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

To: "" <>
Subject: Re: [Amps] Slow start-up of Amps on CW
From: "Jeff in Mali: via Amps" <>
Reply-to: "Jeff in Mali:" <>
Date: Mon, 11 Mar 2024 22:15:56 +0000 (UTC)
List-post: <>
I only saw the issue once on my KPA 1500. I don't think it's a problem for me. 
But on reception, because people only send their callsigns once, the second 
call often has the same issue as the first:  no first letter, or so weak I 
can't copy it in a noisy pileup.

    On Monday, March 11, 2024 at 05:41:44 PM GMT, 
<> wrote:  
 Hi Jeff,
I think there are multiple reasons for the first character missing at the 
beginning of a transmission with an amplifier.  

Number 1 reason:  The sender is using an automatic band selection amplifier.  
One amp, can block 26ms from the beginning of RF input to the amp.  This is 
"independent of the RF Delay setting" in the rig.  This link provides an 
explanation. ; 
ALL Automatic Band Selection amps have this problem in CW.  Use rig control  or 
manual band selection.

Number 2 reason:  The RF delay in the rig from keying the amp until rig RF 
output is less than the amp T/R relay closing time.  If not using automatic 
band selection in the amp, the RF Delay in the rig should be at least 15ms, 
preferably 20ms, for the amp T/R relay to settle.

I am sure there are other reasons.  I did not know about the KPA-1500 amp power 
ramp up?  
Your hearing is not going bad!
.... Bill K3HZP

---------- Original Message ----------
From: "Jeff in Mali: via Amps" <>
To: "" <>
Subject: [Amps] Slow start-up of Amps on CW
Date: Mon, 11 Mar 2024 14:57:01 +0000 (UTC)

Dear All:
I find that on CW, I miss the first letter or two letters of people's call. I 
thought that it was just me not paying attention or half-deaf from too many 
years cutting grass as a kid with lawn-mowers with no mufflers. 
However, more and more I'm convinced that some amps are not instantaneous, not 
picking up immediately as the first letter(s) is (are) keyed on CW or spoken on 
SSB. The other night I was watchin my own amp (Elecraft KPA-1500) and it seemed 
only to come up to full-power after a few characters.
Is this a generalized phenomenon, or just my imagination?
JeffTZ4AM/K1MMBBamako, Mali 
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