Elecraft

SDRPlay connection to K3S

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Steve Muenich

SDRPlay connection to K3S

Hello gang,

Is there a proper port on the K3S to connect a SDRPlay that would allow for sharing the main antenna while receiving, then be disconnected and isolated when the K3S go into transmit?

Thanks
Steve, NA5C
K3S 10121

Sent from my mobile device
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Bob McGraw - K4TAX

Re: SDRPlay connection to K3S

Yes, you will need a Y cable, connect to RX ANT IN and OUT. The junction
of the Y goes to the SDR Play. To activate, press the RX ANT on the
radio. This sends the ANT 1 or ANT 2 signal to the Out and then back to
the In via the Y cable, while feeding same to the SDR play.

Works great. I use HDSDR with OmniRig to control my K3S from the
computer and if configured as such the SDR play follows the K3S.

In order to simplify a nest of cables and forgetting to push the RX ANT,
I finally resorted to using the IF OUT to the SDR play. Again the HDSDR
software allows configuring such that it tracks the K3S in all modes and
frequencies.

73

Bob, K4TAX

On 7/17/2018 8:16 AM, Steve Muenich wrote:

> Hello gang,
>
> Is there a proper port on the K3S to connect a SDRPlay that would allow for sharing the main antenna while receiving, then be disconnected and isolated when the K3S go into transmit?
>
> Thanks
> Steve, NA5C
> K3S 10121
>
>
> Sent from my mobile device
> ______________________________________________________________
> 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]
>

Joe Subich, W4TV-4

Re: SDRPlay connection to K3S

In reply to this post by Steve Muenich

You will need a (hybrid) splitter ... connect the common port of
the splitter to the RX ANT Out jack, connect one output of the
splitter to RX ANT IN and connect the other output of the splitter
to the SDRPlay antenna jack.

A splitter is necessary to keep one receiver from loading the
other resulting in loss of sensitivity. The receivers (K3, SDRPlay)
do not have identical input impedance across their range and one
receiver or the other can become (relatively) deaf on certain
frequencies depending on the characteristics of the input circuits.

There are those who will say use a BNC T ... that may or may not
be satisfactory depending on cable lengths and receiver input
characteristics. Unlike a hybrid splitter, the BNC T connector has
no isolation between output ports which allows spurious signals
generated in one receiver to be coupled directly into the other.

73,

... Joe, W4TV

On 2018-07-17 9:16 AM, Steve Muenich wrote:

NK7Z

Re: SDRPlay connection to K3S

Joe,
Got a recommendation for one commercially?

73s and thanks,
Dave
NK7Z
https://www.nk7z.net

On 07/17/2018 07:16 AM, Joe Subich, W4TV wrote:

>
> You will need a (hybrid) splitter ... connect the common port of
> the splitter to the RX ANT Out jack, connect one output of the
> splitter to RX ANT IN and connect the other output of the splitter
> to the SDRPlay antenna jack.
>
> A splitter is necessary to keep one receiver from loading the
> other resulting in loss of sensitivity. The receivers (K3, SDRPlay)
> do not have identical input impedance across their range and one
> receiver or the other can become (relatively) deaf on certain
> frequencies depending on the characteristics of the input circuits.
>
> There are those who will say use a BNC T ... that may or may not
> be satisfactory depending on cable lengths and receiver input
> characteristics. Unlike a hybrid splitter, the BNC T connector has
> no isolation between output ports which allows spurious signals
> generated in one receiver to be coupled directly into the other.
>
> 73,
>
> ... Joe, W4TV
>
>
> On 2018-07-17 9:16 AM, Steve Muenich wrote:
>> Hello gang,
>>
>> Is there a proper port on the K3S to connect a SDRPlay that would
>> allow for sharing the main antenna while receiving, then be
>> disconnected and isolated when the K3S go into transmit?
>>
>> Thanks
>> Steve, NA5C
>> K3S 10121
>>
>>
>> Sent from my mobile device
>> ______________________________________________________________
>> 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
> Message delivered to [hidden email]

tomb18

Re: SDRPlay connection to K3S

In reply to this post by Steve Muenich

HiMiniCircuits makes them. There usually are a few on ebay. 73 Tom

Sent from my Samsung Galaxy smartphone.
-------- Original message --------From: "Dave Cole (NK7Z)" <[hidden email]> Date: 2018-07-17 10:31 AM (GMT-05:00) To: [hidden email] Subject: Re: [Elecraft] SDRPlay connection to K3S
Joe,
Got a recommendation for one commercially?

73s and thanks,
Dave
NK7Z
https://www.nk7z.net

On 07/17/2018 07:16 AM, Joe Subich, W4TV wrote:

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Nr4c

Re: SDRPlay connection to K3S

In reply to this post by Steve Muenich

Might try IF Out port on the KXv3b Panel. (Page 4, tag 35 of manual).

Sent from my iPhone
...nr4c. bill

> On Jul 17, 2018, at 9:16 AM, Steve Muenich <[hidden email]> wrote:
>
> Hello gang,
>
> Is there a proper port on the K3S to connect a SDRPlay that would allow for sharing the main antenna while receiving, then be disconnected and isolated when the K3S go into transmit?
>
> Thanks
> Steve, NA5C
> K3S 10121
>
>
> Sent from my mobile device
> ______________________________________________________________
> 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]

Bob McGraw - K4TAX

Re: SDRPlay connection to K3S

In reply to this post by Joe Subich, W4TV-4

My measurements indicate the SDR Play input Z is well above 50 ohms and no degration in signal strength was noted.

Bob, K4TAX

Sent from my iPhone

> On Jul 17, 2018, at 9:16 AM, Joe Subich, W4TV <[hidden email]> wrote:
>
>
> You will need a (hybrid) splitter ... connect the common port of
> the splitter to the RX ANT Out jack, connect one output of the
> splitter to RX ANT IN and connect the other output of the splitter
> to the SDRPlay antenna jack.
>
> A splitter is necessary to keep one receiver from loading the
> other resulting in loss of sensitivity. The receivers (K3, SDRPlay)
> do not have identical input impedance across their range and one
> receiver or the other can become (relatively) deaf on certain
> frequencies depending on the characteristics of the input circuits.
>
> There are those who will say use a BNC T ... that may or may not
> be satisfactory depending on cable lengths and receiver input
> characteristics. Unlike a hybrid splitter, the BNC T connector has
> no isolation between output ports which allows spurious signals
> generated in one receiver to be coupled directly into the other.
>
> 73,
>
> ... Joe, W4TV
>
>
>> On 2018-07-17 9:16 AM, Steve Muenich wrote:
>> Hello gang,
>> Is there a proper port on the K3S to connect a SDRPlay that would allow for sharing the main antenna while receiving, then be disconnected and isolated when the K3S go into transmit?
>> Thanks
>> Steve, NA5C
>> K3S 10121
>> Sent from my mobile device
>> ______________________________________________________________
>> 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
> Message delivered to [hidden email]
>

Bob Wilson, N6TV

Re: SDRPlay connection to K3S

In reply to this post by NK7Z

MiniCircuits ZFSC-2-6+ 50 ohm splitter with BNC connectors.

https://www.minicircuits.com/WebStore/dashboard.html?model=ZFSC-2-6%2B

You can also get away with a cheap 75 ohm Cable TV splitter, but they use
F-connectors.

Of course to get anything out of RX ANT OUT you have to press the RX ANT
button on the K3 (at least once on each band).

73,
Bob, N6TV

On Tue, Jul 17, 2018 at 7:31 AM, Dave Cole (NK7Z) <[hidden email]> wrote:

> Joe,
> Got a recommendation for one commercially?
>
> 73s and thanks,
> Dave
> NK7Z
> https://www.nk7z.net
>
>
> On 07/17/2018 07:16 AM, Joe Subich, W4TV wrote:
>
>>
>> You will need a (hybrid) splitter ... connect the common port of
>> the splitter to the RX ANT Out jack, connect one output of the
>> splitter to RX ANT IN and connect the other output of the splitter
>> to the SDRPlay antenna jack.
>>
>

Joe Subich, W4TV-4

Re: SDRPlay connection to K3S

In reply to this post by Bob McGraw - K4TAX

Doesn't matter if the SDR Play input is well above 50 Ohms. What
matters is the *RELATIVE DIFFERENCE* between the SDR and the K3.
Unless both track closely the lower impedance device will "suck out"
signal from the higher impedance device.

In addition, one still needs isolation to prevent spurious signals
(e.g. Local oscillator, phase noise, harmonics etc.) generated in
one device from impacting the other.

73,

... Joe, W4TV

On 2018-07-17 1:08 PM, Bob McGraw K4TAX wrote:

> My measurements indicate the SDR Play input Z is well above 50 ohms and no degration in signal strength was noted.
>
> Bob, K4TAX
>
>
> Sent from my iPhone
>
>> On Jul 17, 2018, at 9:16 AM, Joe Subich, W4TV <[hidden email]> wrote:
>>
>>
>> You will need a (hybrid) splitter ... connect the common port of
>> the splitter to the RX ANT Out jack, connect one output of the
>> splitter to RX ANT IN and connect the other output of the splitter
>> to the SDRPlay antenna jack.
>>
>> A splitter is necessary to keep one receiver from loading the
>> other resulting in loss of sensitivity. The receivers (K3, SDRPlay)
>> do not have identical input impedance across their range and one
>> receiver or the other can become (relatively) deaf on certain
>> frequencies depending on the characteristics of the input circuits.
>>
>> There are those who will say use a BNC T ... that may or may not
>> be satisfactory depending on cable lengths and receiver input
>> characteristics. Unlike a hybrid splitter, the BNC T connector has
>> no isolation between output ports which allows spurious signals
>> generated in one receiver to be coupled directly into the other.
>>
>> 73,
>>
>> ... Joe, W4TV
>>
>>
>>> On 2018-07-17 9:16 AM, Steve Muenich wrote:
>>> Hello gang,
>>> Is there a proper port on the K3S to connect a SDRPlay that would allow for sharing the main antenna while receiving, then be disconnected and isolated when the K3S go into transmit?
>>> Thanks
>>> Steve, NA5C
>>> K3S 10121
>>> Sent from my mobile device
>>> ______________________________________________________________
>>> 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
>> Message delivered to [hidden email]
>>
>
>
>