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Electronics => RF, Microwave, Ham Radio => Topic started by: dexters_lab on January 29, 2016, 05:46:39 pm

Title: DIY 446mhz PMR Handheld Antenna?
Post by: dexters_lab on January 29, 2016, 05:46:39 pm
i have a baofeng uv5r that i have tuned only to the PMR channels, which are on 446mhz

the supplied short 'rubber duck' style antenna is generally regarded as shit and ebay is full of fake aftermarket antennas for this radio that seem to be no better

given i have no experience with RF and no suitable equipment for testing would it be possible to rip out the existing spring in the stock baofeng antenna and make my own, tuned to 446mhz?
Title: Re: DIY 446mhz PMR Handheld Antenna?
Post by: johnkenyon on January 30, 2016, 06:02:37 pm
i have a baofeng uv5r that i have tuned only to the PMR channels, which are on 446mhz

the supplied short 'rubber duck' style antenna is generally regarded as shit and ebay is full of fake aftermarket antennas for this radio that seem to be no better

given i have no experience with RF and no suitable equipment for testing would it be possible to rip out the existing spring in the stock baofeng antenna and make my own, tuned to 446mhz?

You do realise there's a limit on the ERP for PMR446, hence the crap two mile/3km line of site range.

Title: Re: DIY 446mhz PMR Handheld Antenna?
Post by: dexters_lab on January 30, 2016, 08:44:06 pm
i have a baofeng uv5r that i have tuned only to the PMR channels, which are on 446mhz

the supplied short 'rubber duck' style antenna is generally regarded as shit and ebay is full of fake aftermarket antennas for this radio that seem to be no better

given i have no experience with RF and no suitable equipment for testing would it be possible to rip out the existing spring in the stock baofeng antenna and make my own, tuned to 446mhz?

You do realise there's a limit on the ERP for PMR446, hence the crap two mile/3km line of site range.

yes, i am aware of that and the other limitations, output power etc
Title: Re: DIY 446mhz PMR Handheld Antenna?
Post by: Lord of nothing on March 28, 2016, 08:26:12 pm
1) no removal Antenna is allowed
2) no more than 0,5W

so any Baofeng is ilegal on 446.  :=\
Title: Re: DIY 446mhz PMR Handheld Antenna?
Post by: SeanB on March 28, 2016, 08:40:24 pm
My one surprised me, by being able to work the regular repeater I used at a distance of a little over 30km, using the stock antenna on 144Mhz. It is not great, but pretty usable though.

You would probably be better off putting on a counterpoise using a small crimp ferrule and a short length of wire leading down the handset.
Title: Re: DIY 446mhz PMR Handheld Antenna?
Post by: stj on April 17, 2016, 04:58:20 am
take a look at the "Kinnota" antenna's at 409shop
Title: Re: DIY 446mhz PMR Handheld Antenna?
Post by: CJay on April 22, 2016, 01:28:01 pm
i have a baofeng uv5r that i have tuned only to the PMR channels, which are on 446mhz

the supplied short 'rubber duck' style antenna is generally regarded as shit and ebay is full of fake aftermarket antennas for this radio that seem to be no better

given i have no experience with RF and no suitable equipment for testing would it be possible to rip out the existing spring in the stock baofeng antenna and make my own, tuned to 446mhz?

Yes, but you're not going to benefit much, at best you'll end up with something as good as the original unless you spend a bit of time researching antenna design and experimenting (a perfectly valid use of time IMHO)

For a few quid you can buy a replacement whip antenna for it that will work well.

If you're determined to build something then buy one of the SMA to BNC or SO239 adapters on eBay and tinker away.

Title: Re: DIY 446mhz PMR Handheld Antenna?
Post by: Lord of nothing on April 22, 2016, 05:55:12 pm
 :popcorn: Its illegal to use an Baofeng on PMR. Even an Replacement Antenna make it more illegal.
Title: Re: DIY 446mhz PMR Handheld Antenna?
Post by: stj on April 23, 2016, 02:27:15 pm
so?

the post is about antenna quality, not relative laws.
Title: Re: DIY 446mhz PMR Handheld Antenna?
Post by: Lord of nothing on April 24, 2016, 06:17:42 am
So on PMR you cant chance the Antenna so the Tread is useless.  :-//
Title: Re: DIY 446mhz PMR Handheld Antenna?
Post by: CJay on April 24, 2016, 07:05:39 am
So on PMR you cant chance the Antenna so the Tread is useless.  :-//

Beg to differ, antenna theory is applicable to all areas of radio, man made laws only apply to men, not physics so information about antenna design is useful so if we can get rid of the 'it's illegal' comments then it could be a useful thread