Rotatable dipole with spiral capacity hats
Rotatable dipole with spiral capacity hats
(OP)
How well will the antenna work on 40 and 80 meters?
See the attached picture.
Best regards.
Tom
KE6YNH, 73
San Diego, CA
See the attached picture.
Best regards.
Tom
KE6YNH, 73
San Diego, CA





RE: Rotatable dipole with spiral capacity hats
Anyway - it's not common to have anyone to volunteer to model someone else's design (even if all the details were provided).
But it'll probably work about as well as any other short antenna.
73
RE: Rotatable dipole with spiral capacity hats
The spiral coil is 1 foot square and has 24 turns of 1/8"
aluminum tubing.
How's that for a starting point?
I would settle for a *rule of thumb* when it comes to flat spiral coils.
I plan on using ladder line rather than coax, since the
SWR may be quite high as a multiband antenna.
Thanks for taking a stab at it.
Tom
KE6YNH, 73
San Diego, CA
RE: Rotatable dipole with spiral capacity hats
Here's one more tidbit on the use of flat spiral
loading coils for dipoles.
Apparently, there is a commercial version already
made, that uses spiral, flat, loading coils at:
http://www.tak-tenna.com/
I am not an agent nor am I involved with that firm.
Regards to the Group.
Tom
KE6YNH, 73
San Diego, CA
RE: Rotatable dipole with spiral capacity hats
http://home.ict.nl/~arivoors/
RE: Rotatable dipole with spiral capacity hats
Tom
KE6YNH, 73
San Diego, CA
RE: Rotatable dipole with spiral capacity hats
If you can see the VSWR while you trim those coil lengths, you could tune it into the right frequency.
to improve your VSWR, if possible, I'd suggest making the tubes (going to the coils on the end) as wide as possible. Or add some metal to make wings, converting the tubes to sheets of metal. VSWR bandwidth is often improved by increasing the antenna size.
kch