Ok folks! I don't have the schematic handy or the website that
I pulled it from BUT I will
get around (eventually) to posting it up!
The purpose of this project was to be able to tune my tuner without
having to transmit into the
antenna constantly causing interference on the bands. I had been
putting off this little project
for a while but decided that when I wanted to get on 60m that I had
two choices, go outside and
cut a resonant dipole or just load up my 75m dipole or the vertical.
Obviously loading won!
It's not perfect but it does get me pretty close! Anyway to some pictures!
Finished winding my first torroid! :)
Above I am mounting the project into a SONY box that was used
for some audio beakout project. I was fortunate
enough to get a number of these. The cool part is they
had lots of connectors already on the box!
Above: I just used one screw and attached the board to an aluminum
heat sink on the parts that were
already in the box. I didn't even bother taking them out! hehehe
:) There are a lot of good parts that I
could scavenge off of the board that is in there. If I had a
larger project I could have either de-soldered
everything off of the board and mounted my new thing on standoffs on
the board or cut a new board
the same size that would slide in the aluminum chassis.
Check out all of the cool stuff on the face plate! I'm using
the on/off switch and the BNC coax connectors.
Currently I'm running the thing off a 9v battery inside the case but
I might eventually hook up the 12v
on the front. Two screws and the entire project slides out or
two screws on the back and I can
change the battery. This would make a good QRP rig box!
With the two connectors I could put
in two qrp rigs and then would only have to add a toggle switch to
go between the two radios and
add cw jacks and headphone jacks. I could actually
just wire up a jack to plug into that RS232 port
on the front and have the wires coming out of that go to the key and
headphones. I wouldn't have to
drill anything!
Better shot of the front. Here you can see the two BNC to UHF
adapters I've screwed on.
COMPLETE! Check out that top hat! heh. I cut it down later
and it is flush. The piece of coax on top
of the box has 2 resistors soldered in parallel between the center
and shield to give me approximately 50 ohms
so that I can set the knob on top to 50 ohms. I found it close,
but no cigar. I wound up using the dummy load
in my tuner to set it to 50 ohms. Also in this shot I've added
some BNC to UHF adapters.
The only down side to the thing is you HAVE to take it out of the line
after you use it. Applying RF to the
circuit could easily fry it! I've thought about wiring it differently
with a strong momentary switch so that the RF
normally bypasses the circuit unless you hold down the button.
It's on my later later list! :)
M@
Return to Projects Page