CP4

How to decode CP4 telemetry #1

How to decode PolySat CP4 telemetry
CP4, FSK 1k2 AX.25 Telemetry (SSB Mode)
#31122, 437.325MHz, Interval 5 minutes

Subject:  AW: Setting for CP4 ?
From:     Mike Rupprecht
To:       Mineo Wakita
Date:     Mon, 23 Apr 2007 16:57:29 +0200

Hi Mineo,

it is a little bit tricky. I was still wondering about the different
sizes of the packets.
The packet should be 115 bytes (99 payload + 16 AX.25 header).
(I found the mistake in my software and now I get the whole 115 bytes :-)

Let me explain, how I decode the beacons. I record all into a wav file.
Because of mode USB it is no easy to find the exactly frequency.
So I use MixW32 in mode Custom AFSK. I analyze the audio file and find
the 2 frequencies for lower and higher tones. With these both frequencies
I can decode the frame.

I think that is the main problem for decoding. We have no fix AFSK tones
(1200Hz / 2200Hz) like FM AFSK.

In MixW32 you can emulate an KISS TNC. So I get the kiss frame and
I convert this into hexvalues with a program written by myself. See here:
http://www.dk3wn.info/software.shtml programm called KISS Dump. 

If you can send me a wav file (or download from your website)
I will try to convert this.

Good luck and 73, Mike
DK3WN

-----Ursprungliche Nachricht-----
Von:      Mineo Wakita 
Gesendet: Montag, 23. April 2007 15:02
An:       Mike Rupprecht
Betreff:  Setting for CP4 ?

Hi Mike,

I can hear a strong signal but can't decode it.

CP4, FSK 1k2 AX.25 Telemetry (SSB Mode):

     TNC    Rig
----------------
(1)  FSK    USB
(2)  PSK    USB
(3)  PSK    FM

Which do you set for PC4 ?

de JE9PEL, Mineo Wakita


===================================================================
Subject:  [amsat-bb:98038] CP-4  Apr 24, 2007
From:     Mike Rupprecht
To:       amsat-bb
Date:     Tue, 24 Apr 2007 22:42:22 +0200

All,

CP-4 over europe at 19:54 - 20:09 UTC
-------------------------------------------------------------------
20:02 cw header: FPEA
ctrl: 3 {UI}  PID: F0 {No L3}  Total Frame Bytes: 23
from N6CP to N6CP:
   1 > 04 43 4F 4D 4D 20 41
.COMM A
-------------------------------------------------------------------
ctrl: 3 {UI}  PID: F0 {No L3}  Total Frame Bytes: 115
from N6CP to N6CP:
   1 > 01 D2 14 0B 34 30 D2 02 07 03 58 AE A6 B3 C0 97 03 00 03 7D
  21 > C5 80 7E C1 C7 1A 08 08 A4 28 97 9E BD BA 03 04 04 8E 3E F3
  41 > E5 C4 93 00 00 03 70 92 C1 C5 C0 00 05 B8 A0 B8 B8 A7 10 0F
  61 > 0B 04 0E 01 75 87 87 B9 B9 83 C7 68 F4 EE FF 88 EC 83 C7 68
  81 > F5 D9 FF 8E EE 03 01 00 00 26 26 08 65 01 26 2A 2B 5C BB
-------------------------------------------------------------------

20:08 cw header: FPEA
ctrl: 3 {UI}  PID: F0 {No L3}  Total Frame Bytes: 23
from N6CP to N6CP:
   1 > 04 43 4F 4D 4D 20 42
.COMM B
-------------------------------------------------------------------
ctrl: 3 {UI}  PID: F0 {No L3}  Total Frame Bytes: 115
from N6CP to N6CP:
   1 > 01 D5 14 0B 3A 2E CE 02 06 03 40 7D 77 85 C0 C0 03 00 02 78
  21 > 95 52 50 C2 9D 01 00 08 97 0F 5A 65 BD 9E 03 02 03 7F 73 E5
  41 > D9 C5 C7 61 76 03 6C AA 97 8F C0 00 05 B8 96 B8 B9 BE 11 0F
  61 > 0A 0C 04 02 78 89 87 B9 BA 8B C7 6A F3 FE FF 8C EC 83 C7 6B
  81 > F4 06 00 8E EE 03 01 00 00 66 26 08 62 01 2A 2B 29 5D 37
-------------------------------------------------------------------

73, Mike
DK3WN


===================================================================
Mail to California Polytechnic State University (USA)
Subject:  How to decode CP4 ?
From:     Mineo Wakita
To:       calpoly edu
Date:     Mon, 30 Apr 2007 08:59:46 +0900

I can hear CP4 sound, but I can't decode it by TNC.
The following sound was recorded at SSB mode in Apr 29.
http://www.ne.jp/asahi/hamradio/je9pel/70429cp4.wav

How to set for decode these wav file from CP4 by TNC ?


Reply from California Polytechnic State University (USA)
Subject:  Re: How to decode CP4 ?
From:     Keith McCabe at calpoly edu
To:       Mineo Wakita
Date:     Mon, 30 Apr 2007 00:03:12 -0700

Hi Mineo,

CP4's beacon can be decoded with your TNC in AFSK 1200 baud mode.
We use MixW2 here; this is very useful because it displays the
audio frequencies which is helpful for tuning, as well as using
custom AFSK modes.  If you are using a hardware TNC, you have to
line up the beacon very carefully on 1200/2200 Hz.

The beacon you sent is pictured below; as you can see, the audio
frequencies were too low to be decoded by 1200/2200, but could be
decoded using 500/1500 hz tones.  In USB mode, this means you need
to lower the radio frequency  (USB goes backwards, lower radio
frequency makes a higher audio frequency)!

Good luck!  Feel free to ask any more questions.
-Keith



                                                                              bottom top

Cf.1  Setup TNC
I could receive CP4 beacon using with a hard TNC and WiSP3215
by a different method in the explanation as later.

WiSP Broadcast Callsigh: N6CP
Rig: 437.323 MHz, USB
TNC: 1200 bps, FSK

wisp3215:
> 2007-06-10-01.kss (199 bytes)

kiss2asc.exe:
> fm N6CP to N6CP ctl UI pid F0
> .COMM B

kissdump.exe:
> ctrl: 3 {UI}  PID: F0 {No L3} Frame Bytes: 24 [Payload Bytes: 7]
> from N6CP to N6CP: 
>    1 > 04 43 4F 4D 4D 20 42 
> .COMM B



Cf.2  Setup MixW2




Cf.3  Setup Sound Recoder




    



Cf.4  Generation KISS file on MixW2

http://www.dk3wn.info/sat/afu/sat_cp.shtml
http://www.dk3wn.info/mixw_kiss.shtml
How to decode CP4 telemetry #1

How to decode PolySat CP4 telemetry CP4, FSK 1k2 AX.25 Telemetry (SSB Mode) #31122, 437.325MHz, Interval 5 minutes
