Ok, I have decided to go with the 102" steel whip with 6" spring for a
total of 108" or 1/4 wave. I am planning on mounting the antenna
behind the driver side on the bedrail approx. 12-18" from the cab. It
is an older Dodge ram long-wheel base, so the drilling is not a problem
for where I am going to mount the antenna. (long wheel base may give me
a real good ground plane, hopefully) I am running a Cobra 25 LTD in
the truck. The antenna mounting bracket is aluminum I believe, so I
may need to fabricate one myself from steel for good grounding.


Also, I am hunting some coax for my base setup. I want to go with RG8
I believe, but RG58 is all I can seem to find in the 30-50' range.
Will there be too much loss with the RG58? I can get a length custom
made, but I need it soon and the CB shop is down for now. It is a
Cobra 142 GTL radio with an Antron 99 antenna with the top section
replaced with another 102" steel whip after the wind took the original
someplace else.

Any thoughts or suggestions on these two setups will be greatly
appreciated.

Thanks

wrote:
Ok, I have decided to go with the 102" steel whip with 6" spring for a
total of 108" or 1/4 wave. I am planning on mounting the antenna
behind the driver side on the bedrail approx. 12-18" from the cab. It
is an older Dodge ram long-wheel base, so the drilling is not a problem
for where I am going to mount the antenna. (long wheel base may give me
a real good ground plane, hopefully) I am running a Cobra 25 LTD in
the truck. The antenna mounting bracket is aluminum I believe, so I
may need to fabricate one myself from steel for good grounding.


Also, I am hunting some coax for my base setup. I want to go with RG8
I believe, but RG58 is all I can seem to find in the 30-50' range.
Will there be too much loss with the RG58? I can get a length custom
made, but I need it soon and the CB shop is down for now. It is a
Cobra 142 GTL radio with an Antron 99 antenna with the top section
replaced with another 102" steel whip after the wind took the original
someplace else.

Any thoughts or suggestions on these two setups will be greatly
appreciated.

Thanks


Get some RG-8m and put your own connectors on it. Coax length
does NOT matter. A properly installed 1/4 wave will have an
SWR of 1.56:1 because it is a 30 ohm antenna. Do not trim
antenna or coax trying to get less then 1.56:1, it won't
happen and it won't affect the radio either.

Scott in Baltimore wrote:

wrote:

Ok, I have decided to go with the 102" steel whip with 6" spring for a
total of 108" or 1/4 wave. I am planning on mounting the antenna
behind the driver side on the bedrail approx. 12-18" from the cab. It
is an older Dodge ram long-wheel base, so the drilling is not a problem
for where I am going to mount the antenna. (long wheel base may give me
a real good ground plane, hopefully) I am running a Cobra 25 LTD in
the truck. The antenna mounting bracket is aluminum I believe, so I
may need to fabricate one myself from steel for good grounding.


Also, I am hunting some coax for my base setup. I want to go with RG8
I believe, but RG58 is all I can seem to find in the 30-50' range.
Will there be too much loss with the RG58? I can get a length custom
made, but I need it soon and the CB shop is down for now. It is a
Cobra 142 GTL radio with an Antron 99 antenna with the top section
replaced with another 102" steel whip after the wind took the original
someplace else.

Any thoughts or suggestions on these two setups will be greatly
appreciated.

Thanks


Get some RG-8m and put your own connectors on it. Coax length
does NOT matter. A properly installed 1/4 wave will have an
SWR of 1.56:1 because it is a 30 ohm antenna. Do not trim
antenna or coax trying to get less then 1.56:1, it won't
happen and it won't affect the radio either.

It should be a 50 ohm antenna. RG-8 is fine, NOT radio shack junk.
If not RG-8X (or M) is fine. If you use the 8X or M, you will need a
reducer.
THe one for 59 U is the one you will need, NOT a reducer for 58U. RG-8X
is the physical size of RG-59U (cable stuff)

It should be a 50 ohm antenna. RG-8 is fine, NOT radio shack junk.
If not RG-8X (or M) is fine. If you use the 8X or M, you will need a
reducer.
THe one for 59 U is the one you will need, NOT a reducer for 58U. RG-8X
is the physical size of RG-59U (cable stuff)

For CB use, the RS RG-8m is just fine. You need RG-175 reducers for RG-58,
and RG-176 reducers for RG-8m. I'm using Belden "Truck King" RG-8m that I
picked up at a CB shop some years ago. I'm also using a bunch of RS RG-8m
for short runs on 2 meters. (20 feet maximum) For HF, RG-8m is fine for
runs of up to 50 feet. On VHF you want something better if you run more
then 15 or 20 feet. Couplers get touchy at VHF. Imagine UHF!!!

Would there be too much loss in RG-58 coax for the base? Only a 30-50'
run.

I don't think the mobile installation matters all that much, but I
could be wrong. I might try to find some Mini 8 for the mobile, RG 8
will prolly be too bundlesome. If not, I will try some RG-58 with it
as well.

Will this be going in the wrong direction entirely (too much loss)?

Another thing, I see lots of discussion on the 102 vs 108" (spring)
whip. Does anyone have a straight answer. I can discontinue the use
of the spring if it is that advantageous. Please, someone let me know.
I just want (like everyone else) low SWR, and max power out the whip.

Thanks again