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Re: What was done to amp


 

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Agree 100 percent

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In CA people use 1500W

Ridiculous and distort the whole frequency

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Robert T. Devine, KC6AWX

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"Save a Life...Become an Organ Donor"

'Be kinder than necessary, for everyone you

meet is fighting some kind of battle.'

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From: [email protected] [mailto:[email protected]] On Behalf Of N3BNA - Dale
Sent: Friday, October 15, 2021 2:14 PM
To: [email protected]
Subject: Re: [W7DXXREMOTE] What was done to amp

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Simple. Use only 30w on digital modes.? Problem solved.? ?It is beyond me why anyone (yes anyone) needs 100w.? You will be an alligator station. There is nothing to be proud of getting a stronger report, you should be embarrassed to get a stronger report.? Never, ever use 100w on FT8/FT4.

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73


Dale N3BNA

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On Friday, October 15, 2021, 05:00:29 PM EDT, Don Nesbitt via groups.io <n4hh@...> wrote:

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A few thoughts for the group's consideration:

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The scenario that Dan has cited is, unfortunately, very possible and likely.

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Re:? #3? - I have been unable to find an "already included in software" or "in the current hardware" solution that would lock out any change in Xmit parameters - band, power, etc. - if someone hijacks when the remote is already in xmit - and - in particular using an audio based digital mode - for example FT8.? In the contesting world of SO2X (single op, 2 xmtrs) there are lockout safeguards available both in "some" contesting software as well as in "some" hardware.? Such that if you are xmitting on one radio the second radio is inhibited from xmitting.? And, yes - there is an "inhibit" mode associated with the KPA1500 but it looks like it only is useful under very specific circumstances and ours does not "seem" to apply.? I'm exploring this but don't have a solution - - - yet.

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Depending on folks to be aware of, and actually do the "right" thing is usually not effective - hey, we all make mistakes!

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I don't know what Keith will do or what decision he will make on this issue.

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But - IF you are going to use an audio based digital mode - like most folks favorite - FT8,? my advice would be:

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1.? Make sure your digital software is NOT running when you log in to the remote - yes, yes,? I know, I know - but mine is always only set to decode and not transmit, etc., etc., - yah - right - sure!

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2.? When you log on to the remote - make sure that someone is not already using the remote and transmitting.

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3.? Make sure that the amplifier is in STBY when you do use FT8 -

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NOTE:? Once again, we are trying to have the drive level to automatically set at 100 watts when the amp is in STBY and 27 watts when the amp is in OP.? This has worked in the past but with intermittent switching problems.? Finger's crossed that this holds - this time!

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FYI - the KPA1500 is back and currently online and operational.? While there are few more tweaks to deal with - - - - we're back :))?? -- Don N4HH

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On Friday, October 15, 2021, 02:49:02 PM EDT, Dan N5TM <n5tm@...> wrote:

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Joe,

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The problem is systemic with WSJTX CAT.? The software will change the frequency to match what you may have selected, and it does this without asking first.? As an example if you simply change the mode from FT4 to FT8, WSJTX will immediately move the frequency to the FT8 frequency.? It is possible that you could force a band change without intending to do so, just by clicking the wrong button or dropdown on WSJTX.? I have also observed WSJTX sending out ¡°hijack¡± commands when you first launch the program.

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As my initial email stated, if this happens when someone else is running FT8 and in a TX sequence, you are likely to have a hot switch occurrence.

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Ideas on how to avoid this:

  1. Never run the amp when operating FT8/4 or any other digital mode which keys the transmitter for a long time period.
  2. Do not run CAT with WSJTX, instead, only use VOX to key the remote.
  3. Implement software or hardware lockout on the amp, so that a hot switch cannot occur.? (Don N4HH is looking into this.)

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Points 1 and 2 would require full compliance by all users of digital modes on w7dxx, and even so, there could still be an inadvertent hot switch through someone forgetting to turn off CAT, or failing to notice the amp was still enabled.

Never running the amp with digital modes is still not completely failsafe, as Elecraft warns, even 100W hot switched can damage the contacts.

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Dan n5tm

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From: [email protected] <[email protected]> On Behalf Of Joe KI5QZW
Sent: Friday, October 15, 2021 10:33 AM
To: [email protected]
Subject: Re: [W7DXXREMOTE] What was done to amp

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Post how to avoid "Hot Switching"

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On Wed, Oct 13, 2021 at 3:17 PM Dan N5TM <n5tm@...> wrote:

Elecraft states that the most common cause of burned contacts is hot switching.? I have observed that WSJTX will hijack the remote when you bring up a new instance.? My best guess would be:? a second operator hijacked the remote without intending to do so, just by opening or changing a setting on WSJTX? This could have happened while the first operator was Key down on FT8, likely causing a hot switch of the contacts.

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Dan n5tm

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From: [email protected] <[email protected]> On Behalf Of kh6dc@...
Sent: Tuesday, October 12, 2021 1:31 PM
To: [email protected]
Subject: Re: [W7DXXREMOTE] What was done to amp

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What caused the burned relay contacts and the overheated coil?? Not running MTUNE or not running MTUNE in low power? or not waiting a few seconds for the amp to follow the K3 when changing bands?

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