TopBand: Re: Another Beverage Question.

[Bob Eldridge]

>in 500 foot Beverages and found the signals to be severely attenuated by
the time they went that far.  .....
> why unterminated Beverages don't seem to work very well for signals
>off their backside. 

This is paradoxical, because: 
One job of the terminating resistor is to dissipate the signal from the
rear. If there is little signal to dissipate......?

The operation of two-wire Beverages depends on the reflection from the far
end.  I swear they work.

Reflection transformers have nothing to do if there is little signal left to
reflect.

If loss is that high why do we need a hefty terminating resistor for a
travelling wave transmitting antenna?

My experience is that when looking into the darkness path off the far end of
a 250 or 500 ft Beverage it makes no difference whether I terminate or not.
But looking into the darkness path off the back removes the signal.  So
removing the termination does not hurt the signal from the front, and
putting in on 'activates' the rear.

BUT:
This is with Beverages not longer than 500 ft (Harold Beverage said that is
the optimum length). If the Beverage were very long (several wavelengths)
you would not need a terminating resistor at all and it would not receive
much off the back end (just like the long wire antennas we used to use on
VHF - many many wavelengths.)

There may be lengths that inhibit rear end signal when the far end of the
'transmission line' is open.

You kept me awake Bill, but at least I'm up. Pity there's nothing there but
V73GT.
Bob Eldridge VE7BS,
Erickson Rd, Pemberton B.C. V0N 2L0
                        eldridge@whistler.net 


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