Rick, KV9U wrote:
...Unfortunately, it did so in a way that also limits J2D
emissions -- data sent by modulating an SSB transmitter --
to 500 Hz bandwidth.
...
Can anyone explain for sure what the FCC has decided?
Hi Rick,
It would be a huge step backward for the Amateur Radio Service
All:
Performed a few informal path simulator tests with the AOR-9000 modem and
WinDRM. I used two laptops and Moe Weatley's PathSim.
I wanted to first test each mode for sensitivity without any ionospheric
distortion. I used direct-path and slowly increased the white noise.
I found that the
Below 30 MHz it would be a very popular step, but I agree that this
most likely was not the intention of the FCC.
73,
Mark N5RFX
It would be a huge step backward for the Amateur Radio Service in USA
if FCC were to limit Data transmissions to less than 500Hz bandwidth
Need a Digital mode
Rick,
The text in the RO indicates that the 500Hz maximum occupied
bandwidth only applies to the new emissions designators added to the
definition of data. and the affected bands are below 30 MHz. This
is what I asked for in my petition. However, the FCC did put J2D in
the list of 500Hz
Gerhard OE3GBB and I tried to work digital voice with
WinDRM today but signals were too weak this morning. Below is the Hamcap
prediction for 20M conditions to Austria today from my Western New York
location. Gerhard will be back later, looks like 1800 UTC is the best time
today. The plot
Thanks Bonnie,
I had those settings in the config file, I
rechecked and have found the problem.
The output setting of my sondcard was only half
way, incresing it has fixed the problem.
I am now transmitting.
Now to connect to somebody and find out what
happens,
Can I use QRZ and will it
OK, Mark, then it does look like we are not going to be able to use the
wider modes in the CW/RTTY/Data area. I am not sure what wide modes you
are referring to that are not sent with J2D as all of the ones I can
think of are done with injecting tones into an SSB transmitter.
I did find the
Great information, Tony. Just the kind of real world stuff that we need.
By the way, although there are similarities between the systems, it is
interesting to note that:
AOR is a 50 baud OFDM system using 36 DQPSK carriers. For voice it uses
AMBE2020 which I think is the same voice codec as in
Rick,
All of the modes that claim to be J2D are really J2B when sending
text. When sending images they would be J2C and fall under the 500
Hz maximum occupied bandwidth limit.
73,
Mark N5RFX
OK, Mark, then it does look like we are not going to be able to use the
wider modes in the
There's another way to look at spectrum use. It is better to use a
3kHz bandwith for 10 minutes than to use a 500Hz bandwidth for 1 hour
to pass the same traffic. On HF, with short propagation openings, it
is better to be able to quickly send the message. Approximately 3kHz
is the defacto
10 matches
Mail list logo
