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CX2SA > SATDIG 09.08.13 21:00l 151 Lines 5398 Bytes #999 (0) @ WW
BID : AMSATBB8259
Read: GUEST
Subj: AMSAT-BB-digest V8 259
Path: IZ3LSV<IK2XDE<ON4HU<CX2ACB<CX2SA
Sent: 130809/1901Z @:CX2SA.SAL.URY.SA #:9527 [Salto] FBB7.00e $:AMSATBB8259
From: CX2SA@CX2SA.SAL.URY.SA
To : SATDIG@WW
Today's Topics:
1. Rotator Positioning questions (Ing. Pavel Milanes Costa)
2. HF Amsat net (damon runion)
3. ArduSats and ITAR (M5AKA)
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Message: 1
Date: Fri, 09 Aug 2013 09:25:06 -0400
From: "Ing. Pavel Milanes Costa" <co7wt@xxxxxx.xx.xx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Rotator Positioning questions
Message-ID: <5204EDB2.6010807@xxxxxx.xx.xx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Ok, I have now a paper design with the goal for my rotor project.
This rotor is really a 0-360o, but I have managed (designed) to make it
full stop on 0-450o (even 540o if I like... with two contact switches
that cuts power to motor when in position) and will use a mixed
reference setup, the same for elevation as 0o (horizon) to 90o (cenit)
I can attach a plastic overlay to a wheel on the gear reduction for
making a 90 shift signal (2 wires for AZ and 2 for EL) an then down in
the controller a 74hc74 decoding the 90o to say/count not only the
position, but also the real rotation direction, the reduction cuadrature
signal outputs ~ 750 pulses for full 450o as per my calculations, this
after decoding by 74hc74 will be ~375 pulses for 450o and about 1.2o of
accuracy, and the controller knows if the system if de-phased by high
winds as it gets extra pulses when no moving was requested... so it can
correct this deviation... (this is not possible with "simple" pulse
counting or "time" counting as Bob, WB4APR proposed)
High winds here normal here, and as I say in a previous email the brake
mechanism is working poorly, remember this is for a "small" camera
mounted on top the device, not a "sail" of 2 crossed yaguis for 70 and 2
more for 2m
The "motor running/motor stop" signal will be a current probe on the AC
24V motor feeding wires down the control, as when the motor reach 0o or
450o it automatically switch's off
Now the real question is how to orient the rotor physically, I have ZERO
rotor experience here... knowing it can do 0o-450o...
0o is north, and 450o is east, this is the way I see, so I can do E-W
north (up) and south (down) ways as well as N-S in east (right) and west
(left) ways
This is correct?
And from the point of view of the controller and PC, lets imagine a ~NNE
to NW pass (80o to 300o pass, north way)
The PC(software) knows that ZERO will be crossed and send the controller
a 450-(real zimuth) to the controller?
Or this job must be done IN the controller it self?
With Azimuth and Elevation you can flip the direction of the pass an
then flip elevation 180o and cover it 100%, but how to do this in
azimuth only rotors?
Another... in 450o rotors (no elevation) How you cover a 110 to 300
(~SEE to ~NNW) pass if 450o is East and 0o is Noth?
Assuming the software can figure the ZERO crossing and can do the math,
110o is beyond the 450o (450 = 360+90)... How to manage this?
If I make a 540o rotor: softwares can manage it? (1+1/2 turns against
1+1/4 turns of 450o?)
I have the serial comms working on the pic (MCU) but this questions are
hammering my head...
Can anyone help me with this?
73 the CO7WT
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Message: 2
Date: Fri, 9 Aug 2013 11:44:08 -0500
From: damon runion <damonwa4hfn@xxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] HF Amsat net
Message-ID:
<CACNBj2q0mhqLz8prP9_ZLrQokaQg4Ecd0srKzxJAZnHCxJq1fw@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Is there still a net on 20 meters for AMSAT and what would the time ,
day and freq.?
The DSTAR AMSAT net is coming along pretty good,thanks to all I
would like to have someone to be a backup net control .If intrested
please email me
wa4hfn@xxxxxxx.xxx
Also don,t forget about the 5 in em55 award, look me up at wa4hfn
qrz.com for the new rules. We have been tossing around the
possiblity of having a 5 in EM55 contest. Comments welcomed
Lets all work together to help AMSAT grow.
Don't forget board elections . Im thinking about only voting for the
people I hear on the birds.,
Thanks Damon WA4HFN em55
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Message: 3
Date: Fri, 9 Aug 2013 19:21:30 +0100 (BST)
From: M5AKA <m5aka@xxxxx.xx.xx>
To: AMSAT BB <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] ArduSats and ITAR
Message-ID:
<1376072490.80428.YahooMailNeo@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
One of the designers of the ArduSat-1 and ArduSat-X CubeSats, Australian
Jonathan Oxer who passed his amateur radio Foundation exam last February,
was interviewed for an article that has been published in The Register.
In the interview he mentions that ITAR has currently stopped the design of
the payload being released under the TAPR Open Hardware License.
See http://amsat-uk.org/2013/08/09/ardusat-open-source-ham-radio-cubesats/
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73 Trevor M5AKA
AMSAT-UK website http://amsat-uk.org/
Facebook https://www.facebook.com/pages/AMSAT-UK/208113275898396
Twitter https://twitter.com/AMSAT_UK
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End of AMSAT-BB Digest, Vol 8, Issue 259
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