| Author |
Message |
    
Sixtiesmania
| | Posted on Wednesday, January 07, 2004 - 10:19 pm: | 
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Hey Guys,
I am fidling with some cheap FRS radios and alot of them, when taken apart, the antenna falls straight off, mmmm. So I would like to make a better whip antenna for these units. It is pretty hard to solder on a BNC connection to radio as they are pretty flimsy, but to run a better whip (ie 1/4 wave length) seems pretty easy. What is the best length antenna to make out of wire, etc?? Is it possible to make a 5/8 length vertical or do you need loading etc. I took some of these radios back to Australia in Dec (they don't have these freq available there) and got incredible distance just stock standard, over 5-6 miles easily with .500 watts! But it was all to do with elevation and line of site etc. I am sure I could've got further but ran out of time to experiment. Okay, I await your thoughts, ps. radio shack has 2 x gmrs 2 watt radios , with charger & batts for $30!! I mean talk about a disposable radio, those recharge batts are over 15 bucks alone! Go figure eh?
Cheers
Andrew
739 |
Sixtiesmania
| | Posted on Thursday, January 08, 2004 - 4:25 am: |
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Also, I would like to check on the ground connection if I decide to add a bnc connection? Would I just run the earth connection of the bnc to the negative terminal of the battery connection? Sorry if this seems a no brainer, just want to be sure before I do the re-fit.
Cheers
Andrew
739 |
Bruce
| | Posted on Thursday, January 08, 2004 - 4:46 am: |
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2770/f=length in inch or 5.97 in = 1/4 wave
also 467 in austraila is in their poilce/fire band. |
Bruce
| | Posted on Thursday, January 08, 2004 - 5:05 am: |
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There are several FRS bands around the world europe in 446.006 ( YES in our 440 ham band!) austraila has a 40 ch cb band at about 470 and our FRS 462-467 It is not smart to inport radios... here at disney world you can hear many of the 446.006 radios being carried by visiters ... even with the short range its not uncommon for local hams to hear them ouside the park. LEAGALY these people could be charged by our FCC...... if we had one. |
Barracuda
| | Posted on Thursday, January 08, 2004 - 11:25 am: |
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Doesn't Part 95 says FRS radio antennas cannot be replaced? Yet GMRS radios can have relacement antennas. So, these days, when manufacturers label radios as FRS/GMRS which rule set applies? |
Bruce
| | Posted on Thursday, January 08, 2004 - 12:59 pm: |
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correct and replacing one is illeagal unless its a exact one for FRS now GMRS you can replace antennas.
NOTE MURS HAS NO ANTENNA RESTRICTION YOU CAN RUN A 100 ELM BEAM. |
Sixtiesmania
| | Posted on Thursday, January 08, 2004 - 2:25 pm: |
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okay, thanks for the info, BUT what about my questions guys!!ha ha... Any more input from anyone who has added an external antenna on these radios? Also, good point Barracuda, if you pay for an GMRS license, why are antennas non-removable (yes I am sure it has to do with the FRS frequencies, but it is a good point eh?). I look forward to some replies from experimenters, not FCC rule experts!! (just kidding, honest!)
Cheers
Andrew
739 |
Bruce
| | Posted on Thursday, January 08, 2004 - 8:24 pm: |
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Andrew....
IEAGALY you cant do it expermently wise im with you A simple antenna attached to the radio probly not going to matter PERSONLY this no swap is a stupid rule |
Barracuda
| | Posted on Thursday, January 08, 2004 - 9:39 pm: |
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Sixtiesmania,
I'm not the ultimate antenna or radio electronics expert on this forum, but, I think that Bruce answered the question about how long a 1/4 wave antenna needs to be. As I understand it, you are correct in that you would need a coil to create a 5/8 wave antenna (to increase the length electrically to 3/4). As for the ground, I would try to ground it to the metal frame of the radio if there is one (which should be a dead short to the (-) battery terminal), or the PCB groundplane if not.
Chime in anybody, if I got anything wrong.
Barracuda |
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