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K3 won't unkey properly: Rear panel PTT

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Dan Sherwood

K3 won't unkey properly: Rear panel PTT

I have discovered an issue with my K3, (ser 5820).

When using my Tigertronics Signalink USB device, the unit keys the rig fine,
but when the interface unkeys, transmission ceases, but red XMIT light stays
on and reception is muted. Like an indeterminate state.

I did the following:

Updated firmware no difference.

Unplugged Signalink rig cable to r/o a short no difference.

Ran a different digital program on laptop no difference.

The rig is configured to accept audio input from the line in jack on the
rear when placed in DATA-A mode. In SSB mode it accepts input from either
the front panel or the rear MIC jack depeng on whether I am using a headset
or the boom mic. PTT is asserted through a foot switch via the front panel
MIC jack. This keys and UNKEYS normally.

The Signalink assertes PTT through the PTT jack on the rear panel of the K3.
It has an internal relay acting like VOX.

When I use the signalink to key up in data mode, it works OK for a few
cycles, then reverts to the indeterminate state. Rig will not receive until
I tap one of the keys mentioned below.

To rule out RF feedback issues, I keyed the signalink in SSB mode, so
line-in not selected, Rig keys up but no power made, (signalink audio not
selected). Problem persists.

Normal CW and SSB using foot switch PTT and either full or semi break in CW
has no issues, even when driving an amp and lots of RF.

CW through FLDIGI uses CAT keyup and release. No issues there. PSK uses
PTT asserted through rear panel. Issue seems with rear panel PTT only.

Now here¹s the really strange thing: When in this indeterminate muted
state, if I tap band up or down, mode up or down, AFX, XIT, or RIT keys, the
unit goes back to normal receive. That initial tap DOES NOT perform the
key¹s design function. This is like a computer keyboard when a screensaver
is running the first keypress is ³swallowed² to wake up the screen, then
subsequent keypresses work normally. Any ideas here?

Thanks,

Dan Sherwood W6DAS

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Don Wilhelm-4

Re: K3 won't unkey properly: Rear panel PTT

Dan,

That sounds more like a Signalink problem than a K3 problem.
Please monitor the voltage on the PTT input from the Signalink to the K3.

If the voltage when transmission is to stop is in the range of 3 volts,
that is the problem - that voltage is in the indeterminate range for the
typical logic levels.
OTOH, if the PTT voltage from the Signalink goes reliably to 5 volts,
then you have a K3 problem.

73,
Don W3FPR

On 7/13/2014 10:01 PM, Dan Sherwood wrote:

> I have discovered an issue with my K3, (ser 5820).
>
> When using my Tigertronics Signalink USB device, the unit keys the rig fine,
> but when the interface unkeys, transmission ceases, but red XMIT light stays
> on and reception is muted. Like an indeterminate state.
>
> I did the following:
>
> Updated firmware no difference.
>
> Unplugged Signalink rig cable to r/o a short no difference.
>
> Ran a different digital program on laptop no difference.
>
> The rig is configured to accept audio input from the line in jack on the
> rear when placed in DATA-A mode. In SSB mode it accepts input from either
> the front panel or the rear MIC jack depeng on whether I am using a headset
> or the boom mic. PTT is asserted through a foot switch via the front panel
> MIC jack. This keys and UNKEYS normally.
>
> The Signalink assertes PTT through the PTT jack on the rear panel of the K3.
> It has an internal relay acting like VOX.
>
> When I use the signalink to key up in data mode, it works OK for a few
> cycles, then reverts to the indeterminate state. Rig will not receive until
> I tap one of the keys mentioned below.
>
> To rule out RF feedback issues, I keyed the signalink in SSB mode, so
> line-in not selected, Rig keys up but no power made, (signalink audio not
> selected). Problem persists.
>
> Normal CW and SSB using foot switch PTT and either full or semi break in CW
> has no issues, even when driving an amp and lots of RF.
>
> CW through FLDIGI uses CAT keyup and release. No issues there. PSK uses
> PTT asserted through rear panel. Issue seems with rear panel PTT only.
>
> Now here¹s the really strange thing: When in this indeterminate muted
> state, if I tap band up or down, mode up or down, AFX, XIT, or RIT keys, the
> unit goes back to normal receive. That initial tap DOES NOT perform the
> key¹s design function. This is like a computer keyboard when a screensaver
> is running the first keypress is ³swallowed² to wake up the screen, then
> subsequent keypresses work normally. Any ideas here?
>
> Thanks,
>
> Dan Sherwood W6DAS
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

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Dan Sherwood

Re: K3 won't unkey properly: Rear panel PTT

Don,

If I'm not mistaking, all the signalink does is use a relay to ground out
the PTT line voltage, much as a foot switch would do. A logic high on the
PTT center pin would indicate a key up condition and should cause the rig to
return to receive state.

I could see where a flaky pull-up resistor could float the pin and cause
erratic behavior.

I yanked the PTT line, but the problem persisted. I would think it would go
unconditionally to receive. If it went high, it did not cause the rig to go
to receive.

The good news is I'm beginning to see the possible cause of the problem, and
it appears to be in the CAT rig control. When I finally get CAT disable,
requiring a restart of FLDIGI, the problem seems to have mitigated.

Funny how you can run a configuration for 2 years and never have a problem,
until one day "poof"! Perhaps the issue is software related after all.

73,
Dan

On 7/13/14, 8:43 PM, "Don Wilhelm" <[hidden email]> wrote:

> Dan,
>
> That sounds more like a Signalink problem than a K3 problem.
> Please monitor the voltage on the PTT input from the Signalink to the K3.
>
> If the voltage when transmission is to stop is in the range of 3 volts,
> that is the problem - that voltage is in the indeterminate range for the
> typical logic levels.
> OTOH, if the PTT voltage from the Signalink goes reliably to 5 volts,
> then you have a K3 problem.
>
> 73,
> Don W3FPR
>
> On 7/13/2014 10:01 PM, Dan Sherwood wrote:
>> I have discovered an issue with my K3, (ser 5820).
>>
>> When using my Tigertronics Signalink USB device, the unit keys the rig fine,
>> but when the interface unkeys, transmission ceases, but red XMIT light stays
>> on and reception is muted. Like an indeterminate state.
>>
>> I did the following:
>>
>> Updated firmware no difference.
>>
>> Unplugged Signalink rig cable to r/o a short no difference.
>>
>> Ran a different digital program on laptop no difference.
>>
>> The rig is configured to accept audio input from the line in jack on the
>> rear when placed in DATA-A mode. In SSB mode it accepts input from either
>> the front panel or the rear MIC jack depeng on whether I am using a headset
>> or the boom mic. PTT is asserted through a foot switch via the front panel
>> MIC jack. This keys and UNKEYS normally.
>>
>> The Signalink assertes PTT through the PTT jack on the rear panel of the K3.
>> It has an internal relay acting like VOX.
>>
>> When I use the signalink to key up in data mode, it works OK for a few
>> cycles, then reverts to the indeterminate state. Rig will not receive until
>> I tap one of the keys mentioned below.
>>
>> To rule out RF feedback issues, I keyed the signalink in SSB mode, so
>> line-in not selected, Rig keys up but no power made, (signalink audio not
>> selected). Problem persists.
>>
>> Normal CW and SSB using foot switch PTT and either full or semi break in CW
>> has no issues, even when driving an amp and lots of RF.
>>
>> CW through FLDIGI uses CAT keyup and release. No issues there. PSK uses
>> PTT asserted through rear panel. Issue seems with rear panel PTT only.
>>
>> Now here¹s the really strange thing: When in this indeterminate muted
>> state, if I tap band up or down, mode up or down, AFX, XIT, or RIT keys, the
>> unit goes back to normal receive. That initial tap DOES NOT perform the
>> key¹s design function. This is like a computer keyboard when a screensaver
>> is running the first keypress is ³swallowed² to wake up the screen, then
>> subsequent keypresses work normally. Any ideas here?
>>
>> Thanks,
>>
>> Dan Sherwood W6DAS
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to [hidden email]
>>
>

Don Wilhelm-4

Re: K3 won't unkey properly: Rear panel PTT

Dan,

Yes, if you have both the CAT PTT turned on and are using the SL PTT
line, that may cause "strange happenings". Good to hear that you now
have a handle on it.

Let me throw in a suggestion since you say it has been working before -
look carefully at your serial port or USB to serial adapter (or the CAT
output of the SL). It may have developed a hardware fault on the DTR or
RTS signals.

73,
Don W3FPR

On 7/14/2014 12:23 AM, Dan Sherwood wrote:

> Don,
>
> If I'm not mistaking, all the signalink does is use a relay to ground out
> the PTT line voltage, much as a foot switch would do. A logic high on the
> PTT center pin would indicate a key up condition and should cause the rig to
> return to receive state.
>
> I could see where a flaky pull-up resistor could float the pin and cause
> erratic behavior.
>
> I yanked the PTT line, but the problem persisted. I would think it would go
> unconditionally to receive. If it went high, it did not cause the rig to go
> to receive.
>
> The good news is I'm beginning to see the possible cause of the problem, and
> it appears to be in the CAT rig control. When I finally get CAT disable,
> requiring a restart of FLDIGI, the problem seems to have mitigated.
>
> Funny how you can run a configuration for 2 years and never have a problem,
> until one day "poof"! Perhaps the issue is software related after all.
>
> 73,
> Dan
>

Richard Ferch

Re: K3 won't unkey properly: Rear panel PTT

In reply to this post by Dan Sherwood

You may have fallen afoul of what seems to be a "race condition" in the
K3's firmware. When software (CAT) PTT and hardware PTT (from any of the
hardware inputs, be it the AUX jack, the PTT IN jack or RTS or DTR on
the RS232 port) are both configured from the same software, and both
methods trigger at the same time, sometimes the K3 fails to switch back
to receive. It doesn't necessarily happen every time; there may be minor
timing differences in the software that affect whether it happens or not
on any particular cycle. This problem has been around for years,
probably since day 1. I have seen this from the beginning with my
2008-vintage K3, and I am told that there are other transceiver models
besides the K3 that have similar problems.

The solution is never to have two methods of PTT configured in parallel.
This is a case where "belt and suspenders" is less reliable than either
the belt or the suspenders alone. If you have Fldigi configured to use
CAT for PTT, then do not connect or configure any of the K3's PTT
inputs. If you want to use hardware PTT, e.g. from the SignaLink, then
disable PTT via CAT in your software.

Incidentally, the hung up state is not an "indeterminate" state as you
suggested in your first post. The K3 is in transmit; the reason nothing
is being transmitted is simply that the software is not sending any
audio to the radio, exactly as if you were in SSB with the rig in
transmit but no sound coming from the microphone.

73,
Rich VE3KI

WA6PZK wrote:

> The good news is I'm beginning to see the possible cause of the problem, and
> it appears to be in the CAT rig control. When I finally get CAT disable,
> requiring a restart of FLDIGI, the problem seems to have mitigated.

______________________________________________________________
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NK7Z

Re: K3 won't unkey properly: Rear panel PTT

In reply to this post by Dan Sherwood

Interestingly enough I have something like that happen now and then as
well...

I am driving the K3 directly with a serial port from my computer, and in
DATA A mode, so far only when in DATA A. I operate 90% in DATA A so
take that last one with a grain of salt... Although it has never
happened in CW mode.

Once the problem has been triggered, if I tap the XMIT button and it
drops out of transmit. Next time, I'll try a different button...

I am using no interface...
--
Thanks and 73's,
For equipment, and software setups and reviews see:
www.nk7z.net
for MixW support see;
http://groups.yahoo.com/neo/groups/mixw/info
for Dopplergram information see:
http://groups.yahoo.com/neo/groups/dopplergram/info
for MM-SSTV see:
http://groups.yahoo.com/neo/groups/MM-SSTV/info

On Sun, 2014-07-13 at 19:01 -0700, Dan Sherwood wrote:

CAS

Re: K3 won't unkey properly: Rear panel PTT

I have had this problem for a long time with the
KX3 and ultimately figured out that the solution
is exactly what Dan had stated. When using the
SignalLink USB only use VOX (on the KX3), or on
the K3 use the back panel PTT and do not use the
CAT for PTT. Without this the combination
consistently creates exactly the race condition
that puts the K3/KX3 in an indeterminate state
requiring the XMIT panel button to clear. I
think the problem is that the delay in the
SignalLink release of the PTT line. That is the
CAT control tries to open PTT while the
SignalLink USB is still grounding PTT so the
radio does not know what state it is in.

I use this system and it works fine as long as I
do not try CAT control for PTT.

Thanks,
-CAS

At 09:23 7/14/2014, David Cole wrote:

>Interestingly enough I have something like that happen now and then as
>well...
>
>I am driving the K3 directly with a serial port from my computer, and in
>DATA A mode, so far only when in DATA A. I operate 90% in DATA A so
>take that last one with a grain of salt... Although it has never
>happened in CW mode.
>
>Once the problem has been triggered, if I tap the XMIT button and it
>drops out of transmit. Next time, I'll try a different button...
>
>I am using no interface...
>--
>Thanks and 73's,
>For equipment, and software setups and reviews see:
>www.nk7z.net
>for MixW support see;
>http://groups.yahoo.com/neo/groups/mixw/info
>for Dopplergram information see:
>http://groups.yahoo.com/neo/groups/dopplergram/info
>for MM-SSTV see:
>http://groups.yahoo.com/neo/groups/MM-SSTV/info
>
>
>On Sun, 2014-07-13 at 19:01 -0700, Dan Sherwood wrote:
> > I have discovered an issue with my K3, (ser 5820).
> >
> > When using my Tigertronics Signalink USB
> device, the unit keys the rig fine,
> > but when the interface unkeys, transmission
> ceases, but red XMIT light stays
> > on and reception is muted. Like an indeterminate state.
> >
> > I did the following:
> >
> > Updated firmware Â no difference.
> >
> > Unplugged Signalink rig cable to r/o a short Â no difference.
> >
> > Ran a different digital program on laptop Â no difference.
> >
> > The rig is configured to accept audio input from the line in jack on the
> > rear when placed in DATA-A mode. In SSB mode it accepts input from either
> > the front panel or the rear MIC jack depeng on whether I am using a headset
> > or the boom mic. PTT is asserted through a foot switch via the front panel
> > MIC jack. This keys and UNKEYS normally.
> >
> > The Signalink assertes PTT through the PTT
> jack on the rear panel of the K3.
> > It has an internal relay acting like VOX.
> >
> > When I use the signalink to key up in data mode, it works OK for a few
> > cycles, then reverts to the indeterminate
> state. Rig will not receive until
> > I tap one of the keys mentioned below.
> >
> > To rule out RF feedback issues, I keyed the signalink in SSB mode, so
> > line-in not selected, Rig keys up but no power made, (signalink audio not
> > selected). Problem persists.
> >
> > Normal CW and SSB using foot switch PTT and either full or semi break in CW
> > has no issues, even when driving an amp and lots of RF.
> >
> > CW through FLDIGI uses CAT keyup and release. No issues there. PSK uses
> > PTT asserted through rear panel. Issue seems with rear panel PTT only.
> >
> > Now hereÂ¹s the really strange thing: When in this indeterminate muted
> > state, if I tap band up or down, mode up or
> down, AFX, XIT, or RIT keys, the
> > unit goes back to normal receive. That initial tap DOES NOT perform the
> > keyÂ¹s design function. This is like a
> computer keyboard when a screensaver
> > is running Â the first keypress is
> Â³swallowedÂ² to wake up the screen, then
> > subsequent keypresses work normally. Any ideas here?
> >
> > Thanks,
> >
> > Dan Sherwood W6DAS
> >
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:[hidden email]
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> > Message delivered to [hidden email]
>
>______________________________________________________________
>Elecraft mailing list
>Home: http://mailman.qth.net/mailman/listinfo/elecraft
>Help: http://mailman.qth.net/mmfaq.htm
>Post: mailto:[hidden email]
>
>This list hosted by: http://www.qsl.net
>Please help support this email list: http://www.qsl.net/donate.html
>Message delivered to [hidden email]