[Lowfer] Re: JASON - up and running?

[Alberto di Bene]

Eric KD5UWL <eric@willow.nutstreet.net> wrote:

> Hmmm -- ok, I understand the table now ... this gives you the (NATIVE 
> format) codes that will be delivered to your DDS board and the frequencies 
> your DDS board needs to generate given those codes.
> 
> Does not apply to me.


Hi Eric,
correct. that table is only for those who want to program their own DDS.

>I'm all the way up to the point where I'm trying to decode it myself with 
>my receiver...so far, no luck -- my receiver ... leaves alot to be 
>desired.  It only tunes in 1 kHz steps and then tune around with the SSB 
>knob -- not exactly an R75 (*almost*, but not quite :)
>
>  
>
Beware that the waterfall window of Jason is only  abt 21.5 Hz wide, and 
the two yellow lines,
which is the zone where decoding takes place, is abt 6 Hz wide. So the 
tuning must be done with
some care.

>Still having trouble finding my own signal with the JASON waterfall 
>display - again, due to my receiver, or lack of one.  There are white 
>lines _everywhere_ I look.  Can't tell the JASON ones from whatever is 
>causing the rest of them.
>  
>
In the waterfall display of Jason there is a strong (stronger than that 
of Argo) visual AGC
applied, so if you manage to put a signal inside the two yellow lines,  
the noise outside them
should almost disappear (unless the signal is very weak, but this should 
not be your case, as
you are tuning a local emission). If you continue to see white lines 
everywhere, then the
tuning is not correct.

>I am unsure of the keying speed needed.  Alberto says 11.89 seconds per 
>character but I don't know what that translates to -- don't know how to 
>set that in my exciter as there are more than one JASON command per 
>character.
>  
>
Well, no. I said 11.89 seconds per *baud*. A baud is a change in the 
signalling, and with Jason
each baud carries with itself four bits of the eight needed for one full 
character. So each
character takes 11.89 * 2 = abt 23.78 seconds, which means a data rate 
of of abt 2.52
characters per minute (will become  20.16 with the new version).
So, each code sent to the ZL1BPU exciter should last 11.89 seconds, but 
this is taken care
of by Jason. I don't know the details of the ZL1BPU exciter (I don't 
have one), but I don't think
you have to set this time in it. The exciter runs continously, and just 
changes frequency when
it receives a new code from Jason via the serial port 

73  Alberto  I2PHD