Good Site For Part 15 Info & Specs

and if you'd like to see what it looked like when it was originally published: http://home.att.net/~weatheradio/part15.ht m" target="_blank"> http://web.archive.org/web/20060831162219/http://home.att.net/~weatheradio/part15.htm

Is there anyone here that has done any Part 15 broadcasting on the 22 meter band like that web page above describes?

No antenna restrictions, 1.8 mW into a 1/2 wave dipole, enough bandwidth to do AM on 13.560 mhz... Sounds like a cool place to experiment!

Unfortunately, I don't know a whole lot about creating a working circuit from a schematic, but if someone was to create a kit I would buy it in a heartbeat!

--Chris ^_^

No antenna restrictions, 1.8 mW into a 1/2 wave dipole, enough bandwidth to do AM on 13.560 mhz... Sounds like a cool place to experiment!

This does not appear to be the case. According to the FCC rules:

Section 15.225 Operation within the band 13.110 – 14.010 MHz.
(a) The field strength of any emissions within the band 13.553-13.567 MHz shall not exceed
15,848 microvolts/meter at 30 meters.

and so on for the frequencies involved. There is no mention that I could find in the rules of antenna or power alternatives to the field strength limit. The power and antenna would have to be adjusted together to produce a field strength meeting the limit. Any antenna and any power would be legal as long as the field strength limit is observed and perhaps the numbers you cited would achieve this, or perhaps not.

Neil

"The lack of experimental broadcast stations operating here is truly amazing, considering the relatively generous field strength allowance and great (world-wide!) propagation in this frequency range. This Part 15 band is available in the USA and Canada for use by people like us: hobbyists, low-power radio and broadcast enthusiasts, and experimenters..."

"Here is a shot of the Wentzel I built for shortwave running on 13.56. It is crystal controlled and runs very nicely with good audio. It was fairly easy to build on perf board and worked right off the bat. My tank coil needs to be improved a bit as I experimented to find the right combination..."

A bit more info about alternate approaches is on Jon Smick's legendary http://home.att.net/~weatheradio/part15.ht m" target="_blank">Part 15 site here:

http://home.att.net/~weatheradio/HFtransmit.ht m" target="_blank"> http://home.att.net/~weatheradio/HFtransmit.htm

However, the link to the oscillator test page noted in Jon's writing is obsolete. The new location for the oscillator test page is here:

http://www.mlecmn.net/~lyle/epson/epson.htm

And what do you know, but Lyle's reference to the Epson site is also 404, but I found a current copy here:

http://www.eea.epson.com/portal/pls/portal/docs/1/503460.PDF

Lyle provides additional transmitter info here:

http://www.mlecmn.net/~lyle/proto/LFproto.htm

Then there is this interesting piece from a completely different source about using crystal oscillators in AM broadcasting, modulating with a transformer, here:

http://sci-toys.com/scitoys/scitoys/radio/am_transmitter.html

Note that the Smick/Koehler unit is CMOS, while the Sci-Toys unit is TTL

Experimental broadcasting for a better tomorrow!