The q of a halfwave dipole is about 10. Due to losses in a mobile mounted
vertical the Q will be much less due to radiation resistance and ground losses
due to the poor coupling to ground. However, the antenna is also resonant to
odd harmonics. This makes it an effective radiator on other frequencies which
is not desirable.
73
Bill wa4lav
________________________________________
From: amps-bounces@contesting.com [amps-bounces@contesting.com] On Behalf Of
Bill, W6WRT [dezrat1242@yahoo.com]
Sent: Thursday, April 08, 2010 6:49 PM
To: amps
Subject: Re: [Amps] CB amp directly coupled via cap to antenna
ORIGINAL MESSAGE:
On Thu, 08 Apr 2010 17:09:08 -0400, Ron Youvan
<ka4inm@tampabay.rr.com> wrote:
> By adjusting the antenna length to be resonate at the exciter's frequency
> the antenna
>is that "tank circuit," it's just lossy by the radiation resistance. A
>variable coupling
>capacitor is not necessary.
REPLY:
Upon further consideration, if the antenna impedance matched the
tube's plate load impedance, wouldn't the Q be just one? I think you
still need the simple LC tank circuit for the flywheel effect.
73, Bill W6WRT
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