| |
CX2SA > SATDIG 24.02.13 21:01l 699 Lines 24948 Bytes #999 (0) @ WW
BID : AMSATBB859
Read: GUEST
Subj: AMSAT-BB-digest V8 59
Path: IZ3LSV<IV3YXW<HB9TVW<DB0ANF<CX2SA
Sent: 130224/2002Z @:CX2SA.SAL.URY.SA #:3724 [Salto] FBB7.00e $:AMSATBB859
From: CX2SA@CX2SA.SAL.URY.SA
To : SATDIG@WW
Today's Topics:
1. Re: inquiry about homebrew az-el systems (Samudra Haque)
2. Re: inquiry about homebrew az-el systems (Lizeth Norman)
3. Re: inquiry about homebrew az-el systems (Hans Lourens)
4. Pendulum type elevation measurement (Richard Ferryman)
5. STRaND-1 TLE's (Trevor .)
6. Re: Pendulum type elevation measurement (Joe)
7. Mars Flyby 2018 (Trevor .)
8. Re: inquiry about homebrew az-el systems (Thomas Doyle)
9. Re: inquiry about homebrew az-el systems (Hector, CO6CBF)
10. Re: Pendulum type elevation measurement (Greg Dolkas)
----------------------------------------------------------------------
Message: 1
Date: Sat, 23 Feb 2013 23:03:24 -0500
From: Samudra Haque <samudra.haque@xxxxx.xxx>
To: Lizeth Norman <normanlizeth@xxxxx.xxx>
Cc: Amsat-bb <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: inquiry about homebrew az-el systems
Message-ID:
<CAJEM476Y4Vs2s1R3w9pWqb7P13TUVkQSwJCew02m1qtX5X82aA@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
hi, thanks for addressing this question. And I invite others to
participate, or get in touch with me for a phone conversation, and discuss
simple steps that can be taken IMHO within 50-100 USD. I suggest we adopt
AMSAT friendly tips:
http://www.amsat.org/amsat-new/tools/downloads/iROTOR.pdf (will need
additional interface to PC, any kind)
(cool idea, but only as concept)
http://www.amsat.org/amsat-new/echo/Az_El_Pos.pdf
http://dgg.gotdns.com/doc/XOX_rotor.pdf (Semi professional..)
http://ka6puw.tripod.com/azimuth1.html <--- what do you think of this
style? Looks simple enough.
But I have only done a simple google search here. Any other projects worth
investigating? Focus on the "mount" only now.
-samudra
On Sat, Feb 23, 2013 at 10:41 PM, Lizeth Norman <normanlizeth@xxxxx.xxx>wrote:
> Samudra,
> This is a good question for a first year engineering student like
> myself: How does one bring home the best bang for the buck out of an
> engineering dollar?
>
> Feel free to ask around. A few on the list have driven unusual devices
> to get antennas moved.
>
> How does a project get into the hands of people who will actually do
> it? A one off I can do for you in my basement. Probably with parts
> from radio shack, a grinder and a few hand tools.. A reproducible
> project 10 years from now? Hardly likely.
>
> I submit to you that irrespective of the metalwork this is a simple
> project as you propose, however it must be reproducible. With a
> student copy of SolidWorks, a circular saw, drill and the Arduino IDE
> it could be prototyped by two people in a weekend. Refining it so that
> a relatively new ham with a smidgin of technical ability could do it
> might take a little longer. These days with the internet and cad, the
> real issue is the tooling. How do you design/layout such that it can
> be done with snips/file/saw/fill in the blunt instrument here..
> 73 es have fun..
>
> Norm n3ykf
>
>
>
>
>
> On Sat, Feb 23, 2013 at 10:19 PM, Samudra Haque <samudra.haque@xxxxx.xxx>
> wrote:
> > I hope it is evident, I am not focusing on the
> > controller/microcontroller/computer interface/az-el controller/etc. The
> real
> > issue is how cheaply can an antenna be mounted on a kingpost somewhere
> on a
> > surface, with a view towards the sky, and how conveniently can that
> mount be
> > motorized, with a sensor to give feedback to the ground station.
> > electronics, seem to be, (apologises to EE friends) a dime a dozen,
> cheaper
> > if made in hundreds, but the key drawback of any design is the mechanical
> > and electromechanical (can we use, mechatronics) system that serves as
> the
> > actuators. I am not referring to a hand held antenna assembly, but rather
> > something that we can all use in cold/hot weather and that can be put
> > together by one / two persons on an average post.
> >
> > Comments welcome, I think the future holds bright for amsats and edu
> based
> > cubesats.
> >
> >
> > -samudra
> >
> >
> > On Sat, Feb 23, 2013 at 9:50 PM, Lizeth Norman <normanlizeth@xxxxx.xxx>
> > wrote:
> >>
> >> Gus and the group:
> >> Lots of birds going up in the next year. Success rate not 100% as it's
> >> rocket science oftentimes on a budget. Hopefully we'll get a few out
> >> of it.
> >> The Arduino IDE install supports PPM. The nice thing about that
> >> platform is that configuration is doable for just about all forms of
> >> hardware that you might drive with it and scaling can be done in
> >> software for the various different bits of kit.
> >>
> >> I am sure that with the appropriate development environment and having
> >> the hardware on hand IN a well equipped lab, it should be a weekend
> >> project to get running.
> >>
> >> The hard bit in my opinion is how to mount the antennas to the az/el
> >> clockwork. Will require a little woodwork/metalwork to finish.
> >>
> >> Everyone who does this will have a problem with some phase of it.
> >> Needs to be simple and repeatable.
> >>
> >> Norm n3ykf
> >> _______________________________________________
> >> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the
> author.
> >> Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> >> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
> >
> >
>
------------------------------
Message: 2
Date: Sat, 23 Feb 2013 23:25:30 -0500
From: Lizeth Norman <normanlizeth@xxxxx.xxx>
To: Samudra Haque <samudra.haque@xxxxx.xxx>
Cc: Amsat-bb <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: inquiry about homebrew az-el systems
Message-ID:
<CAJUhCTOd_LnKvTLHzTcJx48sWMqvDRoFP+KF0tjNSxXcLQdX7g@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Samudra,
It's an interesting question as to how much antenna that can be hung
on those gearhead motors. At 20 bux plus shipping, that's reasonable
for a hobbist budget. need two, the cable and metal (cool how the
worst of the metal work is done for you with KA6PUW's design.) Need to
do a BOM but should work out less than 100$ Probably kit it for less,
particularly the metal bits. Cheaper to buy by the 100's of feet, of
course.
The reference to SolidWorks is that the math needs to be worked out
regarding the shaft torque. Haven't been that far yet.
A thought is to have three build scales. One portable. One for
home/regular sized arrays, and a monster, no expenses spared version.
This is pretty easily doable with the electronics package you suggest,
just a different ,motor drive block, assuming DC motors and some sort
of feedback loop.
Curious to know, but the budding ECE in me wants to know what
development environment / microcontroller product families are in
consideration. The processors keep getting smaller and smaller. What
about a rasberry pi with a display in HD??? Amazing..
Norm n3ykf
On Sat, Feb 23, 2013 at 11:03 PM, Samudra Haque <samudra.haque@xxxxx.xxx>
wrote:
> hi, thanks for addressing this question. And I invite others to participate,
> or get in touch with me for a phone conversation, and discuss simple steps
> that can be taken IMHO within 50-100 USD. I suggest we adopt AMSAT friendly
> tips:
>
> http://www.amsat.org/amsat-new/tools/downloads/iROTOR.pdf (will need
> additional interface to PC, any kind)
>
> (cool idea, but only as concept)
> http://www.amsat.org/amsat-new/echo/Az_El_Pos.pdf
>
> http://dgg.gotdns.com/doc/XOX_rotor.pdf (Semi professional..)
>
> http://ka6puw.tripod.com/azimuth1.html <--- what do you think of this style?
> Looks simple enough.
>
> But I have only done a simple google search here. Any other projects worth
> investigating? Focus on the "mount" only now.
>
> -samudra
>
>
>
>
>
>
> On Sat, Feb 23, 2013 at 10:41 PM, Lizeth Norman <normanlizeth@xxxxx.xxx>
> wrote:
>>
>> Samudra,
>> This is a good question for a first year engineering student like
>> myself: How does one bring home the best bang for the buck out of an
>> engineering dollar?
>>
>> Feel free to ask around. A few on the list have driven unusual devices
>> to get antennas moved.
>>
>> How does a project get into the hands of people who will actually do
>> it? A one off I can do for you in my basement. Probably with parts
>> from radio shack, a grinder and a few hand tools.. A reproducible
>> project 10 years from now? Hardly likely.
>>
>> I submit to you that irrespective of the metalwork this is a simple
>> project as you propose, however it must be reproducible. With a
>> student copy of SolidWorks, a circular saw, drill and the Arduino IDE
>> it could be prototyped by two people in a weekend. Refining it so that
>> a relatively new ham with a smidgin of technical ability could do it
>> might take a little longer. These days with the internet and cad, the
>> real issue is the tooling. How do you design/layout such that it can
>> be done with snips/file/saw/fill in the blunt instrument here..
>> 73 es have fun..
>>
>> Norm n3ykf
>>
>>
>>
>>
>>
>> On Sat, Feb 23, 2013 at 10:19 PM, Samudra Haque <samudra.haque@xxxxx.xxx>
>> wrote:
>> > I hope it is evident, I am not focusing on the
>> > controller/microcontroller/computer interface/az-el controller/etc. The
>> > real
>> > issue is how cheaply can an antenna be mounted on a kingpost somewhere
>> > on a
>> > surface, with a view towards the sky, and how conveniently can that
>> > mount be
>> > motorized, with a sensor to give feedback to the ground station.
>> > electronics, seem to be, (apologises to EE friends) a dime a dozen,
>> > cheaper
>> > if made in hundreds, but the key drawback of any design is the
>> > mechanical
>> > and electromechanical (can we use, mechatronics) system that serves as
>> > the
>> > actuators. I am not referring to a hand held antenna assembly, but
>> > rather
>> > something that we can all use in cold/hot weather and that can be put
>> > together by one / two persons on an average post.
>> >
>> > Comments welcome, I think the future holds bright for amsats and edu
>> > based
>> > cubesats.
>> >
>> >
>> > -samudra
>> >
>> >
>> > On Sat, Feb 23, 2013 at 9:50 PM, Lizeth Norman <normanlizeth@xxxxx.xxx>
>> > wrote:
>> >>
>> >> Gus and the group:
>> >> Lots of birds going up in the next year. Success rate not 100% as it's
>> >> rocket science oftentimes on a budget. Hopefully we'll get a few out
>> >> of it.
>> >> The Arduino IDE install supports PPM. The nice thing about that
>> >> platform is that configuration is doable for just about all forms of
>> >> hardware that you might drive with it and scaling can be done in
>> >> software for the various different bits of kit.
>> >>
>> >> I am sure that with the appropriate development environment and having
>> >> the hardware on hand IN a well equipped lab, it should be a weekend
>> >> project to get running.
>> >>
>> >> The hard bit in my opinion is how to mount the antennas to the az/el
>> >> clockwork. Will require a little woodwork/metalwork to finish.
>> >>
>> >> Everyone who does this will have a problem with some phase of it.
>> >> Needs to be simple and repeatable.
>> >>
>> >> Norm n3ykf
>> >> _______________________________________________
>> >> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the
>> >> author.
>> >> Not an AMSAT-NA member? Join now to support the amateur satellite
>> >> program!
>> >> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>> >
>> >
>
>
------------------------------
Message: 3
Date: Sun, 24 Feb 2013 11:28:30 +0100
From: "Hans Lourens" <pa4pcj@xxxxx.xxx>
To: "'Amsat-bb'" <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: inquiry about homebrew az-el systems
Message-ID: <000301ce1279$b09e4bf0$11dae3d0$@xxx>
Content-Type: text/plain; charset="us-ascii"
Hi fellow hams,
Some years ago I have made a complete rotating system based on old and due
to battery fail her useless small screwdriver machines, there must be ton
off loads from these small machines and with a simple mechanics it is quite
easy to make uses off these small but very powerful machines
Vy 73,
PA4PCJ
------------------------------
Message: 4
Date: Sun, 24 Feb 2013 11:45:44 -0000
From: "Richard Ferryman" <g4bbh@xxxxxxxxxx.xxx>
To: <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Pendulum type elevation measurement
Message-ID: <1A1349BE8A88481D8D81D557A210654E@xxxxxxxxxxxxx>
Content-Type: text/plain; charset="iso-8859-1"
For some time I have wanted a more accurate antenna elevation measurement
system. Shaft encoders are beyond my budget. It seems sensible to use a
pendulum operated system. Digging through my 'junk' box I find I have a new
Spectrol precision potentiometer still sealed in it's package. This pot is
21mm diameter, has a servo type mount,, ball race bearing, 340 degree track
(continuous rotation possible) and specification is 0.5% linearity.and is
very low torque. Does anyone know if there are any drawbacks to using this
method of position measurement.
73 de Dick G4BBH
------------------------------
Message: 5
Date: Sun, 24 Feb 2013 11:55:02 +0000 (GMT)
From: "Trevor ." <m5aka@xxxxx.xx.xx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] STRaND-1 TLE's
Message-ID:
<1361706902.45255.YahooMailClassic@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
These provisional TLE's have been released for the launch of STRaND-1
currently planned for on Monday, February 25 at 125 UT. 437.568 MHz.
STRaND-1
1 44871U 58056A 13056.56026665 .00000000 00000-0 +10729-3 0 330
2 44871 98.6073 245.8068 0005347 261.8502 98.1779 14.33079817200821
The Surrey Space Centre twitter feed @xxxxxxxxxxxxx #S1Launch #STRaND1
https://twitter.com/SpaceAtSurrey
AMSAT-UK - http://www.amsat-uk.org/
73 Trevor M5AKA
------------------------------
Message: 6
Date: Sun, 24 Feb 2013 08:05:43 -0600
From: Joe <nss@xxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Pendulum type elevation measurement
Message-ID: <512A1E37.1060807@xxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
I see no problems at all. I have done it with that method in the past.
The only thing I noticed that was a problem was if the pendulum is
exposed to the elements. As in weather not antenna elements. Gusty winds
would move the pendulum and cause a not steady reading..
but not that much of a problem did not happen all that often.
Joe WB9SBD
Sig
The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com
On 2/24/2013 5:45 AM, Richard Ferryman wrote:
> For some time I have wanted a more accurate antenna elevation measurement
system. Shaft encoders are beyond my budget. It seems sensible to use a
pendulum operated system. Digging through my 'junk' box I find I have a new
Spectrol precision potentiometer still sealed in it's package. This pot is
21mm diameter, has a servo type mount,, ball race bearing, 340 degree track
(continuous rotation possible) and specification is 0.5% linearity.and is
very low torque. Does anyone know if there are any drawbacks to using this
method of position measurement.
> 73 de Dick G4BBH
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>
>
------------------------------
Message: 7
Date: Sun, 24 Feb 2013 14:15:28 +0000 (GMT)
From: "Trevor ." <m5aka@xxxxx.xx.xx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Mars Flyby 2018
Message-ID:
<1361715328.30461.YahooMailClassic@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
Saw the item in ANS about the proposed Mars flyby by the Inspirational Mars
Foundation in 2018.
Although lots of sites are implying there will be a human onboard the
Inspirational Mars Foundation press release does not actually state that:
http://www.spaceref.com/news/viewpr.html?pid=40141
You'd have thought a small automatic uncrewed spacecraft would be a better
bet for a flyby and return given the timescale. Guess we'll find out at the
press conference on Wednesday afternoon.
73 Trevor M5AKA
------------------------------
Message: 8
Date: Sun, 24 Feb 2013 08:22:15 -0600
From: Thomas Doyle <tomdoyle1948@xxxxx.xxx>
To: Gus <8p6sm@xxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: inquiry about homebrew az-el systems
Message-ID:
<CAHnRQR+tq0W5BfJq_r6wqWET84Hu_u_-_Z7nMHfDxA=kHZdqcw@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Gus,
Check this out.
http://www.tomdoyle.org/simplesattracker/SimpleSatTracker.html
73 W9KE tom...
On Sat, Feb 23, 2013 at 8:35 PM, Gus <8p6sm@xxxx.xxx> wrote:
> I think AMSAT-UK even has software available.
>
> And with the addition of a bit of EEPROM, you could even pre-load the
> controller with ephemeris data for several satellites for several days in
> advance. Emergency / field-day / portable operation without needing a
> computer.
>
> Add a bluetooth module and an Android app, and you could have an all
> singing, all dancing, full-featured satellite station in a briefcase.
>
> I'D buy one...
>
> On 02/23/2013 10:01 PM, Lizeth Norman wrote:
>
>> Samudra and the gang,
>> The bee's knees would be an Arduino Mega 2560 talking over one of it's
>> serial ports to the pc. Using the output of the Orbitron (or insert
>> your fave rave software here) DDE server to drive the microcontroller.
>> There are enough digital/analog pins to drive/slave anything from
>> there.
>> Simple serial port setup. Repeatable. Extensible. The chip has several
>> other HARDWARE (i.e has it's own hardware buffers for i/o) serial
>> ports for more and more fun stuff.
>> Have a look on youtube or google for code to drive steppers / selsyns..
>> Norm n3ykf
>> ______________________________**_________________
>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings:
http://amsat.org/mailman/**listinfo/amsat-bb<http://amsat.org/mailman/listinfo
/amsat-bb>
>>
>>
>>
>
> --
> 73, de Gus 8P6SM
> Barbados, the easternmost isle.
>
> ______________________________**_________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings:
http://amsat.org/mailman/**listinfo/amsat-bb<http://amsat.org/mailman/listinfo
/amsat-bb>
>
--
Sent from my computer.
tom ...
------------------------------
Message: 9
Date: Sun, 24 Feb 2013 11:37:22 -0500
From: "Hector, CO6CBF" <co6cbf@xxxxxx.xx.xx>
To: "'Samudra Haque'" <samudra.haque@xxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: inquiry about homebrew az-el systems
Message-ID: <000401ce12ad$511d4d00$f357e700$@xx.xx>
Content-Type: text/plain; charset="iso-8859-1"
Hello Samudra
Two years ago, I constructed a rotating system using as main part a blood
pump?s motor reducer from a discontinued dialysis machine. The circuit to
give feedback to the ground station was based on operational comparators and
sensors were 360 degrees potentiometers. It was my first rotator! Even
though it was very elementary and primitive, it performed perfectly and got
me into satellites. All the parts required were recycled from discontinued
equipments.
This rotating system is still working. I have improved the feedback and
control stages but mechanical parts are as before.
In a separate email I have sent to you an .odbc file with my feedback
circuit design ready to simulate on Proteus.
73!
Hector, CO6CBF
EL92sd
-----Mensaje original-----
De: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx En nombre
de Samudra Haque
Enviado el: s?bado, 23 de febrero de 2013 22:19
Para: Lizeth Norman
CC: Amsat-bb
Asunto: [amsat-bb] Re: inquiry about homebrew az-el systems
I hope it is evident, I am not focusing on the
controller/microcontroller/computer interface/az-el controller/etc. The
real issue is how cheaply can an antenna be mounted on a kingpost somewhere
on a surface, with a view towards the sky, and how conveniently can that
mount be motorized, with a sensor to give feedback to the ground station.
electronics, seem to be, (apologises to EE friends) a dime a dozen, cheaper
if made in hundreds, but the key drawback of any design is the mechanical
and electromechanical (can we use, mechatronics) system that serves as the
actuators. I am not referring to a hand held antenna assembly, but rather
something that we can all use in cold/hot weather and that can be put
together by one / two persons on an average post.
Comments welcome, I think the future holds bright for amsats and edu based
cubesats.
-samudra
On Sat, Feb 23, 2013 at 9:50 PM, Lizeth Norman
<normanlizeth@xxxxx.xxx>wrote:
> Gus and the group:
> Lots of birds going up in the next year. Success rate not 100% as it's
> rocket science oftentimes on a budget. Hopefully we'll get a few out
> of it.
> The Arduino IDE install supports PPM. The nice thing about that
> platform is that configuration is doable for just about all forms of
> hardware that you might drive with it and scaling can be done in
> software for the various different bits of kit.
>
> I am sure that with the appropriate development environment and having
> the hardware on hand IN a well equipped lab, it should be a weekend
> project to get running.
>
> The hard bit in my opinion is how to mount the antennas to the az/el
> clockwork. Will require a little woodwork/metalwork to finish.
>
> Everyone who does this will have a problem with some phase of it.
> Needs to be simple and repeatable.
>
> Norm n3ykf
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>
_______________________________________________
Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 10
Date: Sun, 24 Feb 2013 10:18:05 -0800
From: Greg Dolkas <ko6th.greg@xxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: Pendulum type elevation measurement
Message-ID: <e14490a1-d17c-4448-b65b-5942d008f3bb@xxxxx.xxxxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
I made an El rotor years ago, and used the weighted pendulum method for
feedback. Besides the weather pushing the weight around, the other problem
was hysteresus. Small changes in reverse position didn't cause any change
in indication. If you are looking for improved position accuracy (vs
what?), you should figure out a way to anchor the pendulum. That should
solve both problems.
Greg KO6TH
Joe <nss@xxx.xxx> wrote:
>I see no problems at all. I have done it with that method in the past.
>
>The only thing I noticed that was a problem was if the pendulum is
>exposed to the elements. As in weather not antenna elements. Gusty
>winds
>would move the pendulum and cause a not steady reading..
>
>but not that much of a problem did not happen all that often.
>
>Joe WB9SBD
>Sig
>The Original Rolling Ball Clock
>Idle Tyme
>Idle-Tyme.com
>http://www.idle-tyme.com
>On 2/24/2013 5:45 AM, Richard Ferryman wrote:
>> For some time I have wanted a more accurate antenna elevation
>measurement system. Shaft encoders are beyond my budget. It seems
>sensible to use a pendulum operated system. Digging through my 'junk'
>box I find I have a new Spectrol precision potentiometer still sealed
>in it's package. This pot is 21mm diameter, has a servo type mount,,
>ball race bearing, 340 degree track (continuous rotation possible) and
>specification is 0.5% linearity.and is very low torque. Does anyone
>know if there are any drawbacks to using this method of position
>measurement.
>> 73 de Dick G4BBH
>> _______________________________________________
>> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the
>author.
>> Not an AMSAT-NA member? Join now to support the amateur satellite
>program!
>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>>
>>
>
>_______________________________________________
>Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the
>author.
>Not an AMSAT-NA member? Join now to support the amateur satellite
>program!
>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
--
Sent from my Android phone with K-9 Mail. Please excuse my brevity.
------------------------------
_______________________________________________
Sent via amsat-bb@xxxxx.xxx. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
http://amsat.org/mailman/listinfo/amsat-bb
End of AMSAT-BB Digest, Vol 8, Issue 59
***************************************
Read previous mail | Read next mail
| |
