Thanks for the replies (also to Dave and Pete who replied off the list).
I am aware of the approach that keys the K2 with the one transistor-circuit
using the CTS/DTS control line, but will be running a small netbook under
WindowsXP - mainly because this computer produces less rf noise than my
Hi Lyle,
So I actually measure a quantity that is proportional to the energy (signal +
noise) that has been collected in the display update time, am I getting this
right?
Greetings
Ralf, DL6OAP
Am 20.10.2014 um 14:31 schrieb Lyle
The DSP uses audio samples at a 12 kHz rate and performs a
Harlan,
You should get 0.1 volts when you terminate your attentuator with 50 Ohms - are
you probably using a high z voltmeter? The output of the attentuator can be
seen as a 0.2 V voltage source with 50 ohms internal resistance - if you
terminate it with a 50 ohms load, the 0.2 volts are
Hi Gerry,
The charger is a constant current source (which adapts its voltage to supply a
constant current) and my guess would be that, at the end of the charging
process, the difference between the voltages of power supply and batteries is
not high enough for the charger to supply its current.
I am no expert in the field, but maybe the device named HackRF is what you
are looking for.
It is a low power SDR transceiver with an interface to GNU radio, and, with a
20 Ms/s sampling (if I remember correctly - don't have the data sheet here)
rate, the baseband should be broad enough for
Hi George,
The 130 feet corresponds to lambda/2 on 80 and you can use the far field
approximation (that Ed is using) there...
At short distances (less than a quarter or a sixth of the wavelength), however,
1/r^2 and 1/r^3 (near field) components of E and H fields are still present
(or
Hi Ed,
Actually, my S9+67 dB for 0dBm turned out to be wrong - I lost one 6 dB in my
book keeping, so 0dBm is S9+73 dB - or S9 equals -73 dBm (which is the number I
had in mind).
No doubt about the space loss formula and the far field - free space loss is
no dissipative loss like for example
My guess would be that the local oscillator of the KX3 (which is on the rx qrg)
is emitted via the shield of the coax cable (common mode?) received by the
charger's usb cable, modulated with the 60Hz by non-linearities in the charger
and than re-emitted (maybe by the wiring a a whole) and
my imagination or that the static had just
become sufficiently loud that my own hearing wasn't responding to it anymore.
Nick
On 10 February 2014 03:02, Ralf Wilhelm r...@super-deutschland.net wrote:
When I got my KX3, I connected it to a piece of wire lying on the floor
in this context, and how does it
provide the benefit of keeping the buzz out of the detector (or to ask the
question in the reverse, how does the buzz get in, in the absence of
additional isolation)?
Nick
On 10 February 2014 08:40, Ralf Wilhelm r...@super-deutschland.net wrote:
Hi
because it's so much further away from the
house wiring (and the house).
Nick
On 10 February 2014 09:40, Ralf Wilhelm r...@super-deutschland.net wrote:
The problem with all receivers using a local oscillator (direct conversion or
superhet) is that they emit a small part of the local
The main approach for solving the multipath problem would be a long symbol
duration and some interleaving for error correction. The symbols should be
longer than a typical delay between two paths.
Since the phase measurements on a typical hf channel cannot be very sensitive
because of noise,
In my MarkV Field, I can switch the (2.4k?) SSB filter into the path while
receiving in CW mode (500 Hz pitch) and don't see the other sideband at all
due to the DSP which adds the sideband suppression almost for free (I can turn
the DSP off and then I hear the other sideband). The same should
Hi Josh,
I think you are right, am no native english speaker but I think that is the
better way to read it.
In my understanding, the main purpose of the ALC is to reduce the power drive
to keep the plate oder grid currents from being driven into the non-linear
region in order to prevent
There seem to be more than version of the manual around. Mine is from
radiomanuals.com (I think so) and just checked; it doesn't not have the word
only in the ALC description on page 8.
So, the basic line is NO ALC for ssb,cw...
Actually I hope Chris will show up again because I got an
Hi Chris,
Am no expert (have no k3 and no om2500a) but I was courious and checked both
manuals.
My understanding is that you (or Elecraft) don't want the ALC and the keying
of the amp is not done via Elecraft's PIN 10.
So, you would key the amp via the Keyout jack of the K3, connect amp's pin
Just noticed that OMPower recommend using the ALC if duty cycle is high (but
don't have it in their illustration)
So, better connect amps pin 1 and k3's pin 15 (ALC) and turn on ext alc in K3's
menu...
__
Elecraft mailing list
Home:
Hi Gary,
The maximum specified output power of the KX3 is 8 Watts on 12, 10 and 6 meters
(I think so).
This would explain folding back on 10 but not on 15 meters and certainly does
not explain the display issue.
Greetings
Ralf,DL6OAP
Am 13.12.2013 um 01:36 schrieb Gary Hawkins
In 1985, Wayne had a very special trip in a DeLorean DMC12 that had some very
special aftermarket parts (one was called fluxcapacitor). He travelled back
into 1955 and played the song on a guitar at a high school senior party, and
his parents fell in love there. Lefty's cousin Martin called
That kind of chart is e. g. in the ARRL antenna book (I have two older editions
but am sure it is in both of them). Since the measurement assumes that the
fraction of the power that is put into the line and not being converted into
heat in the coax is completely reflected at the far end, it
Hi Joel,
I have seen the message once while I was charging my eneloop batteries using a
16 h charge. I am not completely sure if the KX3 was on, but I think so. As far
as I know, the message occurs when the batteries are getting too warm while
charging, don't know if this is said in the KX3
Hi Mike,
I have no K3, but my understanding is that the 10138.7 is the frequency of the
suppressed carrier and that 10140.2 means that you set your rig to 10138.7 kHz
USB and feed audio at about 1.5 kHz, resulting in TX at 10140.2.
So, the QRG reading should not change.
Greetings
Ralf
Hi Arno,
If your fully charged batt reads 11.4 V AFTER the KX3 has switched back to 5 W,
the voltage reading with 10 W (maybe 50% more current?) will most probably be
below 11 V.
I would suggest that you try to gradually increase the output power from 5
Watts and read the voltage and
Hi Richard,
If it really is 12 V, the voltage might be too low. I don't have the manual for
the charger at hand in the moment, but I think it says it would like to see
13.8(?) V or something very close to this.
Vy 73
Ralf, DL6OAP
Am 31.07.2013 um 14:37 schrieb Richard Neese
Hi Klaus,
My understanding is that the iso amp is identical to the 10 dB preamp but with
a reduced gain (there is a iso amp hi control signal which seems to be used
to set the overall gain of that stage). So I would expect the IP3 to settle
somewhere between the no preamp and the 10 dB preamp
Hi Klaus,
I tried to provoke some AM breakthrough with my active antenna in april and
used a very strong (peaked up to 0 dBm (!) on my Perseus SDR the next day)
broadcast signal on 3965 (I think). The only thing I could provoke even with
this signal was some AM on the second harmonic, however
Sorry but I do not agree:
If the mixing process involves the local oscillator (cross-modulating the
local oscillator's carrier in the AC mains), the KX3 detects the AM wherever
it is set and would not show discrete signals. If the modulated local
oscillator's signal is re-radiated by the AC
Hi Frank,
I would not expect the waterfalls for the JT modes to change because the JT
modes transmit only one tone at a time. Apart from turning the tx on and off,
the amplitude of the signal does not change. Therfore there is no source for
IMD that could result in a broader signal or
Hi Larry,
I don't think it is very hard. The band data of the 817 is a dc voltage between
300 mV and 4 V dependent on the band. I think a pic decoding the KX3 RS232 data
and driving a DAC for generating the voltage would probably do the job.
Maybe this page
http://g4fre.com/KX3_RS232_hf.htm
Hi Tom,
I just read and like your review.
I don't know for sure, but my understanding is that the 4.2 kHz filter
actually corresponds to a conventional 8 KHz filter. My understanding is that
all signals between carrier frequency minus 4.2 kHz and carrier frequency
plus 4.2 kHz are
Joe is right...
Maxwell's equations relate time dependant electrical and magnetic fields. If B
is changing with time, E cannot equal zero everywhere in space and if E is
changing with time, B cannot be zero everywhere in space (otherwise you can not
fulfill the two equations for the curl of
Hi Gernot,
your ATU problem looks similar to mine, maybe you changed antennas and some
settings for a different antenna are still in the tuner? If this is the case,
you probably have to clear the ATU's memories.
Maybe you want to see this discussion:
(or your licence course materials) and
connect at least this pedestrian trailing wire to it and don't blame it on
the tuner (or Elecraft) ;-)
Vy 73
Ralf, DL6OAP
Am 19.05.2013 um 23:14 schrieb AG0N-3055 mcduf...@ag0n.net:
On Sun, 19 May 2013 22:59:50 +0200, Ralf Wilhelm wrote:
Obviously
I'm no expert in assembling the K2, but, in RX, the SSB option only uses the
additional xtal filter. If SSB sounds like SSB received on AM, my guess would
be that the BFO (RF board) is not oscillating. Maybe pulling the crystal to far
makes it instable. Is it on both sidebands?
Since the K2
Hi, Christophe and Don,
There is a point I don't understand: The K2 switches to VFO below rx
frequency on 15 and above (main manual page 85) thus resulting in sideband
inversion. So, if Christophe can receive USB on 15, shouldn't that mean that
the BFO is properly set for LSB reception on 17
the actual width of the filter other than using an audio spectrum analyzer
like Spectrogram.
73,
Don W3FPR
On 5/20/2013 1:25 PM, Ralf Wilhelm wrote:
Hi, Christophe and Don,
There is a point I don't understand: The K2 switches to VFO below rx
frequency on 15 and above (main manual page 85
Exactly... Talking about Dayton discounts and hats (are they equipment?),
that is why I became radio amateur ...
73, Ralf, DL6OAP
Am 19.05.2013 um 16:19 schrieb tomk7zz . tomk...@gmail.com:
Can we possibly get back to topics that are relevant to Elecraft
equipment. Find a different forum to
Hi Joel,
The ground beneath the antenna can have two effects:
1. It can become a part of the antenna's equivalent electrical circuit.
2. It has an effect on the antenna's far field due to reflection of the
antenna's field
By burying the radials and mounting the antenna on the ground, you
Hi Mike,
There is one: it is related to the menu item ATU MD, there is an option
CLR. To be honest, I haven't checked yet, but Wayne told me last week...
Greetings
Ralf, DL6OAP
Am 05.05.2013 um 20:39 schrieb Mike Weir ve3...@hotmail.com:
Good afternoon all, I was wondering if there was a
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