CB whip antenna hold downs

[Sonicadventure]

Hey everyone, I am running a Larsen NMO27 on top of a station wagon. It works fine but I am having trouble as I park in a garage and I hate taking it off all the time.

I have a luggage rack and I was thinking of buying or fabricating a hold down clip so the antenna can stay mounted all the time.

Will that baseload coil sustain the whip being bent back most of the time or would I need to add an adaptor and a small spring?

Also, if I made a small l-bracket and attached itnto my aluminum roof rack, would the pet that touches the antenna have to be plastic so the antenna doesnt make a second ground connection? Or could I just mount the bracket right to the roof rack and only use the CB once the antenna has been removed from the clip?

 

[jonwienke]

You would have to add a spring to be able to bend the antenna that far without janking the mount or the whip.

Adding a spring will throw off the tuning; the whip would have to be shortened by the length of the spring.

TX with the antenna folded is a bad idea. Even if you have a plastic clip, the antenna being folded next to the roof is going to throw off tuning and raise SWR to the point where it would probably be unhealthy for the radio.

Something like this would be a much better solution:
https://www.gigaparts.com/diamond-antenna-k9000lrmo.html

 

[Ravenkeeper]

There's also the folding mount option or the QD.

https://cdn.shopify.com/s/files/1/0661/9627/products/Fold_Down-5_1024x1024.jpg

https://images-na.ssl-images-amazon.com/images/I/31JICCOztvL.jpg

 

[Rred]

Do you have enough clearance to just replace the antenna whip with a two foot long helical wound antenna? Like a FireStik 2' model?

Yes, there's a performance compromise, there always is when you need an antenna that won't break off, but not bad.

 

[FiveFilter]

Yeah, you wouldn't want to use the radio with a bowed antenna. It would throw off the SWR tuning, along with the rest of the antenna's performance characteristics.

My solution is twofold: a 3-foot shorty antenna which accommodates most low garage ceilings, or a homemade device I fashioned to allow me to bow a longer 4.5-foot Wilson 500 antenna downward without the need of a spring. Stop reading here if you don't want to be irritated by a tinker's shenangians. To wit:

I use a few inches of plastic or rubber hose that fits on the antenna from the top to about 1/4 down its length. Inside that hose, I slipped a piece of nylon cord big enough to go through the hose along with the antenna. A knot on the end of the cord prevents it from coming back out of the hose. At the other end of the cord, I fashioned a "hook" of sorts that fits on my license plate on my sedan (the most convenient spot for that particular car.) So, when I need to use this silly device, such as when entering a low-ceiling parking garage and a too-tall antenna, I get out of the car, place the hose-and-cord device over the tip of the antenna and slip it down about 1/4 or so of its length, and secure the other end of the cord to the license plate via the hook. This takes maybe a minute to do. Upon leaving the garage, I reverse the process. See, I warned you about reading too far.

Since I use a magnet-mount antenna, I could just pull it off the roof and store it in the car. The first part is easy to do; the second part gets a little tricky sometimes.

 

[Project25_MASTR]

Personally I'd just drag it...but that's just me.

 

[Trainguy1997]

I have the Hustler 102 inch setup, I was using a piece of headphone wire tied to the mounting base on the Streethawk light bar I have.

 

[FiveFilter]

Quote: "Personally I'd just drag it...but that's just me."

I tried that once, but it was disturbingly loud from the cabin, and the "looks" from others didn't exactly convey the warmest of feelings.

Also, I figured the condo association wouldn't take kindly to the Corona Ball skid marks on the ceiling.

 

[Sonicadventure]

I got a 2 1/4” spring off an old Larsen NMO 800 base...would that be ok to hook that onto the Larsen NMO 27 base coil and then shorten the antenna by that much, or do I need a certain length or thickness of spring to use for CB vs. 800mhz?

Speaking of cutting the antenna, I never got a chance to truly tune this antenna, as I live in the city and there is nowhere I am ever around that would be clear enough to test accurately with an SWR meter; I’d have to drive for hours to find a big wide open space suitable for SWR tuning. While the antenna works ok, I’d like to at least go by the cut chart Larsen provided, which will now have to be modified if I plan to use the 2 1/4” spring as above. How reliable is the cut chart Lersen provides? Thanks.