty close.
 
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dave3825

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#6
Thanks for the replies. I snapped a better picture. Both are 1/8 thick. So the one with the coil, bumping it out about a half inch would bring it from what to what?

Sorry

 
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#7
OK, those are familiar. As others said these were often included with the Motorola antenna/mount kits.

The top antenna in the photo above is an 800MHz antenna.
The bottom antenna in the photo above is a 1/4 wave VHF whip.

For reception purposes, just leave them as is. You won't be able to tell the difference if you start adjusting them.
The 1/4 wave antennas are naturally very broad banded, so it's fine as is.
The 800's work well from 806 up to 870 as is out of the box. You can tweak them a bit to lower SWR on a transceiver setup, but that isn't necessary for scanning. The trouble with the loaded antennas like that is that it's limited by the coil and upper whip as to which frequencies it'll work on.

For indoor use, they'll work fine. Avoid using those on a vehicle or outdoor install. Those antenna types are notorious for water getting down inside the base and corroding everything out. I replaced a lot of those at work and tossed them all in the trash.
 

dave3825

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Yeah, I see what your saying about the water. I did see a little corrosion inside them so I cleaned the contacts. I am using for indoor at this time. I thru the mount into a 2 gang metal box. The hole is slightly larger than the hole they tell you to drill but it did catch. I am looking for a mag nmo for my truck to help with the lousy NYS Police for my parkway travels. But its not a priority.

Is there anything special in the base? I ask because I have the whip from a rs 20-032 like in the pic below and wonder if it would work in the nmo mount being that it's also 1/8 thick. While I like an antenna tuned for the band I am scanning, I would like a more indoor broadband solution for when scanning different bands like air, 155 vhf, tband and 700/800. Really can't wait to find a house and have a scantenna mounted high like when I lived with my folks.....

 
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N5TWB

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I use the whip from that old RS multi-band mag-mount in an Antenna Specialists MOSAIC NMO base and it works great. I have it roof-mounted on my SUV and it does a fine job feeding a couple of scanners in the truck thru a Stridsberg multi-coupler.
 
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#10
Nothing in the base of those 2 antennas you posted. If the whip from the RS antenna will fit, give it a try.

As for a mobile antenna for your truck, go with a new 1/4 wave or similar. Those bases suck and they'll fall apart in short order. A new 1/4 wave antenna will be about $10. Well worth the investment to save the headaches later on -when-, not if, those Motorola type antennas fail.
 
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