tune up "abort" - How to??

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  • Updated 4 years ago
When tuning a freq, is there a way to abort if it looks like "trouble"? Some times the rig tunes quickly (good match). Other time (if the swr is higher?) it seem to take longer and "struggle" and I'd like to abort, before I hurt something.

I was just give a homebrew 40m loop. The guy who build it stated the limit on the capacitor was maybe 12 watts! (his CW rig was about 3" square, 5 W and ran on AA batteries!) The loop is really good on receive and I'd like to test it in transmit on very low power, but if it start arcing I'd want to quickly abort!!

Probably safer to make it just a receive only antenna.

Brent W8XG
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Brent Parker

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Posted 4 years ago

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Ken - NM9P, Elmer

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To abort ATU tuneup, simply hit the MOX button.
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Duane, AC5AA

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And be sure to have your full output power below 10W!
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Brent Parker

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I believe the auto tune, runs 10w and is fixed??  So, that's going to be somewhat close to the limit!

My trapped dipole has a noise floor right now about-96, with a weak signal at -87 so the signal is only 9db above the noise.

The loop has a higher noise floor of -92, but the same weak signal is -70 so is 22db above the noise. Pretty impressive!

It's a 1/2 copper tube (plumbing pipe) 6' diameter. Feed with a torrid in the middle with 4 turn into the torrid.

Manual tuning cap is opposite the feed point.  Have to walk out to my balcony to manuall turn the cap. (I see a stepping motor, in my future)

Brent  W8XG
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Duane, AC5AA

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I don't see an obvious way to reduce power on tuneup with the autotuner.  I just measured mine, and with an unmatched load, it's showing around 15W of power (remember, the power meter is calibrated for 50 Ohms).  So, it looks like it would be on the edge of taking out the cap you are describing.  If you used a manual tuner, then you could reduce the tune power in the "Settings."
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Tim - W4TME, Customer Experience Manager

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SmartSDR v1.4 will have a separate power level control for TUNE
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Brent Parker

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Tim, I've been watching Dudley's livestream when he's on the 14.329 net on Sundays and have been watching the Alpha of 1.4 for a few weeks now. However I missed that coming feature. Nice!  Thanks,

Brent W8XG
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Ken - NM9P, Elmer

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Nice!  Thanks, Tim (and the other FRS Staff).
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Brent Parker

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Ken - Thank You. I knew it had to be simple like that, but I read the manual thru and simply didn't see it.

This community "stuff" is great for something like this.

Brent  W8XG

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Nigel - G0JKN/W2

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I thought you could change the tune power by moving the power slider while tuning? I'm probably wrong.....

Nigel
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Duane, AC5AA

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You're thinking the manual "Tune" button. He's asking about the ATU auto tuner button.
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Reggie-k6xr

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I set the tune power level in    settings / transmit / tune power. I have mine set to 10 watts and it works in auto or using outboard tuner. I have a 6500.
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AA0KM

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I ran into this too. Adjustable default. It may well go lower than 10watts.

I don`t have a meter to test that low. 2 will stay in the tab.


(Edited)
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Duane, AC5AA

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The control you show only sets the MANUAL tune power.  The ATU (Autotuner) will still put out around 12-15W according to my wattmeters.  It probably requires this to have an adequate SWR reading to make adjustments.  The original question was regarding the ATU tuning power, which I don't see any adjustment for.
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George Salinas

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I had a similar incident this evening where I had to abort.  I was attempting load up on 40m with an antenna
designed for twenty (my mistake).  I could see that the ATU was struggling and became suspicious but I
could not turn off the transmitter from attempting to load the wrong antenna.  I got an SDR message that the Flex 6500 had disconnected.  I relaxed but then noticed that the on/off switch was still on and it was
a red color (indicating still transmitting).  I panicked as the on/off switch would not turn off  the transmitter.
I ended turning off the power supply.  After that I had some trouble getting the Flex 6500 to register on the SDR dialogue box when I turned it back on.  Turning off the Flex, the SDR software and then the computer fixed the problem when I next brought everything back on line.   The on/off switch needs to be fixed so that when you push it once the Flex either turns on or off.

George
KD4FJ
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Jon - KF2E

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If you push and hold the on/off for a few seconds it will force a shutdown.

Jon...kf2e
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k3Tim

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Another way to abort a ATU-tune in progress is to press the key / bug, instantly stops ATU.  My opinion is the PA can take a lot of abuse at the 10 watt tune level and one shouldn't panic to much if there is a misfire.  The PA in the Flex 6K series seems "bullet proof".

k3Tim  / MSEE - PE - PPSEL / IFR
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Duane, AC5AA

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Thanks, Tim!  I hadn't tried that yet, but it's good to know.  I have a Palstar autotuner, and sometimes I accidentally hit the ATU instead of the Tune button . . . then it's a race! Ha, ha!