[TenTec] ORIONII_INTERNAL_AT_TUNER

[Robert & Linda McGraw K4TAX]

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 at chilitech.net>
To: "Discussion of Ten-Tec Equipment" <tentec at 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 at 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 at highstream.net>
>  To: "Discussion of Ten-Tec Equipment" <tentec at 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
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