The best thing I've built
Wehttamman asks: My dad and I once built a go-kart from chipboard, pram wheels and an engine from a lawn mower. It didn't work... so tell us about your favourite things you've made, and whether they were a triumph or complete failure.
( , Thu 11 Oct 2012, 12:00)
Wehttamman asks: My dad and I once built a go-kart from chipboard, pram wheels and an engine from a lawn mower. It didn't work... so tell us about your favourite things you've made, and whether they were a triumph or complete failure.
( , Thu 11 Oct 2012, 12:00)
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How exactly did you amplify a 100MHz FM transmission with a random wire antenna?
I don't want to call bullshit or owt but even a basic grasp of how RF works suggests that this is ... unusual.
( , Sat 13 Oct 2012, 13:59, 2 replies)
I don't want to call bullshit or owt but even a basic grasp of how RF works suggests that this is ... unusual.
( , Sat 13 Oct 2012, 13:59, 2 replies)
If it's not resonant...
... it'll radiate pretty well along its length. So if you're within about 20-30m of the wire you'll have a good strong signal.
If you want to go any distance you want the aerial to be resonant. There's a whole bunch of stuff that involves fiddly stuff with Maxwell's equations that explains all this, but I'm not in the mood for maths.
( , Sat 13 Oct 2012, 15:34, closed)
... it'll radiate pretty well along its length. So if you're within about 20-30m of the wire you'll have a good strong signal.
If you want to go any distance you want the aerial to be resonant. There's a whole bunch of stuff that involves fiddly stuff with Maxwell's equations that explains all this, but I'm not in the mood for maths.
( , Sat 13 Oct 2012, 15:34, closed)
all i know and remember
back then was wrapping around the end of the wire around the antenna, the wire ran out to the top of a telegraph poll at the end of the garden and the range of the walky talky was bigger.. who the hell knows it worked and i got in trouble...that's all that matters as I pissed off Mr Brian who listened to classic fm in his shed, as he complained to my mum that all he could hear was me and my friends over his radio... awaits backlash for annoying shed owners...
( , Sat 13 Oct 2012, 20:14, closed)
back then was wrapping around the end of the wire around the antenna, the wire ran out to the top of a telegraph poll at the end of the garden and the range of the walky talky was bigger.. who the hell knows it worked and i got in trouble...that's all that matters as I pissed off Mr Brian who listened to classic fm in his shed, as he complained to my mum that all he could hear was me and my friends over his radio... awaits backlash for annoying shed owners...
( , Sat 13 Oct 2012, 20:14, closed)
Two way radios don't transmit at the same frequency as FM broadcasts.
And the thing you wrapped wire around would have been the outside of a coaxial antenna. I don't know what you think you did, but you definitely didn't talk to the radio in Mr Brian's shed. Soz for being a spoilsport.
( , Sun 14 Oct 2012, 15:26, closed)
And the thing you wrapped wire around would have been the outside of a coaxial antenna. I don't know what you think you did, but you definitely didn't talk to the radio in Mr Brian's shed. Soz for being a spoilsport.
( , Sun 14 Oct 2012, 15:26, closed)
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