Hardware ALC not turning off with v1.10.8 even through it shows disabled, cant turn tx power down

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I got the custom cable for Expert 1K amplifier from your approved vender. I thought I would try hardware ALC on my Flex 6700 since the cable came with an ALC connector. After enabling it I decided I did not want to use it. I disabled it and while the button shows disabled, the P/CW tab still shows the ALC meter and I can't turn down the RF power as it springs back to full power when I release the mouse. This makes my amplifier unusable because I am overdriving it. I have tried restarting the software and the radio
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Dick Illman

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Posted 2 years ago

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Paul - K6HR

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I have a similar problem with 1.10.8.30 beta. When I set Max power in the /radio setup/tx tab the power cannot be set lower. The power gets stuck at that setting, can't lower it or raise it. Maybe this will be sorted in the next version...
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Dick Illman

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I have downgraded to the previous version. Unfortunately I lost all my profiles and memories.
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Jim Runge

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You can set the max input power for each band by using the up and down arrows on the amp, not the L or C arrows, while in the operate mode on the amp.  As you hold the arrow down on the amp you will see the RF Power change on the radio. When you take the amp out of operate the radio will go back to whatever you have set as max power in the radio setup screen.
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Dick Illman

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I will certainly try this. I had not seen this documented before.
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Gary

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I had posted this in response to someone elses thread re SPE amps and ALC ... I thought it might also apply here or at least provide some reference and show what appears to be an issue:

This is in response to your statement re using the ALC on the SPE amps and Tim's saying the ALC does work.... I've noted that the SPE says the ALC signal can be as low as -11V whereas the hardware instructions for the Flex 6700 say not to go lower than -4V or damage might ensue... I've no reason to doubt what SPE is saying - so since you connected the two up were you just lucky or does the flex actually have protection against lower levels of ALC coming in? As I understand ALC it is nominally at its lowest level - so when not 'active' the SPE would be outputting -11V!

[its been a couple months since I looked at this in their respective manuals... I'm pretty sure the numbers are accurate... it seems strange that the Flex would say this - its so easy and cost pennies to clamp a signal so that neither the input nor itself is effected detrimentally.]

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Dick Illman

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I had used ALC with a IC756pro3 for many years. I will check the voltage for sure.
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Ria - N2RJ, Elmer

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I would not recommend ALC as a primary means of drive power control. It may work but it's almost a misuse of ALC. Flex discourages it and Elecraft discourages it. Instead, use the power setting via CAT control. You need a working CAT cable and need to set the CAT mode to "FLEX" on the amp. Then per band and per power level (Low, Mid, Max) you need to set the power level using the arrow keys on the amp. Set once and you're good for life.