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K3S with more than one device on the Band Data signals

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NOEL POULIN

K3S with more than one device on the Band Data signals

Hi to all,
I am on the way to connect a Bandpasser2 (band data mode) on a K3s.
Later I would like also to connect a band decoder on the same radio to
switch coaxial stubs.
I wonder if the K3s can handle more than one device connected to the
Band Data signals.
I suppose that Elecraft band output is probably designed to drive one
decoder and this decoder is designed with current maximums for each port.
I would appreciate comments and good tips about that fact...
Thanks
Noel
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Jim Brown-10

Re: K3S with more than one device on the Band Data signals

On Fri,3/10/2017 2:38 PM, NOEL POULIN wrote:
> I wonder if the K3s can handle more than one device connected to the
> Band Data signals.

My guess is that the answer is yes. I would expect the decoder you're
driving to have a high-Z input. Also, study the manual for that unit.
It's part of a system, and may have band data output. Lots can be
learned from studying manuals.

73, Jim K9YC

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Bob Wilson, N6TV

Re: K3S with more than one device on the Band Data signals

In reply to this post by NOEL POULIN

Using band data mode, I've simultaneously driven both the KPA500 and a Top
Ten Devices band decoder from a single K3 with no problems.

73,
Bob, N6TV

On Fri, Mar 10, 2017 at 2:38 PM, NOEL POULIN <[hidden email]>
wrote:

> Hi to all,
> I am on the way to connect a Bandpasser2 (band data mode) on a K3s.
> Later I would like also to connect a band decoder on the same radio to
> switch coaxial stubs.
> I wonder if the K3s can handle more than one device connected to the Band
> Data signals.
> I suppose that Elecraft band output is probably designed to drive one
> decoder and this decoder is designed with current maximums for each port.
> I would appreciate comments and good tips about that fact...
> Thanks
> Noel
> ______________________________________________________________
> 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
> Message delivered to [hidden email]
>

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Jack Brindle-2

Re: K3S with more than one device on the Band Data signals

In reply to this post by NOEL POULIN

As I recall, it is a standard LS TTL style open-drain driver, which means it has a fan out of about 10 LS loads. You should be able to connect several devices. Be sure they do not have pull-ups that are connected to higher that 5 volts (some band decoders have pull-ups to 12V). The K3 has internal pull-ups to 5V, so having 12V on these lines will subject the K3 to 12V. The internal pull-ups will limit the current, but if the K3 is off when the decoder is on, you could get damage or even false powering of some of the K3 internal components.

False powering means that the component is actually powered through an IO port instead of its main supply line. This is a very bad situation that can damage the part since it is powered incorrectly. It is also maddening to debug since the part (possibly a processor) seems to be working when it should not be and can actually do some very strange things.

73!

Jack, W6FB

> On Mar 10, 2017, at 2:38 PM, NOEL POULIN <[hidden email]> wrote:
>
> Hi to all,
> I am on the way to connect a Bandpasser2 (band data mode) on a K3s.
> Later I would like also to connect a band decoder on the same radio to switch coaxial stubs.
> I wonder if the K3s can handle more than one device connected to the Band Data signals.
> I suppose that Elecraft band output is probably designed to drive one decoder and this decoder is designed with current maximums for each port.
> I would appreciate comments and good tips about that fact...
> Thanks
> Noel
> ______________________________________________________________
> 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
> Message delivered to [hidden email]

briancom

Re: K3S with more than one device on the Band Data signals

Back a bit, I had the need to drive a remote switch and something else
with the BCD band data.

For me there was simple PIC based solution. BCD input to PIC. PIC
programmed to switch to appropriate antennas . Input BCD data echoed to
other PIC outputs. PIC outputs buffered by a ULN2003's or 2n2222's.

73 de Brian/K3KO

On 3/11/2017 1:47 AM, Jack Brindle wrote:

> As I recall, it is a standard LS TTL style open-drain driver, which means it has a fan out of about 10 LS loads. You should be able to connect several devices. Be sure they do not have pull-ups that are connected to higher that 5 volts (some band decoders have pull-ups to 12V). The K3 has internal pull-ups to 5V, so having 12V on these lines will subject the K3 to 12V. The internal pull-ups will limit the current, but if the K3 is off when the decoder is on, you could get damage or even false powering of some of the K3 internal components.
>
> False powering means that the component is actually powered through an IO port instead of its main supply line. This is a very bad situation that can damage the part since it is powered incorrectly. It is also maddening to debug since the part (possibly a processor) seems to be working when it should not be and can actually do some very strange things.
>
> 73!
>
> Jack, W6FB
>
>
>> On Mar 10, 2017, at 2:38 PM, NOEL POULIN <[hidden email]> wrote:
>>
>> Hi to all,
>> I am on the way to connect a Bandpasser2 (band data mode) on a K3s.
>> Later I would like also to connect a band decoder on the same radio to switch coaxial stubs.
>> I wonder if the K3s can handle more than one device connected to the Band Data signals.
>> I suppose that Elecraft band output is probably designed to drive one decoder and this decoder is designed with current maximums for each port.
>> I would appreciate comments and good tips about that fact...
>> Thanks
>> Noel
>> ______________________________________________________________
>> 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
>> Message delivered to [hidden email]
>
> ______________________________________________________________
> 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
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>

Elecraft mailing list

Re: K3S with more than one device on the Band Data signals

In reply to this post by NOEL POULIN

You could use a line buffer.Check this page http://www.kotarov.com/projects/k3-and-acom-2s1This is an adapter for acom 2S1 switch, but he also added a buffer to drive more then one decoder, just use that part :-)BobYO8RNI

From: NOEL POULIN <[hidden email]>
To: [hidden email]
Sent: Saturday, March 11, 2017 12:38 AM
Subject: [Elecraft] K3S with more than one device on the Band Data signals

Hi to all,
I am on the way to connect a Bandpasser2 (band data mode) on a K3s.
Later I would like also to connect a band decoder on the same radio to
switch coaxial stubs.
I wonder if the K3s can handle more than one device connected to the
Band Data signals.
I suppose that Elecraft band output is probably designed to drive one
decoder and this decoder is designed with current maximums for each port.
I would appreciate comments and good tips about that fact...
Thanks
Noel
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