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KAT500 question: using the KAT500 with multiple transceivers using a coax switch

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KAT500 question: using the KAT500 with multiple transceivers using a coax switch

Greetings all and thank you for a great list with lots of great information!

Help me understand something on the KAT500. I have the Elecraft “Dream” setup as I think it is called with the K3s, KAT500, KPA500, and P3. I love it.

I have trained the KAT500 according to instructions.

My question is, now that the KAT500 is trained, can I plug in any source (transceiver) and the tuning will be remembered? That is, it really doesn’t matter what the source is, the KAT500 doesn’t know or care and the source device will get the benefit of the KAT500?

What I want to do is take the cable that goes from my KPA500, run it through an Alpha Delta 4B coax switch, then to the KAT500. Another connection to the coax switch will come from a Collins KWM-2 I recently purchased. I want the KWM-2 to get the benefits of the KAT500 tuner. So I just change the switch to decide which transceiver is connected to the KAT500.

Sound correct? If not, suggestions?

Thanks,
Michael
KK6RWK

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Bob McGraw - K4TAX

Re: KAT500 question: using the KAT500 with multiple transceivers using a coax switch

The KAT500 will sense the RF and apply the previously stored matching
elements for the frequency.

73

Bob, K4TAX

On 6/1/2019 8:37 AM, Michael Gillen via Elecraft wrote:

> Greetings all and thank you for a great list with lots of great information!
>
> Help me understand something on the KAT500. I have the Elecraft “Dream” setup as I think it is called with the K3s, KAT500, KPA500, and P3. I love it.
>
> I have trained the KAT500 according to instructions.
>
> My question is, now that the KAT500 is trained, can I plug in any source (transceiver) and the tuning will be remembered? That is, it really doesn’t matter what the source is, the KAT500 doesn’t know or care and the source device will get the benefit of the KAT500?
>
> What I want to do is take the cable that goes from my KPA500, run it through an Alpha Delta 4B coax switch, then to the KAT500. Another connection to the coax switch will come from a Collins KWM-2 I recently purchased. I want the KWM-2 to get the benefits of the KAT500 tuner. So I just change the switch to decide which transceiver is connected to the KAT500.
>
> Sound correct? If not, suggestions?
>
> Thanks,
> Michael
> KK6RWK
>
> ______________________________________________________________
> 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

Nr4c

Re: KAT500 question: using the KAT500 with multiple transceivers using a coax switch

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 <[hidden email]> wrote:
>
> The KAT500 will sense the RF and apply the previously stored matching elements for the frequency.
>
> 73
>
> Bob, K4TAX
>
>
>> On 6/1/2019 8:37 AM, Michael Gillen via Elecraft wrote:
>> Greetings all and thank you for a great list with lots of great information!
>>
>> Help me understand something on the KAT500. I have the Elecraft “Dream” setup as I think it is called with the K3s, KAT500, KPA500, and P3. I love it.
>>
>> I have trained the KAT500 according to instructions.
>>
>> My question is, now that the KAT500 is trained, can I plug in any source (transceiver) and the tuning will be remembered? That is, it really doesn’t matter what the source is, the KAT500 doesn’t know or care and the source device will get the benefit of the KAT500?
>>
>> What I want to do is take the cable that goes from my KPA500, run it through an Alpha Delta 4B coax switch, then to the KAT500. Another connection to the coax switch will come from a Collins KWM-2 I recently purchased. I want the KWM-2 to get the benefits of the KAT500 tuner. So I just change the switch to decide which transceiver is connected to the KAT500.
>>
>> Sound correct? If not, suggestions?
>>
>> Thanks,
>> Michael
>> KK6RWK
>>
>> ______________________________________________________________
>> 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
>
> ______________________________________________________________
> 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

k6mrmagnet

Re: KAT500 question: using the KAT500 with multiple transceivers using a coax switch

True. However, the advantage of the K3/KAT500 (assuming you have the AuxBus connected) is that the KAT500 will follow the K3 frequency without transmitting. KPA1500 tuner does the same thing.

Ken K6MR

________________________________
From: [hidden email] <[hidden email]> on behalf of Nr4c <[hidden email]>
Sent: Saturday, June 1, 2019 9:18:41 AM
To: Bob McGraw K4TAX
Cc: [hidden email]
Subject: Re: [Elecraft] KAT500 question: using the KAT500 with multiple transceivers using a coax switch

The KAT500 has no clue what provides the RF when sensing the Freq.

Sent from my iPhone
...nr4c. bill

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Elecraft mailing list

Re: KAT500 question: using the KAT500 with multiple transceivers using a coax switch

In reply to this post by Nr4c

No, but it does respond to frequency changes from the K3 which may provide some strange results. If the K3 is on and you spin the big knob while using the KWM2, the KAT will respond to the K3’s QSY. If you change bands on the K3, BOTH the KAT and the KPA will also change bands. And (most strangely), if you power off the K3, shortly the KPA will switch to 60 meters. The latter occurs because the K3 pulls the band lines up to internal Vcc (0V when power is off), which is the combination for 60 meters.

In other words, leaving the aux cable connected from the K3 to the KAT and KPA may have some unintended consequences.

The best description for connecting multiple transceivers to the KPA500/KAT500 combo is in Fred Cady’s book “The Elecraft KPA500 Amplifier and KAT500 Tuner". You might want to refer to it when setting this up.

73!
Jack, W6FB

> On Jun 1, 2019, at 9:18 AM, Nr4c <[hidden email]> 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 <[hidden email]> wrote:
>>
>> The KAT500 will sense the RF and apply the previously stored matching elements for the frequency.
>>
>> 73
>>
>> Bob, K4TAX
>>
>>
>>> On 6/1/2019 8:37 AM, Michael Gillen via Elecraft wrote:
>>> Greetings all and thank you for a great list with lots of great information!
>>>
>>> Help me understand something on the KAT500. I have the Elecraft “Dream” setup as I think it is called with the K3s, KAT500, KPA500, and P3. I love it.
>>>
>>> I have trained the KAT500 according to instructions.
>>>
>>> My question is, now that the KAT500 is trained, can I plug in any source (transceiver) and the tuning will be remembered? That is, it really doesn’t matter what the source is, the KAT500 doesn’t know or care and the source device will get the benefit of the KAT500?
>>>
>>> What I want to do is take the cable that goes from my KPA500, run it through an Alpha Delta 4B coax switch, then to the KAT500. Another connection to the coax switch will come from a Collins KWM-2 I recently purchased. I want the KWM-2 to get the benefits of the KAT500 tuner. So I just change the switch to decide which transceiver is connected to the KAT500.
>>>
>>> Sound correct? If not, suggestions?
>>>
>>> Thanks,
>>> Michael
>>> KK6RWK
>>>
>>> ______________________________________________________________
>>> 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
>>
>> ______________________________________________________________
>> 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
>
> ______________________________________________________________
> 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

Bob McGraw - K4TAX

Re: KAT500 question: using the KAT500 with multiple transceivers using a coax switch

In reply to this post by Nr4c

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 <[hidden email]> wrote:
>>
>> The KAT500 will sense the RF and apply the previously stored matching elements for the frequency.
>>
>> 73
>>
>> Bob, K4TAX
>>
>>

Jim Brown-10

Re: KAT500 question: using the KAT500 with multiple transceivers using a coax switch

In reply to this post by Elecraft mailing list

On 6/1/2019 6:37 AM, Michael Gillen via Elecraft wrote:
> Sound correct?

Right.

73, Jim K9YC

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Jim Brown-10

Re: KAT500 question: using the KAT500 with multiple transceivers using a coax switch

In reply to this post by Elecraft mailing list

On 6/1/2019 10:21 AM, Jack Brindle via Elecraft wrote:
> In other words, leaving the aux cable connected from the K3 to the KAT and KPA may have some unintended consequences.

Right. I've never used an AUX cable between any of my Elecraft gear,
only the keying interrupt lines (as RCA-RCA cables). Frequency detection
in the tuners and amps is plenty good enough to switch near
instantaneously and call up memorized settings. A dit or a bang on the
mic is more than enough.

What IS needed is to either switch the keying interrupt line or loop it
through both amps, depending on the keying logic for the other amp.

73, Jim K9YC

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