Total posts : 45366
I found the second 49 MHz walkie talkie. I wired
my station audio processor output directly into the
circuit board of the first 49 MHz unit and shorted out
the transmit switch so it would always stay in transmit
mode.
Then I wired directly into the board of the second 49 MHz
unit that will be used as the receiver.
I turned my audio board and audio processor, and put a record
on the turntable. Then I was running audio into the
49 MHz transmitter. Then I brought audio out of the
49 MHz receiving unit and fed it to my C Crane transmitter,
which has been modified for mono and is transmitting on
88.3 MHz.
Listening to the FM radio on 88.3 – well – it sounded pretty good.
The fidelity was acceptable.
(In other words, the music had highs and lows, it
didn’t sound like a telephone.) Both 49 MHz units and the
C Crane are running on batteries right now.
Right now there are no antennas on the 49 MHz transmitter
or receiver. The units are about 15 feet apart and there
is no noise, just a little hum because the 49 MHz units are
not in shielded boxes.
I bought some diodes to isolate the solar cells because they
will be in parallel with each other. Running the C Crane will
be no problem in sunlight (I think) as I was able to run it under
a light bulb (well, almost touching the bulb). Although I haven’t
measured the current the C Crane needs, I don’t think it is much.
I need a few more solar cells to power the 49 MHz receiver.
Right now my local Radio Shack
doesn’t have any, but I will get more when they are in stock.
Again – the solar cells that were given to me are the same as
the ones obtainable at Radio Shack. Each one is 6 volts at
50 mA.
So I have almost all of the pieces for a remote 49 MHz receiver
and Part 15 FM repeater that will run off of sunlight. No attempts
will be made to charge batteries at this point of the experiment.
And as mentioned before, I want to get onto a 49 MHz link frequency that is
in between the baby monitor channels.
So far so good.
Best Wishes
Bruce, MICRO1690/1700
