Hey guys... a friend of mine bough a couple or walkkie talkies, but got send an extra few by mistake... and as a result, ive been playing.

its also got a built in scanner, but before anyone has a go at me it only scans and transmits on the "un-registered bands" or whatetever... im not sure of the frequency... but its definatly not police or anything illegal.

anyways, so far ive overheard conversations between some guy and his gurlfrend,,, and other boreing stuff...

anways #2.. it has a 5 kilometer range... and just to annoy the h3ll outa me, i can talk to 2 of my friends.. but the closest geographically is just out of range... reception is PERFECT literally 10 meters away from his home, but inside, its all scrambled.

so ive been planning thigs... for example.... How could i modify the arial to get a better signal ???

i can find out what frequency range it works on 2morrow.

im considering either putting a few meter long copper pipes on the roof, and running a coax cable somwhere to plug the radio into.... Bigger arial = better ??? or would adjusting the length of the arial screw with the frequency's ?


Also, ive been consitering constructing a directional arial... like the ones TV's use.
if i remember correctly, the length of those metal parallel bars and the spacing between them is to do with the amplitude and wavelength the arial is designed to pickup...
maybe i could construct a minni version and simply point it at my friends house (for recieving) and use some kind of silver foil satalite dish for transmitting ???

i know micro waves bounce off silver foil maybe lower frequency does too ?
whats that mathematical curve called that reflects all (light) from a center point to a directinal parallel beam ??? anyways, construct one of them with the arial in the middle...


anyways, those are my thoughts...
anyone got any ideas ? any links on relevant websites ?

ALSO... i would be interested in any hacks for altering the frequncy ranges... (altering capacitors / crystals) to other toally legal frequency's

The Radio Society of Great Britain produces an excellent book called the "VHF-UHF Manual". You can check out their webpage. There will be lots of info for transmitting & receiving aerials. Another book is Joe Carrs Receiving Anteena Handbook - excellent. the ARRL Handbook is also very good. Expect to pay a pretty penny for these volumes though unless you pick them up 2nd hand.

Regarding the modifications, unless you have A LOT of soldering iron experience, dont even open the lid of a modern radio to look inside. Modern radios just dont change frequencies by altering a coil, crystal and capacitor anymore, they are usually controlled by PLL. And if you dont know what a PLL is - then just leave the insides alone.

Check out your legal situation first for Great Britain before you do anything as you can land in very hot water for doing the wrong thing. Check out your nearest amateur radio club to get the "good oil" ( good advice ).

live long and prosper
floppyl

Thanks...

ive found out my radio is a 500 milli wat, 5 mile range 466mhz 8 channel, 36 codec radio. its pretty standard and covers the whole "free to transmit" range.

it comes with a coil arial.
the only modification available to me, it to replace the compact coil arial with a quater wavelength or half wavelength arial.
none are sold, so it would be a custom job.

ive calculated the wavelength (its about 66.3 cm) but i dont have electronic equipment sencitive enough to measure the 50 ohms the arial needs to be, so their is not much i can do to improve it at the moment.

i have some high quality coax cable laying around, so i might put an arial on the roof of my house, i will have to just hope the resistance is somewhere neer 50 ohms (im told 4mm thich brass at half wavelength should be approx 50 ohms) ill give it a try.

thanks for the recomentadion... im a poor student, so ill look out for those books on ebay and other second hand books for sale..

In all honesty - I seriously think you should leave the radio alone and if you want to transmit further, then join your local radio club and study to become an amateur. If you start doing mods to a radio it will soon be noticed by the authorities one way or another.

Seriously - its about as silly as installing a pirate windows XP and pirate MS office and then ringing the MS help desk. There are plenty of good clubs in Britain where, just like these forums, there are people willing to help a newbie get started. And I'm sure if you mention Linux you will welcomed with open arms as Debian has good support for Ham Radio programs. Though I dont know about other Linux Distros.

Live long and prosper
floppy

like i said, im only transmitting on the Free unlicenced 466Mhz bands.

And installing a larger more efficiant arial for better range and quality isnt illegal.

i dont know anything about this but from what i understand adding a large arial would shorten the transmition range. because it would need more power to fill the arial so the signal would become week. i think if you had a large areal you would need dome sort of signal amplifier of some sort! the signal booster for Tvs you can buy might work but i think they only boost the signal going one way! and doing this if you are using the unlicenced range you shouldent have any bother with the authorities and they wouldent notice iether the police are stupd in england and especialy hull i mean about a month ago a saw 2 cops on the beet walk pas a car with a smashed window and the car alarm going off and they just walked past it without looking at it! i dont know what its like in australia though! and out of intrest floppywhopper with you been in australia do you support RL and if so what team my ausie team is southsidney

like i said though i know nothing about radios so i might be compleatly wrong

The reason they give you a small antenna is to deliberately limit your range. And I would definately advise you to check the legalities of using a larger antenna. Dont assume anything on this issue. Great Britain has some pretty hefty fines on these issues and the inspectors are world renowned for their lack of a sense of humour.

At the risk of sounding overly "big brother", check the legalities from a authentic source.

BTW in these instances, changing an antenna probably would be classed as doing a mod to the radio

live long and prosper
floppy

Just to answer Berrances Q's
No - a longer antenna - correctly made - would definately increase the range, and a lot more than you would think, particularly if it were raised high off the ground. What would limit power output would be the length of cable to the radio and the type chosen.

I can't comment on your local police but I can safely say your radio inspectors are not stupid on these issues. I would suggest however that your police are not stupid just lazy, having had 2 brothers in the NZ police however I would imagine that the subject of paperwork and court appearances might have crossed their minds.

If by RL you mean Rugby League - No not interested, although I would have to confess its a lot safer than Rugby Union, which I played a season of at school. I can still remember the headmaster waving his umbrella over our heads while we practiced scrumming saying "keep those heads down boys". Yeah like whose going to be stupid enough to pop your head up and say "what was that sir ?" duh

My idea of sport is Powermanga and Maelstrom.
cool !

live long and prosper
floppy

the law in england is...
1) 446Mhz is free..... dont go any higer or lower without a licence.
2) scanning to find the frequncy of the person you want to talk to is okay, but scanning to listen to other conversations isnt.. (very stupid law.. if you are scanning to find your friends radio frequency, you are bound to stumble on others !!!
3) the maximum power output of the tranmition is 500 milliwats.

these are the only laws on the matter.

anyways DXing is legal... which invols using a horizontal 2 meter arial to bounce radio off the ionosphere on rare wether ocnditions to talk around the curveture of the earth, and communicate at ranges larger than a radio is rated at.

see i told you i didnt know much about radios! lol my uncles a sargent and he hasnt done bad having either 4 or 5 (i think 5) comendations wile heas been in the force! i think its just the odd police man thit is like that and gives you an over all impresion of the police but saying that hull does have the worst police force in england and thats acording to the government!!

and i dont follow union at all, and forgive me for starting on about sport on a non-sport forum its just im intrested in what teams any ausies follow as i often watch the ausie games aswell as the english ones. and after the ausies beet us in the tri nations final which i was there didnt they nearly loose to the USA! come one You usa lol

right i will shut up about sport now for the time been!

Agree with your comments re scanning
except with telephone calls they should be private and many countries use HF, VHF and UHF for telephone.
any thing sensitive should be scrambled - Police , Military etc.
as for an antenna, ( if its legal ) go for a vertical co-linear, good all round all direction and good gain. Though I doubt whether you'll do any serious dxing on 466 mhz with 500 milliwatts. If you are really interested join a club.

I used to do a lot of HF ( short wave ) listening, its a lot of fun but when it comes to antennas and UHF you really need to know what you're doing.

live long and prosper
floppy