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Using SDR Play with KX3 Ocsilator Noise?

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Fred Nassar

Using SDR Play with KX3 Ocsilator Noise?

I am using the KX3 with SDR play as a pan adapter. I have noticed that
there is some type of signal (quite strong) showing up on the pan adapter
on the frequency that the KX3 is tuned. This signal moves as I move the
VFO, so it seems to be some local oscillator issue. The result is the sdr
play seems to be desensitized and signal levels on the KX3 are lower. When
I engage the RX pre-amp, this signal goes away and all is right with the
world. On most bands 10 db is enough to do the trick. On 17 meters it takes
30 db to get rid of it and remove the desensitization from the RX. Wonder
if anyone else has seen this working with an SDR play and KX3? I have the
2.9 firmware installed. Thanks...Fred, WD5F
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wayne burdick

Re: Using SDR Play with KX3 Ocsilator Noise?

Administrator

Turn on MENU:RX ISO on the KX3. This turns on a isolation amp to keep the LO frequency out of the antenna input.

73,
Wayne
N6KR

> On May 29, 2018, at 7:55 AM, Fred Nassar <[hidden email]> wrote:
>
> I am using the KX3 with SDR play as a pan adapter. I have noticed that
> there is some type of signal (quite strong) showing up on the pan adapter
> on the frequency that the KX3 is tuned. This signal moves as I move the
> VFO, so it seems to be some local oscillator issue. The result is the sdr
> play seems to be desensitized and signal levels on the KX3 are lower. When
> I engage the RX pre-amp, this signal goes away and all is right with the
> world. On most bands 10 db is enough to do the trick. On 17 meters it takes
> 30 db to get rid of it and remove the desensitization from the RX. Wonder
> if anyone else has seen this working with an SDR play and KX3? I have the
> 2.9 firmware installed. Thanks...Fred, WD5F
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
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> Please help support this email list: http://www.qsl.net/donate.html
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Bob McGraw - K4TAX

Re: Using SDR Play with KX3 Ocsilator Noise?

In reply to this post by Fred Nassar

As I have found, it may be necessary to set the LO to an offset value
from the TUNE frequency of the SDR Play receiver. I use HDSDR for my
software with the SDR Play. The feature is in the F7 Options menu,
look for Misc menu options of HDSDR. Also, it may be necessary to set
the DC Removal to a value in F7 Calibration menu. A bandwidth of 5 to 25
Hz seems to work OK.

73

Bob, K4TAX

On 5/29/2018 9:55 AM, Fred Nassar wrote:

> I am using the KX3 with SDR play as a pan adapter. I have noticed that
> there is some type of signal (quite strong) showing up on the pan adapter
> on the frequency that the KX3 is tuned. This signal moves as I move the
> VFO, so it seems to be some local oscillator issue. The result is the sdr
> play seems to be desensitized and signal levels on the KX3 are lower. When
> I engage the RX pre-amp, this signal goes away and all is right with the
> world. On most bands 10 db is enough to do the trick. On 17 meters it takes
> 30 db to get rid of it and remove the desensitization from the RX. Wonder
> if anyone else has seen this working with an SDR play and KX3? I have the
> 2.9 firmware installed. Thanks...Fred, WD5F
> ______________________________________________________________
> 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]
>