[SixClub] db 212

[Chris Boone]

Hey Doc!! I see you like 2 of my fav bands (10 and 6...as well as 220
:)...Poor Joey has had some major health problems because of his tower
accident...so I try to go easy on him (but he can take it :)

DB 201 is a folded monopole groundplane (like a dipole of the DB-212 series
but ground plane instead of bottom half of dipole)....the folded monopole is
DC grounded and thus provides some lightning and static protection. The
ground plane radials are longer than normal and I THINK its because of the
monopole being used instead of a normal series fed vertical 1/4wl.

As for altering the harness, NO, that's not what I suggested...in fact, the
harness itself is always cut to frequency; it MUST be to match properly and
keep the pattern correct...the DIPOLES themselves is what DB altered in
length....and the normal 1/2wave dipole formula of 468/freq in MHZ= length
in feet doesn't apply (if you take the length of the dipole and plug it in
the formula, you get a frequency 10 MHz higher than what the dipole
resonates to; the dipoles I have been told are cut to 100ohm also; not 50ohm
to allow a wider bandwidth of the dipole & overall antenna array but I
haven't confirmed that..yet ;)

Chris
WB5ITT

-----Original Message-----
From: sixclub-bounces at mailman.qth.net
[mailto:sixclub-bounces at mailman.qth.net] On Behalf Of kd4e
Sent: Tuesday, August 05, 2008 9:04 PM
To: World Wide Six Meter Club
Subject: Re: [SixClub] db 212

Hey Chris, I had a little fun with Joey ...  :-)

I read your other post re. the 212 and 224 and am
curious to learn a little more about the DB-series.

What is a DB201?

Also, it sounds as if you were suggesting that altering
the phasing harness could move the resonance as much
as 10MHz?  Cool hack!