[Elecraft] K3 transmit/amplifier relay

[Guy Olinger K2AV]

Joe, I do not understand what you mean by VOX in your assertion below.

There is no VOX steady state input from anywhere.  There is no VOX jack or
ACC pin named VOX.  There is a steady state VOX segment in the LCD display,
but that is driven from the CPU across the LCDSCL LCDDI LCDCE LCDMODE
multiplex lines. There is no VOX trace on the boards.

The VOX input on the BAND- button is momentary.  The CPU has to retain the
steady state which means "the-operator-wants-VOX operation".  You can call
it anything you want, but the steady state, as evidenced by the lit VOX
segment on the display, only exists in the CPU and somewhere inside the LCD
display.

Set your K3 to CW mode. Do not assert PTT IN at any time in the procedure
below.

Turn on VOX, key the rig via PADDLE or KEY,  You get both keyed power out
and "closure" on KEY OUT with the usual TR switching. The TX led lights
roughly following the CW.

Turn off VOX, key the rig via paddle or Key.  You do not get power out, but
you get closure on KEY OUT, and (with the hard connection to 7'r) the rig
drops RX with the keying. The TX led does NOT light, even though the radio
has done a 7R/7T flip.

Whether you call VOX an input, a state, an imperative, or a glizzywichit,
VOX on or off has no bearing on whether KEY OUT together with 7R is flipped
by KEY or the results of PADDLE.

Are you arguing that the behavior just described does not occur?

73, Guy


On Mon, Mar 14, 2011 at 4:15 PM, Joe Subich, W4TV <lists at subich.com> wrote:

>
> > KEY OUT in CW mode is the logical or of straight key, internal
> > keyer and PTT.  Turning on VOX neither asserts nor gates KEY OUT
>
> No, when any of the (input) signals I named - straight key, internal
> keyer CW, PTT or VOX (note VOX is an input *not* a control state) -
> is active, Key Out is closed (low impedance to common).  That is a
> logical-or (more specifically logical-NOR since it is a low going
> signal).  It would properly be written:
>  NOT (Straight Key OR Internal Keyer OR PTT OR VOX)
>
> What you want is for PTT (input), VOX (input) or QSK (control state)
> to gate the Key and Keyer.  In other words, written as:
>  NOT (((Straight Key OR Internal Keyer) AND (PTT OR VOX)) OR
>      (PTT OR VOX OR QSK))
>
> 73,
>
>   ... Joe, W4TV
>
>
> On 3/14/2011 3:59 PM, Guy Olinger K2AV wrote:
>
>> On Mon, Mar 14, 2011 at 3:01 PM, Joe Subich, W4TV<lists at subich.com>
>>  wrote:
>>
>> Key Out is the logical or of the key input
>>
>>> (straight key, internal keyer, PTT and VOX).
>>>
>>>
>> WRONG. To use your terms and convention, as currently coded in firmware...
>>
>> KEY OUT in CW mode is the logical or of straight key, internal keyer and
>> PTT.  Turning on VOX neither asserts nor gates KEY OUT
>>
>> To prove that, place in CW mode, and hit the key or the paddle with VOX
>> off
>> and PTT not asserted. If your amp is connected, out of standby, and uses
>> KEY
>> OUT, it will change state with the CW.
>>
>> This *IS* a FIRMWARE directed behavior.  It is not implicit in physical
>> circuitry anywhere.  The requested behavior change does not require a
>> hardware change, even though the KEY OUT jack is a hard conversion of 7R
>> from zero state to high voltage short at KEY OUT.
>>
>> When in CW mode, with neither VOX nor PTT asserted, leave the K3 in
>> receive
>> mode, use straight or internal keyer assertion to place monitor audio on
>> the
>> three RX audio DAC's only. This is entirely a firmware change, though
>> possibly an ugly one.
>>
>> 73, Guy.
>>
>>