[AMRadio] Low powered FM

[Brett Gazdzinski]

Jeff,
I have thought about replacing the cordless headphones with an fm
transmitter and a walkman type receiver.
Ramsey makes a syntisized stereo fm transmitter kit that looks
good, and I spoke to someone who had one and used it with the built in
wip antenna and got blocks of coverage.

Ramsey has FM broadcast info on their web page I think.

I think its mostly radiated power, not restrictions on actual
power output.
The Ramsey kit I mentioned can be hooked up to an outside antenna
to extend the range a lot.
The cordless headphones I have don't work well outside, as the
transmitter is in the basement, and its cheap radio shack junk.
(you would think I would learn not to buy there, but it was on sale)

I have heard there are cordless microphones with a remote
switch built in for keying, but never actually saw one.

It would be interesting to be able to key, talk and listen
remotely while mowing the lawn say...


You could do the cordless headphones and wireless mike on vox
using headphones with a boom mike......


Brett
N2DTS

>
> It maybe off-topic, but I'm sure someone has the answer, here.
>
> I'm curious about something... Low-powered FM broadcast.
> Somewhere in the FCC
> Rules and Regs, it says that anyone can transmit anything, as
> long as it's below
> (_blank_) amount of milliwatts, and the antenna is less than
> (_blank_) feet, or
> has than (_blank_) ERP.  Can someone fill in the blanks?
>
> Implementations are endless.  Remote keying of Transmitter,
> and remote listening
> of receiver?
> How much quality audio could you put over say, 100kc of
> bandwidth into your
> speech-amp, and then filter it out with a band-pass filter
> from say 30cycles to
> around 3kc's, in the speech-amp?
>
> I'm thinking that with a line input, and filtering
> thereafter, that some "solid"
> audio would be 'flat' from the bottom end of the band-pass
> filter to the top.
>
> Personally, I wouldn't want to get too far away from the main
> transmitter, just
> in case something goes horribly wrong, but within the same
> house would be cool.
>
> Keying a small FM kit transmitter would be as simple as
> receiving enough signal
> at the FM receiver to drive a transistor (like a 2N3904) to
> key the transmitter
> (or close a relay to handle more current).  As simple as
> flipping a switch, at
> the LP-FM xmtr
>
> but, what are the limits?
>
> 73 = Best Regards,
> -=Jeff/W5OMR=-
>
>
> _________________________________________________________
> Do You Yahoo!?
> Get your free @yahoo.com address at http://mail.yahoo.com
>
> _______________________________________________
> AMRadio mailing list
> AMRadio at mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/amradio