[Elecraft] K3 + XV144, how the PTT/ sequencer works

Don Wilhelm w3fpr at embarqmail.com
Sun Apr 1 09:47:58 EDT 2012


Samir,

You have several choices to work with.

There is little internal delay, you can set the K3  TX DLY (see the 
manual page 61) from its normal 008 setting to something greater, but if 
you are using QSK CW, that setting may chop off the leading edge of your 
keying elements.
You could also take advantage of the TX INH function (See the menu page 
61) to inhibit RF until the TX Inh input changes - that requires an 
output from your slowest relay indicating that it has closed and stopped 
contact bounce.

The simplest way to set it up is to use PTT (not VOX) and wait a bit 
after you hit the footswitch to start keying (or talking), but that 
carries the risk of not waiting long enough some of the time.

Other alternatives are to update the amplifier relays to faster ones, 
vacuum relays will pull in in less than 8 ms. (likely 3 ms.), or build 
an external sequencer to control the timing of everything - the K3 TX 
INH can use the output if the sequencer.

73,
Don W3FPR

On 4/1/2012 2:59 AM, Samir Popaja wrote:
> Hello,
>
>
>
> I'm getting to use K3/ XV144 with tube amplifier on 2m. I'm wondering how
> the PTT/ sequencer in this kombo K3 + XV144 works?
>
> I don't use extern LNA (no need).
>
>
>
> When I push the microphone or beginning to send CW has the coaxial relays in
> the amplifier already switched?
>
>
>
> Thanks
>
>
>
> Samir, sm7vzx
>
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