[Amps] hot keying the amp?

[Jim W7RY]

With todays modern transceivers, there is really no reason to use key in and key out. I have measured the RF vs. amplifier keying line, (both relay and solid state amplifier PTT) on lot of rigs. With good speed on the amplifier relays, (3 ms) there is really no reason to use key in an key out. Most rigs are 5-10 ms after the amplifier switching relay energizes till RF starts out the stack.

73
Jim W7RY




From: Vasiliy Gokoyev 
Sent: Monday, February 11, 2013 7:14 PM
To: Jim W7RY 
Cc: amps at contesting.com 
Subject: Re: [Amps] hot keying the amp?

Hi Jim 

Yes, your SB-200 QSK board is next as soon as I fix this LK500 :) (got the mouser parts today).

LK500 has a key-in and key-out on the QSK board.  So the amp keys the transceiver after it thinks it's ready.  An interesting solution.  There is a 555 timer that supposed to hold off the relays for an additional 11ms after the the key (or PTT) goes back to high. But this is not happening, the amp turns off immediatedly as the PTT goes high, while the radio (kenwood ts-590) continues to transmit for another 4-5 ms.  Trying to figure out what's wrong with the 555 circuit...  May be it's the caps like Carl and others suggested


On Mon, Feb 11, 2013 at 8:44 PM, Jim W7RY <w7ry at centurytel.net> wrote:

  Take a look here on how to measure QSK circuits and your radio:

  http://www.w0qe.com/amplifier_timing.html

  You need to measure the radio and the amplifier response. What radio are you using?  Have you measured the relay speed in the amplifier?

  Email me privately if you wish to discuss further.

  73
  Jim W7RY

  http://www.ebay.com/sch/radioamplifiers/m.html?item=281051269896&ssPageName=STRK%3AMESELX%3AIT&rt=nc&_trksid=p2047675.l2562




  -----Original Message----- From: Vasiliy - K3IT
  Sent: Sunday, February 10, 2013 8:38 PM
  To: amps at contesting.com 

  Subject: [Amps] hot keying the amp?


  the new amp LK500ZB and I continue our bonding process :)

  I've wired up the QSK circuit and recorded the CW signal on my scope.  I
  can see a small bump after each dot and dash, like on the picture here
  http://goo.gl/74HO3
  Does it look like hot keying the amp?   There is also a very sharp fall off
  - the dot is supposed to be 87ms but cut off early.  Is anybody familiar
  with the QSK circuit on LZ500ZB and/or have words of wisdom? I wonder if
  the QSK circuit has been played with and I can't operate it like this.
  (I'm really knew to "QRO" stuff).

  73

  P.S. Thanks to all for answers regarding the LK500Z output on 10m.  I've
  been testing and re-testing and now consistently get good power on all
  bands.

  _______________________________________________
  Amps mailing list
  Amps at contesting.com
  http://lists.contesting.com/mailman/listinfo/amps 





-- 
Vasiliy