[Elecraft] Missing first piece of dash or dot when sending CW with K3S USB input with Wintest.

[Bob Wilson, N6TV]

Are you connecting the amplifier to the TX Inhibit pin of the K3 ACC port?
Do you have CONFIG:TX INH set to Low=Inh or Hi=Inh?  You must first set
CONFIG:TECH MD ON to see it.  Try changing TX INH to OFF.

>From the Expert 2K-FA manual, section 13.3:

"All modern transceivers have a delay before the transmission to allow the
linear to
stabilize their relays avoiding damage to them and possible effects of "Hot
Switching".
The Expert 2K-FA has a settling time of only 6.5 msec. compatible with all
modern
transceivers (see the manual of the transceiver).
Some transceivers have an input (called TX-INHIBIT, LINEAR, MUTE, etc..)
which
disables the transmission.
*This input can be used with transceivers that do not have such delay *or,
more generally,
to improve the safety of switching."

So unless you are using CW QRQ mode in the K3 (and PTT lead=0 in Win-Test),
the relay should close well before the RF is output, so it   should not be
necessary to enable TX INH at all.

73,
Bob, N6TV

On Jul 13, 2017 7:58 PM, "VA2EW" <va2ew at videotron.ca> wrote:

> Thanks guys for your fast answers and suggestions.
>
> After having read you, I made several tests.
>
> I have observed some very strange things leading me to think that the K3
> USB by itself is not involved:
>
> The problem occurs only when the amplifier (Expert 2K-FA) is in operate
> mode and whatever the output power even 50W in a dummy load (the RF is not
> involved).
>
> The problem disappears when I put 0 ms as well as 30ms in the "CW-PTT ON
> delay" of the interface configuration of Win-test.
> That delay is the time between the initial PTT ON signal and the first CW
> sending.
> The problem comes back when I put my initial 12ms setting. So why 0 and 30
> are ok and not 12ms...that's the strange thing?
>
> I'm starting to think that there is something related with the inhibit
> output of the amplifier, when there is an inhibit signal at the input of
> the K3, the transmission stops and we cannot hear anymore the transmitted
> CW. So, maybe the USB is correctly doing its job but the inhibit signal is
> hiding it.
>
> You could tell me :" you have found a solution so stop digging" but I do
> not like when things are floating around in the station so I have to put an
> oscilloscope in all that and check the timings.
>
> I'll tell you if I find something interesting for the reflector
>
> 73, Gilles VA2EW
>
>
>
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