[Elecraft] K3s feature request: deadman timer

[Joe Subich, W4TV]

> One of the Elecraft wattmeteror P3 sensor elements and a little bit
> of circuitry external to the transmitter would meet your
> requirements.
Would not even take that ... an NE555, some resistors, capacitors, maybe
a couple NAND or NOR gates is all it takes.  Set up an "N" minute timer
triggered from Key Out (or Key Out LP) that is retriggered (reset when
Key Out is released). Use the output of the timer to drive the Inhibit
input and lock out RF if the timer ever expires.

There are probably more elegant timer than the NE555 but it's cheap
and easy to work with <G>.  These days, one could probably do all of
it with a simple PIC (one IC).

73,

    ... Joe, W4TV


On 6/5/2017 4:26 PM, Fred Jensen wrote:
> My early K3 with late FW quits after 30 seconds of continuous dits or 
> dahs[kitten on the paddle problem]. The radio works fine on JT<mumble> 
> and RTTY modes, so it's really a "semi-deadman" based inside the device 
> which may be stuck in transmit. That wouldn't meet the requirements you 
> originally described or the FCC's. One of the Elecraft wattmeteror P3 
> sensor elements and a little bit of circuitry external to the 
> transmitter would meet your requirements.
> 
> 73,
> 
> Fred ("Skip") K6DGW
> Sparks NV USA
> Washoe County DM09dn
> 
> On 6/4/2017 1:55 PM, Jim Miller wrote:
>> In reviewing what I need to do to remote my K-Line a good solution to a
>> hung transmitter has remained elusive. The only sure way to kill the
>> transmitter is by pulling the plug, potentially scrambling the firmware.
>> Note that sending commands from an attached PC is not a solution since it
>> may have been the culprit in the hang in the first place. Likewise 
>> internet
>> access may have been disrupted making remote reset impossible.
>>
>> I believe the solution is best solved by putting a deadman timer 
>> option in
>> the K3 firmware.
>>
>> I envision this as having an adjustable period (0-99) of minutes, zero
>> would be the default and make the deadman timer off.
>>
>> The deadman timer would be reset each Key out went inactive.
>>
>> I'm not sure what the K3 should do other than cease transmitting. It 
>> may be
>> best to do a full orderly shutdown. That way external logic could 
>> sense via
>> the Aux connector Pin8 (Power On) or the RCA 12v DC out jack that the 
>> K3 is
>> off and take station specific action.
>>
> 
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