[Lf] Improved QRS pgm ?

[Andre' Kesteloot]

Rik Strobbe wrote:

> Hello Marco,
>
> I will see what I can do to adapt QRS, I will have to use the parallel port
> for power switching as all 'output pins' off the serial port are alrteady
> in use.
> Alternative I could try to put some softawre in a PIC16F84 processor, I
> already have some 'beacon software' for it, just have to change speed and
> add the power switching. I am willing to send you a programmed PIC on a
> ready-to-use PCB. This would have the advantage that you do not need your
> PC for it.
>
> Regarding power switching and the WX-related detuning :
> It should be possible to built a small class-D TX and adjust the
> powersupply voltage to regulate output power. If we incorporate some
> feedback from the amp-meter to the voltage regulation it should be possible
> to have a TX that runs at constant antenna current (= constant ERP).
>
> The above are just some thoughts and a lot of work will be involved it we
> want to realize it. So maybe we first have to check if there is enough
> interest from the 'listeners side' and if we can share the work, it
> wouldn't be fair if we expect you to do it all.
>
> 73, Rik  ON7YD
>
> >>At the risk of being 'greedy' I would suggest following to Marco : would it
> >>be possible to have a series a characters at reduced power after the call ?
> >>eg. : 'IK1ODO X Y Z' where IK1ODO is tranmitted at 10mW ERP, X at 5mW ERP,
> >>Y at 2.5mW ERP and Z at 1.25mW ERP (of course any other 3 characters can be
> >>used).
> >>
> >>73, Rik  ON7YD
> >>
> >Rik, I will take this seriously. What about writing a modified version of QRS
> >to command an attenuator and step power levels?
> >I may build a linear amplifier, of some 10W output, and reduce the power
> >in four steps of 5 dB (3W, 1W, 300 mW, 100 mW for instance).
> >The big problem is to have an automatic tuning. I started the beacon
> >on Thursday evening, then left home Friday, and it was raining; so I had to
> >raise the power, since the aerial current was down from the nominal.
> >The rain stopped on Saturday, and the antenna current rose to (probably)
> >+5 dB respect to Friday evening. I was not able to transmit a fixed power
> >level;
> >my station currently can't run unattended (in effect, my wife was attending
> >and checking for smoke, HI).
> >
> >I returned home by Tuesday, and found the tuning of the variometer
> >completely different from Friday.
> >
> >Thanks to all for the reports. I think we have to go on.
> >
> >Well, Rik, what signal may we use to change the power levels ? go to
> >the parallel port, or use an UART on the serial ?
> >
> >73 - Marco IK1ODO
> >
> >
> >