External aerial for two way comms

[Nickel Arse]

Hi Boris
that’s UK regulations not EU so you can get external antennae for most radios, you would just have to bodge your radio to except the cable or get a new one from the likes of these


Pmr-Funkgerät Albrecht G7 Mag, MIDLAND | SMDV - weil Spiele Abenteuer sind


Funkshop.de - Magnetantenne fur 70cm-Band für LPD & PMR mit SMA-Stecker


https://www.pmr-funkgeraete.de/artik...197-seite-.htm

[East Coast]

wavelenght = speed of light divided by frequency

Or

Landa = c / f

I think the frequency of a PMR is 466Mhz and the speed of light is around 300000000m/s

So 466000000 divided by 300000000 is the length of aerial you need in meters.

This is probably a bit on the long side so divide it by 4 (quarter wave length aerial)

Should give you 16cm which i think sounds about right if you consider a telescopic radio on a car is about 75cm and is designed for FM frequencies around 100Mhz

Good luck and dont worry about the law, you would need a directional antenna with gain to boost the power and this is not your intention, you just are just compensating to get the power you would ordinarily have

[Nickel Arse]

But... But... But... But...

you listen at the speed of sound

[East Coast]

But... But... But... But...

you listen at the speed of sound

maybe but the frequency of voice for example is around 2 - 3kHz and it's these frequencies that move your ear drum which translates into the signals sent to your brain...

I would therefore suggest that you receive these signals to your ear at the speed of sound relative to their source and actually listen at frequencies in the region of 60Hz to 20kHz (depending on how old you are)

[Dee Duble Yuh]

Since the speed of sound is about 340 m/s at sea level, to hear frequencies in the 2 - 3 kHz area I need an ear trumpet about 0.858 m diameter. Is that correct? Eh? What?

[Nickel Arse]

Can you type a bit bigger

I'm a bit hard of hearing

[largewayround]

Metal Coat-Hanger

[Dee Duble Yuh]

Yes, half past six.