I received one of Mike W3IRZ's Beta NOGAwatt kits at the beginning of the
project and like most things stacked it on the TO DO pile. The BETA kit had all the parts but only the template of the PCB etch layout.
The PCB has been producted now by FAR Circuits and is included in the kits.
Otherwise the Beta unit complete kit. I had talked to Mike about trying to
make it as small as possible for field use and we both thought that it would
in one Altoids Box. Mike had decided he wanted to build one directly in an
Altoids using the metal can itself as the ground plane and using ugly
construction techniques to keep the parts away from the metal where
necessary. We have had several BETA builders putting the components in two
Altoids boxes (back to back, meters in one box and circuit board in the
other box) and some in slightly slarder boxes. All function well and
calibration is very straight forward.
I liked the idea of one box but was unsure about soldering and "adjusting"
things once inside the box so I elected to build the circuit up in an ugly
manner but on a piece of PCB board that would fit into the bottom of the
Altoids box when finally checked out. So I cut a piece of PCB to fit and
laid out the circuit in pencil on the board and Dremeled the few isolated
pads needed. I also installed the dummy load resistors right on the board so
I could add a small SPST switch in the dummy load and use the unit has a
power meter when testing stuff on the bench.
Sorry my hand held camera pictures are a little blurry but you get the
idea.
The bare HB ugly construction board and assembled parts are at:
http://ae4gx.home.mindspring.com/uglywatt.jpg
The two coax connectors are holding the front toroid assembly and the two
pairs of 100 ohm resistors are holding the back toroid assembly. Small
isolated pads are created where necessary. The two meters have the movement
enclosures that stick out and come down to about half way into the box s+o
you need to offset the circuit slightly to allow the meters to miss the
circuit parts.
The unit assembled in the box are at:
http://ae4gx.home.mindspring.com/nogawatt.jpg
The Meters for this unit have the original meter scales and I haven't yet
put on the neat NOGA calibrated scale faces that Picket AD4S designed. You
can see the small slide switch top coming out from the side of the box. That
cuts the dummy load into the out bound coax point.
So if you decide to make the unit (I thing it's a great piece of QRP gear)
you have choices on the construction method, the enclosures and options.
That's the way QRP projects should be.
I current have my unit set for full scale at 1 watt to use with my GA
Sierra. But you can calibrate it easily for other QRP power values too.
I also have a production NOGAwatt kit and plan to build it in a slightly
bigger tin box and incorporate a two range scale switch (2W and 6W) and a
resistor bridge to help protect my field rigs when tuning up untried antenna
configurations.
Thanks Mike for putting together a neat and very useful accessory that
everyone should have. I sure hope someone can pick up the ball and get the
club kit deployed on a wider basis.
BTW for more info on the NOGAwatt email Mike Branca W3IRZ at w3irz@att.net
Hopefully in the near future the NOGA web page will have more info.
Sam AE4GX NOGA member Atlanta, GA
Link: Check out the North Georgia (NOGA) QRP web page