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

Subject: Re: [Amps] Slow start-up of Amps on CW
From: "" <>
Date: Mon, 11 Mar 2024 20:44:44 GMT
List-post: <>
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 
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 
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: Pete Smith N4ZR <>
To: "" <>
Subject: Re: [Amps] Slow start-up of Amps on CW
Date: Mon, 11 Mar 2024 15:29:26 -0400

On the other hand, there are workarounds available.  People started 
telling me that my callsign was being clipped soon after I got my 
KPA-1500 (my old SB-220 had homebrew QSK).  I found lead-time settings 
in my Winkeyer setup and in N1MM that let me delay CW until my amp was 
up to speed (50 ms) and similarly hold-in after the last character was 
sent.  No more problems here.

I wondered if the pattern of busted spots on the RBN might also reflect 
such issues, but so far, running together of characters - "TES TN4ZR" - 
seems much more prevalent.

73, Pete N4ZR

On 3/11/2024 3:05 PM, Jeff in Mali: via Amps wrote:
>   Actually Bahamian stn from Spain.
>      On Monday, March 11, 2024 at 06:52:42 PM GMT, Jeff in 
> Mali:<>  wrote:
>    Then of course there is the famous Cayman station from Spain C6AAE.
>      On Monday, March 11, 2024 at 06:24:32 PM GMT, Jim 
> Brown<>  wrote:
>   On 3/11/2024 7:57 AM, Jeff in Mali: via Amps wrote:
>> 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?
> R/T delay is quite real. When contesting, I regularly hear JA calls as
> OA. It's not me mis-copying.
> 73, Jim K9YC
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