[amsat-bb] Delfi-n3Xt Telemetry Equations & Format

Clive Wallis clive at g3cwv.co.uk
Tue Mar 29 01:15:01 PDT 2011


I note that in another thread  Wouter PE3WJ mentions the the next Delfi 
satellite n3Xt currently being constructed.

Can we be assured that full details of the telemetry equations and 
decoding format for defli-n3Xt will be published, preferably before launch.

With the considerable interest shown in the Funcube Dongle I'm sure that 
many satellite enthusiasts will want to write their own decoding software.

In the case of delfi-C3 I received a large number of packets using my 
G3RUH hardware decoder, but was unable to decode them, due to not having 
the telemetry details.  I had hoped to publish details of my experiments.

After repeated requests for the information I was eventually told that 
it was commercially confidential and could not be published.

IIRC this information has to be made available to the IARU satellite 
coordinator before launch, and updated when there any changes, following 

AFAIK it is against amateur radio license regulations to transmit coded 
information in the amateur bands, unless the decoding information is 
freely available.  The only exception being access codes to control the 
satellite, for obvious reasons.

I trust that delfi-C3 won't set a precedent for future projects and this 
problem will not arise again.  We want to encourage radio amateurs and 
students to experiment and avoid the 'black box' culture as much as 

I will be interested in any comments.

73     Clive   G3CWV

Hitchin, North Hertfordshire, UK

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