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gordyburdo

Joined: Fri, Nov 29th 2013, 18:14 Roles: N/A Moderates: N/A

Latest Topics

Topic Created Posts Views Last Activity
Sweep Tub amps and freq. response Nov 4th 2019, 11:43 4 873 on 6/11/19
ARRL Antenna Book OCF dipole & 4nec2 Apr 10th 2014, 17:08 5 2,825 on 15/4/14

Latest Posts

Topic Author Posted On
Sweep Tub amps and freq. response gordyburdo on 4/11/19
Hello all, I have 2 sweep tube amps, a Swan 1200X and a converted Palomar 350Z. Both use 6lb6s in grounded grid. They are both working fine, but I noticed that the output on 75, 40, and 20 is over 400 watts with 100 watts drive. This drops to 380 on 15 and 350 on 10. Is this normal or do I have a problem with the rig? Thanks for any responses and 73, Gordy - WA2RUP
ARRL Antenna Book OCF dipole & 4nec2 gordyburdo on 15/4/14
Zack,
That got me close. When I set the length to 137' and changed from inverted V to horiz. dipole at 60' I got great results. Again, thanks for your help.
Gordy - WA2RUP
ARRL Antenna Book OCF dipole & 4nec2 gordyburdo on 10/4/14
Thanks, Zack. I put in the numbers you gave me and the lowest SWR I could find was 2.5 at 3.9, 6.0 at 7.3, and 6.0 at 14.3.
I've tried all sorts of numbers without much luck and haven't seen any coordinates that give a good swr at 200 or 300 ohms.
Gordy WA2RUP
ARRL Antenna Book OCF dipole & 4nec2 gordyburdo on 10/4/14
I entered the parameters of the OCF dipole listed in the latest Antenna Book and ran it on 4nec2 modeling software, using specified lengths (45.3' & 84.7'), a height of 66', sloping to 33' and 14 gauge antenna wire. At an impedance of 200 ohms it gives high swrs on all the bands. Any suggestions?
Thanks, Gordy - WA2RUP

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