[Antennas] TUNER_WONT_TUNE_ANTENNA

Sun Dec 25 11:10:37 EST 2005

>-----Original Message-----
>From: George K
>Sent: Sunday, December 25, 2005 9:40 AM
>Subject: [Antennas] TUNER_WONT_TUNE_ANTENNA
>>>My question is; how can I make my 270 foot flat-top fed with 200
>feet of 450 ohm ladder line and terminating at a 4:1 balun outside
>the shack where it takes 15 feet, approximately, of 50 ohm coax
>into the house and to my auto tuners, tune the low ends of 160 and 80?
>I like this antenna as it is basically a all frequency non
>resonate antenna. I'm fighting putting up dipoles!
>I find that my rigs internal tuner baulks at anything below
>1.875MHZ on 160M and 3.620MHZ on 80M. All other bands and
>frequencies up to 30 meters tunes fine. I do a lot of CW DX'ing.
>My question is; If I lengthen the flat top from 270 feet to, say,
>290 feet will this help my lower ends of 160 and 80? It is
>extremely inconvenient to alter either the ladder line or coax
>lengths. The flat top is the easiest to alter as both ends are on
>pulleys and I can lower them in minutes.
>Anyone got suggestions?
>George

1. You should insert an added length of coax, and no one accepts that is
difficult or inconvenient, to determine if this resolves the problem. That's
a textbook answer, and nothing in your description of the problem negates
it.
2. The so-called tuner or autotuner you seem to be referring to are inside
your transceivers. These are not generally accepted to be anything more than
line-flatteners, and incapable of any real work. So you could try a real
tuner.
3. You could either use coax feedline and a Balun, or ladderline
with/without a Balun, but the combination of all three is a fatherless
child. Radio Works offers a remote Balun designed for users who desire this
anyway.
4. Some rigs are simply poor performers at the ends of the bands you
specified. When coupled to a challenging impedance as you may be presenting
them (which may be corrected per 1-3 above) the outcome is often poor.
5. Once you can get a match with feedline length adjustments and a real
tuner, then you could experiment with elevations and slope-angles of the
antenna to achieve best results, not before.
Good luck,
Jack