[Elecraft] KPA1500 ATU - ability to handle more than two antennas

[Matt NQ6N]

I think this is a very important aspect of station design and a big
consideration for any future amp purchase I make.

I'd like to respectfully suggest that Elecraft consider designing a
bulletproof 16x2 antenna switch rated for 5KW and 10:1 SWR (and lots of
isolation between ports) that integrates seamlessly with the amp and
tuner.

There is typically a need to switch both antennas and high power bandpass
filters, or at least the high cost of high power bandpass filters makes
using only one for each band (via switching) very useful.

So when the amp QSYs to 40m the ideal scenario allows the switching in of a
40m bandpass filter after the amp, and then whichever antennas are usable
on 40m, with the tuner knowing which antenna was chosen so that it can
switch to the previously known settings for instant TX.

73,
Matt NQ6N



On Fri, Jan 26, 2018 at 1:45 PM, K9MA <k9ma at sdellington.us> wrote:

> How about using an external switch to select which ATU settings the amp
> uses?  Perhaps with a digital INPUT line?
>
> Scott K9MA
>
>
> On 1/26/2018 11:15, Wayne Burdick wrote:
>
>> This is definitely doable from the amp. All it takes is an external
>> antenna switch with a control port compatible with RS232, Ethernet, USB, or
>> one of the amp’s multi-purpose digital output lines. (These have other
>> uses, too, such as SWR alarm output.)
>>
>> To select among antennas from the amp, you could do any of the following:
>>
>> - tap the ANT switch to go between two or more antennas in rotation
>>
>> - tap ANT then use the UP/DN switches
>>
>> - assign two frequently-used antennas to the front-panel PF1 and PF2
>> switches
>>
>> In all cases, the LCD would show your selection from among N external
>> antenna jacks.
>>
>> We can adapt the firmware to handle any such scenario.
>>
>> Wayne
>> N6KR
>>
>>
>> On Jan 25, 2018, at 7:58 PM, K9MA <k9ma at sdellington.us> wrote:
>>>
>>> I'm concerned about the same issue:  Multiple antennas on one band. I
>>> have an automated antenna selection system.  In addition to following the
>>> band data from the transceiver, there are switches to select antennas.  I
>>> frequently have to very quickly switch antennas, so it must involve only a
>>> single switch.  Using a mouse with the computer is nowhere near fast enough
>>> and I really don't want to make it dependent on the computer, anyhway.
>>> However, my antennas have different impedances, so require different ATU
>>> settings.  So, how can I tie the KPA1500 ATU into my antenna control switch
>>> so it automatically switches settings?  All the antenna switching is
>>> external to the amp, so only a single amp output is used.  The ideal would
>>> be a control line to the amp, controlled by the same switch that selects
>>> antennas, which would select ATU settings.  I really don't want to make it
>>> dependent on the computer.  I expect others have the same issue.  Can the
>>> KPA1500 be made to do something like this?
>>>
>>> 73,
>>> Scott K9MA
>>>
>>> --
>>> Scott  K9MA
>>>
>>> k9ma at sdellington.us
>>>
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>>
>
> --
> Scott  K9MA
>
> k9ma at sdellington.us
>
>
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