Dual Coax with single 102"

[Palletburner]

Hello, i'm new here. I have a Uniden Pc68XL, 18' (If I remember right) dual rg-58 coax from GI-Joes and dual 4" hotrods mounted on the sides of a toolbox in the bed of my 76 F250. It puts out and recieves quite well right now. I bought a 102" SS whip for cheap to use as a base station, along with an old Panasonic RJ-3050 CB I've had, and a Radio Shack 13.8v power supply.

I was just wondering, for the heck of it, If I could put the 102" on my truck, just the single 102" in one of the mounts, but leave the dual coax on, with the other side disconnected? Or do I need a single coax to run the single antenna for it to work right? It wouldnt be permanent, just temporary to see how it works. I'd like to see what the difference in dual 4 footers and a single 102" is. If its alot better I may switch to the single 102".

Thanks for any help in advance.

 

[distortion]

I'll save you the trouble.. the 102" by a long shot vs the 4 ft.

You will have a hard time getting your swr low either with the 102", as the 102" does not work effectively without some sort of metal (ie. your vehicle) serving as the counterpoise (I believe that's the correct term).

I would suggest a bazooka dipole. I used one with moderate success at almost no height when living on the ground floor of an apt complex.

Peace,
Josh

 

[Palletburner]

Thanks. I figured the 102" would work better on the truck than the dual 4 footers.

But can I use the single 102" with my dual coax? And just leave one end unplugged and taped up?

 

[W5LZ]

Palletburner,
Depending on exactly what your 'dual coax' is made from, just using one 'side' of it probably isn't going to work very well. I'd suggest just buying some coax to hook the thing up on your truck.
The whip without the 'other half' of it, the metal of the car body, groundplane, counterpoise, whatever, isn't going to work as a base antenna. You will need that 'other half' for it to work. There are several ways of going about that and most of them really aren't that difficult.
Good luck...
- 'Doc

 

[Palletburner]

The base station will be in a Double wide mobile home, if that makes any difference.

Would I be better off buying one of those 18'6" base station antennas off of ebay, or somewhere?

Im not too familiar with actual base stations, just mobiles with the power converters in quarry scalehouses, truck shops, gravel pit office, etc., where they only need to reach out about half a mile or so to trucks in the yard. Im using this base station to get out to the pit and shop/office without having to go out to a truck to use the radio. It'll need to reach atleast 3-5 miles, but I'd like to be able to talk to guys a ways away.

 

[SR385]

If memory serves a co-phasing harness (2 antennas) is 75ohm coax so using that with a single antenna will throw your SWR off.

To really test it properly, remove both antennas, unscrew them from their mounts and run a fresh piece of 50ohm coax ("normal coax") from the radio to the 102". This way the other antenna won't interfere with your signal and the match with the coax will be correct feeding the 102.

 

[W5LZ]

Palletburner,
If your mobile home is metal, and if you don't mind a few holes in it, you might get away with using that whip on the mobile home. I'm just not real sure I'd want to start poking holes in 'my' mobile home, though. You would undoubtedly do better with a real live base antenna of some kind. Where you get that base antenna is your business, "eBay" is a great place to sell things! It is an absolutely terrible place to buy things! But that's your decision.
Good luck...
- 'Doc

 

[Hc714]

"eBay" is a great place to sell things! It is an absolutely terrible place to buy things!

Doc, hope you don't mind if I make a copy of this to post in many places. Truer words would be hard to find. Ebay should have this as a banner on their home page.

 

[BIONIC_TEXAN88]

just get a single run of rg8 coax to feed that 102" on your pickup. It will outperform you current setup, and no, you just cant feed that 102" with 1 side of you co-phase coax. You will need a 50ohm single run of coax.

 

[W5LZ]

Hc714,
I very much doubt if I 'invented' that phrase / idea, so, attributing it to me would be sort of "iffy"! Having said that, put it where you'd like. Most people will eventually figure it out anyway.
- 'Doc

 

[smokercraft]

102

There is a guy about 20 miles south of me that lives in a double wide that has a metal roof. It's in a park so he has to limit his antenna's. The guy has a wilson 5000 planted in the middle of the roof and gives me about the same signal as the guys over there with there verticals up about 35 feet.he even talks quite a bit ssb skip.Seems to work for him.

 

[freecell]

dual antennas will not operate properly using a dual antenna harness made up of RG58 or any other 50 ohm feedline.

before you go making any tests between the duals and the 102" you might want to try feeding the dual antennas with the right feedline.

 

[BOOTY MONSTER]

since its a mobile home how about a mag mount ?

i know , i know......im going to hell . :twisted:

 

[FL Native]

how about you just get another 102 and replace the 4 footers. that way you wont have to replace the coax. if it works why try to fix it.

 

[Captain Kilowatt]

since its a mobile home how about a mag mount ?

i know , i know......im going to hell . :twisted:

Usually aluminum so you're safe as far as hell is concerned