Is resonance overrated, or confused with something else?
An SWR dip and a happy transmitter doesn't necessarily equal resonance,
particularly if the system as a whole is not balanced.
If you want a resonant antenna, you have to measure it independently of the
feed system and once it is resonant find an appropriate way to feed it.
When you consider that very few "resonant" verticals, with sufficient
radials, have a feedpoint impedence of exactly 50 ohms, if you have 1:1 SWR
at the rig with only a 1:1 balun at the base, there's more going on than
resonance. Indeed, a 1:1 SWR in such an instance probably means the vertical
is off resonance enough to compensate for its likely 15-40 ohm feedpoint
impedance. (Or it's a reflection of the amount of radials, as feedpoint
impedance decreases as radials, and therefore efficiency, is added.)
None of this means that there's something wrong with an antenna that plays.
A 1:1 SWR does mean maximum power transfer. But if you made your antenna
resonant and matched to its actual feedpoint impedance, the efficiency would
be improved. As well, you'd have a balanced system with less chance of stray
RF issues.
Whether it's improved ENOUGH to warrant the added work is in the eye of the
perfectionist. If it plays really well now, you wouldn't likely notice the
difference.
IOW: If you like it, be happy!
Note: my understanding of the science it not as in-depth as W8JI or N6BV.
This is just what has managed to sink in after 26 years... Any corrections
welcome.
73, kelly
Ve4xt
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Dave Harmon
Sent: August-06-09 11:22 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Resonance is over rated
My HT IS resonant at 3800....it squirts more than a non-resonant HT and the
transmitter IS comfy....HEH
Mine has 90, 70' radials stapled to the surface of the ground.
This put the resonance at about 4300kc so I added several feet of pipe to
the stinger to get it resonant at 3800.
I have no matching devices, coils or anything else other than the DXE 1:1
coax balun at the base and the DXE radial ground plate mounted to a 4th pipe
in the cement base.
Other than that, it is unmodified.
Regards
Dave Harmon
K6XYZ[at]sbcglobal[dot]net
Sperry, Ok.
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Mark Beckwith
Sent: Thursday, August 06, 2009 7:35 AM
To: towertalk@contesting.com
Subject: [TowerTalk] Resonance is over rated
> resonance is 'over rated'
Resonance is definitely over rated. All that matters is that the radio
waves squirt out and your transmitter is comfortable.
73 - Mark, N5OT
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