Re: [TenTec] Antenna Tuner 238

["Ron Castro" <ronc@sonic.net>]

The tuner can be improved on.  I found that under high power on 160 and 80 
the SWR would change as the fixed disc ceramic capacitors heated up, which 
they do, so I replaced them all with doorknob caps that I found on e-bay and 
now it's rock stable at full legal power.
        Ron  N6IE
     www.N6IE.com


----- Original Message ----- 
From: "Bob McGraw - K4TAX" <RMcGraw@Blomand.net>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Tuesday, January 22, 2008 8:31 PM
Subject: Re: [TenTec] Antenna Tuner 238


> In certain cases, for 160M and sometimes 75M, the external cap needs to be
> greater than the 1000 pf item provided.  I've found that up to 2700 pf 
> might
> be needed in some cases.  This tuner will usually match any load Z, any
> phase angle between 10 ohms and 3000 ohms.
>
> FYI - This series of tuners will have some of the lowest loss figures of 
> any
> on the market today.  Typically less than 1 dB.  Plus, being a L network,
> unlike the T networks tuners, there is only one set of adjustment 
> parameters
> that produce a proper match.
>
> 73
> Bob, K4TAX
>
>
> ----- Original Message ----- 
> From: "Jim Brown K9YC" <k9yc@audiosystemsgroup.com>
> To: "Tony Dangelo" <tony@ammocomp.com>; <tentec@contesting.com>
> Sent: Tuesday, January 22, 2008 5:45 PM
> Subject: Re: [TenTec] Antenna Tuner 238
>
>
> > On Tue, 22 Jan 2008 17:26:20 -0500, Tony Dangelo wrote:
> >
> > > Am I missing something?
> > The 229 and 238 (essentially the same tuner in a different color
> > case and with their dial cords wound in the opposite directions) are
> > really excellent tuners, and can be tuned to match almost any
> > reasonable antenna. Sometimes, if the antenna is far from 50 ohms
> > resistive, it can take a while to find the match. And if it's TOO
> > far from 50 ohms, you may not be able to match it. I've had this
> > happen when the antenna is a half wave vertical on 80 or 160, which
> > is a VERY high impedance.
> >
> > TenTec supplies a capacitor that you can connect between two
> > terminals on the back panel to extend the tuning range of the tuner
> > on 80 and 160. That solves the problem I described above.
> >
> > 73,
> >
> > Jim Brown K9YC
> >
> >
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>
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