[sarex] Re: ariss, PCSAT2
Frank H. Bauer
ka3hdo at comcast.net
Mon Aug 17 16:53:09 PDT 2009
I am having a hard time understanding your intent. Is it to assassinate the
character of every ham radio operator that has flown hardware to ISS or in
Space? And in the process, boost your own ego? This is really bizarre..
While you are at it, why don't you start at the beginning..with OSCAR-1. Do
you think you could have done a better job? Oh, I forgot.if you built it,
you would have added solar cells.
And for the record, I consider Bob Bruninga, WB4APR, a genius. One of my
favorite "mad scientists." And Bob, I mean that very affectionately.
Thanks Bob, for all you have done for amateur radio and those interested in
Frank Bauer, KA3HDO
Date: Mon, 17 Aug 2009 08:36:08 -0700 (PDT)
From: MM <ka1rrw at yahoo.com>
Subject: [sarex] Re: ariss, PCSAT2
To: sarex at amsat.org, Bob Bruninga <bruninga at usna.edu>
Message-ID: <319281.84402.qm at web56404.mail.re3.yahoo.com>
Content-Type: text/plain; charset=utf-8
Bob Bruninga and I are similar that we both love Amateur Radio satellite
operations and we are both a bit if a loose cannon. Actually I prefer the
tile of ?Pirate? that was given to me by Roy Neal (SK).
However Bob is modest in his connections with the Military.
The PCSAT2 project was military funded project with an Amateur Radio project
as a Piggy-Pack project.
The PCSAT2 project did not take the normal route required for ARISS Amateur
radio projects. Bob was able to use his Military back door without prior
ARISS approvals. The ARISS team was basically required to accept the PCSAT2
project at face value. The backdoor bypassed what few ARISS check/balances
that were in place. The ARISS Hardware team was not fully aware of all of
the different modes of operation that PCSAT2 supported.
The PCSAT2 project went live from ISS on August 5, 2005. A few weeks later
we discovered that was a problem with PCSAT2 causing interference during a
Soyuz and Progress docking operations.
During an ARISS teleconference in November 2005, I specifically ask Mr.
Bruninga ?Did you inform the ARISS Hardware team of all of the operating
modes and frequencies used by PCSAT2??
Mr. Bruninga responded ?No I did not?.
Then Frank Bauer responded ?Thanks Miles?.
The PCSAT2 fallout:
This project may have long ramifications for installing Future amateur radio
transmitters on ISS. If we are required to reduce harmonic radiation by 80
db on future transmitters we will need to modify our transmitter with
additional external filters.
Amateur radio projects on ISS were often touted as low power systems that
could not interference with ISS systems. Now NASA knows that our project do
have the potential for causing potentially serious interference.
Another project that was accepted at face value from Bob Bruninga, was the
Kenwood TM-D700 transceiver project. The Kenwood TM-D700 radio is a Very
good radio and supports many great features. Unfortunately the users have
the ability to change the setup parameters on the TM-D700 in such a way,
that the radio can become unwieldy.
I do no have time to go into all of the problems with the Modified TM-D700
in the memo. So of the basic issues are:
Note these issues are only with the Modified TM-D700 and not with a common
factory version of the Terrestrial TM-D700.
Only 6 Channels are easily accessible. The rest of the channels require
knowledge of how configure separate Transmit and Receive channels on two
different radios at the same time.
Packet Mail Data throughput (at 1200 baud) has been reduced from
approximately 300 bits per second to less than 50 bits per second. For all
practical purposes the Packet Mail Box is unusable.
Note: If you turn off the TM-D700 internal modem and connect the radio to
an external modem (KPC-3 or KPC-9612) the Packet Mail data throughput
increased to approximately 500+ bits per second.
Digital Repeater modes such as Unproto and APRS are much slower than
terrestrial versions of the TM-D700.
The User interface is too complicated and some ISS crew members have been
blamed for screwing up the settings when they tried to dial up their
favorite channels. Others such as Bill MacArthur just forced the radio into
VFO mode to disable the excessive features.
Additional information can be found in the ARISS meeting minutes.
4. PCSAT2, Presenter: F. Bauer
Frank asked Bob Bruninga to give a status of PCSAT2 operations.
[There ] have been safety issues with PCSAT2 that have impacted the rest of
ARISS hardware currently on orbit, and these could have implications for
future amateur radio payloads.
Frank asked Bob to describe PCSAT2 safety concerns. JSC required 4 inhibits
on his 2W transmitter during EVA and operating the robotic arm. PCSAT2 was
designed with a load across the battery to prevent overcharging, which
limits how long the payload can be turned off. PCSAT2 used astronauts as a
backup command-off path, but coordination of that effort is difficult as
well as coordinating the ground commands.
Frank noted that PCSAT2 has spurs that are interfering with the Soyuz and
Progress docking and undocking TV operations. Bob noted that there is a ~450
MHz spur that is more than 60dB down (per commercial specs), but NASA wants
it to be 80 dB down. Frank noted that there was a time when there were
high-priority discussions with the crew regarding PCSAT2 ops, including
using ARISS internal hardware by the crew to command PCSAT2 off, but the
main ARISS team was not totally informed or brought in to help.
More information about the SAREX