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K3 & 2 x Amplifiers

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Mike VE3YF

K3 & 2 x Amplifiers

Hi:

I am thinking about purchasing a KPA500, as a backup amp as well as
having the ability to work 6m, but have a question about hooking it up.

Currently I have a tube amp hooked up to Antenna Port 1, and using
the Key out jack to key the amplifier. I also have a Microham MK2R+ hooked
up to the Aux DB15 Port.

I would like to know if it is possible to hook up the KPA500 to the
Antenna Port 2, use the KPAK3AUX cable and splitter cable from the K3
to KPA500,
and then other half of the splitter cable to the MK2R+. When in
normal use the I would use Antenna Port #1, and when I want to work
6m or the KPA500
amp use Antenna Port #2.

I guess a question comes to mind, is the key out jack isolated from
the keying line on the KPAK3AUX cable. I see that is being the major
issue, but I am
sure I am not the first one to think of this possible setup. I
welcome any comments etc. Tnx

73 De Mike
VE3YF

http://www.ve3yf.com
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Michael Eberle

Re: K3 & 2 x Amplifiers

Hi Mike,

I'm not sure if the Key Out and key line on the Aux port are isolated or
not. At one time I had the KPA500, a tube amp, and a 2M amp for the
internal transverter all connected. I used a KRC2 band decoder
connected to a couple of relays that would switch the Key Out signal
among the three depending on what band I am on. It requires some extra
cabling because it needs to also needs to connect to the AUX port as
well as the KPA500/KAT500.

With only 2 amps, you may be able to use a relay to switch the Key Out
signal controlled by the DIGOUT 1 pin on the Aux connector. You would
have to set DIGOUT 1 in the K3 config menu to 'OFF' on every band except
for 6M where it would be set to ON. You would have to make sure to use
a relay small enough that it doesn't pull more current than the DIGOUT 1
pin can handle though.

73
Mike - KI0HA

On 8/15/2015 5:20 PM, Mike VE3YF wrote:

> Hi:
>
> I would like to know if it is possible to hook up the KPA500 to the
> Antenna Port 2, use the KPAK3AUX cable and splitter cable from the K3
> to KPA500,
> and then other half of the splitter cable to the MK2R+. When in normal
> use the I would use Antenna Port #1, and when I want to work 6m or the
> KPA500
> amp use Antenna Port #2.
>
> I guess a question comes to mind, is the key out jack isolated from
> the keying line on the KPAK3AUX cable. I see that is being the major
> issue, but I am
> sure I am not the first one to think of this possible setup. I welcome
> any comments etc. Tnx
>
>
> 73 De Mike
> VE3YF

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Jim Brown-10

Re: K3 & 2 x Amplifiers

On Sat,8/15/2015 7:09 PM, Michael Eberle wrote:
> At one time I had the KPA500, a tube amp, and a 2M amp for the
> internal transverter all connected.

For as long as I've had my KPA500, I've had both it and a TenTec Titan
425 connected to the K3's amp key line. The Titan key input is the base
of a transistor.

73, JimK9YC
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Vic Rosenthal

Re: K3 & 2 x Amplifiers

In reply to this post by Michael Eberle

All you need are diodes to isolate the keyout lines going to the amplifiers. Just turn off the amp you aren't using. You can use a simple transistor switch operated by DIGOUT1 to increase the current it can provide.
I would like to see Elecraft add the ability to control all the DIGOUT lines via macro to provide more station control functionality.

Vic 4X6GP/K2VCO

> On Aug 16, 2015, at 5:09 AM, Michael Eberle <[hidden email]> wrote:
>
> Hi Mike,
>
> I'm not sure if the Key Out and key line on the Aux port are isolated or not. At one time I had the KPA500, a tube amp, and a 2M amp for the internal transverter all connected. I used a KRC2 band decoder connected to a couple of relays that would switch the Key Out signal among the three depending on what band I am on. It requires some extra cabling because it needs to also needs to connect to the AUX port as well as the KPA500/KAT500.
>
> With only 2 amps, you may be able to use a relay to switch the Key Out signal controlled by the DIGOUT 1 pin on the Aux connector. You would have to set DIGOUT 1 in the K3 config menu to 'OFF' on every band except for 6M where it would be set to ON. You would have to make sure to use a relay small enough that it doesn't pull more current than the DIGOUT 1 pin can handle though.
>
> 73
> Mike - KI0HA
>
>> On 8/15/2015 5:20 PM, Mike VE3YF wrote:
>> Hi:
>>
>> I would like to know if it is possible to hook up the KPA500 to the Antenna Port 2, use the KPAK3AUX cable and splitter cable from the K3 to KPA500,
>> and then other half of the splitter cable to the MK2R+. When in normal use the I would use Antenna Port #1, and when I want to work 6m or the KPA500
>> amp use Antenna Port #2.
>>
>> I guess a question comes to mind, is the key out jack isolated from the keying line on the KPAK3AUX cable. I see that is being the major issue, but I am
>> sure I am not the first one to think of this possible setup. I welcome any comments etc. Tnx
>>
>>
>> 73 De Mike
>> VE3YF
>
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