S/N has no real meaning in data
transmission , the decode level is
decided by various parameters , the channel
b/w has no influence on the decode decision
, other than to influence the analogue value ,
which in this case may be set at
a lower level than it actually is
, the level of false decodes is a guide to
the system design or lack of ,
But, I quite like vintage motor
sports and wspr is now a vintage
mode, , requiring disproportional external
support , it was fine but has been overtaken now
by modes that have a minimal of hardware
requirements and make no use
of embedded call sign lists , double
passes or ultra stability or external time
locking and looking on the web , seem to
have a absence of comments round
issues of decode integrity ?
G,
Sent: Saturday, September 28, 2013 1:14 AM
Subject: Re: LF: Re: QRSS OP WSPR
G
Given an available amount of PEP and a multimode
transmitter WSPR wins. Get over it.
Jay W1VD WD2XNS WE2XGR/2
WG2XSR/2
p.s. In this day and age with all of the hardware
and software available, there's no good reason a capable radio man cannot
generate an SSB signal - VLF to microwave.
----- Original Message -----
Sent: Friday, September 27, 2013 3:15
PM
Subject: Re: LF: Re: QRSS OP WSPR
Engineering Engineering Engineering
Another -3 dB at the Rx in this case
is 1000 watts at the Tx
10 db = 10KW
The advantages of Opera is that it
works simple as that
from shf to vlf with normal equipment
[very]
wspr-15 was a ill conceived botch
of a inefficient existing system
with increasing the time by 7 ,
resulted in a stability requirement
of x7 as well and a decode
engine that was / is not reliable
and non compatible with average equipment
Opera was conceived , designed , tested on simple
CW
Tx's and crossed the Atlantic in 3 months and
remained
stable ever since , that's Engineering not BF&I
This is radio Ham , but not
all involved are amateurs , some seem
to take advantage of this , while others ,
take the opposite view
73-G,
Nb Why should a CW tx cause key
clicks ? Opera was designed with
a 10 mS rise time cw envelope , part of of
a CW tx design is
click suppression
Sent: Friday, September 27, 2013 6:12 PM
Subject: Re: LF: Re: QRSS OP WSPR
G,
Am 27.09.2013 18:07, schrieb Graham:
Which
, if you take into account , Opera is
single tone on/off with app
50% duty cycle , self sync mode
and wspr is a 4 mfsk
externally time locked
That doesn't
matter at all! A successful detection is all that counts, not the energy (or
average power) needed. If Bob can TX 3 kW WSPR-15, then the RF energy is 0.75
kWh. With 50% duty cycle it may be 0.375 kWh but who cares????
For the test to be valid , the
wspr carrier level would of needed
to be 50% less that of the Opera system
No.
Transmitting amateur radio
stations have a certain transmit antenna with certain limitations (say 0.1 %
efficiency) and they have a PA giving a certain RF power (say 100 W). This
results in a certain ERP. The goal of the amateur radio station could be to be
received/decoded in a distance as high as possible. It is usually completely
uninteresting if you need 0.1 kWh or 0.2 kWh for a transmission, except in /p
mode using batteries.
From my point of view the only real advantage
of Opera is that you can use a simple keyed VFO, like in CW. But then some
will complain about the key clicks :-)
73, Stefan
