NMO-4 NMO to N female adapter, can I use this as an antenna mount?

[62Scout]

Working on setting up my new to me truck for the antenna farm. One of which will the classic 102" whip that I use for 10 meters and HF RX, and frankly..I really don't want to run a PL-259/SO-239 on this thing. It's going on an aftermarket front bumper, with a 1/8" stainless steel plate fabricated to hold it. No room to put antennas anywhere else due to other things on the truck.

On my last truck, I had a large CB antenna style mount but had an N-female on the bottom, which I didn't take off due to it starting to corrode a bit...and I figured I'd just buy a new one. Similar idea to the common UHF-3/8 stud and coupler nut style, just much larger in diameter, and did an excellent job in keeping an antenna with a lot of leverage from vibrating loose. I THINK it was made by Hustler, but I got it so many years ago that I'm not 100% on that memory.

Problem is - I can't find anything like it now, and Google ain't giving me much love tonight. I'm thinking about using one of these NMO to N-female adapters, then topping it with a NMO to 3/8 female adapter. Something like this - OPEK NMO-4 Just as an example..never heard of Opek, no idea if it's quality. I'd just as soon grab the PC-Tel version or a Larsen if they have one.

Will something like this hold up to larger antennas in a mobile environment? Or a better idea that still involves a connector at the mount. I don't want to have to cut coax when I periodically have to remove the bumper.

 

[mmckenna]

I'm not sure I'd want a whip that long on an NMO mount. While they are strong, it's really not the right tool for the job.

I think what you may be looking for is something from here:

Puck SO-239 # 610

3 inch Puck mount with pedestal mount and SO-239 connector .The Pedestal is 1-1/2 inches in diameter and 1-1/2 inches tall.3/8-24 thread in the top for the antenna .Model # 610

breedlovemounts.com

 

[62Scout]

I'm not sure I'd want a whip that long on an NMO mount. While they are strong, it's really not the right tool for the job.

I think what you may be looking for is something from here:

Puck SO-239 # 610

3 inch Puck mount with pedestal mount and SO-239 connector .The Pedestal is 1-1/2 inches in diameter and 1-1/2 inches tall.3/8-24 thread in the top for the antenna .Model # 610

breedlovemounts.com

Except that uses the connector I specifically said I didn't want to use. I get that it's been the standard for longer than we've been alive, but I still think it's a lousy connection for an outdoor mobile environment.

Maybe the solution here is just to go to a ring terminal connection, goop the heck out of it, and then add a coax stub with an N connector there.

 

[mmckenna]

Except that uses the connector I specifically said I didn't want to use. I get that it's been the standard for longer than we've been alive, but I still think it's a lousy connection for an outdoor mobile environment.

Maybe the solution here is just to go to a ring terminal connection, goop the heck out of it, and then add a coax stub with an N connector there.

I understand, N connectors are ideal, but you'll have a hard time finding them for these sorts of applications.

An adapter would be easy to add, and as long as it was well waterproofed, that should do the trick. That might be a better solution than ring terminals, which would also require a lot of waterproofing.

 

[K9KLC]

I'm thinking about using one of these NMO to N-female adapters, then topping it with a NMO to 3/8 female adapter

I've broken two of those, trying to hold up a 6 foot long antenna thru out the years, of course, YMMV...

I get that it's been the standard for longer than we've been alive, but I still think it's a lousy connection for an outdoor mobile environment.

it's not the ideal choice but, it's been the choice of a lot of long haul truckers (including myself when I did that line of work) for years and years now. I dunno 100,000 plus miles a year and more for some guys, must be something to it.

An adapter would be easy to add, and as long as it was well waterproofed, that should do the trick.

While this would work, is this any better than actually having just the SO-239 connector itself on the bottom? I don't know just a question I guess needing to be answered.

On my last truck, I had a large CB antenna style mount but had an N-female on the bottom

I think I actually remember this mount, it was rare and even in the mid 90's hard to find by itself. I had a friend that ran the Hustler CG-144 on his big truck and I think we got it in some kind of package deal or something at that time that had that stud included. I remember we had to make him a cable with a Pl-259 on one end and the N connector on the other end for it.

Good luck finding a solution that works out for you.

 

[billdean]

Still cutting down the NMO30 whip. The dip on the NanoVNA is about channel 40 now. I still have acceptable SWR on channel 19 but if I go anymore I will probably have unacceptable SWR soon. I am able to use the 10 meter band but how well I don’t know. I have the radio set to cancel the mic out at SWR 3.0 to 1. The SWR on 28.300 to 28.500 is about 2.25 to 1. Here are NanoVNA graphs.

 

[62Scout]

I get that as soon as I mention "102 inch whip", most people immediately think CB, but I really was running it on 10m, minus the spring, and it worked excellent that way with just enough headroom to go down into 11m if needed for traffic info... Though I found myself rarely getting anything useful on 11.

Though I'm thinking I might just be better off at this point to experiment with some cut down low band NMO antennas, and maybe add a CB radio in the mix with a NMO27. I just hate running the shorter antennas on HF, knowing the truck will block much of the signal to the rear

 

[K9KLC]

I get that as soon as I mention "102 inch whip", most people immediately think CB,

I get that. A friend of mine had a 102 on his truck for HF. Icom 7100, Icom AH-4 tuner and the tuner was mounted within 5-6 inches of the antenna to help with feed line looses. We used that from 80 meters (not too good there but it tuned there) up to 6 meters. It excelled on 20 and 40 meters many accusing him of running an amp but it was just the 100 watt radio. I don't think he ever used the 102 on the CB band he had a Wilson 5K for that and 10 meters.

 

[slowmover]

I’ve run big truck almost thirty years.

I find that UHF is fine given high-quality terminations & adapters (AMPHENOL).

A dab of blue Loctite after using De-Oxit on all and then cover with self-fusing tape over Scotch 33 (reversed; adhesive outwards) and a couple layers of Scotch 88 over all of that. Coax inside split-loom conduit.

Inspect 1X -2X annually or more.
For me that’s 120-140k miles.

Good luck.

.

 

[62Scout]

Or maybe...just maybe...my use case is very different than a trucker's use case.

Since I can't seem to edit the original post, I'll just add it here that I'm in watching the thread, because it's pointless to continue on when everyone is just assuming I'm running a CB on an OTR truck.

 

[mmckenna]

OK. I think you said 10 meter band, above.

The issue you are up against is that the 3/8" x 24 stud mounts are fine for low band, but not really a good choice on higher frequencies. N connectors are really designed for higher frequency performance. That's why you'll have a difficult time finding a 3/8" x 24 stud mount with an N connector.

But I understand wanting to use something better than a UHF connector.

For 10 meters, there likely isn't a noticeable difference between an antenna mount with a UHF connector versus an N connector.

What is your reasoning for sticking with the N connector and not using UHF? Maybe if you can answer that, we can help you a bit better.

 

[prcguy]

A bumper is about the worst place to mount an HF/CB antenna and it incurs extra ground loss being that low, not to mention more blockage from the vehicle than any other location. Have you considered a trunk lip mount on the hood near the cowl? That can work well and a 5ft antenna there should outperform a 9ft on a bumper. Maybe something like a Tram 1140, Browning BR-140-B, Laird CB27 or Larsen NMO27?