Ascom SE550 4m radio information  

last updated 12th June 2011

The following information I've obtained whilst converting several hundred Ascom SE 550's to 4m Amateur radio use.

In the UK, I've come across radio's made available via the Rugby and Reading radio clubs. I sold the ones that I had here, via the Ridgeway Repeater group, to assist in financing the repeater network for the Swindon, North Wilts/South Gloucestershire area.

Some parts of the manual are missing on the web, presumably due to the large page sizes and number of pages involved with digitising - I'm always on the lookout for more info and, as people request, have been adding odd pages myself. I've now got a couple of CD's with info - one, a full manual in German - a huge pdf file!.  I've also got a photocopied workshop manual - really useful !. Drop me an email if you are looking for circuits that I've not yet published on this page.


I hope this on-line info helps.... de Andy G0BEQ....                         email me to: mail@<no spam>  (remove <no spam> before sending)


All the files below are in Adobe Acrobat (.pdf) format...and require Acrobat reader to view them. Files that are available inBlue text.


My Version of of the User manual for MK3 firmware

G0BEQ User Manual  (version 2.81 - Mar 2009)

(I find my user manual and pics gets referred to a lot on ebay adverts !!!)

Installing BATTERY backup details (found in the last few pages of the above manual)   


Contents of the Ascom Technical Handbook (SE 550-08-25-1)     (I've listed all the chapters found in the manual for ease of understanding)

SE 550 Index     (Index from manual)                         

SE 550 Part 1   (description)                                              

SE 550 Part 2  (installation instructions)

SE 550 Part 3  (functional description)                             

SE 550 Part 4   (maintenance)                                           

SE 550 Part 5   (alignment instructions)                                        

SE 550 Part 6   (circuit diagrams & parts lists)

SE 550 Part 7   (carrying case TB 550)

SE 550 Part 8   (desktop base station TF 550 [German language]

SE 550 Part 9   (remote control (wire version)) [German language]


Extracts from the manual

SE550 main circuits only   (the RF bits only)                                                        

SE550 circuits   (most of the radio circuits excluding microprocessor)

SE550 control unit   (microprocessor cct)

SE550 RX audio circuits  (Useful when fault finding RX audio problems)

Power connector schematic  (The internals of the power plug - make your own with a 15Pin D connector)


Other Useful SE 550 Knowledge & Info

EPROM change guide        Download the MK3 Eprom HERE

Tune-up details thanks to Denis G4KWT

4m Slim Jim dimensions    (The slim Jim I made and what dimensions were used)


Links that you may find of use...

PA3EKI... Website (note the radio is known as the Condor 3000 over there)

Four Metre UK website    (The UK 4m web-site)

F5JZT's Ascom site    (Good site but in French !)