[Elecraft] K3 Internal Tuner and 43' Vertical

[Phil & Debbie Salas]

"Just curious if anyone else is using the K3 internal tuner with a 43'
vertical.  Will handle all the bands 10 - 160?  Or do I need to purchase
an external tuner.  I'm about to put one up to get me on the air.  This
will be a temporary antenna while I build the antenna farm here at the
new qth.  What I would really like is the new Elecraft tuner located at the 
base
of the vertical.  I have an sgc-239 that I used at my last qth, and it
was located at the base of the vertical.  Worked great."

The K3 internal tuner may or may not be able to tune 160-meters - I suspect 
it will have no problem on 80 meters.  It depends on the length and loss of 
your feedline.  The 43-foot vertical has HORRIBLE SWR on 160- and 80-meters. 
And so your line loss will be very high.  You need about 55uhy of total 
inductance to match the 43-footer on 160 meters at the antenna base which I 
believe is more than the K3 tuner has available.  But if the feedline length 
and loss is just right, the matching range of the K3 tuner may be sufficient 
on that band.  Incidentally, the SGC-239 does not have enough inductance to 
match the antenna on 160 meters.  If you were able to do this, you were 
simply matching into the internal losses in the tuner.  I did an evaluation 
of the SGC-230 with the 43-foot vertical (info on my website at 
www.ad5x.com), and as part of that I found that the SG-230 would match into 
an open circuit.  Obviously it was matching into its own internal losses.  I 
built an external inductor for use with 43-footers that worked well with my 
MFJ-927.

The new MFJ remote autotuners look interesting, but they also do not have 
enough inductance to match a 43-footer on 160 meters.  It will be 
interesting to see if the remote KAT500 will have enough inductance to match 
a 43-footer on 160 meters.  Meanwhile, if you use your 43-footer on 160- and 
80-meters (like I do) consider base matching on those bands.  See the base 
matching article on my website.

Phil - AD5X