Re: How much power can I receive from a FM station

Eeyore <rabbitsfriendsandrelations@xxxxxxxxxxx> hath wroth:

Converting to milliwatts across 50 ohms,
9.7dBm = 9.3 milliwatts.

Which is 682 mV

Or 21.5 mV @ 30km.

Yep, into 50 ohms. However, the question was how much power, not
voltage, could be received. If I increase the receive antenna gain to
a small yagi antenna, I can probably get 6dB more gain out of the
system. That will yield 15.7dBm or 37.2 milliwatts. That should be
enough to ran a flea power FM receiver.

If you want more voltage, a tuned RF step up transformer will do the
trick.

Now scale for those transmitters that transmit rather less power. 100kW is
unknown in the UK for FM. 10kW would result is a signal of 2.15 mV @ 30km.

Graham

The OP is in Boston, Mass, USA. 100Kw EIRP is legal but not very
common. Most run about 5,000 to 20,000 watts EIRP. The maximum in
most metro areas is 50,000 watts EIRP.

<http://en.wikipedia.org/wiki/Effective_radiated_power>


--
Jeff Liebermann jeffl@xxxxxxxxxx
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
.