On 23 Mar, 03:40, "Kevin J." wrote:
I have more portable radios than I know what to do with and was
wondering if I could somehow convert one of them for use as an
extremely low-powered AM transmitter for use around my apartment. I
need only a range of 10 feet or so and I really don't want to buy any
sort of kit as Part-15 regulations in the US prohibit their use but do
allow homebuilt units. I had one of those toys called a Wild Planet
Radio DJ that was FCC type-approved but it got misplaced in my last
move and now my old-time radio shows are just sitting there waiting to
return to life on my antique radios.

Or, should doing that prove impractical, how hard is it to learn how
to solder? :-)

Oh Wow! You opened up a whole can of worms with this post.

1) What part of Part-15 does not allow kits? I think it only
requires low power levels (depends on frequency) and compliance with
antenna size restriction (also depends on frequency). You can
purchase Part-15 compliant transmitters, Part-15 compliant
(supposedly) kits, or could build your own Part-15 compliant
transmitter. There is, as far as I know, no formal "Type Approval"
process for Part-15 transmitters. If you purchase a pre-built Part-15
compliant transmitter, be sure it contains a label by the manufacturer
stating that it complies with Part-15 regulations. If you build a
kit, or build something up from a magazine article or your own design,
you will be responsible for insuring that it is Part-15 compliant.

2) It would be possible to modulate the internal local oscillator on
one receiver and use it as a transmitter to other radios, but that is
somewhat complex and does require soldering, component removal,
component addition, etc. Again, you would be responsible for insuring
that the resulting transmitter device was Part-15 compliant.

3) For local in-house use you only need a few milliwatts of RF
power. There are kits available for that, or you could build up your
own crystal oscillator and modulator circuit. Just be sure to keep
the power and antenna size within FCC Part-15 requirements for the
frequency you are using.

4) Ham Radio is not the answer for what you want to do, because ham
regulations in the US do not allow "broacasting" (i.e one-way-only
transmission) and also do not allow music transmission.

Arv
_._