A COMIC
OPERA
Just some observations on the recent posts
As to the legality of this or
any other digital mode , the words of
Gilbert and Sullivan , in
there satire of the RN , HMS Pinafore seem's to fit as
to the use of such thing?s
What, never? / No, never! / What, never? / Well, hardly
ever!
As pointed
out , ?we? all use code packages that are locked , commercial modem?s , the parasitic development and commercialisation of
D-Star , the MS Windows
system being used to type this message are all locked, so yes would be nice , but then so
would many thing?s...
My
licence prohibits the use of
secret code or cipher , as the
author is identified and the code my be freely downloaded, I hardly regard it?s use as a
breach, further more,
with development being undertaken on 500, is that not what the experimental permit was all about.
Band Co Occupancy,
A the start of testing , 500 was quite empty , with the split of allocations even wspr activity from EU had all but ceased , the zone occupied at the moment has traditionally been used for data transmission in
the UK.
Data
Efficiency
The
only real test of data transmission is
the carrier power required , Gary?s transmission to
VO1NA , is significant , if
comparison is made with existing techniques.
The
full call sign was received six times in a two hour period , using a
Tx time of eight minutes per cycle . The duty cycle of
OP is approx 50% , therefore , the total carrier required was four minutes .
Using
4 minutes of carrier 250 mW erp was enough to
cross 3500 Km from the s/n levels at the rx , its possible that -3dB lower could of been used , round 100 mW .. At the
moment Opera offers a beacon mode with
s/n performance far in excess of existing systems
with access to all
Surely this opens 136 to
more users ?
