Elecraft › [K3]

K3: Hears stations twice

Classic

List

Threaded

8 messages Options

Martin-2

K3: Hears stations twice

Elecrafters,
i tune across 80m and hear UN8GV calling cq on 3514.5 loud and clear.
As I tune further down i hear UN8GV deep in the noise exactly 3 khz
below, on 3511.5. Bad TX, i think.

But wait ... someone is calling him. After a few minutes, a few stations
create a pileup. I can hear each and every station deep in
the noise on 3511.5 and loud and clear on 3514.5 .
No matter if i use the Main RX only or the Main and SUB.

Huh?

I tried to duplicate this on different frequencies, with different
stations, but no "luck".

Anyone has experienced this?

A merry christmas to all

--

73,
Martin DM4iM
______________________________________________________________
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

Leigh L. Klotz Jr WA5ZNU

Re: K3: Hears stations twice

Administrator

Elecraft is on vacation so here's something to try in the mean time:
Does it happen with all filters, if you have more than one quartz crystal filter?
What are your filter center and bandwidth settings for the filters it happens on?
Have you performed the filter offset calibration from Appendix A?

Leigh/WA5ZNU

Lou Kolb

Re: K3: Hears stations twice

And is your noise blanker on? That seems to cause all kinds of anomalies.
Lou WA3MIX
----- Original Message -----
From: "Leigh L. Klotz Jr WA5ZNU" <[hidden email]>
To: <[hidden email]>
Sent: Saturday, December 25, 2010 2:33 AM
Subject: Re: [Elecraft] K3: Hears stations twice

>
> Elecraft is on vacation so here's something to try in the mean time:
> Does it happen with all filters, if you have more than one quartz crystal
> filter?
> What are your filter center and bandwidth settings for the filters it
> happens on?
> Have you performed the filter offset calibration from Appendix A?
>
> Leigh/WA5ZNU
>
> --
> View this message in context:
> http://elecraft.365791.n2.nabble.com/K3-Hears-stations-twice-tp5865819p5866049.html
> Sent from the [K3] mailing list archive at Nabble.com.
> ______________________________________________________________
> 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

______________________________________________________________
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

John_N1JM

Re: K3: Hears stations twice

In reply to this post by Martin-2

You don't have a receiver birdie near that frequency by any chance?

Merry Christmas and Happy New Year!

OE5CSP-Chris

Re: K3: Hears stations twice

In reply to this post by Martin-2

Hi,

During the Christmas holidays I spent a lot of time on 80m and I came across the problem mentioned on the reflector some time ago.Sometimes I can hear a strong station twice.Yesterday,for example I heard a strong German station on 3514 and a few khz down I heard the same signal again, but much weaker.I did not use the NB or NR. This happened a few times already.Is this a known issue and will it be fixed in the next firmware release?

73,Chris-OE5CSP

Steve Ellington

Re: K3: Hears stations twice

I've heard the same thing but with many other receivers. It usually turns
out that the transmitting station has a problem though. Low power supply
voltage is a common cause of transmitted spurs. I know one guy in PA (state)
who has a TS-450 with a spur down about 200Hz, weak but strong enough to be
heard 600 miles away. I've told him about it several times but he says he
has no idea what to do about it and continues to broadcast "CW Stereo".

Steve
N4LQ
----- Original Message -----
From: "OE5CSP-Chris" <[hidden email]>
To: <[hidden email]>
Sent: Saturday, January 08, 2011 5:29 AM
Subject: Re: [Elecraft] K3: Hears stations twice

>
> Hi,
>
> During the Christmas holidays I spent a lot of time on 80m and I came
> across
> the problem mentioned on the reflector some time ago.Sometimes I can hear
> a
> strong station twice.Yesterday,for example I heard a strong German station
> on 3514 and a few khz down I heard the same signal again, but much
> weaker.I
> did not use the NB or NR. This happened a few times already.Is this a
> known
> issue and will it be fixed in the next firmware release?
>
> 73,Chris-OE5CSP
> --
> View this message in context:
> http://elecraft.365791.n2.nabble.com/K3-Hears-stations-twice-tp5865819p5902107.html
> Sent from the [K3] mailing list archive at Nabble.com.
> ______________________________________________________________
> 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

Steve Ellington

Re: K3: Hears stations twice

Correction:
The PA station was running a Kenwood TS-570. His spur was down frequency
about 400Hz. I have also head spurs from SGC 2020's and TenTec Paragons both
caused by low PS voltage.

Steve
N4LQ
----- Original Message -----
From: "Steve Ellington" <[hidden email]>
To: "OE5CSP-Chris" <[hidden email]>; <[hidden email]>
Sent: Saturday, January 08, 2011 9:06 AM
Subject: Re: [Elecraft] K3: Hears stations twice

> I've heard the same thing but with many other receivers. It usually turns
> out that the transmitting station has a problem though. Low power supply
> voltage is a common cause of transmitted spurs. I know one guy in PA
> (state)
> who has a TS-450 with a spur down about 200Hz, weak but strong enough to
> be
> heard 600 miles away. I've told him about it several times but he says he
> has no idea what to do about it and continues to broadcast "CW Stereo".
>
> Steve
> N4LQ
> ----- Original Message -----
> From: "OE5CSP-Chris" <[hidden email]>
> To: <[hidden email]>
> Sent: Saturday, January 08, 2011 5:29 AM
> Subject: Re: [Elecraft] K3: Hears stations twice
>
>
>>
>> Hi,
>>
>> During the Christmas holidays I spent a lot of time on 80m and I came
>> across
>> the problem mentioned on the reflector some time ago.Sometimes I can hear
>> a
>> strong station twice.Yesterday,for example I heard a strong German
>> station
>> on 3514 and a few khz down I heard the same signal again, but much
>> weaker.I
>> did not use the NB or NR. This happened a few times already.Is this a
>> known
>> issue and will it be fixed in the next firmware release?
>>
>> 73,Chris-OE5CSP
>> --
>> View this message in context:
>> http://elecraft.365791.n2.nabble.com/K3-Hears-stations-twice-tp5865819p5902107.html
>> Sent from the [K3] mailing list archive at Nabble.com.
>> ______________________________________________________________
>> 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
>
> ______________________________________________________________
> 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

Guy, K2AV

Re: K3: Hears stations twice

In reply to this post by OE5CSP-Chris

If your radio is doing it, you will hear that on ALL loud radio
signals. This would be especially true of the carrier on AM broadcast
stations. If only on one signal, it's their problem.

There are a LOT of transmitters that have transmitted frequencies well
down besides the main transmission. A common one, heard on analog
transmitters that are using a keyed audio tone through SSB circuitry
to reduce manufacturing cost, is carrier balance in the balanced
modulator, and ultimate filter rejection of the other sideband. These
could be anywhere between 700 and 4000 Hz away depending on the
circuit and settings.

Your K3 does not do this (transmit artifacts of analog SSB generation)
because it is digital and does not have a balanced modulator. 15 kHz
SSB is generated by the transmit DAC directly from a number stream
created by a firmware algorithm from the audio number stream created
by running microphone audio through an analog to digital chip. The
slightly unbalanced carrier and the opposite sideband that allow the
analog artifacts simply do not exist anywhere.

For a while the K3 TX had a clean and coherent microphonic spur on CW
when using the MON tone and the internal speaker on CW. This has been
remedied for some time now (see "stiffener" mod).

73, Guy.

On Sat, Jan 8, 2011 at 5:29 AM, OE5CSP-Chris <[hidden email]> wrote:

>
> Hi,
>
> During the Christmas holidays I spent a lot of time on 80m and I came across
> the problem mentioned on the reflector some time ago.Sometimes I can hear a
> strong station twice.Yesterday,for example I heard a strong German station
> on 3514 and a few khz down I heard the same signal again, but much weaker.I
> did not use the NB or NR. This happened a few times already.Is this a known
> issue and will it be fixed in the next firmware release?
>
> 73,Chris-OE5CSP
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/K3-Hears-stations-twice-tp5865819p5902107.html
> Sent from the [K3] mailing list archive at Nabble.com.
> ______________________________________________________________
> 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
>