[Elecraft] KPA500+KAT500 interfacing

[Jack Brindle]

Two things. First, you are right, it passes the signals through from the radio. The second is that it can break the PTT line (in that pass-through) when the KAT needs to tune or otherwise change the relays while the system is transmitting (PTT being active).

Note that both the KAT and the KPA use many of the signals on the AuxIO. These include the BAND lines, PTT, and importantly, the AuxBus line. The KPA500 talks on the Auxbus (but does not listen), while the KAT listens on the Auxbus. Because of the way the KPA encodes its data, the KAT cannot receive any data from the KPA, but only that coming from the transceiver. That is kind of an important point - there is no communications between the KPA500 and the KAT500, which eliminates the ability to do really close control between the two.

73!
Jack, W6FB


> On Nov 18, 2020, at 10:15 AM, john at kk9a.com wrote:
> 
> So what does the HD15 cable do from the KAT500 to the KPA500?  I thought that the KAT controlled the amp but perhaps it is just passing the K3 data through.
> 
> John KK9A
> 
> 
> 
> Jack Brindle W6FB wrote:
> 
> I received a bit of further information this morning. The KAT500 only uses the band data to validate that the received frequency (from the K3) is on the indicated band. It does not use it for anything else.
> 
> Further, the KPA500 only uses band data to select the band. In general, the KPA doesn’t care about the frequency - it really has no frequency-sensitive elements. The KPA does not receive frequency from the K3, and only uses the Kenwood data (or Icom band voltage) to select a band. Thus there is no data to be sent.
> 
> I believe you are searching for a solution that gathers transceiver frequency and sends it to the KAT500. Or, allow the KAT500 to use its built-in frequency measurement system to select the bin.
> 
> Jack, W6FB
> 
> 
>> On Nov 18, 2020, at 8:00 AM, Wes <wes_n7ws at triconet.org> wrote:
>> 
>> Thanks Andy.
>> 
>> I'm starting to get my head around this.  "Tis a pity that Elecraft didn't allow for the KPA500 to control the KAT500 via the band data bus and have an integrated Amp/Tuner combo that didn't require a proprietary interface.
>> 
>> The tuning solutions are in the tuner memory so telling it, or letting it measure, the frequency recalls them.
>> 
>> Wes
> 
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