222 Beacon Project : Update

Some good news and some not-as-good news.

Click here for previous info on this project.

The good news is that Doug (VE3XK) and I were
able to fix the 222 board up a bit today (added
a cap and re-soldered some connections) and we
peaked the power output. The transmitter is
transmitting at 223.400 (we could not tune it
down to the Crystal freq of 223.340).

The other good news is that Doug brews a great
cut of coffee (even if is was decaf ;-)

The not-so-good news is that the power output,
as measured using Doug's QRP power meter, is
about 15mW. In reviewing the board it seems that
it was built as an exciter only with no final PA
stage included.

As well, we tried to key the transmitter via DC,
but there was a very strong "chirp" that may make
this not a viable option. The tone produced by
the transmitter, however, sounded great and the
freq seemed very stable.

I am still hoping to trace out the schematic to
better understand exactly what this thing is doing.

As I have the 1-10w amplifier provided by Al,
vo1no, one option may be leave the Tx on and key
the amp. This assumes that the amplifier will then
produce about 150mw output.. not really enough but
enough for testing the setup. Doug gave me a 12v
relay that I am going to use to try this... e.g.
use my keyer to trip the relay to turn the amp
on/off.

Another option, once I have the schematics figure
out, is to add the final transister and components
thus adding the final PA stage. Not sure if this
is doable or practicle... hmm I wonder if this is
a kit out there for a mini-amp for 222?

Comments and suggestion are most welcome (other
than suggesting I buy a 28 Mhz IF and a 28-222
Transverter for this beacon ;-)

I am not going to order a crystal until I have
all else figured out.

Tom

VA3NFA