Jay, Scott, Steve and All,
Thanks for the note.
The Variometer is built with two coils in both the stationary and rotory
windings.
Each of these have a one inch space between the coils to allow for the
rotating shaft.
The stationary coils are wound on a 10-3/4 inch former at 19 or 20 TPI
closewound
with about #16 solid electric motor wire. The two coils are each 3-1/8 inch
long.
The bottom coil has a number of taps.
The rotary coil is 7-1/2 inches long and 6 inches in diameter close wound
with the
same wire. Subtracting 1 inch gives 6-1/2 inches and makes the two coils
total
3-1/4 inches length each. This is as close as I could match the inner coils
to the
outer ones.
If someone knows how to estimate how much inductance range this variometer
is likely to have I would appreciate knowing.
I have built a ScopeMatch which works well with the dual trace scope which
Scott, VE7TIL, leant me.
I do NOT have the ferrite cores you mention. I have only a few small cores
of
unknown composition removed from computer power supplies. And a big
black core from an old HF antenna tuner?
2, 1.3 inch-light green and blue
2, 1 inch yellow and white
I can take apart more dead computer supplies and get more of the above.
1, 2.4 inch black I think it was from a tuner.
I tried winding a transformer from an old Horizontal output core but
it delayed the current significantly, so I scrapped that idea.
I have two of these cores but they are of different sizes.
I have a large quantity of motor wire. I went to a winding shop and
they had a couple of different spools which had broken and the wire
was in a pile of loops. Perhaps 50# of about #16 wire which they sold me
for
the value of scrap copper. It took two days to re-coil that wire without
kinks in it.
I have a quantity of PVC conduit bits 5, 6, 10, 12 inches in diameter and
up to 5 or 6 feet long.
These are my resources. What I am trying to accomplish is an antenna tuner
or matching unit which will take the power required to generate 1W ierp.
Different opinions have been put forward concerning the power which
will required from the transmitter. I am prepared to keep boosting the
transmitter power until I get the 2.85 amps of antenna current that
was calculated to be required.
Thanks again,
JA
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