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Kx3 rfi when power set to 0watt

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Eben Bruyns

Kx3 rfi when power set to 0watt

I'm a new ham and this is my first radio...

So far I've managed to make contact on 80m but it leaves a lot to be desired.

While messing around I tuned a portable receiver to the same frequency
as the kx3. I had the kx3 power set to 0 watts and keyed the mic. The
receiver produced qrm every time I did this.

Is this normal?

--
Regards,

Eben Bruyns
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Lynn W. Taylor, WB6UUT-2

Re: Kx3 rfi when power set to 0watt

I would expect 0 watts to be zero watts for all practical purposes.

I wouldn't be at all surprised to find out that 0 watts was very close
to, but not exactly 0.

... and if your receiver is any good at all, picking up a signal that is
for all practical purposes zero within 100 meters is kind of expected.

If you want to practice with the radio, get a 50 ohm dummy load. Even
that is likely to be heard on your other receiver.

73, and welcome to the hobby!

-- Lynn

On 7/21/2017 1:47 PM, Eben Bruyns wrote:

> I'm a new ham and this is my first radio...
>
> So far I've managed to make contact on 80m but it leaves a lot to be desired.
>
> While messing around I tuned a portable receiver to the same frequency
> as the kx3. I had the kx3 power set to 0 watts and keyed the mic. The
> receiver produced qrm every time I did this.
>
> Is this normal?
>

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Don Wilhelm

Re: Kx3 rfi when power set to 0watt

In reply to this post by Eben Bruyns

Eben,

I have not tried it, but I suspect that is normal with a receiver tuned
to the same frequency and its antenna close to the KX3.
The KX3 is an SDR which means that it is using an internal oscillator
tuned to the signal frequency. That internal oscillator could be heard
by a nearby receiver.

If you want to hear your own signal, work the KX3 into a dummy load at
some medium power level and place the antenna for your monitoring
receiver in whatever proximity to the dummy load that will give you an
S-9 signal on that receiver - do not overdrive the receiver, or it may
make 'funny noises'.

Keep trying to make contacts. At this point in the sunspot cycle,
propagation is poor on the higher frequency ham bands and 80 or 160
meters are normally not very good for daytime contacts. Try 40 meters
during the day and early evening, and 80 meters after dark.

73,
Don W3FPR

On 7/21/2017 4:47 PM, Eben Bruyns wrote:
> I'm a new ham and this is my first radio...
>
> So far I've managed to make contact on 80m but it leaves a lot to be desired.
>
> While messing around I tuned a portable receiver to the same frequency
> as the kx3. I had the kx3 power set to 0 watts and keyed the mic. The
> receiver produced qrm every time I did this.
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k6dgw

Re: Kx3 rfi when power set to 0watt

In reply to this post by Eben Bruyns

Welcome to the hobby Eben! To your question first: I'm not sure what you
mean by "produced QRM," but if you mean audio feedback [various
squeals], yes, I'd expect that a receiver close to the KX3 is going to
hear it even with the power at zero.

Regarding difficulty in making contact(s)on 80, what are you using for
an antenna? How are you feeding power to it?

73,

Fred ("Skip") K6DGW
Sparks NV USA
Washoe County DM09dn

On 7/21/2017 1:47 PM, Eben Bruyns wrote:

Dave Fugleberg

Re: Kx3 rfi when power set to 0watt

Welcome to ham radio, Eben!
As others have said, it's pretty normal to hear your transmitter on a
receiver that's right next to it, even with the power turned way down.
About your difficult making contacts on 80m... Your antenna system (type of
antenna, height, feedline ), mode, and time of day are all going to have a
big influence. Can you elaborate on those?
On Fri, Jul 21, 2017 at 5:06 PM Fred Jensen <[hidden email]> wrote:

> Welcome to the hobby Eben! To your question first: I'm not sure what you
> mean by "produced QRM," but if you mean audio feedback [various
> squeals], yes, I'd expect that a receiver close to the KX3 is going to
> hear it even with the power at zero.
>
> Regarding difficulty in making contact(s)on 80, what are you using for
> an antenna? How are you feeding power to it?
>
> 73,
>
> Fred ("Skip") K6DGW
> Sparks NV USA
> Washoe County DM09dn
>
> On 7/21/2017 1:47 PM, Eben Bruyns wrote:
> > I'm a new ham and this is my first radio...
> >
> > So far I've managed to make contact on 80m but it leaves a lot to be
> desired.
> >
> > While messing around I tuned a portable receiver to the same frequency
> > as the kx3. I had the kx3 power set to 0 watts and keyed the mic. The
> > receiver produced qrm every time I did this.
> >
> > Is this normal?
> >
>
> ______________________________________________________________
> 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]
>

pa0pje

Re: Kx3 rfi when power set to 0watt

In reply to this post by Eben Bruyns

Hi Eben,

Welcome to "Radio-land"

If that is normal is not for me to decide but...

I actually measured the power level of my KX3 in CW with 0.0 watt as set
level.

It varies from band to band. On 50 MHz I found -18 dBm and on the HF
bands between -20 and -30 dBm.

On 14 MHz I found -23 dBm as carrier level and the noise over the range
from 3 to 18 MHz -50 dBm, dropping rapidly to -80 dBm on 20 MHz and above.

-23 dBm = 0.005 mW or in "S-units" S9+50 dB. Enough to drive a sensitive
receiver nuts in close proximity. A good dummmy load to terminate the
KX3 is always a good idea when "dry-land swimming" the radio.

73,
Peter - PA0PJE

Op 2017-07-21 om 22:47 schreef Eben Bruyns: