Hi Stepan ...
Good idea this FSK pattern applied to the
carrier freq. This remind me several years ago at 13.55MHz or so,
a segment called HiFer (there was lowfer/medfer too) ... was funny
detect NA & EU stations that run a few miliwatts on a 1/4WL
verticals using TTL/CMOS clock oscilators as transmitters. ID was
done by frequency and freq change pattern? qrss, dfcw, sawthoot,
square, triangle etc ... just a fraction of hertz was enough.
73
Marcus
PY2PLL + PY3CRX
GG66rf (near S Paulo - BRA)
Em 10/11/2018 06:21, DK7FC escreveu:
Hi Marcus and Markus,
Exciting and amazing what can be done with 3 W in AM. My congrats
to
this success. Seems to be an amazing challenge.
You won't belive it, i did NOT receive the signal. I tried with a
TECSUN PL-660er and its telescope antenna, out of the house in an
urban
region. No chance with this sort of QRM here :-(
Markus, maybe you can convince Ralph to transmit a 20 Hz modulated
QRSS-10 signal along with the music channel he wants to transmit
in the
final state. The 20 Hz signal would not be audible in a speaker
but
would give a fine signal to detect for the QRSS / spectrogram
friends
worldwide. Or, even simpler and more effective: The AM carrier
could be
shifted by 1 Hz or so, keying some QRSS. This can be done with a
simple
circuit, the capacitiy diode pulling an xtal a bit, like in the
old
days ;-) Great stuff :-)
73, Stefan
Am 10.11.2018 04:07, schrieb Markus Vester:
Hi
Marcus,
I think you've got it.
I just did another frequency measurement,
by injecting a 1475.990 kHz
Rubidium-derived local carrier into my AM
receiver. Ralph's carrier is
at 10.41 Hz (i.e. 1476 kHz +0.41 Hz), with
0.5 Hz sidebands from the
AGC acting on the beeps. I'm also seeing
that triangle carrier, which
is probably from another unidentified
broadcast station. During the
night it has been swinging between -0.12
Hz and + 0.45 Hz with a 15
minute period, and has now moved up very
slightly. Ralph at +0.41 Hz is
just inside the top of the swing, just
like the weak line in your image.
That's an awesome 9943 km then. Ralph,
hold on tight to your coffee cup
;-)
Best 73,
Markus (DF6NM)
-----Ursprüngliche Mitteilung-----
Von: Marcus PY3CRX PY2PLL <[email protected]>
An: rsgb_lf_group <[email protected]>;
markusvester
<[email protected]>
Verschickt: Sa, 10. Nov. 2018 2:16
Betreff: Re: LF: 1476 kHz AM
Well ... just for
fun
...
I set 2 receivers sharing the
same mini whip: a SDR-IQ and a
KiWi SDR.
On both there is two signals:
one at 1476000, another at
1476260 (I
read somewhere about Iran 260Hz
above).
Using Argo QRSS20 I got two
signatures: one that looks like
an old
ovenized xtal osc and a stable
one.
I verified both signals using an
KiWi SDR in Germany too. Of
course
that the 1KHz bips are there.
But the same signals are there
as well:
the ~85mHz wanderin' carrier and
the 3W one (this one stable,
~400mHz
above 1476000)
May be tomorrow I check this
again earlier.
Capture attached. Who knows ...
73
Marcus
PY2PLL + PY3CRX
GG66rf.
Em
09/11/2018 13:05, Markus
Vester escreveu:
Thanks
Tom and Clemens, that's very
nice!
Indeed there are some issues
with GoogleMaps, for example
last time I
looked https://sdr.hu/map
didn't show the Kiwi SDR
locations. As Clemens
indicated, http://k7fry.com/grid/?qth=JN59MN21HF
should work. Or in proper
coordinates, the wire
antenna is attached
to the tower at 49.546575
N, 11.019437 E.
Best 73,
Markus
-----Ursprüngliche
Mitteilung-----
Von: DK1IS <[email protected]>
An: rsgb_lf_group <[email protected]>
Verschickt: Fr, 9. Nov. 2018
14:13
Betreff: Re: LF: 1476 kHz AM
Am
09.11.2018 um 00:39
schrieb Markus Vester:
After
the sad demise
of all LW and
MW broadcasts
in Germany, a
handful of
pioneers came
up who are
operating
legal
low-powered
medium wave
stations in
the context
of a radio
museum or
for educational
purposes.
One of them is
Ralph (DL2NDO,
one of the
participants
in the
legendary
Donebach 137
kHz activation
in 2002).
He has
obtained a
transmitting
license for
1476 kHz
(former
frequency of
Vienna
Bisamberg), built a
3
Watt AM
transmitter,
and with the
help of a
small team
raised a
quarterwave antenna on the Fraunhofer premises south of Erlangen
(JN59MN21HF).
Yesterday they
got on air for
the first
time, running
a preliminary
test
transmission
consisting of
a switched
1000 Hz beeps
(one second
on, one second
off, audio
frequency
locked to the
RF carrier).
This
pattern will
be continued
for a few
days, before
they will
eventually.take over the audio from the local DAB student radio
"funklust".
The current
test pattern
is relatively
easy to make
out in the
noise so
it may be a
good chance
for some DX
detections.
At night
we've
actually heard
the beeps
on Twente SDR
and a couple
of German
Kiwi-SDRs. But
I guess
using narrowband
signal
processing
techniques,
the carrier
and coherent
tones coud
make it much
further. The
carrier
frequency is
derived from
an OCXO and is
currently at
1476000.411
Hz.
Will anyone in
the group take
the challenge?
Best 73,
Markus (DF6NM)
Fb audible signal at
DL0AO (JN59VK)! RX
Perseus, Ant Miniwhip,
see
screenshot. Slight
selective QSB. Similar
results with their North
America beverage.
By the way: all
programs using
GoogleMaps for
QTH-locator
identification seem to
be inactive because of
new Google restrictions.
73,
Tom, DK1IS
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