Auto Antenna Tuner - MP


WC2S@...
 

I am not certain I understand how the internal antenna tuner on the MP is supposed to work, and would appreciate some help.

When the tune light is on, and I hold the button for one second, I hear the wheels turning and then stop.

I thought that the correct settings would then be “memorized” and returned to after one QSYs and comes back to the original frequency later, as do many external automatic antenna tuners.

However, I never hear the tuner in action again on transmit, unless I initiate it.

To test this, and because I have a SteppIR on autotrack, I thought that perhaps the SWR would be low enough already so that the antenna tuner on the MP would not need to do anything further.  Just to make sure, with the autotrack on I then tuned the MP to the already tuned SteppIR antenna and I heard the wheels turn.  I am not sure that means anything, but I wanted to make sure that the MP itself was tuned to the frequency via the internal tuner.

Now turning the autotrack off, if I QSY to another band where I had already tuned the MP, I thought I should hear the tuner come into action when I initiate a transmission into a purposely mistuned SteppIR antenna.  However, I do not.

The manual refers to a "momentary" press which should turn the tuner on, and a press and "hold" to begin the tuning process.

My experiment above was done with the antenna tuner light on, and theoretically in the circuit.

What behavior should I expect from the antenna tuner on the MP, or what am I doing wrong?

Or is there a problem with the tuner?


Lou W7HV
 

Page 57 on the US manual states the ATU only remembers tunes that are below 2:1, and for each 10kHz segment.  If the load is greater than 2:1, then you must tune again.  I haven't exhaustively tested this, but that does to be how it works. When switching between memorized tunes, there's very little fuss as only the few necessary relays simultaneously click, unlike the 10 second cacophony that goes on when it's searching for a new tune.

On Monday, March 1, 2021, 3:55:45 PM MST, <wc2s@...> wrote:


I am not certain I understand how the internal antenna tuner on the MP is supposed to work, and would appreciate some help.

When the tune light is on, and I hold the button for one second, I hear the wheels turning and then stop.

I thought that the correct settings would then be “memorized” and returned to after one QSYs and comes back to the original frequency later, as do many external automatic antenna tuners.

However, I never hear the tuner in action again on transmit, unless I initiate it.

To test this, and because I have a SteppIR on autotrack, I thought that perhaps the SWR would be low enough already so that the antenna tuner on the MP would not need to do anything further.  Just to make sure, with the autotrack on I then tuned the MP to the already tuned SteppIR antenna and I heard the wheels turn.  I am not sure that means anything, but I wanted to make sure that the MP itself was tuned to the frequency via the internal tuner.

Now turning the autotrack off, if I QSY to another band where I had already tuned the MP, I thought I should hear the tuner come into action when I initiate a transmission into a purposely mistuned SteppIR antenna.  However, I do not.

The manual refers to a "momentary" press which should turn the tuner on, and a press and "hold" to begin the tuning process.

My experiment above was done with the antenna tuner light on, and theoretically in the circuit.

What behavior should I expect from the antenna tuner on the MP, or what am I doing wrong?

Or is there a problem with the tuner?


F5PNI
 

Hi,
The auto tuner it's for make 50ohm image to your final unit view.
If you use the SteppIR who send this 50ohm information to transceiver, your auto tuner don't have to make something. 50ohm view is correct for it.

What is your previous transceiver and what do you don't understand on antenna line ?

Best 73


ray sylvester nr1r
 

push tuner button and hold down fo 3 seconds it will  beep 3 times take finger off let tuner tune when done it will stop and red light will be on .If your antenna is more than 3 to 1 swr it will not tune the tune range is limited to 3 to 1 


S S
 

On Mon, Mar 1, 2021 at 02:55 PM, <WC2S@...> wrote:
I am not certain I understand how the internal antenna tuner on the MP is supposed to work, and would appreciate some help.

When the tune light is on, and I hold the button for one second, I hear the wheels turning and then stop.

I thought that the correct settings would then be “memorized” and returned to after one QSYs and comes back to the original frequency later, as do many external automatic antenna tuners.

However, I never hear the tuner in action again on transmit, unless I initiate it.

To test this, and because I have a SteppIR on autotrack, I thought that perhaps the SWR would be low enough already so that the antenna tuner on the MP would not need to do anything further.  Just to make sure, with the autotrack on I then tuned the MP to the already tuned SteppIR antenna and I heard the wheels turn.  I am not sure that means anything, but I wanted to make sure that the MP itself was tuned to the frequency via the internal tuner.

Now turning the autotrack off, if I QSY to another band where I had already tuned the MP, I thought I should hear the tuner come into action when I initiate a transmission into a purposely mistuned SteppIR antenna.  However, I do not.

The manual refers to a "momentary" press which should turn the tuner on, and a press and "hold" to begin the tuning process.

My experiment above was done with the antenna tuner light on, and theoretically in the circuit.

What behavior should I expect from the antenna tuner on the MP, or what am I doing wrong?

Or is there a problem with the tuner?
I've noticed this on my 101D as well. It doesn't seem to remember anything about the previous tunes that it's done, on the same antenna and frequency range, even though it gets the SWR below 2:1.


Lou W7HV
 

>>>It doesn't seem to remember anything about the previous tunes that it's done, on the same antenna and frequency range, even though it gets the SWR below 2:1<<<

If the SWR is greater than 2:1 with the tuner off, it won't remember the tune irrespective of what the resultant SWR is with the tuner on.  example:  If the SWR the radio sees is 2.2:1 with the tuner off, and the tuner then tunes it to 1:1, it won't remember it.  The SWR is still 2.2:1 at the antenna connector at the back of the radio. 


WC2S@...
 

This information regarding the 2:1 SWR minimum to trigger the antenna tuner is helpful - thanks.
Perhaps I was not clear in the description of my experiment to see if the tuner was working or not.
I will try again.
On 12 meters, I tuned up both the SteppIR and the MP and had 1.1:1  SWR.
I then did the same on 30 meters, again achieving 1.1:1 SWR on 30 meters.
I chose 12 and 30 meters hoping that harmonically they would be different enough to see a difference when I switched between them.
I went back to 12 meters, but this time leaving both the SteppIR and the MP tuned to 30 meters, and with both the MP tuner and the autotrack off.  For those unfamiliar with the SteppIR, autotrack automatically readjusts the SteppIR as one changes frequency - one can turn it on or off.
Into this purposely mistuned system, the SWR was high, as expected.
I then turned the antenna tuner on in the MP expecting the wheels to turn to try to make a match on 12 meters.
Nothing heard from the MP and the SWR remained high.
Was it because the SWR was over 5 that the MP did not even try to make a match, or do I have a problem?


Barry D. Jacobson
 

I believe over 3:1 rig flashes High SWR and doesn't adjust.

--
Barry Jacobson
WA2VIU
bdj@...
@bdj_phd

On Wed, Mar 3, 2021, 1:55 PM WC2S via groups.io <WC2S=arrl.net@groups.io> wrote:
This information regarding the 2:1 SWR minimum to trigger the antenna tuner is helpful - thanks.
Perhaps I was not clear in the description of my experiment to see if the tuner was working or not.
I will try again.
On 12 meters, I tuned up both the SteppIR and the MP and had 1.1:1  SWR.
I then did the same on 30 meters, again achieving 1.1:1 SWR on 30 meters.
I chose 12 and 30 meters hoping that harmonically they would be different enough to see a difference when I switched between them.
I went back to 12 meters, but this time leaving both the SteppIR and the MP tuned to 30 meters, and with both the MP tuner and the autotrack off.  For those unfamiliar with the SteppIR, autotrack automatically readjusts the SteppIR as one changes frequency - one can turn it on or off.
Into this purposely mistuned system, the SWR was high, as expected.
I then turned the antenna tuner on in the MP expecting the wheels to turn to try to make a match on 12 meters.
Nothing heard from the MP and the SWR remained high.
Was it because the SWR was over 5 that the MP did not even try to make a match, or do I have a problem?


Lou W7HV
 

Yes.  I haven't quantified it, but there is an SWR threshold above which it will refuse to tune.  It'll click, and immediately quit.  It worked for me around SWR 3.5 on a few occasions, but of course it won't remember the tune.  I figure it's only rated for 3, so going much beyond that is pushing things.  The currents and voltages experienced in the ATU can go up at greater mismatches.  My other rig's ATUs are also only rated for 3.  Elecraft's internal ATUs are a notable exceptions.


F5PNI
 

I probably explained it wrong too.
If your SteppIr antenna is tuned to send a 1: 1 image, your 101 Tuner will tune for the first time to make the correct adjustment, but if there is 1: 1, it means that your antenna impedance is correct.
So it will go into Bypass mode while being activated, as long as you do not start again a forced tuning of the tuner.
Because in his memory, it is recorded that the last time the agreement was OK.
Except if you distort the system while being with your SteppIr out of tune, the tuner will not know it, without again restarting the measurement and forced adjustment.
I want to understand that the 101 is not perfect, like other RIGs, but you should not look for the defect where there is none.

And I confirm, max tuner possibility is 3:1, you can read this in your user manual...


WC2S@...
 

Thank you all for your thoughts.

I will keep an ear open for the wheels to turn, even when the SteppIR runs SWRs that are a bit higher, such as on 30 meters using the 30/40 meter element..

Otherwise, I will not expect to hear anything because the SWR is generally under 2:1 when using the SteppIR in autotrack mode.