Using FM Radios without cables as PA for the Neo1973 - Question, in which countries is it legal to use 50 nW (nano Watt) FM 87.5-108.0 Mhz transceiver?

Robert Michel openmoko at
Sun Dec 17 18:11:17 CET 2006


I haven't found a page with info in which contries 50 nW FM transceiver
would be legal to use - I know only that in Germany (mayby EU) owning
and using has become legal in spring 2006 (German official note):

There are several small adaptors on the market,
quite handy are the solutions for the ipod:

This transceiver need 40mA - so in case tha Neo1973 would have
an stereo mic in with bias (I hope so) the Wolfson's bias
would be with 2 x 3mA not enough - the tranceiver would need
a battery and would be bigger than the ipod solutions.
Would a higher phantome power for the mic help?
Or a special solution for the mini-USB port to serve 
power, the audio signal and maybe an I/O to select the frequency
with the Neo1973?

Autotuning with help of the mic? Tune your radio to a "free"
frequency and start autotune that the Neo1973 let the 
tranceiver run from 87.5 to 108 untill audio software has
detecte with the help of the audio-in (mic) that the tranceiver
has now the same frequency than the radio you are using as
PA for your Neo1973.

So the smartest solution would be an internal solution, it would
make the power supply and antenna question more easy and would have
the posibility of autotuning.

Otherwise selling propritary adapters are IMHO only profitable
when there is a big market for this propritary adapters (ipod)...

Comming to friends or to a kitchen, or just in the car and play music 
from the Neo1973 via a FM stero radio is *very* usefull and sooner
or later a build in solution would be a great argument to sell

Build in solution would bear problems to travell into countries
that doesn't allow this 50 nW transceiver.
-Would a software configuration help?
-Would be a hardware switch, removing of a jumper, removing of
 a part of the tranceiver circuit, rmoving of the tranceiver
 itself necessary?

So can you contribute your know how in which contries (in yours?)
are these transceiver legal now?


More information about the community mailing list