[Elecraft] KAT500 question: using the KAT500 with multiple transceivers using a coax switch

[Bob McGraw K4TAX]

I use two transceivers with my station.  The K3S, P3, KPA500 and 
KAT500.   Also have a Tentec Eagle which is the 2nd transceiver. I have 
a  A / B switch in the coax line between the transceivers output and the 
input to the KPA500.  The AUX buss is connected in the K3S 
configuration.  The Eagle has only the RF coax to the A / B switch as 
does the K3S.  There is also an AMP KEY line from the Eagle to the 
KAT500.  {See Fred Cady book on this point.}  This assures the Eagle 
when in TUNE mode does not activate the KPA500 as the PTT line is opened 
in the KAT500.  I can switch radios without any issues.   However, If I 
choose to use the Eagle, the K3S must be OFF.   Otherwise the system is 
seeing and responding to the frequency of the K3S VFO supplied by the 
AUX Buss.     When using the Eagle, the Amp and ATU respond to the 
applied RF.

Thus.......only one radio at a time is powered ON.  This also prevents 
transmitting into a dead short thus from having the A / B switch in the 
wrong position.

With this configuration, the KPA500 and the KAT500 will switch bands and 
resolve a match automatically. But......you must understand the station 
you wish to use must be ON and the other station OFF.     I'm sure there 
are other ways to do this but mine works for me.

73
Bob, K4TAX


On 6/1/2019 11:18 AM, Nr4c wrote:
> The KAT500 has no clue what provides the RF when sensing the Freq.
>
> Sent from my iPhone
> ...nr4c. bill
>
>
>> On Jun 1, 2019, at 11:18 AM, Bob McGraw K4TAX <rmcgraw at blomand.net> wrote:
>>
>> The KAT500 will sense the RF and apply the previously stored matching elements for the frequency.
>>
>> 73
>>
>> Bob, K4TAX
>>
>>