> Just for fun, I ran my whole-tower model with a zero-current source at
> the junction between the top 40m yagi's reflector and boom. At 200w
> input to the shunt feed (2A @ 50 ohms, if I did it right) the model
> shows 580v there, vs only 68 volts across a similar point on the
> tribander 7 feet below it.
For arcing, use peak voltage. Peak voltage is 1.414 times 580 or
just over 800 volts. The insulation has to hold off that voltage in all
sorts of weather with a safety factor, and any transients or
momentary discharges that start an arc can cause an insulation
failure if the transmitter is running.
73, Tom W8JI
W8JI@contesting.com
________________________________________________________________________
Where do you get ICE bandpass filters & beverage matching boxes? The
same place that pays for the hosting of this list: The eHam Store.
Order online at http://store.eham.net.
-----------------------------------------------------------------------
-----
FAQ on WWW: http://www.contesting.com/FAQ/towertalk
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
|