af4k at EARTHLINK.NET
Tue Nov 16 17:53:01 EST 1999
No, they must be similar to those "antenna matching units" that were
hawked in QST a few years ago, and had a fancy PC board inside them.
The ads claimed that they could give you a 1:1 SWR when placed across
the terminals of ANY mismatched antenna in the range 1.5 to 30 MHz.
In fact it turned out that these sealed, potted gadgets had only a 100 ohm 50
watt resistor as the functional element. (or was it a 52 ohm one, I forget now!)
Yes of course you got a great-looking SWR reading, but dumped about half
or 2/3 of your RF into heat conversion, dissipating it away into the resistor!
TRULY a "DUMMY load!" to those who bought one!
On 16 Nov 99, at 11:50, Don Buska wrote:
> On Tue, 16 Nov 1999 11:13:13 -0800, George Maier wrote:
> >Hey Dick:
> >This one way filter thing is terriffic.... If I put one in my transmission
> >line, I never have to worry about standing waves again, 'cause nothing will
> >ever be reflected back to my transmitter. Unless I get in there backwards.....
> >George - K1GXT
> Hey ain't they called isolators. Although, for high power HF I'd assume they
> would be a might bit bigger than the ones they use in cell phones ;)
> Don N9OO
More information about the Boatanchors