AO-07 分析結果

● (No.505) AO-07 分析結果 (2006年11月16日)

Suject: AO-07 healthy CW
From: Mineo Wakita, JE9PEL/1
Date: 2006年11月14日 18時58分13秒

本日(11/14) 夜18時30分頃、久しぶり(10ケ月ぶり)に、AO-07 の シャン とした
CW (145.972MHz) 信号を聞きました。ノイズの向こうに、はっきりと聞こえます。
デコードも可能です。 (80秒)


Subject: [amsat-bb:95510] Re: AO-07 healthy CW
From: "Garie Halstead K8KFJ"
Date: 1:09, 15 Nov 2006

--- Mineo Wakita wrote:

> I heard today CW (145.972MHz) from AO-07.
> 80 seconds

180 180 180 180
252 252 252 252
324 324 324 324
496 496 496 496
568 568 568 568
696 696 696 696

//Gary  -K8KFJ- 

Subject: [amsat-bb:95513] Re: AO-07 healthy CW
From: "Martin Gillen"
Date: 7:54, 15 Nov 2006

I plugged that data into the AO-7 telemetry calculator and got:

CH   CHANNEL NAME            Value
==   ============            =====
1A   Total Solar Array Cur   2360 ma.
1B   +X Solar Panel Cur      370 ma.
1C   -X Solar Panel Cur      370 ma.
1D   +Y Solar Panel Cur      370 ma.
2A   -Y Solar Panel Cur      930 ma.
2B   RF Pwr. Out 70/2        1.8432 watts
2C   24 Hr. Clock Time       811.2 minutes
2D   Batt Chg/Dischc Cur.    80 ma.
3A   Battery Voltage         8.8 volts
3B   Half-Batt Voltage       2.4 volts
3C   Bat. Chg. Reg. #1       3.6 volts
3D   Battery Temperature     60.28 C
4A   Baseplate Temp.         -46.28 C
4B   PA Temp 2/10 Rptr       -46.28 C
4C   +X Facet Temp.          -46.28 C
4D   +Z Facet Temp.          -46.28 C
5A   PA Temp. 70/2 Rptr      -4.84 C
5B   PA Emit. Cur. 2/10      793.56 ma.
5C   Modul. Temp. 70/2       -4.84 C
5D   Instr. Sw. Reg.         66.76 ma.
     Input Cur.
6A   RF Pwr Out 2/10         5907.69230769231 mw.
6B   RF Pwr Out 435          956.6 mw.
6C   RF Pwr Out 2304         377.856 mw.
6D   Midrange Telemetry      0.96 V    Typ.(0.50 +- 0.01)

Subject: [amsat-bb:95520] Re: AO-07 healthy CW
From: "Sil - ZL2CIA"
Date: 18:02, 15 Nov 2006


Firstly, thanks to Mineo Wakita (JE9PEL), Gary Halstead (K8KFJ) and
Martin Gillen (VA3SIE) for the reception, copying, and decoding the data
from AO-07.

I remember some of the discussion posted here, when AO-07 started
working again. The consensus seemed to be that the satellite had failed
25 years previously because too many of the NiCd cells in the battery
had become short circuited (as NiCd do with time). This had caused the
battery voltage to fall to a level too low to operate the transponder.
Time,(and perhaps corrosion caused by the battery chemicals) had
eventually created an open circuit and the satellite was now operating
directly from the solar panels. Certainly, it goes very dead once it is
in darkness which rather supports this idea.

However, channel 2D of the telemetry shows a Battery Charge/Discharge
current of 80 ma. Since this is positive, I assume that it represents a
"charge" current. I see too that the "half battery voltage" is 2.4
volts, while the full battery voltage is 8.8 volts. So the dead battery
is behaving like a 110 ohm resistive load and consuming 0.704 watts.

This doubtless explains why the battery is at a toasty 60 C and most of
the rest of the satellite is at -46 C.

Also freezing is the 10m PA (channel 4B). This is not surprising since
it was "off" when JE9PEL recorded the CW. Yet this PA is drawing almost
0.8 amps of emitter current and producing nearly 6 watts of RF. It's
consumming 7 watts (8.8V * 0.8A)making the PA about 86% efficient). Does
this mean that the telementry is unreliable (fair enough, it a very old

The 2m PA (channel 5A) is a whole bunch warmer at -5 C. This makes sense
since the 2m transmitter was the one sending the data (or perhaps it's
installed next to the battery!) I presume that the 2m beacon signal is
simply injected into the 2m PA. Is this correct?

The battery voltages (and half battery voltages) give some indication of
where the remaining short circuit cells might be (in case anybody wants
to go up and fix them - actually, I will do that if someone can give me
a lift). I wondered about this in a sort of hypothetical way. I'm
curious for its own sake (and clearly have too much time on my hands).

I tried to find some details of the satellites design via google, but
didn't (I'm sure others will succeed in this).

I also looked in my own humble Ham library for details of the design,
but didn't find any.

I guess that the satellite battery consisted of cells in series and
batteries in parallel, or perhaps of cells in parallel then in series to
make a battery. Does anybody know exactly? Can anybody point me in the
right direction?

Sil - ZL2CIA

Subject: [amsat-bb:95523] Re: AO-07 healthy CW
From: "i8cvs"
Date: 21:55, 15 Nov 2006

----- Original Message -----
From: "Sil - ZL2CIA"
Sent: Wednesday, November 15, 2006 9:01 AM
Subject: Re: AO-07 healthy CW

> Hi,
> I guess that the satellite battery consisted of cells in series and
> batteries in parallel, or perhaps of cells in parallel then in series to
> make a battery. Does anybody know exactly? Can anybody point me in the
> right direction?
> Sil - ZL2CIA

Hi Sil, ZL2CIA

Unfortunately Larry Kayser VA2LK the expert of the OSCAR-7 batteries
passed away 5 october 2004

I believe that actually the right people to supply you with the informations
about the batteries and BCR are Jan King W3GEY and Dick Daniels W4PUJ

However you can get many useful informations about the batteries of
OSCAR-7 reading a lot of letters from Larry Kayser wich are available in the
Amsat-BB Archives from june 2001

Best 73" de

i8CVS Domenico

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