Come the New Year cometh a new data mode
In a changing technical world, perhaps
not being an expert allows you to ask questions that may not be considered
technically elegant; such was the case ?..
Passing by
unnoticed on 30/12/2011 on 137.5 from 20:00 z
was a set of variable length pulses over a 8 minuet repeating every 5
minuets, in essence a test transmission of a new data mode , from Gary G4WGT with the intent of
crossing the pond to
Joe V01NA, using a transmitting station that could be described as the standard MK1 UK back garden VLF Array .
A
12 meter end fed vertical with a
contemporary 2 meter square
wire capacity hat, fed via matching transformer and 400 watt class d
amplifier .. ERP maximum? may be round 300mW , certainly well below the 1
W erp max .
Rain had reduced the safe power level to
some 200 watts at the start of
the tests , decodes from UK where achieved, but as
the monitoring computer Joe VO1NA uses , is not web linked , no confirmation could be expected till much later of a decode , or use made of the internet chat link?harsh conditions in a
grabber and wspr world ..
With a break in the weather ,power was increased 3dB to 400 watts round 22:00z , at this point one of the UK monitoring stations closed , leaving myself and it was hoped Joe , on frequency . notably
Joe?s 136 beacon was not running that night ..the only good
sign up till then ?With
no further
UK or
EU decodes other than mine,
the test ended 0020z
Followed one of those silent periods , with no
web reporting , this
was a real vintage attempt using a modern system .
The next day ... Possibly not totally unexpected came a email
Hi Graham,
I hope
the attached resukts in a smiley for you and Gary!
73 es
tnx!
Joe
Using the new OPERA data mode , Gary had sent G4WGT and
had been decoded by
VO1NA six times in a 2
hour time window , at a
signal level of
some -30 dB using a
TX period of only 8 minuets over a distance of
3500K with round 400 watts to a
12mtr vertical,
defiantly something to
sing about !.
Definitely one for the
scrap book !
73 - Graham
G0NBD
