[Lowfer] Beacon DIR on the air...
Jim
w4jbm at bellsouth.net
Sat Oct 3 12:58:14 EDT 2009
> > The final is a slightly modified LEK design. It's operating at 11
> > volts and pulling 9 mA (measured at the xmitter).
>
> Any hope of getting it up to full power?
I can crank the voltage up a bit without things overheating (I'm using a 12
volt supply and have a diode in-line for protection, so between that and
line-loss I'm down to the 11 volts). I've tried different taps on the
matching coil and this is where I get the best signal strength. (I can draw
more current going closer to ground, I just see the near field signal
strength drop instead of rise when I do that.)
I think the fundamental problem is that the antenna impedance is too low and
I'm not able to get it matched at all. Building an RF current meter and also
looking at something like a 1:3 RF transformer are on the to do list.
So the short answer is that I think I'm down 10 dB for now. Or maybe a 2E26
would load up better. :-)
73 de
Jim W4JBM
Receiver - Ten Tec RX320D
Antenna - Butternut Vertical (SW) and mini-whip (LF)
Location - Bowdon Junction, GA USA (33.6581,-85.1249 EM73)
http://www.hamuniverse.com/w4jbm/
"With a soldering iron in one hand, a schematic in the other, and a puzzled
look on his face..."
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