Re: [A-DX] ca.5071khz Zeitzeichen???

["Thomas M. Rösner" <dl8aam@xxxxxx>]

> Hallo Ralf!  Auf 5071kc muß ein Bakensender sein.Diesen höre ich schon
> viele Jahre.Vor allen wenn ich auf 5070kc WWCR hören
>  will,stört er.Auf meiner Spezialfr.Liste steht(NATO Luftverdeidigung).

Hi,

keine Zeitzeichen, das sind nur Bursts eines NATO-Datenübertragungssystems
(der Luftwaffe/Luftverteidigung) genannt TADIL oder "Link-11". 
Die 5071 kHz stammt aus Italien.

Aus der UDXF Yahoogroups-Liste:

>>>

That is a NATO Link-11 air defence data transmission, usually transmitted 
in the USB but can have components in both sidebands (ISB).

>>From Wikipedia:

« TADIL-A/Link 11 is a secure half-duplex TADIL radio link used by NATO 
that receives or transmits--but not both simultaneously--a sequential 
data exchange digital link. It exchanges digital information among 
airborne, land-based, and ship-board tactical data systems. It is the 
primary means to exchange data such as radar tracking information beyond 
line of sight. TADIL-A can be used on either high frequency (HF) or 
ultrahigh frequency (UHF). However, the U.S. Army uses only HF.

Link 11 will be replaced by Link 22. »

TADIL = TActical Digital Information Link.

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>... but this signal is a link 11A (or tadil A) signal (in most
>cases they leave the "A"). i meant link 11B (or tadil B). that have to
>be different... i guess. if i am wrong... sorry for that ;)

It is difficult to find two specifications which agree about what
constitutes A and which constitutes B.

It seems TADIL-A is/may be/is possibly a parallel system running at 1364
or 2250 bps.

It is possible that TADIL-B runs at either 1200 or 2400 bps and may be
a serial system originally designed for UHF but probably running at the
higher speeds on HF. Some authorities say it is a parallel system.

If you log it, then simply call it TADIL without the A or B as it's
not possible to say which is which.

Sometimes they make use of both sidebands: whether these are in parallel
(carrying the same informatio) or whether they are true independent 
sidebands can be no more than a guess.

Link 11 has a so-called 'doppler' pilot at f+605 Hz, then 14 channels
110 Hz apart between f+935 and f+2365. There is a further pair of tones, 
narrowly spaced at f+2915 Hz. With a good clear signal, this structure is 
easily seen on a spectrum analyser.

The "plink, plink" tapping sound is the doppler pilot which you should 
tune to put it on f+605 Hz in a spectrum analyser, then switch sidebands 
and if the pilot is still there then you have what you can call a TADIL 
in ISB.

If you can't measure the speed then call it 2250; no-one will be any the
wiser.

They're tactical data links, usually naval air defence, often using TDM to
address several net users individually on the one TADIL transmission, but 
they can also be simplex or half-duplex apparently.

Hope this helps, but as you can probably imagine, I don't really know very
much about it. Perhaps someone else has some definitive information?

To confuse matters further there is a system called SLEW sometimes called
Serial Link Eleven Waveform and sometimes Single-tone Link Eleven 
Waveform. It's not very common, but fairly easily recognisable - but 
that's another story.



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