28 Sep
2017
28 Sep
'17
8:25 p.m.
Someone asked me how to tune the antennas on a cubesat without the
instrumentation totally becoming part of the antenna system itself?
I said you have to put the SWR instrument inside the cubesat as we did
here: http://aprs.org/PSAT2/SWR-testing-0160x.jpg
But that only works on a 1.5U cubesat where and MFJ Antenna Analyzer will
fit!
The other method is to just put in a bidirectional coupler chip, and then
feed the forward and reflected voltage taps to the internal cubesat
telemetry system and then compute the SWR from these two Forward and
Reflected power telemetry channels.
Bob, WB4APR
28 Sep
28 Sep
9:02 p.m.
New subject: [amsat-bb] TUning the antennas on a Cubesat
Can't you just tune for maximum signal level received, and bypass measuring SWR?
________________________________________
From: AMSAT-BB <amsat-bb-bounces(a)amsat.org> on behalf of Robert Bruninga
<bruninga(a)usna.edu>
Sent: Thursday, September 28, 2017 1:25 PM
To: amsat-bb(a)amsat.org
Cc: Jin Kang
Subject: [amsat-bb] TUning the antennas on a Cubesat
Someone asked me how to tune the antennas on a cubesat without the
instrumentation totally becoming part of the antenna system itself?
I said you have to put the SWR instrument inside the cubesat as we did
here: http://aprs.org/PSAT2/SWR-testing-0160x.jpg
But that only works on a 1.5U cubesat where and MFJ Antenna Analyzer will
fit!
The other method is to just put in a bidirectional coupler chip, and then
feed the forward and reflected voltage taps to the internal cubesat
telemetry system and then compute the SWR from these two Forward and
Reflected power telemetry channels.
Bob, WB4APR
_______________________________________________
Sent via AMSAT-BB(a)amsat.org. 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: http://www.amsat.org/mailman/listinfo/amsat-bb
2 Oct
2 Oct
8:27 p.m.
New subject: [amsat-bb] TUning the antennas on a Cubesat
Yes
On Thu, Sep 28, 2017 at 5:02 PM, Franklin Antonio <antonio(a)qti.qualcomm.com>
wrote:
Can't you just tune for maximum signal level
received, and bypass
measuring SWR?
________________________________________
From: AMSAT-BB <amsat-bb-bounces(a)amsat.org> on behalf of Robert Bruninga <
bruninga(a)usna.edu>
Sent: Thursday, September 28, 2017 1:25 PM
To: amsat-bb(a)amsat.org
Cc: Jin Kang
Subject: [amsat-bb] TUning the antennas on a Cubesat
Someone asked me how to tune the antennas on a cubesat without the
instrumentation totally becoming part of the antenna system itself?
I said you have to put the SWR instrument inside the cubesat as we did
here: http://aprs.org/PSAT2/SWR-testing-0160x.jpg
But that only works on a 1.5U cubesat where and MFJ Antenna Analyzer will
fit!
The other method is to just put in a bidirectional coupler chip, and then
feed the forward and reflected voltage taps to the internal cubesat
telemetry system and then compute the SWR from these two Forward and
Reflected power telemetry channels.
Bob, WB4APR
_______________________________________________
Sent via AMSAT-BB(a)amsat.org. 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: http://www.amsat.org/mailman/listinfo/amsat-bb
_______________________________________________
Sent via AMSAT-BB(a)amsat.org. 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: http://www.amsat.org/mailman/listinfo/amsat-bb
--
Bob McGwier
Founder, Federated Wireless, Inc
Founder and Technical Advisor, HawkEye 360, Inc
Research Professor Virginia Tech
Chief Scientist: The Ted and Karyn Hume Center for National Security and
Technology
Senior Member IEEE, Facebook: N4HYBob, ARS: N4HY
Faculty Advisor Virginia Tech Amateur Radio Assn. (K4KDJ)
Director of AMSAT
Member of PVRC (Roanoke-Blacksburg), TAPR, life member of ARRL and AMSAT,
NRVR.ORG (Rocketry)
8:34 p.m.
New subject: [amsat-bb] TUning the antennas on a Cubesat
Bob, doesn’t this assume a perfectly resistive load presented by the antenna? If the
antenna presents a reactive load, it will be non-linear, so a peak on the fundamental may
well result in spurious emissions. No?
73, art…..
W4ART Arlington VA
On 2-Oct-2017, at 04:27 PM, Robert McGwier
<rwmcgwier(a)gmail.com> wrote:
Yes
On Thu, Sep 28, 2017 at 5:02 PM, Franklin Antonio <antonio(a)qti.qualcomm.com>
wrote:
To thrive in life, you need three bones: a wish bone, a back bone, and a funny bone.
- Reba McEntire
http://afeller.us <http://afeller.us/>
Can't you just tune for maximum signal level
received, and bypass
measuring SWR?
________________________________________
From: AMSAT-BB <amsat-bb-bounces(a)amsat.org> on behalf of Robert Bruninga <
bruninga(a)usna.edu>
Sent: Thursday, September 28, 2017 1:25 PM
To: amsat-bb(a)amsat.org
Cc: Jin Kang
Subject: [amsat-bb] TUning the antennas on a Cubesat
Someone asked me how to tune the antennas on a cubesat without the
instrumentation totally becoming part of the antenna system itself?
I said you have to put the SWR instrument inside the cubesat as we did
here: http://aprs.org/PSAT2/SWR-testing-0160x.jpg
But that only works on a 1.5U cubesat where and MFJ Antenna Analyzer will
fit!
The other method is to just put in a bidirectional coupler chip, and then
feed the forward and reflected voltage taps to the internal cubesat
telemetry system and then compute the SWR from these two Forward and
Reflected power telemetry channels.
Bob, WB4APR
_______________________________________________
Sent via AMSAT-BB(a)amsat.org. 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: http://www.amsat.org/mailman/listinfo/amsat-bb
_______________________________________________
Sent via AMSAT-BB(a)amsat.org. 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: http://www.amsat.org/mailman/listinfo/amsat-bb
--
Bob McGwier
Founder, Federated Wireless, Inc
Founder and Technical Advisor, HawkEye 360, Inc
Research Professor Virginia Tech
Chief Scientist: The Ted and Karyn Hume Center for National Security and
Technology
Senior Member IEEE, Facebook: N4HYBob, ARS: N4HY
Faculty Advisor Virginia Tech Amateur Radio Assn. (K4KDJ)
Director of AMSAT
Member of PVRC (Roanoke-Blacksburg), TAPR, life member of ARRL and AMSAT,
NRVR.ORG (Rocketry)
_______________________________________________
Sent via AMSAT-BB(a)amsat.org. 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: http://www.amsat.org/mailman/listinfo/amsat-bb
9:35 p.m.
New subject: [amsat-bb] TUning the antennas on a Cubesat
This might be possible, but then EMI testing should reveal any increase in
spurs in radiated emissions...
bob
-----Original Message-----
Bob, doesn’t this assume a perfectly resistive load presented by the
antenna? If the antenna presents a reactive load, it will be non-linear, so
a peak on the fundamental may well result in spurious emissions. No?
73, art…..
W4ART Arlington VA
On 2-Oct-2017, at 04:27 PM, Robert McGwier
<rwmcgwier(a)gmail.com> wrote:
Yes
On Thu, Sep 28, 2017 at 5:02 PM, Franklin Antonio
<antonio(a)qti.qualcomm.com>
wrote:
To thrive in life, you need three bones: a wish bone, a back bone, and a
funny bone.
- Reba McEntire
http://afeller.us <http://afeller.us/>
_______________________________________________
Sent via AMSAT-BB(a)amsat.org. 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: http://www.amsat.org/mailman/listinfo/amsat-bb
Can't you just tune for maximum signal level
received, and bypass
measuring SWR?
________________________________________
From: AMSAT-BB <amsat-bb-bounces(a)amsat.org> on behalf of Robert
Bruninga < bruninga(a)usna.edu>
Sent: Thursday, September 28, 2017 1:25 PM
To: amsat-bb(a)amsat.org
Cc: Jin Kang
Subject: [amsat-bb] TUning the antennas on a Cubesat
Someone asked me how to tune the antennas on a cubesat without the
instrumentation totally becoming part of the antenna system itself?
I said you have to put the SWR instrument inside the cubesat as we did
here: http://aprs.org/PSAT2/SWR-testing-0160x.jpg
But that only works on a 1.5U cubesat where and MFJ Antenna Analyzer
will fit!
The other method is to just put in a bidirectional coupler chip, and
then feed the forward and reflected voltage taps to the internal
cubesat telemetry system and then compute the SWR from these two
Forward and Reflected power telemetry channels.
Bob, WB4APR
_______________________________________________
Sent via AMSAT-BB(a)amsat.org. 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: http://www.amsat.org/mailman/listinfo/amsat-bb
_______________________________________________
Sent via AMSAT-BB(a)amsat.org. 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: http://www.amsat.org/mailman/listinfo/amsat-bb
--
Bob McGwier
Founder, Federated Wireless, Inc
Founder and Technical Advisor, HawkEye 360, Inc Research Professor
Virginia Tech Chief Scientist: The Ted and Karyn Hume Center for
National Security and Technology Senior Member IEEE, Facebook:
N4HYBob, ARS: N4HY Faculty Advisor Virginia Tech Amateur Radio Assn.
(K4KDJ) Director of AMSAT Member of PVRC (Roanoke-Blacksburg), TAPR,
life member of ARRL and AMSAT, NRVR.ORG (Rocketry)
_______________________________________________
Sent via AMSAT-BB(a)amsat.org. 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: http://www.amsat.org/mailman/listinfo/amsat-bb
1697
days inactive
1701
days old
4 comments
4 participants
participants (4)
-
Arthur Feller, W4ART -
Franklin Antonio -
Robert Bruninga -
Robert McGwier