6500 antenna tuning SWR go nuts after recent updates.

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Hello,

It seems that since the 2.6.0 update the antenna tuning is going places (crazy).
I am using an MFJ 993B external tuner and it seems that since update 2.6.0 the Flex 6500 (which is in Byp mode) very often believe there is no Bypass and SWR is just shooting up over 10. MFJ tuner cannot handle it.
I am switching back and forth the Byp/internal tuner of Flex and then for a while everything is OK. Then again.
Factory resetted tuner, tested also with a second rig of 100W and working fine.
Changed the whole Coax, redone the connectors, tested antenna etc. Going nuts here.
It all narrowed down to Flex. Something had changed.
I just wonder if anyone had a similar issue and what would be the next step.
I have updated to v 2.6.1 believing that would correct the issue but no luck.
Going back to v2.4.9 is a no go for the same reason that I would not downgrade to Windows XP just because W 10 sucks :-)
Little help here please.
Rig was sent a few months back to Flex Service for Fan Kit renewal and test super fine on all parameters. So I would exclude a hardware issue.
MFJ tuner is also new. Coax is M&P Ultraflex.

Thanks for the great support of this Community

73
Val
DM1TX
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Val DM1TX

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Posted 2 months ago

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Bill -VA3WTB

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I wonder, did you factory rest you 6500? You should to see if that helps any strange things from happening.
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John - AI4FR

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Bill's comments are valid and surely try that. If I read your post right, I must assume that the MFJ is an auto tuner and it is receiving the SWR details from the Flex and not from the feedline. Have you tried removing the tuner altogether to eliminate it as the cause?


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Val DM1TX

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So I took out the MFJ. Reset Flex to factory settings. First sign is that Flex still behave the same. It is like still in Bypass even Software say no. Will further test tomorrow.  Gotta hit the bunk as it is late here :-) Thanks 73 DM1TX
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John - AI4FR

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Hmm, have you tried a dummy load? Make sure that the Flex is pointing to the right antenna. I guess you could drop to a lover version of the software just to be sure. I know you don't wish to do that. There's also the option of reinstalling SSDR. I sure hope it is not a radio issue.
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Terry T

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I just checked my 6500 it's doing the same thing. Very strange some times will tune other times says success and is no where close. Never did this before, I am not sure when it happened because I don't use the tuner in radio.
terry
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donh

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I've had this problem intermittently since the first v3.x on my 6300.  I addressed the issue with Flex to no final resolution.  My workaround is to:

1. Clear all ATU memories

The First Time on a given antenna / frequency
1. Check the 6300 SWR with the Tune button
2. Select the ATU button, wait until it stops tuning
3. Check the SWR with the Tune button
4. If the SWR is not acceptable, turn off the ATU button and go to step 2.

Later use at the same antenna / frequency.
1. Verify the SWR with the tune button
2.  If the SWR is not acceptable, go to the First Time above

Once stored in memory, the settings seem to be held and remembered well.  I use global profile entries as short cuts for per band / mode settings (e.g. 80m ft8, 20 m ft8, 20 m phone, etc.). 

I have observed the ATU tuning does not always take the same amount of time to complete.  It seems to vary based on its starting point (previous SWR at the start of a new attempt).  I ruled out loose connections and feedline intermittents by using an antenna analyzer while flexing cables, switching between antennas between measurements, etc.

Your mileage may vary.   Good luck.

73,
don
wa0ruf
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VE7ATJ

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Hi guys... I've seen this behaviour and other similar problems with the ATU in versions 2.6.0 and 2.6.1, and I would guess it would show up in 3.x as well, since they are similar.  I've submitted a Help Desk Ticket and this has been identified as a possible software defect #7727.  Best solution I've found is to return to v2.4.9.

Don
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Bill -VA3WTB

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I use an external tuner, so I leave the internal tuner off. I won't need to go back to v2.4.9
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John - AI4FR

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I'm glad some others chimed in here. Whew, so it's not a rig issue but rather a software issue. Well that is good news. I run SSDR ver. 3.1.7 but miss ver. 2.4.9 as well. It was better on several fronts. I fear though that my patience with 3.1.7(basically all the same DAX at 2.5 and above) is wearing thin and I also might drop back to 2.4.9. For example, as I type this I can see both instances of wsjt on two different slices have dax errors as seen here: https://community.flexradio.com/flexradio/topics/dax-rx-issue-on-ver-2-5-and-up





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Val DM1TX

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OK. So I am not (entierly) crazy here. 
I am pretty sure that everything started after update to v2.6.0.
Never had an issue with 2.4.9
I have tested today on a dummy load and everything is looking good.
I have workeed on a local CW contest full power today and thngs running stable so far.
I had a second factory restore and clear ATU memories.
Swtched on and off the ATU multiple times.
I am only using hte internal tuner now.
Will connect again the external tuner in the next few days and test again.

Noted two other things: Tuning takes a very long time now
RF power out shows only maximum 95 W. Used to be a dit over 100 before update.
Also important. Version 2.6.0 somehow screwed CAT. My software using it keep disconnecting from the rig. Good news is that ver 2.6.1 fixed that and now all related software is happy following the Chief.

I am just waiting to see if the issue with antenna tuner manifest itself again.
I have total confidence that Flex Radio will have an eye and fix on this soon.

Another question would be how do I downgrade to v2.4.9 n case a fix does not surface anytime before Christmas ? :-)
73
DM1TX



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Bill -VA3WTB

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Just run the v2.4.9 installer, the radio will down grade
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Val DM1TX

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Hi Bill,
I have dowgraded as you said. Tested. And I have upgraded again. Flowless.
I just remembered why I love Flex Radio so much :-)
Fantastic process and zero errors.
However my issue is still there even on v2.4.9.
It is like SWR is spiking way into the red but no errors or warnings from the radio. Is this normal?
How exactly is the high SWR protection working on these beautiful beasts?
I have to look into some other reasons I guess.
73
Val


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Harold Rosee

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Add me to the list.  I am running 3.1.8 on my 6600M.  My external auto tuner just died so I was going to use the radio's tuner until I get the other one fixed.   The tuner in the radio thinks it's tuned when the SWR is still 3 to 1.  

Is there a fix coming?  Do I need to open a help desk ticket since there is already one open?  

Thanks

Harold
W5ZZT
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donh

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Try to cycle the ATU button off - on, letting it complete its tuning operation every time it turns on.  One of those times may resolve the issue and give you a better SWR.  (See my previous post.)

73,
don
wa0ruf
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HCampbell WB4IVF

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“It is like SWR is spiking way into the red but no errors or warnings from the radio. Is this normal?
How exactly is the high SWR protection working on these beautiful beasts?”

Val, protection is based on reflected power, not SWR.  Output power is reduced when reflected power exceeds 25 watts. 

Howard
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Pat N6PAT

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The amp I use for 160 is in the shop so I've been using the 6700 ATU.  It takes 4 or 5 tries before it will tune at tuning power of 8 watts. I have power out set to 98. The 6700 power meter says about 90 out with SWR about 1.2 but the LDG meter says power is about 110 watts. Odd that it's different but it does show that the ATU is tuning.

Running 2.5.1 - reverted back from 2.6.1 due to power loss during TX.
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Brian Denley KB1VBF

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You might have said and I missed it:
what power are you tuning with?
Brian KB1VBF
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Val DM1TX

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Hi Brian. I have tested tuning with values between 3 to 10 Watts. Never more.
Lately I have tested with  local dummy load attached to antenna port. There are no issues!
Will attach the dummy load at the end of coax and see if cable is to be blamed.
I use a factory manufactured Common RF Filter (for power up to 2 KW)
I do not have an amp.
My attention was drawn by the fact that also external tuner (MFJ) is showing crazy nuts values.

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Val DM1TX

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For information I have found where the problem was. I used a 1:9 balun for my Endfed antenna.
It seem that was the real issue. Ether the resistors or Ferrite ring would not behave properly at high power. I have replaced the Balun and run full tests. No problems whatsoever. So my first assumption that it could be related to a recent version 2.6.1 upgrade was totally wrong. Good luck to all and thanks for all the answers. 73. DM1TX