Clean looking vertical surface VHF/UHF antenna mount?

prerunner1982

Adventurer
About the only thing I have seen is on taxi cabs where they use a NMO mount through the side of the fender and bend the whip to be vertical.
 
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Would something like this work? It is not as low profile as the one you posted. It is a 3/8 mount so you would need to find a VHF/UHF antenna with 3/8" mounting.
molded_1024x1024.jpg


It can be found under the Firestick, Opek, and Workman brand names.
https://www.rightchannelradios.com/products/cb-antenna-molded-side-mount
http://www.firestik.com/index.htm
https://www.amazon.com/Opek-AM-701-Black-Pillar-Antenna/dp/B00L9CZA5I
https://www.amazon.com/WORKMAN-PSM-2-RADIO-ANTENNA-MOLDED/dp/B00TQ14F7I
 
I don't know right off of any good vhf/uhf dual band antennas with a 3/8" mount. To use a mount like I posted above would require a reverse adapter. There are several that will go from UHF or NMO to 3/8" male but not the other way.

One way to over come this is with the Diamond UHF SO239 to 3/8" mount used backward with a double female UHF coupler. Then you can use just about any vhf/uhf antenna with UHF mount.
http://www.diamondantenna.net/dia3824.html
DIA3824_L.jpg

I would use a thick small washer on the male stud to make sure contact was made with the brass mount and not the plastic housing. This is keep the connector tight and not depend on the plastic for security.

https://www.dxengineering.com/parts/aml-83-1j-2
aml-83-1j-2_oh_ml.jpg
 
Perhaps another way would be to use a PL259-3/8" adapter to get a SO239 type antenna to work?

sm1b.jpg


BTW, these guys have some unusual antennas and mounts.

https://www.packetradio.com

I like this idea better than mine. Lot cleaner just use a 3/8" stud and invert the assembly. Will give a much better choice of antennas. Those antennas posted above yes are direct mount but they are unity gain and tuning will be impossible. Better off with a wet noodle or coat hanger. You will be highly disappointed. Go with an antenna from Comet or Diamond and you will be well pleased with the tuning and performance.

Question for the group. Just thinking without a full load of coffee and going on a couple hours sleep. The 3/8" stud is only part of the antenna, the other part is the ground in the side mount itself. Now throw in reversed adapters designed to be used to go from a grounded connector to a single conductor without a ground. Say you use a 5/8 wave or more antenna, something with a loading coil in the base of the antenna. Does that loading coil in the base make use of ground? With the reverse adapter do we need to add a ground from the mounting plate to the SO239 side of the adapter so the loading coil in the base of the antenna can utilize the ground?


ETA: This might be a good question for QRZ or Eham then sit back and watch the popcorn show erupt.
 

DaveInDenver

Middle Income Semi-Redneck
That was running through my mind when I was looking at it, too. There'd be more capacitance between the antenna and ground/counterpoise for the circuit return. So it must be a pretty big impedance discontinuity. That might tune out but I'd think with VHF, and UHF for sure, it would be a poor match. We get away with it on CB and HF antennas but the wavelength is relatively huge compared to the gap so the effect wouldn't be as much concern. Honestly, not 100% sure but I'd probably do a parallel braided strap like you're suggesting.
 
That was running through my mind when I was looking at it, too. There'd be more capacitance between the antenna and ground/counterpoise for the circuit return. So it must be a pretty big impedance discontinuity. That might tune out but I'd think with VHF, and UHF for sure, it would be a poor match. We get away with it on CB and HF antennas but the wavelength is relatively huge compared to the gap so the effect wouldn't be as much concern. Honestly, not 100% sure but I'd probably do a parallel braided strap like you're suggesting.

Somebody is reading my mind. Glad you went into the more technical side of it. Yes a simple ring terminated small braided strap slipped between the brass and the insulator back to the mounting plate.
 

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