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CX2SA > SATDIG 06.03.20 14:37l 860 Lines 29517 Bytes #999 (0) @ WW
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To : SATDIG@WW
Today's Topics:
1. Re: XW-2D Returns to Life! (Zach Metzinger)
2. Re: Wide or Narrow? (Greg D)
3. Re: Wide or Narrow? (Scott)
4. Re: XW-2D Returns to Life! (Hasan al-Basri)
5. Re: APRSdroid (Hasan al-Basri)
6. Re: APRSdroid (Fernando Ramirez)
7. Re: XW-2D Returns to Life! (Zach Metzinger)
8. Re: XW-2D Returns to Life! (Zach Metzinger)
9. Re: XW-2D Returns to Life! (Hasan al-Basri)
10. ANS-065 AMSAT News Service Special Bulletin - AMSAT Academy
to be Held Prior to Dayton Hamvention (Paul Stoetzer)
11. Sequencer advice needed (Hans BX2ABT)
----------------------------------------------------------------------
Message: 1
Date: Thu, 5 Mar 2020 10:38:52 -0600
From: Zach Metzinger <zmetzing@?????.???>
To: amsat-bb@?????.???
Subject: Re: [amsat-bb] XW-2D Returns to Life!
Message-ID: <35fa5982-a20c-e50a-de14-d6feee1aa6a6@?????.???>
Content-Type: text/plain; charset=utf-8; format=flowed
On 2020-03-05 04:06, Hasan al-Basri via AMSAT-BB wrote:
> 1. Connect a 50 ohm resistor to the antenna or preamp input.
> 2. Set the rx for maximum sensitivity (RF Gain)
> 3. Adjust IF Gain so that the 50 Ohm resistor produces a signal level of
> -95 dBM
> 4. This creates a common noise floor level calibration point so that we can
> compare local noise (environmental) as well as satellite signal levels.
Hello Hasan,
Ah, noticed one more thing. This is only true if the measured thermal
noise power bandwidth is the same on both setups.
Thermal noise power is k*T*B, where k is Boltzmann's constant (1.38E-23
J/K), K is "temperature" of your source in Kelvins (290 is about room
temp), and B is the bandwidth of the noise in Hertz (1/seconds).
We assume that there is no current flowing through the resistor for this
example.
(1.38E-23 J/K)(290 K)(1 Hz) = 4.002E-21 Watts
[Kelvins cancel out, leaving Joules/seconds, which is Watts -- math is
cool!]
However, this is an annoying figure to remember, so we convert it to dBm:
(4.002E-21 W)(1000 mW/W) = 4.002E-18 mW
10 * log10(4.002E-18 mW / 1 mW) ~= -174 dBm
(~= is "approximately equal", rounded)
Now that's an easy number to remember, and all radio amateurs should!
Notice that we initially computed this noise floor with Bandwidth of 1
Hz. Not even the slowest CW would fit in that, so let's make it
something more reasonable like 3kHz for voice.
Instead of doing all that math again, we can use logarithms to fix this
up. Multiplication becomes addition when we're in a log scale (mmm,
slide rules..), so:
-174 dBm + log(3000 Hz / 1 Hz) ~= -170 dBm
This is the thermal noise floor in a 3 kHz bandwidth from a noise source
at 290 Kelvin (62 deg F).
Anyway, all of that was to show that bandwidth is very important when
comparing noise power of two receivers.
If anyone is interested in learning more about noise floor, noise
figure, or required SNR, here's a great article:
https://tinyurl.com/t7o4n34
--- Zach
N0ZGO
------------------------------
Message: 2
Date: Thu, 5 Mar 2020 10:29:43 -0800
From: Greg D <ko6th.greg@?????.???>
To: Scott <scott23192@?????.???>
Cc: Amsat BB <AMSAT-BB@?????.???>
Subject: Re: [amsat-bb] Wide or Narrow?
Message-ID: <231db53b-0a87-57bf-6573-82e82f850e1d@?????.???>
Content-Type: text/plain; charset=UTF-8
Hi Scott,
Quick question... AISAT-1 is which catalog number? I recall some
discussion a while back, and I've got #44104 configured in Gpredict.
But I also see AISAT (40054), AISSAT 1 (36797), AISSAT 2 (40075), and a
few others with similar names.
Which is AISAT-1 (one "S", with the dash)?
Thanks,
Greg KO6TH
Scott via AMSAT-BB wrote:
> Hey Steve!
>
> I've found that AISAT-1 works better with FM-Narrow. It's my understanding
> that the other APRS sats have always worked fine with regular FM... that's
> what I use for all but AISAT-1.
>
> Unfortunately, for quite a while now the only active 2m APRS satellite has
> been AISAT-1. However, it has not been heard since 3-Mar. Certainly hope
> that's temporary!
>
> Of course we all look forward to the day that the ISS digipeater is back
> online, too.
>
> -Scott, K4KDR
>
> ========================
>
> On Thu, Mar 5, 2020 at 10:34 AM Steve Kristoff via AMSAT-BB <
> amsat-bb@?????.???> wrote:
>
>> When aiming at the APRS satellites (ISS, AISat, any others?) should I use
>> Wide or Narrow FM? I vaguely recall reading that narrow is good, but I
>> can't find the reference.
>> Your assistance is appreciated!
>> Steve AI9IN
>>
> _______________________________________________
> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
expressed
> are solely those of the author, and do not reflect the official views of
AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 3
Date: Thu, 5 Mar 2020 13:45:22 -0500
From: Scott <scott23192@?????.???>
To: Amsat BB <AMSAT-BB@?????.???>
Subject: Re: [amsat-bb] Wide or Narrow?
Message-ID:
<CAJCSnOYqjX7wZxr+DSw2-EQL19K3AMKnOh-pikJv24HH9iX=NA@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
Yes, I show that as 44104.
Keep in mind that it's attached to a platform with several other objects,
so depending on your TLE source, it might show up as "PSLV R/B" or
something similar.
-Scott, K4KDR
===============
On Thu, Mar 5, 2020 at 1:29 PM Greg D <ko6th.greg@?????.???> wrote:
> Hi Scott,
>
> Quick question... AISAT-1 is which catalog number? I recall some
> discussion a while back, and I've got #44104 configured in Gpredict.
> But I also see AISAT (40054), AISSAT 1 (36797), AISSAT 2 (40075), and a
> few others with similar names.
>
> Which is AISAT-1 (one "S", with the dash)?
>
> Thanks,
>
> Greg KO6TH
>
>
> Scott via AMSAT-BB wrote:
> > Hey Steve!
> >
> > I've found that AISAT-1 works better with FM-Narrow. It's my
> understanding
> > that the other APRS sats have always worked fine with regular FM...
> that's
> > what I use for all but AISAT-1.
> >
> > Unfortunately, for quite a while now the only active 2m APRS satellite
> has
> > been AISAT-1. However, it has not been heard since 3-Mar. Certainly
> hope
> > that's temporary!
> >
> > Of course we all look forward to the day that the ISS digipeater is back
> > online, too.
> >
> > -Scott, K4KDR
> >
> > ========================
> >
> > On Thu, Mar 5, 2020 at 10:34 AM Steve Kristoff via AMSAT-BB <
> > amsat-bb@?????.???> wrote:
> >
> >> When aiming at the APRS satellites (ISS, AISat, any others?) should I
> use
> >> Wide or Narrow FM? I vaguely recall reading that narrow is good, but I
> >> can't find the reference.
> >> Your assistance is appreciated!
> >> Steve AI9IN
> >>
>
------------------------------
Message: 4
Date: Thu, 5 Mar 2020 13:00:37 -0600
From: Hasan al-Basri <hbasri.schiers6@?????.???>
To: Zach Metzinger <zmetzing@?????.???>
Cc: AMSAT-BB <amsat-bb@?????.???>
Subject: Re: [amsat-bb] XW-2D Returns to Life!
Message-ID:
<CAM4UQf38teUqrqnsgXTWqZoTPsDjDS0Q_vrXVxAimmBxrK+TMA@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
Hi Zach,
Since we were speaking of SSB SNR, the bandwidth would be similar. In our
cases we use 2.2 kHz. I forgot to even mention it.
The ...and the point of the whole process was to keep it simple. The more
precise, the more complex and the less likely anyone is going to bother.
The perfect is the enemy of the good.
Suffice it to say, with hours and hours of measurements using the approach
indicated, it is clear that if the antenna gain is increased by x dB or the
uplink power is changed by x dB, the reference calibration between two
setups holds nicely. There are a ton of other factors at any given moment
that one can get lost in, but wash out with repeated measurement.
Using the approach I described, can a minimally equipped (test) station
determine whether they have adequate sensitivity for their sat ops, or if
they have improved their setup? Of course they can and they won't be stuck
doing math they don't understand and has little bearing on the real world
performance of their satellite station.
Many, many years ago Amsat Journal published an article on Link Budget
Analysis that did all the math and painstaking analytics you describe. How
many people made use of it....next to none. I know, because I wrote it.
What I was aiming at was a simple, quick and dirty "rough estimate" of :
1. Is my system sufficiently sensitive
2. Am I running too much power.
Boltzman is not needed for that. We aren't doing EME. Sat ops are a
relatively strong signal mode. It says a lot that many receive setups are
performing so poorly that "rough and dirty" (and simple) approaches like I
outlined can make a big difference in overall efficiency. I just hope that
it helps people hear better.
(and subsequently reduce their uplink power)
73, N0AN
Hasan
On Thu, Mar 5, 2020 at 11:16 AM Zach Metzinger via AMSAT-BB <
amsat-bb@?????.???> wrote:
> On 2020-03-05 04:06, Hasan al-Basri via AMSAT-BB wrote:
> > 1. Connect a 50 ohm resistor to the antenna or preamp input.
> > 2. Set the rx for maximum sensitivity (RF Gain)
> > 3. Adjust IF Gain so that the 50 Ohm resistor produces a signal level of
> > -95 dBM
> > 4. This creates a common noise floor level calibration point so that we
> can
> > compare local noise (environmental) as well as satellite signal levels.
>
> Hello Hasan,
>
> Ah, noticed one more thing. This is only true if the measured thermal
> noise power bandwidth is the same on both setups.
>
> Thermal noise power is k*T*B, where k is Boltzmann's constant (1.38E-23
> J/K), K is "temperature" of your source in Kelvins (290 is about room
> temp), and B is the bandwidth of the noise in Hertz (1/seconds).
>
> We assume that there is no current flowing through the resistor for this
> example.
>
> (1.38E-23 J/K)(290 K)(1 Hz) = 4.002E-21 Watts
>
> [Kelvins cancel out, leaving Joules/seconds, which is Watts -- math is
> cool!]
>
> However, this is an annoying figure to remember, so we convert it to dBm:
>
> (4.002E-21 W)(1000 mW/W) = 4.002E-18 mW
>
> 10 * log10(4.002E-18 mW / 1 mW) ~= -174 dBm
>
> (~= is "approximately equal", rounded)
>
> Now that's an easy number to remember, and all radio amateurs should!
>
> Notice that we initially computed this noise floor with Bandwidth of 1
> Hz. Not even the slowest CW would fit in that, so let's make it
> something more reasonable like 3kHz for voice.
>
> Instead of doing all that math again, we can use logarithms to fix this
> up. Multiplication becomes addition when we're in a log scale (mmm,
> slide rules..), so:
>
> -174 dBm + log(3000 Hz / 1 Hz) ~= -170 dBm
>
> This is the thermal noise floor in a 3 kHz bandwidth from a noise source
> at 290 Kelvin (62 deg F).
>
> Anyway, all of that was to show that bandwidth is very important when
> comparing noise power of two receivers.
>
> If anyone is interested in learning more about noise floor, noise
> figure, or required SNR, here's a great article:
>
> https://tinyurl.com/t7o4n34
>
> --- Zach
> N0ZGO
> _______________________________________________
> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
>
------------------------------
Message: 5
Date: Thu, 5 Mar 2020 13:11:51 -0600
From: Hasan al-Basri <hbasri.schiers6@?????.???>
To: Steve Kristoff <skristof@???????.???>
Cc: AMSAT-BB <amsat-bb@?????.???>
Subject: Re: [amsat-bb] APRSdroid
Message-ID:
<CAM4UQf2-Tw3Kvsdeyk0M54NPwNJnDqafiPxTA4dMsEJ7QhmGnQ@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
Steve,
I have used it just with its internet side on my Samsung S7 and it has
worked flawlessly for years. I use it when I don't have a radio with me.
The internet function makes it act as if a radio is connected, but none is
needed if all you want to do it see where you are, have been and the
network topography itself.
73, N0AN
Hasan
On Thu, Mar 5, 2020 at 10:30 AM Steve Kristoff via AMSAT-BB <
amsat-bb@?????.???> wrote:
>
> Those of you who said that APRSdroid works were right. I'm not the
> sharpest knife in the drawer, but I got it working without much fuss. I
> just confirmed on AISAT-1 that it works on my phone hooked up to my HT. So,
> I agree, don't believe all the bad reviews you see on the app Play Store.
> Steve AI9IN
>
>
> _______________________________________________
> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
>
------------------------------
Message: 6
Date: Thu, 5 Mar 2020 12:21:16 -0700
From: Fernando Ramirez <framirezferrer@?????.???>
To: Hasan al-Basri <hbasri.schiers6@?????.???>
Cc: AMSAT-BB <amsat-bb@?????.???>
Subject: Re: [amsat-bb] APRSdroid
Message-ID:
<CAGHXx8iS+FoJ79UJCMyEB9Q8mWOeCDc=R=kZrT7NKDq8pB8kFQ@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
I use it to work APRS enabled sats along with a Mobilinkd TNC3. Currently
testing the new 9600 bps capabilities of the TNC with Falconsat. It's a
work in progress but have already decoded packets from the satellite.
To make exchanges easier I recommend a keyboard app like CanalRun Macro
Keys (Android). You can store messages and send them with just a couple of
keystrokes, instead of typing everything.
Have fun!
Fernando, KF7R
On Thu, Mar 5, 2020, 12:14 PM Hasan al-Basri via AMSAT-BB <
amsat-bb@?????.???> wrote:
> Steve,
> I have used it just with its internet side on my Samsung S7 and it has
> worked flawlessly for years. I use it when I don't have a radio with me.
> The internet function makes it act as if a radio is connected, but none is
> needed if all you want to do it see where you are, have been and the
> network topography itself.
> 73, N0AN
> Hasan
>
>
> On Thu, Mar 5, 2020 at 10:30 AM Steve Kristoff via AMSAT-BB <
> amsat-bb@?????.???> wrote:
>
> >
> > Those of you who said that APRSdroid works were right. I'm not the
> > sharpest knife in the drawer, but I got it working without much fuss. I
> > just confirmed on AISAT-1 that it works on my phone hooked up to my HT.
> So,
> > I agree, don't believe all the bad reviews you see on the app Play Store.
> > Steve AI9IN
> >
> >
> > _______________________________________________
> > Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> > to all interested persons worldwide without requiring membership.
> Opinions
> > expressed
> > are solely those of the author, and do not reflect the official views of
> > AMSAT-NA.
> > Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> > Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
> >
> _______________________________________________
> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
>
------------------------------
Message: 7
Date: Thu, 5 Mar 2020 13:22:47 -0600
From: Zach Metzinger <zmetzing@?????.???>
To: amsat-bb@?????.???
Subject: Re: [amsat-bb] XW-2D Returns to Life!
Message-ID: <4150b3a8-6068-6c23-f173-e0355b237da5@?????.???>
Content-Type: text/plain; charset=utf-8; format=flowed
On 2020-03-05 10:38, Zach Metzinger via AMSAT-BB wrote:
> -174 dBm + log(3000 Hz / 1 Hz) ~= -170 dBm
>
> This is the thermal noise floor in a 3 kHz bandwidth from a noise source
> at 290 Kelvin (62 deg F).
Thanks go to WB4APR for spotting my math error; I added Bels to
deciBels. At the time, I thought "that seems a bit low", but never went
back to check my work. :-)
The correct answer is:
-174 dBm + 10*log(3000 Hz / 1 Hz) ~= -139 dBm
--- Zach
N0ZGO
------------------------------
Message: 8
Date: Thu, 5 Mar 2020 13:30:33 -0600
From: Zach Metzinger <zmetzing@?????.???>
To: AMSAT-BB <amsat-bb@?????.???>
Subject: Re: [amsat-bb] XW-2D Returns to Life!
Message-ID: <88e81c7b-ad3b-a782-103f-d3cd67e6de3e@?????.???>
Content-Type: text/plain; charset=utf-8; format=flowed
On 2020-03-05 13:00, Hasan al-Basri wrote:
> Since we were speaking of SSB SNR, the bandwidth would be similar. In
> our cases we use 2.2 kHz. I forgot to even mention it.
>
> The ...and the point of the whole process was to keep it simple. The
> more precise, the more complex and the less likely anyone is going to
> bother.
Hello Hasan,
I definitely applaud your efforts to measure relative system
performance, but I did want to make it clear to others on the list that
there was another factor which needed to be taken into account when
doing an apples-to-apples. This additional factor isn't too hard, when
you understand why it matters.
> Boltzman is not needed for that. We aren't doing EME. Sat ops are a
> relatively strong signal mode. It says a lot that many receive setups
> are performing so poorly that "rough and dirty"? (and simple) approaches
> like I outlined can make a big difference in overall efficiency. I just
> hope that it helps people hear better.
> (and subsequently reduce their uplink power)
I also completely agree with you on the need for fewer alligators on the
satellites. With GOLF, where we're building bigger vehicles with larger
orbits and footprints, excessive uplink power becomes an even bigger
issue for more simultaneous users.
That said, GOLF satellites will also incur more path loss, so getting
LEO operators more familiar with the "down in the noise" issues will
make for better MEO/HEO operators, too.
Keep up the good work! I enjoyed your video.
73,
--- Zach
N0ZGO
------------------------------
Message: 9
Date: Thu, 5 Mar 2020 13:54:53 -0600
From: Hasan al-Basri <hbasri.schiers6@?????.???>
To: Zach Metzinger <zmetzing@?????.???>
Cc: AMSAT-BB <amsat-bb@?????.???>
Subject: Re: [amsat-bb] XW-2D Returns to Life!
Message-ID:
<CAM4UQf1Rd86F49q9VUFcSa3vERAx+GQCGtpwZzq47cRPr+SK7w@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
My pleasure, Zach.
KB7IJ and I have logged probably 1000 hours of measurements to arrive at
the "rough and dirty" approach listed and despite all the confounding
variables like:
1. Rotating Polarization
2. Faraday
3. Satellite Body Shading
4. Broken sats (Like XW-2F with it's 20 dB tumble)
etc., etc.
it became apparent that if we were running the same software, same
bandwidth (as you noted), and calibrated to a simple dummy load, we could
isolate variables quite quickly and see if what we "did" made a predictable
difference. Having the ability to record both video and audio and play back
with announcements of the "real time' change, is quite an advantage.
Operating sats without an SDR or a 9700 is operating blindfolded. Once a
person can "see" the entire passband in full duplex in real time, a new
world of what is going on opens up. Of special importance is the ability to
see the beacon 100% of the time and adjust uplink power accordingly.
It is quite interesting to see the CAS series (4A/4B) with not only their
CW beacon, but also the Batwing PSK beacon. Seeing that beacon fade 20 dB
on one polarization and then return to full strength immediately upon
changing to another polarization is quite awakening. There are also
profound pre and post TCA (Zenith) signal strength patterns that can be
strikingly correlated to the "nature of the pass". Very Shallow, Shallow,
Medium, Overhead etc.
There are so many variables involved, even the 3 dB worst case loss from
linear to circular does not hold ...in fact it is very rare that my 2m
EggBeater is within 3 dB of my 5 EL vertically polarized yagi. Close in
vegetation loss, ordinary obstruction loss (EB is only up 7', Yagi up 65')
Of course at very high elevations the EB shines...but only for a very few
minutes.
Bob Bruninga hit on a great find with his Fixed Elevation of 15 degrees for
LEO birds. You can look at my pix on my qrz page and see what his approach
looks like. The performance has been phenomenal and no elevation rotor is
required. I routinely work every one of the Mode B LEO birds down to an
elevation of -0.7 degrees with that setup, and only at EL > 60 deg do I see
the EB outperforming Bob's simple suggestion.
Sats are fun for the curious. Anyone who loves satellites, get an SDR
...you will never go back.
73, N0AN
Hasan
On Thu, Mar 5, 2020 at 1:33 PM Zach Metzinger via AMSAT-BB <
amsat-bb@?????.???> wrote:
> On 2020-03-05 13:00, Hasan al-Basri wrote:
> > Since we were speaking of SSB SNR, the bandwidth would be similar. In
> > our cases we use 2.2 kHz. I forgot to even mention it.
> >
> > The ...and the point of the whole process was to keep it simple. The
> > more precise, the more complex and the less likely anyone is going to
> > bother.
>
> Hello Hasan,
>
> I definitely applaud your efforts to measure relative system
> performance, but I did want to make it clear to others on the list that
> there was another factor which needed to be taken into account when
> doing an apples-to-apples. This additional factor isn't too hard, when
> you understand why it matters.
>
> > Boltzman is not needed for that. We aren't doing EME. Sat ops are a
> > relatively strong signal mode. It says a lot that many receive setups
> > are performing so poorly that "rough and dirty" (and simple) approaches
> > like I outlined can make a big difference in overall efficiency. I just
> > hope that it helps people hear better.
> > (and subsequently reduce their uplink power)
>
> I also completely agree with you on the need for fewer alligators on the
> satellites. With GOLF, where we're building bigger vehicles with larger
> orbits and footprints, excessive uplink power becomes an even bigger
> issue for more simultaneous users.
>
> That said, GOLF satellites will also incur more path loss, so getting
> LEO operators more familiar with the "down in the noise" issues will
> make for better MEO/HEO operators, too.
>
> Keep up the good work! I enjoyed your video.
>
> 73,
>
> --- Zach
> N0ZGO
> _______________________________________________
> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
>
------------------------------
Message: 10
Date: Thu, 5 Mar 2020 15:25:44 -0500
From: Paul Stoetzer <n8hm@????.???>
To: ans@?????.???? AMSAT BB <amsat-bb@?????.???>
Subject: [amsat-bb] ANS-065 AMSAT News Service Special Bulletin -
AMSAT Academy to be Held Prior to Dayton Hamvention
Message-ID:
<CABzOSOqUYLL27xG=-PqqT8FQ=XyDXZrJuDvodYWxgd5mivhiCg@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
AMSAT NEWS SERVICE SPECIAL BULLETIN
ANS-065
The AMSAT News Service bulletins are a free, weekly news and infor-
mation service of AMSAT North America, The Radio Amateur Satellite
Corporation. ANS publishes news related to Amateur Radio in Space
including reports on the activities of a worldwide group of Amateur
Radio operators who share an active interest in designing, building,
launching and communicating through analog and digital Amateur Radio
satellites.
The news feed on http://www.amsat.org publishes news of Amateur
Radio in Space as soon as our volunteers can post it.
Please send any amateur satellite news or reports to:
ans-editor at amsat.org.
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* AMSAT Academy to be Held Prior to Dayton Hamvention
SB SAT @ AMSAT $ANS-065
ANS-065 AMSAT News Service Special Bulletin
AMSAT News Service Bulletin 065.01
From AMSAT HQ KENSINGTON, MD.
DATE March 5, 2020
To All RADIO AMATEURS
BID: $ANS-065.01
Come join us the day before Hamvention, for AMSAT? Academy ? a unique
opportunity to learn all about amateur radio in space and working FM,
linear transponder, and digital satellites currently in orbit.
AMSAT? Academy will be held Thursday, May 14, 2020, from 9:00am to
5:00pm, at the Dayton Amateur Radio Association (DARA) Clubhouse, loc-
ated at 6619 Bellefontaine Rd, Dayton, Ohio.
The $85 registration fee includes:
? Full day of instruction, designed for both beginners and advanced
amateur radio satellite operators, and taught by some of the most
accomplished AMSAT operators.
? Digital copy of Getting Started with Amateur Satellites, 2020 Edi-
tion ($15 value)
? One-Year, AMSAT? Basic Membership ($44 value)
? Pizza Buffet Lunch
? Invitation to the Thursday night AMSAT? get together at Ticket Pub
and Eatery in Fairborn.
Registration closes May 8, 2020. No sign ups at the door. No refunds,
no cancellations.
Registrations may be purchased on the AMSAT store at
https://www.amsat.org/product/2020-amsat-academy-registration/
[ANS thanks Robert Bankston, KE4AL, Vice President - User Services for
the above information]
In addition to regular membership, AMSAT offers membership in the
President's Club. Members of the President's Club, as sustaining
donors to AMSAT Project Funds, will be eligible to receive addi-
tional benefits. Application forms are available from the AMSAT
Office.
73 and Remember to help Keep Amateur Radio in Space,
This week's ANS Contributing Editor,
Paul Stoetzer, N8HM
n8hm at amsat dot org
------------------------------
Message: 11
Date: Fri, 6 Mar 2020 20:23:25 +0800
From: Hans BX2ABT <hans.bx2abt@???.?????.???>
To: AMSAT <amsat-bb@?????.???>
Subject: [amsat-bb] Sequencer advice needed
Message-ID: <fad916ee-41ac-b1c9-165c-cad02101ebc3@???.?????.???>
Content-Type: text/plain; charset=utf-8; format=flowed
I haven't worked with sequencers before as all my LNAs and SDRs have
been used for receive only. But now that I have a Airspy HF+ I want to
get going with APRS on 145.825 and use this on HF as well. So receiving
with the SDR, transmitting with a transceiver. I also want to experiment
with LNAs, so another reason to use a sequencer. I did a lot of
googling, learned some, but still not sure what I need to look out for
when buying one. I prefer a kit or assembled product as a first try.
Below is a list of what I found on line. From a distance the VHF Design
is cheap and has detailed information, so I am leaning towards
purchasing that. Later, for a DIY project, I like the OZ1BXM design
because it uses an Arduino for control, which brings some flexiblity.
Can you all please give me some input on what to look for in sequencers
or comment on the choices below? Any other kits/assemblies I have missed
and should be considered? Cheers,
Hans
BX2ABT
Minikits from Austalia's EME166: AU$45 (=US$27.75)
https://www.minikits.com.au/Sequencer?search=Sequencer
This is the only one that indicates a frequency range: 28 to 500 MHz, so
this will cover the 2m band, but not HF. Also RF input is 4 Watts
maximum, which seems low, so how is this usable?
W6PQL's sequencer (US$20 for kit, US$37.50 assembled)
http://www.w6pql.com/relay_sequencer.htm
No info on frequency range or input power. Not much info on the website.
VHF Design (US$20 assembled)
https://vhfdesign.com/other/sequencer-pcb.html
Website has good information, diagrams and PCB layouts. Again no info on
frequency range, etc.
Downeast Microwave (US$25~80)
https://www.downeastmicrowave.com/searchresults.asp?Search=sequencer&Submit=
3 and 4 step sequencers both in solid state and with relays based on a
design by W5LUA. Which better: solid state or relays? Little indept info.
G3SEK - (DIY)
http://www.ifwtech.co.uk/g3sek/dx-book/sequencer/
Basically only a schematic, so need to build it from the ground up.
OZ1BXM (DIY)
http://oz1bxm.dk/seq/sequencer.html
Another DIY project based on the W6PLQ design. This uses an Arduino as
MCU, so should be flexible. No kits and no PCB designs.
SM2CEW (DIY)
http://sm2cew.com/sequencer/sequencer.html
This one looks very simple to make with very few components. It was
designed for HF, so will it work on VHF?
------------------------------
Subject: Digest Footer
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Not an AMSAT member? Join now to support the amateur satellite program!
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------------------------------
End of AMSAT-BB Digest, Vol 15, Issue 69
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