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Old April 10th 04, 05:50 PM
Mike Knudsen
 
Posts: n/a
Default Homebrew dipole help please?

In article , "BFoelsch"
writes:

Well, seeing that it is cut to be an 80 meter dipole, I would expect success
on 80 meters. It is very difficult to make a dipole work on even harmonics,
so I would expect trouble on 40, 20 and 10 meters. 15 should be usable
however.


This is all true for a center-fed dipole. You might want to try the "Fritzel"
trick, which is to move the feed point from cetner to a 1/3 - 2/3 point
(whichever side is closer to your shack). This feedpoint will give you about
600 ohms on the even-harmonic bands as well as the 80m fundamental. In fact, I
think the only band that my dipole won't load is 18 (aw shucks).

If you really want to do this, I would abandon the balun and coax and use
ladder feeders instead, but you will need a tuner that can feed a very high
impedance balanced load on 40, 20 and 10.


Unless you can find or make a 600:50 or 600:75 balun (like the one that came
with my Fritzel dipole), you can just feed it with 600-ohm ladder line. Your
tuner will need to feed that balanced load, but at only 600 ohms, not that high
an impdenance.


73 es best wishes on your ant -- Mike K. AA1UK




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