Bill - KR8L - came up with the answers, as well as the original calculations
for the windings.
"Well ... I can't imagine that solid or stranded would make a difference in
this application, but that's just a guess. Thinking back to the many
toroidal inductors and transformers that I have done for kits, it seems like
they are usually made with solid, enameled wire. So, I would say that solid
is a safe way to go for sure, but I would bet that stranded would work also.
Looking through the reference * that I sent earlier, I found these words on
page 3-4: "The windings on transmission-line transformers consist of
parallel wires or twisted wires.... Some controversy exists about whether
the parallel-wire winding is better or worse than the twisted-wire winding
in terms of impedance and efficiency, but both methods seem to provide
satisfactory results. Typically, the twisted-wire windings are configured
to have between 8 and 10 turns per linear inch.""
* - A chapter on transformers from an old out of print book -
Clint Talmadge - W5CPT
[mailto:firstname.lastname@example.org] On Behalf Of Clint Talmadge W5CPT
Sent: Sunday, August 21, 2011 8:22 AM
Subject: [TowerTalk] Phasing transformer questions.
I am phasing two verticals together for 30M and using the Trifilar wound
toroidal transformer found in Joe Carr's "Practical Antenna Handbook" to do
so. A friend, (more knowledgeable than I,) calculated 19 turns on a T300-2
core. I recently found the core and now other questions have arisen.
Does the winding have to be solid wire, or can I use stranded wire, or does
it matter? And should the windings be flat wound, such as ribbon cable, or
twisted together? I have seen both methods.
Any other information which I really need to know would also be appreciated.
Clint - W5CPT
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