If this is done then when the antenna feed Z is near 3000 ohms the tuner
will need to match 12000 ohms. Again Na Da on this approach. A 1:1 current
balun works in every case.
Still I vote for putting the 4:1 balun in the trash and putting a 1:1
current balun at the feed point.
73
Bob, K4TAX
----- Original Message -----
From: "JReed" <jhreed@chilitech.net>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Saturday, December 31, 2005 8:00 PM
Subject: Re: [TenTec] ORIONII_INTERNAL_AT_TUNER
> Put the balun in backwards?
> ----- Original Message -----
> From: Robert & Linda McGraw K4TAX
> To: w2yj@highstream.net ; Tentec
> Sent: Saturday, December 31, 2005 8:17 PM
> Subject: Re: [TenTec] ORIONII_INTERNAL_AT_TUNER
>
>
> George:
>
> First from my point of view, 4:1 baluns should not be used in this
> application. I wouldn't expect it to work. Based on your
> antenna/feedline
> configuration the actual feed Z of the antenna may be more near 25 ohms.
> Thus with a 4:1 balun the load the tuner must match is 25/4 or 6.5 ohms.
> Very few if any tuners will match efficiently below about 15 ohms.
>
> You should be using a 1:1 current balun in all applications, all
> configurations. The 4:1 balun should reside in the trash can.
>
> History: 4:1 baluns became popular due to hams making folded dipoles
> from
> TV type line or open wire line. In this configuration the resonant feed
> Z
> is more like 200 to 300 ohms. Thus with a 4:1 balun the load to the
> transmitter is in the order or 50 to 75 ohms which is great for most
> transmitters with those being link coupled outputs or with the new pi
> networks.
>
> Happy New Year
>
> 73
> Bob, K4TAX
>
>
> ----- Original Message -----
> From: "George K" <w2yj@highstream.net>
> To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
> Sent: Friday, December 30, 2005 2:12 PM
> Subject: [TenTec] ORIONII_INTERNAL_AT_TUNER
>
>
> > My original Orion with internal tuner would not tune the lower ends of
> 80
> > and 160 meters.
> > The antenna is a 270 foot center fed with open wire terminating at a
> 4:1
> > balun outside the shack and then on into the OrionII rig with 20 feet
> of
> > coax.
> > The OrionII has no problem with either band on the lower ends tuning to
> > 1.2:1???
> > Did TT beef up the tuners capabilities in the, new and improved,
> > OrionII???
> > If not I can't think of what I may have done since receiving the OII.
> > I'm elated, but in a quandary.
> > George
> > _______________________________________________
> > TenTec mailing list
> > TenTec@contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
> >
>
>
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