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
