Reg:

You know about SWR meters, built any?
I have built one, two so-239's, center conductor between 'em has a toroid
with 20 turns, EACH SIDE of the winding on the toroid has a 50 ohm resistor
to ground AND cathode of a diode to it, EACH SIDE through the diode feeds a
bright LED, and BOTH LEDS share a common ground resistance (variable)...
(cap to drain off rf to ground and supply a dc voltage/current in diodes
circuits) one LED reads forward, other reads reverse... it "seems" to
work, but here everything seems to be as real as "time."
In use, I adjust the forward LED for approx. correct brightness, the rev LED
is "judged" in brightness to make a workable guess at SWR... (I have one
with a meter--different direction coupler design, I just get a kick out of
the leds... I built the one with the meter, it "probably" works correctly
grin)
Operation has been at 100 watts... and, I don't think it would take anymore
power, barely able to dim the led near/at dark condition now (but this make
it highly useable at 10 watts)... probably have to drop secondary turns on
the toroid (but, how many turns would I need to keep to assure accurate
operation of the directional coupler?) and/or supply voltage to the leds
though a resistive divider, if I went more power...


Is my "directional coupler" design correct?
Better ideas for this circuit?

Warmest regards,
John
"Reg Edwards" wrote in message
...
|
|
| You heard correctly. The ground system lowers losses which
| translate
| to more power out. This is not method of controlling TOA, simply
| loss
| - all angles of radiation improve.
|
| ======================================
|
| Some buried wires under a horizontal dipole, at a height of 1/4 or 1/2
| wavelengths, will, in theory, reduce losses. Some old wife, once upon
| a time, must have read something about it in a book without bothering
| about the magnitude of the effect.
|
| It's not enough to be detectable. So don't listen to your voices or
| waste time digging up your back yard and getting back ache.
|
| There's far too much of old wives reading things in books and
| ill-written radio magazines, getting the wrong ideas, and then
| plagiarising them. Which innocent people hear about 3rd or 4th hand
| or n'th hand.
|
| The fabled SWR meter is another example.
| ----
| Reg.
|
|