[Elecraft] Sequencer keying with K3/XV-144 without rigblaster?

[AD6XY]

W7GJ, Lance wrote:
> 
> 
> Unless I am totally missing the boat here (which certainly happens), it
> seems to 
> me that the cleanest way to make the K3 flexible enough to replace
> existing 
> equipment requiring external sequencers, would be to be able to adjust the
> time 
> between K3 PTT keying and the KEY OUT jack and/or KEYOUT-LP pin (or some
> other 
> available pin) closure between standard short delay (20 ms) or a long
> delay (for 
> example, selectable between .2, .4, .6, .8 or 1 second). 
> 
> 

I don't think you are missing the boat but you are likely to miss DX if it
really takes as much as a second to switch from TX to RX. By that time
someone else will have got there first.

I had a discussion with Elecraft about this when the feature was being
enabled, I did some research on the maximum switching time of large VHF
relays and came to a figure of 50mS. Unfortunately Elecraft could not mange
such a long delay at the time in that version of the firmware.

For long delays of VHF equipment I am not sure the K3 is the right place for
a long delay as it is not something configurable by band and should there be
a switching fault, the smoke will still emerge, just 1 second later than it
would otherwise.

If you are using the transverter output you might as well just put a delay
relay or PIN diode in the TX line. No relay is going to object to hot
switching 1mW. This switch should be controlled by the ready signal from the
amplifier, or whatever it is that is taking so long to be ready. To avoid K3
power errors you might need to ensure a good match. A simple alternative
would be to switch the bias to the TX stages of the transverter instead.



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