Survivalism & Self Sufficiency Topics > Amateur Radio How-To's

Inexpensive Vehicle Mount Option for Handheld Tranceivers

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iam4liberty:

--- Quote from: GreekMan on December 31, 2014, 05:19:44 AM ---hmmmm isn't the wire a bit thin?

--- End quote ---

Thanks for pointing that out, GreekMan.  That brings up an important point I failed to mention.  The antenna used in this example is only for HTs and other low power applications.  They compromise power rating for the ability to use thinner (0.1 inch OD), more flexible coax.  This allows the coax to go around turns and put a lot less stress on the connectors (no need for 'pigtail' extensions).


--- Quote from: Carl on December 31, 2014, 05:22:17 AM ---Probably RG 174, it is thin and handles 50 watt or so well. Best use is to take weight off of small HT and connectors.

--- End quote ---

Ding, ding, ding...give that man a cigar!  Yep, it is RG-174.  I believe for some manufacturers the power rating can be as low as 15 Watts maximum.  :o  It is incredible stuff for low power applications but has too be really sealed well against water. That is not a problem for this application as the whip end is completely enclosed in the mount and the connector end is in the vehicle.

For those who are interested, this is a handy chart showing coax types for different applications: http://www.radiobooks.com/products/techinfo/coaxapps.htm

Also, if someone is interested in how well these inexpensive antennas tune see here as an example: https://www.youtube.com/watch?v=GhdOIwDWLK0

Greekman:
I am actually not concerned with power rating, but with losses

RG-174 has some pretty horrendous losses. 0.9db vs 0.5 for the rg-58 in 145MHz for a length of 9feet

Check loses here
http://www.timesmicrowave.com/calculator/?productId=122&frequency=145&runLength=9&mode=calculate

Carl:
A barrel connector has .5 DB loss too, Sometimes you must compromise as 2 inch diameter hard-line will not let the door close.
The HT antenna within an auto will also lose about 20 DB...there is some loss with any path for RF but little problem with the short coax feed on an auto. RG174 survives being shut in the door much better than RG58...I use RG58 but run it through a door that is simply not used on my 4 door auto. I did it because it was the EASY way to feed my $16 antenna.

OOPS , now $25 dollar antenna

http://www.amazon.com/Tram-1185-Amateur-Dual-Band-Antenna/dp/B0045EQUBK/ref=sr_1_cc_2?s=aps&ie=UTF8&qid=1420046001&sr=1-2-catcorr&keywords=tram+mag+mount+antenna

PrepperJim:
Thanks for this thread. I did something similar and it works out better than routing through the sunroof. Routing through the sunroof, I had to remove every time I leave the car (rain).

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