7 July tests

[Andre Kesteloot]

ZL6QH and ZL4OL QRSS TESTING 7 JULY

ZL6QH and ZL4OL are conducting further slow rate digital mode test
transmissions this coming Saturday, on the frequency of 184.3999 kHz. 
ZL6QH
will transmit from 0500 - 1230 UTC, and ZL4OL 1045 - 1215 UTC (targeting
sunrise time in VE7).

The transmission format for ZL6QH is dual frequency keying, with 0.4 Hz
shift, and "dot length" of 120 seconds.  The identifier is Q, sent as
"dah
dah dit dah", with "dah" as 184.4001 kHz and "dit" as 184.3997 kHz. 
Dual
frequency keying has equal length elements for "dit" and "dah", and only
a
brief transition between elements, to save time with very slow keying,
so
each Q in the ten minute repetitious sequence of QQQQQ. has the
following
format:
  Dah of 184.4001 kHz for 2 minutes, then a brief pause
  Dah of 184.4001 kHz for 2 minutes, then a brief pause
  Dit of 184.3997 kHz for 2 minutes, then a brief pause
  Dah of 184.4001 kHz for 2 minutes
  A silent period of 2 minutes
  Repeated for the whole session

The transmission format for ZL4OL is single frequency keying, with
184.3999
kHz carrier, and 120 second "dot length".  This is deliberately arranged
to
be "inbetween" the dual frequency keying of ZL6QH, and allows one
correctly
tuned Argo screen to be able to capture either signal.  The identifier
is O,
sent as "dah dah dah", so each O in the 15 minute repetitious sequence
of
OOOOO. has the following format:
  Dah of 184.3999 kHz for 2 minutes
  Silent for 2 minutes
  Dah of 184.3999 kHz for 2 minutes
  Silent for 2 minutes
  Dah of 184.3999 kHz for 2 minutes
  Silent for 5 minutes
  Repeated for the whole session


73, Bob ZL2CA