[Lowfer] loading coil considerations for UWL at 185 kHz

[Eric Smith]

HI all,

I decided rather than try to modify the loading coil I have for 185 kHz I
will build a new one.  The old one is on a PVC form, uses small gauge
telephone frame wire, and has been modified several times already over its
eight years.

Antenna details:  8m tall #14 stranded Cu building wire, 2m diameter
capacitance hat comprised of five #4 solid Cu radials and a #14 (estimated)
copperweld halo.


   - The original coil was sized (in terms of L) based on a model produced
   from method of moments type software I found on Lyle's site called NF (a
   stripped-down version of AO, his article says).  This coil currently, from
   end to end, measures 7.3 mH.  However, I suspect this may be larger than it
   needs to be.  I could use any help estimating a target for the new coil --
   when winding a 7.3 mH coil it is tough to use a respectable size wire and
   still have a favorable length to width ratio.  If this is the size I need
   then fine, but I wonder..
   - Suggestions on Litz spec and, if possible, a recommended supplier or
   two?
   - I'm planning to do this in the basket weave style.  I have not chosen a
   material for form and rods yet -- suggestions?


Thanks to all in advance,
Eric  KD5UWL / WD2XFX