The SWR specs for the D-40 in real-life compare with the specs in the
brochures. When I installed mine, I set the tip lengths for 7.090 MHz per
the instructions. After I got the antenna onto the mast at 78 feet AGL, I
measured a 200 kHZ 2:1 SWR, just as CC said I would. Obviously, SWR across
300 kHZ of the 40M band would be greater than 2:1 at the band edges.
I would recommend this antenna if you want a fairly rugged rotatable
dipole for this band. The elements droop visibly (my gues is about two feet
at the ends) but my antenna has been up for over three years now without
problems, either mechanical or electrical. If you really have to have the
full 40M BW, then you'll need a tuner in the shack.
Gene Smar AD3F
----- Original Message -----
From: "Rob Santello" <K6DQ@arrl.net>
Sent: Tuesday, November 09, 2004 12:08 AM
Subject: [TowerTalk] Cushcraft D40 SWR question
> Hi all,
> In trying to decide on a 40 meter rotatable dipole, I'm seriously
> looking at the D40. It's relatively cheap and light weight. Can someone
> uses one tell me what the SWR is across the entire band 7.0 - 7.3mhz? They
> claim a 200khz bandwidth but I can't find the readings for the entire
> Someone pointed me to the Optibeam OB1-40 and it looks great but really
> expensive and double the weight. The SWR for it across the band is 1.7:1
> I'm wondering how that compares to the Cushcraft. Thanks for any info!
> --rob-- K6DQ
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
> TowerTalk mailing list
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
TowerTalk mailing list