[amsat-bb] Re: ITUNE with Mic-buttons?

Anthony Monteiro aa2tx at comcast.net
Mon Oct 30 06:08:04 PST 2006

At 08:40 AM 10/29/2006, SV1BSX wrote:

>Hi folks,
>  during last couple of days I was looking for setup of  ITUNE (v1.10) with
>an old
>RIG by using UP-Down Mic-buttons for Doppler correction.
>  ...
>   But,  If I change the command line with "rx", in irder to cover the
>Downlink of
>FO-29, the ITUNE
>does not correspond correctly anylonger! ("itune.cfg" command is now: rx
>micbutton 1 435.850 100).
>The ITUNE seems to accept the command for FO-29 without any obvious problem,
>but the Doppler correction does not work properly (symptom: always ITUNE
>trying to correct the frequency, even the Sat is "out of range". Always
>"Tuning Complete" LED is OFF !)

Hi Mak,

I just tried this and it works perfectly. I think you may be
confused because it takes a long time to complete the tuning.

A mic button radio tunes at a maximum rate of 9 clicks per second.
This is the fastest rate that you can reliably tune most radios
with the mic buttons.

The beacon of FO-29 is 435.795 MHz. If you use your command line:

rx micbutton 1 435.850 100

then the radio has to be tuned by 55KHz in 100 Hz clicks which
takes more than 1 minute at 900 Hz/Sec.

A better command line would be:

rx micbutton 1 435.795 100

which will only take a few seconds to complete tuning.


>And once more question: the Doppler correction is it possible for several
>Satellites without changes in "itune.cfg" or just
>for this one which included in to command-line of  "itune.cfg"?

You can set a different radio config command for each satellite if
you want to so you never need to have multiple copies of the itune.cfg
file. This is mostly useful for micbutton radios so you can set a
different start frequency for each satellite. I would suggest starting with
the beacon as this will require the least amount of tuning to lock.

To do this, just put the radio command line after the satellite
transponder info. You can also have a default if you like which will
be in effect unless you put something different for a particular satellite.

If you have any more questions, please send me email.

Tony AA2TX

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