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Re: [Amps] Slow start-up of Amps on CW

Subject: Re: [Amps] Slow start-up of Amps on CW
From: Pete Smith N4ZR <>
Date: Tue, 12 Mar 2024 21:24:53 -0400
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I think this thread is drifting off-topic.  We're not talking about the waveform of CW, but how long it takes after PTT before the KPA-1500 is ready to amplify incoming signals.  I've been there - at first my N was getting trimmed into a non-character, so I now have a 50 ms. delay in my Winkeyer (which controls PTT) to prevent that.

73, Pete N4ZR

On 3/12/2024 7:52 PM, Jim Brown wrote:
On 3/12/2024 2:40 PM, Robert W5AJ wrote:
Best I can tell, FTdx10 CW with 6ms rise time is in par with K3 looking at QST In Depth review

Fast rise time CAUSES clicks; beginning with the first K3, Elecraft uses a carefully shaped keying waveform that they call "sigmoidal," (which I've heard described as a raised cosine) to provide nice sharp keying without clicks. I've heard that after a bad ARRL review for for their 6500 series rigs, they adopted that shaping or something like it.

But rise time is the wrong thing to measure -- a spectral plot showing sidebands with a string of dits shows where the bodies are buried.

Likewise, modulation with a sine wave, or even an IMD pair of sine waves, fails to expose splatter caused by processing like Yaesu is (was?) doing in those rigs.

Splatter running VHF/UHF rover is far less likely to cause QRM except during band openings on SSB.

FWIW -- I love my K4, but am still quite happy with my 2008-vintage K3 with upgraded synth.

73, Jim K9YC

It is interesting to watch the CW signals now with the BandScope
more so during CW contest!
Still own the K3 but I'm not likely to sport (Buy) a K4
The FTdx10 is ideal rig to carry on the 50Mhz rover trips, gets me band scope & built in sound card

73 Robert W5AJ

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