For the benefit of the List, I am reporting on my results on this topic.  My
initial presumption was correct, and advice I got here was indeed correct
(verifying my presumption).  I tested all this, and below is how this all in
fact works.

If you have an external tuner connected to ANT1 and assuming you use an
interface cable for it, then the internal tuner is disabled for ANT1 only.
This does not disable the internal tuner relative to ANT2.  If you are on
ANT1 and press the "AT" button, then your external tuner is engaged.  On the
other hand, if you are on ANT2 and then press the "AT" button, then the
internal tuner engages.

My particular problem is that I have a power amplifier (Ameritron ALS-1306)
and an external tuner (MFJ-998) on the TS-2000's ANT1 jack.  Using the 998's
(not the TS-2000's Ant 1 and Ant 2 jacks, I wanted to have amplified power
running to two separate antennas; one of which is a 6M J-Pole.  However,
because the SWR is too high on the J-Pole and because the 998 cannot tune
6M, I cannot do this.  I would blow-up my amp due to the J-Pole's high SWR.

The solution, for now, is just to have the J-Pole on the TS-2000's ANT2
jack.  As such, I can utilize the TS-2000's internal tuner to deal with the
high SWR.  Of course, this means that I am running bear foot using only the
TS-2000's 100W.  Until I somehow resolve the J-Pole's high SWR, I cannot
connect it to the 998's Ant 2 jack and thus utilize the amp on it.

73,
Richard KK6MRH/AG

-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of Richard B. McDonald
Sent: Monday, January 04, 2016 4:31 PM
To: [log in to unmask]
Subject: Re: Using Both an External and the Internal Antenna Tuners on the
Kenwood TS-2000

Hi Steve!

You zeroed-in right on my problem.  For my 6M J-pole (ANT2), I have a 4:1
SWR at the range 50 - 51 MHZ, 3:1 51 - 52 MHZ, and less than 2:1 52 - 54
MHZ.  So, I cannot run power from the amplifier to the 6M J-pole until I
somehow deal with its SWR, nor can I use the 998 to tune it.  The "somehow"
is really bumming me out and frustrating me because I *really* want to put
like a kilowatt into the 6M J-pole : (

73,
Richard KK6MRH/AG 

-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of Steve Forst
Sent: Monday, January 04, 2016 4:04 PM
To: [log in to unmask]
Subject: Re: Using Both an External and the Internal Antenna Tuners on the
Kenwood TS-2000

Richard,
The setup you describe is correct.   As long as you have the interface 
cable plugged into the  back of the radio, the internal tuner is disabled on
ant 1.

On another note, the amp will do 6 meters, but the998 tuner won't.  I don't
know how much 6 meter stuff you do, but if you want to run the amp on 6
(assuming your antenna can handle it) you may have to juggle some things.

73, Steve KW3A

On 1/4/2016 6:41 PM, Richard B. McDonald wrote:
> Hi!
>
> Below under the "***" are copied the relevant sections of the 
> TS-2000's manual.  Essentially, I have an external MFJ-998 auto tuner 
> connected to an amplifier (Ameritron ALS-1306), which then connects to 
> ANT1.  On ANT2, I have a 6M J-pole, which does not run through the 
> amplifier.  Is my understanding of the below correct that1) if I am on
> ANT1 pressing the AT button on the TS-2000 engages the MFJ-998 auto 
> tuner relative to the antenna connected to ANT1, and 2) if I am on
> ANT2 pressing the AT button engages the TS-2000's internal antenna 
> tuner relative to whatever antenna is connected to ANT2 (my 6M J-pole?
>
> 73,
>
> Richard KK6MRH/AG
>
> *  * *
>
> Page 72 - [INTERNAL] AUTOMATIC ANTENNA TUNER: 2.Press [FUNC], 
> [AT/ANT1/2] to select ANT 1 or ANT 2. If an external tuner is 
> connected to the ANT 1 connector, select ANT 2 to use the internal 
> antenna tuner. The internal antenna tuner is automatically bypassed if 
> an external antenna tuner is connected to ANT 1.
>
> Page 94 - [EXTERNAL] ANTENNA TUNER: Use the ANT 1 and AT [auto tuner 
> control connection] connectors to connect an external antenna tuner.
> If you connect the external tuner to the ANT 2 connector, the external 
> tuner will not function [by using the rig's tuner control, AT button].