Randall J wrote:
I operate a Part 15 station for my neighborhood (FM) and have
acquired
an AM transmitter. I've seen plans for vertical antennas but would
rather make my own from the few parts I have. I have 8ft of aluminum
tubing and would like to make a loading coil using 3 inch diameter
PVC
pipe. Given the frequency I operate on (1610khz), 8 ft of tubing, and
a
3.5 inch coil form, how many turns of 22AWG insulated wire would I
need
to wrap? (Oh the tubing is in two pieces and I can slide the top
piece
up and down).

Is there a program I can download to find this out?

Randall

Hi Randall, I did this for a friend of mine a few years back.
Download the demo version of EZNEC and model an 8' vertical on 1.610
MHZ. You will find quite a bit of capacitive reactance. Your loading
coil should cancel the reactance. Determine the required inductance by
L=Xl/(2*pi*Fmhz). Xl is reactance you need to cancel.
The coil will be in the millihenries. Consult the ARRL Handbook for
a estimate on the # of turns on a 3.5" form for a given Inductance.

73 Gary N4AST