AO-27 アップデート
JAMSAT 日本アマチュア衛星通信協会

9月9日に北米を昼に通過する時からAO-27衛星のFMリピータ機能は復旧します。 145.850MHzでアップリンクを試みる前に、ダウンリンクがアナログモードになっている(デジタル変調音ではない)ことを確かめてください。

TEPR 4:   36 (地球の陰を出てから18分間は充電期間、その後送信開始)
TEPR 5:   72 (地球の陰を出てから36分後に送信を停止して再び充電期間に入る)
From: "Chuck Wyrick" <>
To: <amsat-bb@AMSAT.Org>
Subject: [amsat-bb:34614] AO-27 Returns
Date: Fri, 8 Sep 2000 13:41:02 -0400

For Immediate Release:

AO-27 will be returned to analog Amateur use on the first North American
daylight pass on Saturday September 9, 2000. Please wait until you hear the
satellite in analog mode (no data being sent) before you transmit on

Uplink:   145.850
Downlink: 436.797

TEPR 4:   36
TEPR 5:   72

Periodically, over the next several months, the analog repeater will be
turned off for a few days at a time, to enable us to gather Whole Orbital
Data, to verify the health of the satellite.

A lot of work has saved AO-27 for many more enjoyable Amateur QSO's.

Chuck, KM4NZ

Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to

From: "Chuck Wyrick" <> To: <amsat-bb@AMSAT.Org> Subject: [amsat-bb:34222] AO-27 Status Date: Wed, 23 Aug 2000 10:55:19 -0400 August 23, 2000 For Public Release AO-27 suffered a software reset on July 31 while in the southern hemisphere several minutes before entering the eclipse. This reset put the onboard CPU back to the Bootloader software that places the satellite in "safe mode." While in safe mode, the transmitters are turned off and all high level functions are suspended. This places the satellite in a condition that ground controllers need to react to. Normally this means uploading the high level software and executing it. It was decided that since the last reset was 6 1/2 years ago, this reboot might be a single event upset or some other "random" reboot. With that in mind, ground controllers downloaded only a small section of memory and started to upload the high level code. This was not an easy task, the primary control station used for uploading code was not used for over 5 years and required days of work to get back online. Once the station was setup for uploading, the code was placed onboard AO-27. When the execute command was given, the satellite ran the high level code for a few seconds, then rebooted. This may show that the reboot was not caused by a random act, but it is not conclusive. Several sections of memory were downloaded from AO-27 and no conclusive data was found to explain the second reboot. Ground controller are looking into several leads. Jumping to conclusions as to cause are not productive during this process. It will take controllers time to analyze and determine the cause for the reboots. It is unfortunate that during this process the analog repeater can not be used, but the work done now may lead to a longer lifetime of AO-27. There is no direct evidence at this time as to cause. During the checkout that has been performed so far, controllers have not found anything onboard to be defective. This is good news and gives us hope that a recovery is possible. Facts known about A0-27 as of August 23, 2000 --------------------------------------------- 1) CPU rebooted on July 31, while in TEPR 6, southern hemisphere, in the Sun This means the batteries did not run down to cause the reboot. 2) TEPR times that were commanded on July 26 where intact and did not cause the reboot, i.e. the batteries where charged. 3) The last CPU telemetry frame was recovered and shows battery charge state as OK. 4) The code was sampling telemetry at the time of the reboot. 5) Software Uptime was over 6 1/2 years, (February 1994) 6) The Amateur Transmitter works at exciter, low, and high power settings 7) The Amateur Receiver works 8) The analog repeater works 9) The Bootloader works 10) Software uploading/downloading and executing works 11) Battery voltages are nominal 12) The 1200 Baud AFSK modulator works 13) The 1200 Manchester demodulators work If you would like to follow AO-27, the exciter on 436.797 is turned on full time and turned on to low power during uploads. A good tracking beam setup can hear the exciter if you place your receiver into USB and listen for the doppler shifting tone. The satellite is transmitting every pass so you can hear it at night as well. Please keep in mind that all AO-27 ground controllers have full time jobs. Several have already taken a week of personal vacation from work to spend time on this problem. Equipment used in the ground station has been purchased by the controllers personal accounts. This is an all voluntary crew. The best help the community can give is to not flood controllers with e-mail about when is AO-27 going to be back on-line. We are working as fast as satellite passes allow, it takes 3 days of passes to upload code. Once high level code is running, we will need to spend a week of on-orbit-checkout and gather whole-orbit-data to evaluate the health of AO-27. This is needed for continued longevity of this resource. The popularity and easy of use to Amateurs getting into satellites is very well known to everyone involved in recovering AO-27. The ground controllers have only one request for amateurs, please do not transmit on the uplink during passes, The analog repeater is turned off so you will not be heard, and you will interfere with the software upload process. Thank you. Michael Wyrick N4USI AO-27 Ground Controller ---- Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA. To unsubscribe, send "unsubscribe amsat-bb" to
To: amsat-bb@AMSAT.Org Date: Mon, 14 Aug 2000 12:07:10 -0400 Subject: [amsat-bb:33901] AO-27 From: Arthur z Rowe <> I just checked with Chuck Wyrick and was told AO-27 was still not on the air and no mention of when it would be back in service. Also ARRL Convention in Boxboro, Mass. is ---- Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA. To unsubscribe, send "unsubscribe amsat-bb" to
From: "Chuck Wyrick" <> To: <amsat-bb@AMSAT.Org> Subject: [amsat-bb:33669] AO-27 Date: Tue, 1 Aug 2000 22:46:56 -0400 For the next several days we will be uploading software upgrades to AO-27. We ask your assistance by not attempting to use AO-27 during this time. Transmitting on the uplink frequency will not be heard by AO-27 and may hinder our attempts to get it back on the air in a timely fashion. We will notify this BBS as soon as the bird is ready for analog amateur use. Chuck, KM4NZ Acting Control Operator for Michael, N4USI Control Operator ---- Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.

  • 2000/09/01 AO-27衛星 Exciter段のみからの信号 by JO2OXL  65KB@16.0K
    2000.09.01 0904JST 436.802MHz USB IC-706MKIIG+8エレ八木 435WH8 10dB
  • 2000/08/31 AO-27衛星 Exciter段のみからの信号 by JH0TOG  188KB@16.0K
    2000.08.31 20:56JST f=436.790MHz IC-820+ 5/8λ3段C-Load X5000 8.3dB