KX3 anomaly, birdie transmitted

[John Kramer]

I have a newish KX3 factory built. I just noticed something odd with my KX3. I usually use my
KX3 for portable use so its not often in the shack, but yesterday I had my Flex radio’s
connected to my SteppIR beam on 15, and I hooked up my KX3 to an EFHW wire
which is about 100 ft away from my SteppIR.
With both the Flex and the KX3 in receive mode on 15 meters, I noticed on the Panafall
display of my Flex rig, that my KX3 is transmitting a birdie about 700 Hz below it’s RX frequency.
When I turn the dial on the KX3 I can see it moving up and down the band on my Flex radio. It is quite
strong, about 70 dBm.

Is this normal ? for the KX3 to put out a “birdie” 700 hertz below it’s displayed RX frequency ?

73
John, ZS5J
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[John Kramer]

Thanks - yes, when I disconnected the EFHW wire antenna going to the KX3, then the birdie
that I could hear on my Flex radio disappeared. So it’s getting out through the antenna that
the KX3 is using

73
John



On 17 Mar 2016, at 4:45 AM, thelastdb <[hidden email]> wrote:

Yes, that's the LO leaking out the antenna jack of the KX3. Set a menu function to RX ISO or some such.



Myron WVØH
Printed on Recycled Data
-------- Original message --------
From: John Kramer <[hidden email]>
Date: 3/16/2016 8:20 PM (GMT-07:00)
To: Elecraft list <[hidden email]>
Subject: [Elecraft] KX3 anomaly, birdie transmitted

I have a newish KX3 factory built. I just noticed something odd with my KX3. I usually use my
KX3 for portable use so its not often in the shack, but yesterday I had my Flex radio’s
connected to my SteppIR beam on 15, and I hooked up my KX3 to an EFHW wire
which is about 100 ft away from my SteppIR.
With both the Flex and the KX3 in receive mode on 15 meters, I noticed on the Panafall
display of my Flex rig, that my KX3 is transmitting a birdie about 700 Hz below it’s RX frequency.
When I turn the dial on the KX3 I can see it moving up and down the band on my Flex radio. It is quite
strong, about 70 dBm.

Is this normal ? for the KX3 to put out a “birdie” 700 hertz below it’s displayed RX frequency ?

73
John, ZS5J
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[GM4JJJ]

Hi John,

That is normal, as the KX3 is a direct conversion receiver and the LO can radiate through the antenna, however to reduce this Elecraft have put in an isolation preamp which you can enable and should reduce the level of this. Try changing  RX ISO to ON in the KX3 menu.

73 from David GM4JJJ

> On 17 Mar 2016, at 02:20, John Kramer <[hidden email]> wrote:
>
> I have a newish KX3 factory built. I just noticed something odd with my KX3. I usually use my
> KX3 for portable use so its not often in the shack, but yesterday I had my Flex radio’s
> connected to my SteppIR beam on 15, and I hooked up my KX3 to an EFHW wire
> which is about 100 ft away from my SteppIR.
> With both the Flex and the KX3 in receive mode on 15 meters, I noticed on the Panafall
> display of my Flex rig, that my KX3 is transmitting a birdie about 700 Hz below it’s RX frequency.
> When I turn the dial on the KX3 I can see it moving up and down the band on my Flex radio. It is quite
> strong, about 70 dBm.
>
> Is this normal ? for the KX3 to put out a “birdie” 700 hertz below it’s displayed RX frequency ?
>
> 73
> John, ZS5J
> ______________________________________________________________
> 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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