Good D700 Packet Mail example

March 27, 2006  

In this section we will discuss some of the quirks associated with the Kenwood D700 operating as a Packet Mail box on ISS.

Successful Packet Mail message upload

Here is an example of a successful packet mail message upload to the D700 on ISS.  After three ties on a quite day, I was finally able to upload a very short message to the D700 packet Mail box on ISS. When I used the old Paccom / Ericcson system on ISS I could “login, Up-load a 500 byte message and log off” in less than 1 minute. With the D700, it takes over 2 minutes. During this test I uploaded a 48 byte message in 2 minutes and 8 seconds.

Setup:
Earth, KPC-3 TNC, Yaesu FT-736R (Doppler correction was used), AZ-EL Antenna system with M2 22 element circular polarized, 12+ dBd gain, ERP more than enough. The pass was a 30-degree pass and the number of active Unproto and APRS packet users was very low. 

Short Packet Lesson:
Packet data is tracked by Index numbers <I23>. The sending station always places their packet index number First, and the receiving stations counter second. When the receiving station sends a packet back, these numbers will look reversed.

Acknowledge packets:
When a receive station gets data, it will respond with ACK packet that will be one number greater than the last packet received.
<<rr5>> which means, I have received packet #4, I am waiting for your next packet number #5. It also means, that if you send multiple packets at once, all packets up to and including #4 were decoded correctly. The small letters “rr” means that this response was generated automatically by the receiving end of the conversation.

The capital <<RR6>> is more like a demand request, “Hey you did you get my packets!”
In this example, did you get packet #5 and are you ready too receive packet #6.

RS0ISS-11>WF1F [03/26/2006 13:53:15]: <<UA>>:
*** CONNECTED to RS0ISS-11

RS0ISS-11>WF1F [03/26/2006 13:53:17]: <<I00>>:
Welcome to RS0ISS's message board
System Ver 1.50 110798 Bytes free

WF1F>RS0ISS-11 [03/26/2006 13:53:18]: <<rr1>>:
RS0ISS-11>WF1F [03/26/2006 13:53:20]: <<RR0>>:
WF1F>RS0ISS-11 [03/26/2006 13:53:22]: <<rr1>>:
RS0ISS-11>WF1F [03/26/2006 13:53:24]: <<I10>>:
CMD(F/K/M/R/W/B/H/?)>

WF1F>RS0ISS-11 [03/26/2006 13:53:25]: <<rr2>>:
WF1F>RS0ISS-11 [03/26/2006 13:53:30]: <<I02>>: s rs0iss
WF1F>RS0ISS-11 [03/26/2006 13:53:40]: <<RR2>>:
RS0ISS-11>WF1F [03/26/2006 13:53:43]: <<rr0>>:
WF1F>RS0ISS-11 [03/26/2006 13:53:44]: <<I02>>:s rs0iss 

RS0ISS-11>WF1F [03/26/2006 13:53:46]: <<I21>>: Subject:
(In this example I am sending a very short message up to the D700 on ISS.)

WF1F>RS0ISS-11 [03/26/2006 13:53:46]: <<rr3>>:
(My TNC just sent an ACK back to the D700
<<rr3>> Means, I have received D700 packet #2, waiting for packet #3. )

WF1F>RS0ISS-11 [03/26/2006 13:53:56]: <<I13>>: miles march 26
RS0ISS-11>WF1F [03/26/2006 13:54:00]: <<I32>>: Message:
(Since the D700 is slow to respond, I sent my first line of text to the mail box before I received the “Message” line from the D700. This is not normally a problem)

WF1F>RS0ISS-11 [03/26/2006 13:54:01]: <<rr4>>:
(After I receive the “Message” line, my TNC acknowledges the packet with <rr4>
I have received D700 packet #3, waiting for packet #4)

RS0ISS-11>WF1F [03/26/2006 13:54:05]: <<RR2>>:
(I finally get an ACK from my Subject title
D700 Received packet #1, waiting for packet #2)

WF1F>RS0ISS-11 [03/26/2006 13:54:06]: <<rr4>>:
(My TNC acknowledges “Message packet a second time with <rr4>
I have received D700 packet #3, waiting for packet #4)

WF1F>RS0ISS-11 [03/26/2006 13:54:19]: <<I24>>: have a safe landing Bill 73 miles
(This part gets a little confusing because of the way my Terminal program buffers and displays data. When I send a bunch of packets at once my Terminal program will only show the first packet in the group. If I had a separate terminal program monitoring with a separate radio you would see all of the packets leaving my computer.
In this example, my TNC just sent two packets:
<<I24>> have a safe landing Bill 73 miles (shown)
and
<<I34>> /ex (Not Shown)


WF1F>RS0ISS-11 [03/26/2006 13:54:41]: <<RR4>>:
(Here is the failure to acknowledge problem with the D700. My TNC waits 22 seconds and never gets the <<rr3>> acknowledge message back from the D700. My TNC has to time out and then specifically Poll the D700, did you get my data? <<RR4>>)

RS0ISS-11>WF1F [03/26/2006 13:54:46]: <<rr3>>:
(The D700 responds, I Received packet I24, but I lost packet I34.
Since the D700 did not receive packet I24 correctly, it should automatically respond with the correct acknowledge message <<rr3>>.  If packet I34 arrived intact, the D700 should send <<rr4>> back to my TNC.  Ether way, I should have received an ACK message back from the D700, without specifically requesting an ACK.
This means, I need to send packet #3 again.)

WF1F>RS0ISS-11 [03/26/2006 13:54:52]: <<I34>>: /ex
WF1F>RS0ISS-11 [03/26/2006 13:55:04]: <<RR4>>:
RS0ISS-11>WF1F [03/26/2006 13:55:12]: <<rr3>>:
(Packet #3 is re-transmitted and the D700 still does not respond with the ACK until I send a demand poll back to the D700. The system still did not receive the packet)


RS0ISS-11>WF1F [03/26/2006 13:55:12]: <<rr3>>:
WF1F>RS0ISS-11 [03/26/2006 13:55:14]: <<I34>>: /ex
RS0ISS-11>WF1F [03/26/2006 13:55:18]: <<I44>>: Thank you for your message.
(On the third attempt the three (3) character packet finally arrives on the D700. Note:  The "/ex" means this is the end of message, please close it. Since this is an End of message packet the D700 closes the mail message and send back a response automatically.)


WF1F>RS0ISS-11 [03/26/2006 13:55:18]: <<rr5>>:
RS0ISS-11>WF1F [03/26/2006 13:55:23]: <<I54>>:
CMD(F/K/M/R/W/B/H/?)>

(This was the end of the Upload of the message. 
To send 1 sentence, approximately 40 characters, it took 1 minute and 23 seconds.
Next I used the M command to verify the message arrived)

WF1F>RS0ISS-11 [03/26/2006 13:55:24]: <<rr6>>:
WF1F>RS0ISS-11 [03/26/2006 13:55:28]: <<I46>>: m
RS0ISS-11>WF1F [03/26/2006 13:55:31]: <<I65>>:
(The clock is not set on the D700, so the date and time show up as trash)
Msg# Size TS Date Time From To @ BBS Subject

17 48 $ /1024 WF1F >RS0ISS miles march 26

110710 Bytes free
Next message Number 18

CMD(F/K/M/R/W/B/H/?)>

RS0ISS-11>WF1F [03/26/2006 13:55:46]: <<RR5>>:
WF1F>RS0ISS-11 [03/26/2006 13:55:47]: <<rr2>>:

Conclusion:

Packet Mail on ISS with theD700 is not for beginners.  It took me 3 tries to successfully upload a 40 character message in to the D700 Mail box.  I was using a 12 dBd gain circular polarized racking antenna system and an excessive amount of power.  I also had to modify many parameters in my TNC to compensate for the long delays for packets returning from the D700. If you are a beginner I would encourage you to experiment with the Unproto side of the D700.  The Unproto section is much easier to use in the D700 current configuration.

Local Interference Issues:  Some of the problems the D700 was experiencing were caused by interference from the PCSat-2 experiment (http://eng.usna.navy.mil/~bruninga/pcsat2.html).  PCSat-2 is an experiment mounted externally to the ISS.  It is attached to one of the trusses and is transmitting packet on 145.825 FM.  The ARISS Packet systems D700 is receiving on 145.990 FM.  The frequency separation between these two devices is insufficient and they will both intermittently "JAM" each other.  The Jamming will explain some of the issues with the Packet Mail box on the D700, but not all of the problems.  The PCSat-2 was returned to earth in September 2006, so this QRM issues should be resolved.

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