[Lf] VE7SL receives ZL6QH, again

[Andre Kesteloot]

Vernall wrote:

> Hi all, Following is the text of an announcement to the amateur radio
> media.  I will email the Argo file to personal addresses, on
> request. 73, Bob ZL2CA A SECOND CLAIM OF ZL TO VE AMATEUR LF DX26
> September 2001<?xml:namespace prefix = o ns =
> "urn:schemas-microsoft-com:office:office" />
>
> On Saturday 22 September ZL6QH, ZL3PN, ZL3JE, ZL4OL and AX2TAR
> (VK7ZAL) transmitted test signals in the 165 - 190 kHz band, for
> so-called trans-Pacific tests.Various DX listeners had prior knowledge
> of the schedule of individual test frequency and coding used by each
> station.
>
> As occurred in the 30 June trans-Pacific tests, Steve VE7SL managed to
> receive signals from ZL6QH before VE7 dawn.This time VE7SL obtained an
> Argo capture of both frequencies of the DFCW transmission.The path
> length is estimated to be 11,709 km.
>
> Refer to the associated Argo graphic.The ZL6QH signal is in the lower
> half of the screen.The transmitted signal used dual frequency keying,
> with 0.4 Hz frequency shift.The uniquely coded transmission consisted
> of repetitive sending of QQQQQ
 sent as 184.4001, 184.4001, 184.3997,
> 184.4001 kHz and then a gap, with all elements being of 120 seconds (2
> minutes) duration.This means sending a single Q took ten minutes.
>
> The Argo graphic of the VE7SL reception shows inverted audio FSK , but
> otherwise agrees with the dot length, sequence and frequency shift of
> the ZL6QH transmission.The explanation for the inversion is that the
> Icom IC-R75 receiver used by VE7SL happens to give inverted FSK in the
> audio output when used in the normal CW mode.VE7SL used an RF signal
> generator to subsequently verify that an Argo trace (showing receiver
> audio output) went lower in frequency when the RF frequency went
> higher.Note that the parallel vertical red lines in the centre of the
> Argo graphic are a software option for selecting either short or long
> "ticks" and once selected, a tick stays on the screen.The left side of
> the long tick is close to 40 minutes before the 1401 UTC sunrise at
> VE7SL.The signal faded rapidly about 3 minutes after sunrise.It was
> still dark in New Zealand at VE7 sunrise.
>
> The ZL6QH LF signal was generated using a modified TS-850SAT, in SSB
> mode, fed with audio from a lap top PC, using soundcard software
> developed by Steve VK2ZTO.TS-850 frequency control was by means of a
> high performance TCXO master oscillator.The low level LF signal from
> the TS-850 transverter port was fed to an external LF power amplifier,
> and the output power was around 500 watts.The radiated power is
> estimated to be 5 watts.The antenna was a long wire at the Quartz Hill
> club station, which is run by the Wellington Amateur Radio Club.The
> ZL6QH operators were Andrew ZL2BBJ and Bob ZL2CA.
>
> ZL6QH is seeking permission to transmit in the 136 kHz band, which
> could widen the scope of testing beyond "trans-Pacific", and give
> European listeners a better chance at receiving amateur LF DX from
> down-under.
>
> Bob Vernall ZL2CA
>
> Organiser of the Trans-Pacific tests



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