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RE: [linrad] Frequency control
- Subject: RE: [linrad] Frequency control
- Date: Wed, 20 Nov 2002 02:29:20 +0100
Hi Roger and All,
> I wrote a short routine to write to the serial port and put it in
> Will it get executed repeatedly at some interval?
> Should I put my open and close statements for the port in hwaredriver.c
> as I did, or elsewhere?
Put it in the main routine in main.c.
> How can I get the Hertz and decimal fractions of a Hertz value that
> Linrad displays as the received frequency so that I can send it (with
> appropriate prefix in MHZ and tenths of MHz) to the transceiver?
The frequency control is in an early stage:-)
I do not know what you want to do, but sending the center
frequency to the transceiver seems not to be a good idea.
I guess you want to control the tx?
Maybe you want to send the frequency of the BFO from the baseband
graph but more likely you would like to send something else.
There should be a tx frequency box also - the present one
is rx frequency.
> What keeps the frequency from jumping around when I am transmitting and
> Linrad sees the transmitter frequency if I have AFC on? There must be
> be a way to lock the frequency in place.
The frequency box is to set the center of the visible spectrum.
There is nothing for tx control yet. Maybe there should be
somewhere to click on something to set the tx to the frequency
of the BFO plus an offset (that you could change) plus a doppler shift
calculated from the EME window if selected.
> I guess what I really want is
> just the frequency I clicked on in the high resolution window; I don't
> want to play tag with the other station. How to I grab that number for
> my routine?
Some day I may provide a tx frequency control. I never owned a modern
transceiver so I do not know one would want to control it. I think
I can figure out how one would like to set the frequency for CW, a little
control box containing:
1) Currently selected tx frequency (could be entered manually)
2) A button to set current RX frequency to the new tx frequency
3) Currently selected offset (RIT control)
4) A button to select current BFO frequency rather than the passband center.
5) Enable/disable EME doppler shift offset.
What more is needed? Remember screen space is very limited!
There are many more things that need space. Particularly the automatic
CW to ascii translation for many stations simultaneously. I like to
see on the screen what the other stations are working;-)
> My routine is very simple ( and doesn't work, although it compiles
> without errors):
It is a good idea to place the open routine in hwaredriver.c as you did.
I will add a dummy routine in the next Linrad version so you will
not have to change any other routine than hwaredriver.c
The open routine has to be called from somewhere else.
I think the best would be to call it from main.c and leave
the device open all the time Linrad is running.
Then a second routine: send_tx_frequency_to_hware();
will be needed too - but I need to know better what it should
look like and I am not so sure it is the right thing for me
to work with in the immediate future. Right now I am working
with low noise oscillators for RX70. I will also change the
LO of RX10700.
Leif / SM5BSZ