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KX3 - UHF emissions

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Dave-5

Re: KX3 - UHF emissions

Here are two more screen grabs for KX3 on and off, but just looking at the
frequency range 100MHz to 500MHz. Everything else is the same between the
test done earlier.

KX3 on
https://dl.dropboxusercontent.com/u/65397105/KX3%20Test%2027-06-2014%201122.jpg

KX3 off
https://dl.dropboxusercontent.com/u/65397105/KX3%20Test%2027-06-2014%201123.jpg

I can't see any additional frequency peaks and moving the VFO on the KX3, or
changing the band, doesn't appear to make any difference to the display on
the analyser.

So, I can say that I'm not seeing seeing any distinct frequency spikes,
which vary as I tune the KX3 VFO up and down, as Darren is seeing from his
KX3.

Dave (G0DJA)

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g0hww

Re: KX3 - UHF emissions

Hi Dave,

Thanks for performing this comparison test. I admit that I found it difficult
to perform repeatable measurements, as levels varied by as much as 10 to 15dB
due to position and orientation of the rig and cables and my position with
respect to the equipment. That is why I chose to provide considered
representative figures derived from multiple observations as opposed to precise
measurements or screen-shots, but I could provide screen-shots by way of
examples if anyone feels that would be really useful.

My KX3 is #01685, purchased complete (not kit) with the roofing filter and ATU
options, from Waters & Stanton in the UK. I fitted the battery charger when it
shipped, and have also recently fitted the SideKX end-plates and a VE7FMN
CoolerKX heatsink (although as noted before, the issue described pre-dates these
retrofits).

Your results lead me to hope that my KX3 might be defective and that the problem
could be resolved by repair or exchange. I suppose I should order a KX3-PCKT
cable set to try in case the official I/Q cable mitigates this issue, but I have
tried the 2.5mm to 3.5mm stereo cable that came with my Sennheiser headphones
and that didn't seem any better.

I look forward to hearing confirmation from Elecraft of whether or not these
emissions are considered typical for this build standard of KX3.

Cheers, 73

Darren, G0HWW

On 27/06/14 11:39, Dave wrote:

> Here are two more screen grabs for KX3 on and off, but just looking at the
> frequency range 100MHz to 500MHz. Everything else is the same between the test
> done earlier.
>
> KX3 on
> https://dl.dropboxusercontent.com/u/65397105/KX3%20Test%2027-06-2014%201122.jpg
>
> KX3 off
> https://dl.dropboxusercontent.com/u/65397105/KX3%20Test%2027-06-2014%201123.jpg
>
> I can't see any additional frequency peaks and moving the VFO on the KX3, or
> changing the band, doesn't appear to make any difference to the display on the
> analyser.
>
> So, I can say that I'm not seeing seeing any distinct frequency spikes, which
> vary as I tune the KX3 VFO up and down, as Darren is seeing from his KX3.
>
> Dave (G0DJA)
> ______________________________________________________________
> 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]

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Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Dave-5

Re: KX3 - UHF emissions

Hi Darren,

I have a later KX3, number 5111, with similar options to you, built in ASTU
and KX3 hardware, but I don't have the battery charger or additional
heatsink options.

I built mine from the kit. It was very straight forward but I did buy an
anti-static mat first.

BTW - I made a mistake in labelling those pictures! The 1st is KX3 off and
the second KX3 on. I'll issue an ammendment just in case it causes
confusion later.

Good luck in tracking it down, I would be interested to see your screen
grabs showing the effects that you are seeing between on and off, so that I
can compare them to my own results. I'm downloading updated software for
the RF Explorer, which may improve the resolution of the pictures.

Cheers - Dave (G0DJA)

----- Original Message -----
From: "Darren Long" <[hidden email]>
To: <[hidden email]>; <[hidden email]>
Sent: Friday, June 27, 2014 2:58 PM
Subject: Re: [Elecraft] KX3 - UHF emissions

> Hi Dave,
>
> Thanks for performing this comparison test. I admit that I found it
> difficult
> to perform repeatable measurements, as levels varied by as much as 10 to
> 15dB
> due to position and orientation of the rig and cables and my position
> with
> respect to the equipment. That is why I chose to provide considered
> representative figures derived from multiple observations as opposed to
> precise
> measurements or screen-shots, but I could provide screen-shots by way of
> examples if anyone feels that would be really useful.
>
> My KX3 is #01685, purchased complete (not kit) with the roofing filter and
> ATU
> options, from Waters & Stanton in the UK. I fitted the battery charger
> when it
> shipped, and have also recently fitted the SideKX end-plates and a VE7FMN
> CoolerKX heatsink (although as noted before, the issue described pre-dates
> these
> retrofits).
>
> Your results lead me to hope that my KX3 might be defective and that the
> problem
> could be resolved by repair or exchange. I suppose I should order a
> KX3-PCKT
> cable set to try in case the official I/Q cable mitigates this issue, but
> I have
> tried the 2.5mm to 3.5mm stereo cable that came with my Sennheiser
> headphones
> and that didn't seem any better.
>
> I look forward to hearing confirmation from Elecraft of whether or not
> these
> emissions are considered typical for this build standard of KX3.
>
> Cheers, 73
>
> Darren, G0HWW
>
>
>
> On 27/06/14 11:39, Dave wrote:
>> Here are two more screen grabs for KX3 on and off, but just looking at
>> the
>> frequency range 100MHz to 500MHz. Everything else is the same between
>> the test
>> done earlier.
>>
>> KX3 on
>> https://dl.dropboxusercontent.com/u/65397105/KX3%20Test%2027-06-2014%201122.jpg
>>
>> KX3 off
>> https://dl.dropboxusercontent.com/u/65397105/KX3%20Test%2027-06-2014%201123.jpg
>>
>> I can't see any additional frequency peaks and moving the VFO on the KX3,
>> or
>> changing the band, doesn't appear to make any difference to the display
>> on the
>> analyser.
>>
>> So, I can say that I'm not seeing seeing any distinct frequency spikes,
>> which
>> vary as I tune the KX3 VFO up and down, as Darren is seeing from his KX3.
>>
>> Dave (G0DJA)
>> ______________________________________________________________
>> 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]

Dave-5

Re: KX3 - UHF emissions

In reply to this post by Dave-5

Very sorry, there's a typo in my message.

The 1st screen shot (timed at 11:22) is with the KX3 off and the one at
11:23 is KX3 on. Sorry for the confusion.

Dave (G0DJA)

----- Original Message -----
To: <[hidden email]>
Sent: Friday, June 27, 2014 10:39 AM
Subject: Re: [Elecraft] KX3 - UHF emissions

> Here are two more screen grabs for KX3 on and off, but just looking at the
> frequency range 100MHz to 500MHz. Everything else is the same between the
> test done earlier.
>
> KX3 on
> https://dl.dropboxusercontent.com/u/65397105/KX3%20Test%2027-06-2014%201122.jpg
>
> KX3 off
> https://dl.dropboxusercontent.com/u/65397105/KX3%20Test%2027-06-2014%201123.jpg
>
> I can't see any additional frequency peaks and moving the VFO on the KX3,
> or changing the band, doesn't appear to make any difference to the display
> on the analyser.
>
> So, I can say that I'm not seeing seeing any distinct frequency spikes,
> which vary as I tune the KX3 VFO up and down, as Darren is seeing from his
> KX3.
>
> Dave (G0DJA)
> ______________________________________________________________
> 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]

g0hww

Re: KX3 - UHF emissions

In reply to this post by Dave-5

Hi Dave,

I've have just repeated my measurements of the 7.080Mhz sprog on 398.4MHz and
posted some screen-shots on my blog. See here:
http://www.g0hww.net/2014/06/kx3-uhf-emissions.html

Cheers, 73

Darren, G0HWW

On 28/06/14 10:30, Dave wrote:

> Hi Darren,
>
> I have a later KX3, number 5111, with similar options to you, built in ASTU and
> KX3 hardware, but I don't have the battery charger or additional heatsink options.
>
> I built mine from the kit. It was very straight forward but I did buy an
> anti-static mat first.
>
> BTW - I made a mistake in labelling those pictures! The 1st is KX3 off and the
> second KX3 on. I'll issue an ammendment just in case it causes confusion later.
>
> Good luck in tracking it down, I would be interested to see your screen grabs
> showing the effects that you are seeing between on and off, so that I can
> compare them to my own results. I'm downloading updated software for the RF
> Explorer, which may improve the resolution of the pictures.
>
> Cheers - Dave (G0DJA)
>

Dave-5

Re: KX3 - UHF emissions

Hi Darren, and everyone else following this...

I've found it! Very low level, but by zeroing in on 385 to 386MHz I found a
small signal that moves when I tune across 7MHz...

At 7.000MHz there's a signal at 385.027MHz (-78dBm) which moves up in
frequency, staying at about the same signal level, and is at -78dBm at
385.571MHz with the dial set to 7.010MHz. Unplugging all of the leads
appears to make no difference to the signal level. Nor does turning off the
backlight or going onto internal batteries.

The problem I had yesterday was that there's a lot of much louder signals
around 385.9MHz which were masking the KX3 signal. With the dial set to
7.080MHz, and really zeroing in so as to exclude other signals, I found it
at 389.419MHz (-75.5dBm) but I would need to go somewhere that excluded the
larger external signals to hear it with another receiver.

I guess that with an antenna with a bit more gain it might be stronger. I
also had to keep resetting the display as it got hidden in much louder
signals which did not appear to alter with VFO setting and I wasn't able to
tell if they were from the KX3 or from external signals, of course.

Dave (G0DJA)

----- Original Message -----
From: "Darren Long" <[hidden email]>
To: "Dave" <[hidden email]>; <[hidden email]>
Sent: Saturday, June 28, 2014 12:22 PM
Subject: Re: [Elecraft] KX3 - UHF emissions

> Hi Dave,
>
> I've have just repeated my measurements of the 7.080Mhz sprog on 398.4MHz
> and
> posted some screen-shots on my blog. See here:
> http://www.g0hww.net/2014/06/kx3-uhf-emissions.html
>
> Cheers, 73
>
> Darren, G0HWW

g0hww

Re: KX3 - UHF emissions

Thanks for following up on this Dave, it is really appreciated. At least I know
that it's not just my KX3 now.

Cheers,

Darren, G0HWW

On 28/06/14 14:10, Dave wrote:

> Hi Darren, and everyone else following this...
>
> I've found it! Very low level, but by zeroing in on 385 to 386MHz I found a
> small signal that moves when I tune across 7MHz...
>
> At 7.000MHz there's a signal at 385.027MHz (-78dBm) which moves up in frequency,
> staying at about the same signal level, and is at -78dBm at 385.571MHz with the
> dial set to 7.010MHz. Unplugging all of the leads appears to make no difference
> to the signal level. Nor does turning off the backlight or going onto internal
> batteries.
>
> The problem I had yesterday was that there's a lot of much louder signals around
> 385.9MHz which were masking the KX3 signal. With the dial set to 7.080MHz, and
> really zeroing in so as to exclude other signals, I found it at 389.419MHz
> (-75.5dBm) but I would need to go somewhere that excluded the larger external
> signals to hear it with another receiver.
>
> I guess that with an antenna with a bit more gain it might be stronger. I also
> had to keep resetting the display as it got hidden in much louder signals which
> did not appear to alter with VFO setting and I wasn't able to tell if they were
> from the KX3 or from external signals, of course.
>
> Dave (G0DJA)
>
> ----- Original Message ----- From: "Darren Long" <[hidden email]>
> To: "Dave" <[hidden email]>; <[hidden email]>
> Sent: Saturday, June 28, 2014 12:22 PM
> Subject: Re: [Elecraft] KX3 - UHF emissions
>
>
>> Hi Dave,
>>
>> I've have just repeated my measurements of the 7.080Mhz sprog on 398.4MHz and
>> posted some screen-shots on my blog. See here:
>> http://www.g0hww.net/2014/06/kx3-uhf-emissions.html
>>
>> Cheers, 73
>>
>> Darren, G0HWW
>