CB install in Expedition

[mmckenna]

I made these two CB antennas from the following parts - EMWAVE X-nut base for NMO mounting, aluminum tripod adapter (1/4"-20 female to M6 -1.0 female thread) and President New Virginia antenna, and a Cobra HG antenna with female 1/4"-20 to male M6-1.0 adapter (see photos). Screwed then together and total length is just under 20". The President antenna is not adjustable, so I can't trim it to dial in VSWR. The Cobra is trimmable for VSWR. What do you all think? Will they work (< 1.5 to 2.0 VSWR?).

Looking at the President antenna whip, it looks like the loading coil is in the base, so if you did everything right, it will probably tune up somewhere close to the CB band, but you'll need to figure in the additional length of the adapter.

The Cobra looks like it's got a coil in the base, so probably same as above.

So, it might tune up, but you'll probably have to do some adjusting.

I have a Laird C27S for highway driving, but I need something short like this to get into and out of my garage each day and airport parking decks (96" max vehicle height) when driving around town. Distance communication not an issue in town. But, I'm betting installing this in the center of the roof of my vehicle on an NMO mount will give adequate reception in town (2-3 miles). Hoping it works. Let me know what you think.

An antenna that short is going to be a very poor performer. You can take an antenna that really wants to be 108 inches long and cram it into 20 inches. As the antenna gets shorter, the performance is really going to drop.

Will it work for receiving over 2-3 miles? That depends on the performance of the transmitter. If it's someone else with a really short stubby antenna, it's going to be a real challenge. If they've got proper antenna, it might work if the physics gods are smiling upon you.

 

[slowmover]

I understand the desire, but radio means one makes some adjustments. Kick the sullen teenager out of the drivers seat. A decent antenna is the definition of performance. (5’, IMO).

.

 

[niceguy71]

I appreciate the input. I am going to move forward with installing the NMO roof mount. Based on the input from mmckenna, I think all will be well.
Okay, with the NMO mounted, next subject... I made these two CB antennas from the following parts - EMWAVE X-nut base for NMO mounting, aluminum tripod adapter (1/4"-20 female to M6 -1.0 female thread) and President New Virginia antenna, and a Cobra HG antenna with female 1/4"-20 to male M6-1.0 adapter (see photos). Screwed then together and total length is just under 20". The President antenna is not adjustable, so I can't trim it to dial in VSWR. The Cobra is trimmable for VSWR. What do you all think? Will they work (< 1.5 to 2.0 VSWR?). The tripod adapters are the big unknown, only a half inch or so thick, but it may throw everything else off. I need to remove powdre coating in the threads, so they conduct current. Currently no continuity with VOM.

I have a Laird C27S for highway driving, but I need something short like this to get into and out of my garage each day and airport parking decks (96" max vehicle height) when driving around town. Distance communication not an issue in town. But, I'm betting installing this in the center of the roof of my vehicle on an NMO mount will give adequate reception in town (2-3 miles). Hoping it works. Let me know what you think.

I would love to hear how that Laird C27S works when you get everything done and get some experience with it.
funny how things work... I just made a video two hours ago on how a whippy antenna will not be any problem for a garage door and here I am reading your post... funny how it works.
for everyday use in your garage I don't think you will have ANY PROBLEM AT ALL those Laird C27S bend a lot and it won't hurt them... as for parking garages if you stand on the sill you can probably reach it and just unscrew it and put the antenna in the vehicle until you leave... they sell a little cap that screws on the NMO mount.

my video.... BTW my hobby is making TERRIBLE Video's and this is one of my worst!

 

[nokones]

Laird calls them Rain Caps. You can get them in Black or Chrome from Arcadian at www.arcantenna.com