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Re: [VHFcontesting] Testing IC-7300 for TX power overshoot

To: John Ackermann N8UR <jra@febo.com>, vhfcontesting@contesting.com
Subject: Re: [VHFcontesting] Testing IC-7300 for TX power overshoot
From: Marshall-K5QE <k5qe@k5qe.com>
Date: Thu, 4 Oct 2018 19:33:07 -0500
List-post: <mailto:vhfcontesting@contesting.com>
Hello John and other VHF Contesters.....I may be completely lost here, but I thought that the "ICOM spike" occurred when PTT was pushed just at the first of a transmission......The overshoot was in the first few milliseconds of TX, not at key-up.  The causes are poor design and have been around for years.  There have been several different "work arounds", but that is what they are.  They are not fixes.

I use the transverter port on my Pro2s and Pro3s to run my transverters.  Those ports are supposed to be -20dbm.....1/100th of a milliwatt.  You cant hurt anything with that, so even if there is a spike, it is so low that no harm is done.

I am also not an instrumentation guy, so it would be nice to see how this spike is measured.  You would have to have a very fast scope to see the spike, but certainly there are such instruments running around.

If I am completely lost on this, here is the chance for the real experts to beat me up......HI.

73 Marshall K5QE

On 10/4/2018 12:19 PM, John Ackermann N8UR wrote:
This may be old news, but I wanted to see if my IC-7300 had the key-up power spike that's been reported on other Icom rigs when the power output is turned down.  The short answer is that I don't see any sign of overshoot, so this rig should be safe to use with amplifiers or transverters that want the wick turned down.  (Of course, you can still blow things up by forgetting to turn the power down...)

Details and pretty screenshots at https://blog.febo.com/?p=321

73,
John

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