RadioBanter - View Single Post - 4 foot vertical for 1.6mhz 100milliwatt tx?

November 29th 03, 03:28 PM

On Sat, 29 Nov 2003 06:17:53 -0000, (gudmundur)
wrote:

I do sound work at horse shows, and would like to provide my audio source
to vehicles parked at the show. I have a real nice 100 milliwatt input
1.6mhz transmitter which shows about 60 milliwatts of output at 50 ohms.

I would like to build a transmitting antenna that would be 4 feet in length
and having the 3/8 24 thread at the bottom so I can fasten it into my hamstick
mag mount base.

I am thinking a 1 inch diameter wooden dowel 4 feet long, and wrapped evenly
from bottom to top with perhaps #22 wire.

Any idea how much wire it would take to begin to act like a 50 ohm impedance
at the base? Would you solenoid wind it bottom to top, or would it work better
with maybe a 4 inch high multilayered coil at the bottom and 3.5 foot steel
whip antenna.

You need one of Reg Edwards' utilities to work this out for you. He's
written a number of small programs for the PC that handle exactly this
kind of problem and they're available for free download. I can't
recall the URL off hand but just Google for "Reg Edwards" on the
newsgroup sci.electronics.design and that'll bring it up.
--

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