[HamWAN PSDR] toys & tennas

[Rob Salsgiver]

And here I was thinking a simple VB or C app.  Silly me. <g>

 

I'm sure there's >some< start/stop lag, but the speed once started seems to
be pretty consistent at least.  With the position resolution we can probably
come up with something one way or the other.  

 

Back to the salt mines.

 

From: PSDR [mailto:psdr-bounces at hamwan.org] On Behalf Of Bart Kus
Sent: Thursday, February 21, 2013 3:58 PM
To: Puget Sound Data Ring
Subject: Re: [HamWAN PSDR] toys & tennas

 

I just got word from Baltic that their next shipment of 5SHPn radios is 6
weeks away, and is for 80 radios.  Looks like we're back to $100 land for
the near term.  Not a tragedy, just an annoyance.

Regarding the rotor, I'm guessing it does smooth start+stop.  This makes the
speed non-constant during rotation.  Which means the angular positions are
not easily deduced through timing and must be sampled from the rotor
controller.  But you mentioned it does provide the current position at all
times, so that should work.  The RF strength samples also take an arbitrary
amount of time to acquire, something in the region of 100ms.  It's sounding
to me like we need asynchronous IO on 2 descriptors with timestamping and
possible interpolation so we can spit out reliable (angle,signal) tuples.
Doing it by coming to a full stop @ each stepping will take too long, so the
measures must be done while in motion and assigned to angles as best as we
can.

Here's <http://pyserial.sourceforge.net/>  a nice python serial port
library.  I use the PyVISA <http://pyvisa.sourceforge.net/>  library to
communicate with the GPIB instruments.  WARNING: It requires Python 2.7
series.  Or at least, I never got it working on Python 3.

--Bart


On 02/21/2013 03:38 PM, Rob Salsgiver wrote:

Got 2 radios - (5SHPn's) and one of the ARC-DA5830SD1's in today from Baltic
Networks.  So far received 2 orders from them and they seem to be a
dependable source.  Got a couple of rubber ducks and some adapters to round
out the package for a garage to house link so I can do some playing around
with the OS and a few other things.

 

Ordered and received a Yeasu 5500 AZ/EL rotor with a FoxDelta ST-2 PC
interface (used).  Had to make the cables between the rotor control box &
rotor.  All tested out very nicely.  FoxDelta is a serial-port driven
interface that can also control the rotor via front panel push-buttons.  The
2 line LCD shows programmed AZ and EL, as well as current AZ/EL.  Protocol
for commanding it seems to be very straightforward and quite simple.
Character codes followed by  text or integer values, sent via serial port.
Current position can be read the same way.   Calibrated the unit and put it
through full rotation testing via Hyperterminal <g>.

 

Commanding and controlling the rotor should be fairly easy - going to start
an application to do a predictable pattern of scanning for measuring the
antenna radiation patterns.  

 

Bart - we traded a basic outline on the scan setup, but we'll need to come
up with however you want to coordinate the position control with the
measurement recording.  Do you want to have the position sent to the test
equipment, output the test equipment values to the PC to be recorded with
the position, or something else?  I don't know that I need the info right
this second, but we can start thinking about it in the background.  Sunday
will be my first day to play with it, but barring Murphy it shouldn't take
THAT long (famous last words..)

 

Cheers,

Rob

 

 






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