PX3 - odd 'missing' signal

[David Orman]

I've noticed on various modes/combinations of spans, I show some what look
like null regions. Sometimes it's right where I'm tuned, sometimes it's
offset. In this picture, I am tuned to 14.055.050, in CW mode, span is 2,
and there is a deep null area centered somewhere around 14.056.05.

In some modes, this is troublesome, especially when it's right on the
cursor where I am tuned. I must be doing something wrong, so would
appreciate any feedback you can give me regarding this / how to fix it.

Here's an image showing what I am talking about:
http://ormandj.corenode.com/images/radio/elecraft/px3-null.jpg

Thank you
David
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I have noticed this null as well. In SSB mode, the null is right at the
carrier frequency. In CW mode, the null is offset from the carrier
frequency by the amount of the sidetone pitch. Engaging ALT switches the
null to the other side of the carrier, again by the amount of the sidetone
pitch.

I don't recall seeing this on earlier versions of the firmware (though
that doesn't mean it wasn't there)

Firmware versions here are:

PX3
Firmware version: 01.16

KX3:
uC: 02.30
dsP: 01.32

73, Dale
WA8SRA

> I've noticed on various modes/combinations of spans, I show some what look
> like null regions. Sometimes it's right where I'm tuned, sometimes it's
> offset. In this picture, I am tuned to 14.055.050, in CW mode, span is 2,
> and there is a deep null area centered somewhere around 14.056.05.
>
> In some modes, this is troublesome, especially when it's right on the
> cursor where I am tuned. I must be doing something wrong, so would
> appreciate any feedback you can give me regarding this / how to fix it.
>
> Here's an image showing what I am talking about:
> http://ormandj.corenode.com/images/radio/elecraft/px3-null.jpg
>
> Thank you
> David

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[Chris Thompson]

It's an artifact of the architecture of the radio - the "Zero-hz crossover".

You can move it by changing the menu item "RX SHFT" from "Nor" to "8.0".
This is a per-band setting.

Be aware that changing "RX SHFT" prevents using the Dual-Watch receiver, and
takes the Roofing Filter out of play (if installed).

Another method to move the artifact when working CW is to use CW Rev. This
will shift the artifact to the other side of your VFO A cursor.

73,
Chris K4HC

Date: Sun, 15 Feb 2015 19:23:16 -0500 (EST)
From: "[hidden email]" <[hidden email]>
To: "David Orman" <[hidden email]>
Cc: Elecraft Reflector <[hidden email]>
Subject: Re: [Elecraft] PX3 - odd 'missing' signal
Message-ID:
        <[hidden email]>
Content-Type: text/plain;charset=iso-8859-1

I have noticed this null as well. In SSB mode, the null is right at the
carrier frequency. In CW mode, the null is offset from the carrier
frequency by the amount of the sidetone pitch. Engaging ALT switches the
null to the other side of the carrier, again by the amount of the sidetone
pitch.

I don't recall seeing this on earlier versions of the firmware (though
that doesn't mean it wasn't there)

Firmware versions here are:

PX3
Firmware version: 01.16

KX3:
uC: 02.30
dsP: 01.32

73, Dale
WA8SRA

> I've noticed on various modes/combinations of spans, I show some what look
> like null regions. Sometimes it's right where I'm tuned, sometimes it's
> offset. In this picture, I am tuned to 14.055.050, in CW mode, span is 2,
> and there is a deep null area centered somewhere around 14.056.05.
>
> In some modes, this is troublesome, especially when it's right on the
> cursor where I am tuned. I must be doing something wrong, so would
> appreciate any feedback you can give me regarding this / how to fix it.
>
> Here's an image showing what I am talking about:
> http://ormandj.corenode.com/images/radio/elecraft/px3-null.jpg
>
> Thank you
> David

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Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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