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

[Lance Collister, W7GJ]

Hi Andy,

Yes, you are right - it is hard to imagine that it would take a whole 
second to transfer all the relays.  I just thought if there were a way 
to provide more of a delay before enabling the RF output, it might as 
well go up to a second so you could accommodate mechanical coaxial 
switches as well as fast relays.  For everything I have here, a half a 
second would probably work fine.

Yep, running power on VHF is sure not like running QSK during an HF 
contest, and you cannot hope to call weak DX in 20 ms!  But for EME, 
most everything is done in one minute sequences, so speed is not usually 
that big an issue.  Still, the beauty about the K3 is that it is so 
flexible that it has the capability to respond to so many far ranging 
applications!

GL and VY 73, Lance


ANDY COOK wrote:
> To make this all simpler I normally run the transverter as the LAST 
> box to be sent to transmit (ensuring that RF switching is disabled!). 
> So Rig->sequencer->Tx relay->PA bias->transverter. This may hot switch 
> the transverter, but that's rarely a problem in reality with the low 
> powers and enables the system to be built with all the normal VOX / 
> Semi-break in facilities on the radio working normally.
>  
> Now just need to find out why some of the Amphenol N-type relays used 
> for high power switching have got into a state that can take up to 0.5 
> second to release after volts have gone. Maybe they've got magnetised 
> - they were originally 115V AC relays re-wound for 28V DC, but one has 
> already bitten the dust from the consequent hot switching where the 
> sequencer didn't figure on needing to take 1 second to changeover!
>  
> 73,
>  
> Andy, G4PIQ
> -----------------------------------
> Brian Alsop wrote :
> I guess I'm missing the boat on this discussion. 
>
> I thought all high power VHF ops used an external sequencer board that
> did the following type of thing.
> RX to xmit:
> 1) Bypass the mast mounted preamp, wait a bit
> 2) Put the amp in the tx mode, wait a bit
> 3) Put the xvtr in the tx mode, wait a bit
> 4) inhibit the RF output from the rig until 1-3 are complete.
>
> With a relay based system 1-3 could easily be 60ms or more.
>
> Going to receive does a similar thing --i.e. unkeying the various
> components with delays..
>
> You're not going to get his set of multiple delays from the K3.
>
> There are external sequencer boards available as kits for about $20. 
> The K3 has an inhibit line for such use.
>
> And yes, the big guns do have difficulty in the bang-bang contest
> mode.   You call them once and occasionally get the comment,  I'm not
> getting your call, my sequencing hasn't completed.
>
> 73 de Brian/K3KO
>
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-- 
Lance Collister, W7GJ (ex: WN3GPL, WA3GPL, WA1JXN, WA1JXN/C6A, ZF2OC/ZF8)
P.O. Box 73
Frenchtown, MT  59834  USA
QTH: DN27UB
TEL: (406) 626-5728
URL: http://www.bigskyspaces.com/w7gj
2m DXCC #11/6m DXCC #815