Bug #3269


osmo-e1-xcvr has magnetics not placed the right way

Added by tnt over 3 years ago. Updated over 3 years ago.

Target version:
Start date:
Due date:
% Done:


Spec Reference:


It seems the footprint for the T1094NL transformer in the library is wrong.

The pads in the schematics are correct but their position on the footprint is wrong. P$16 is where P$1 should be, P$15 is where P$2 should be and so on and so forth.
Also pads have the default P$nn which is probably a clue as to what happened :p

The result is that there is no orientation of the transformer that will give the right result because one side is 1:1 and the other is 1:2.

Currently for the RX path, this has no effect. Primary and secondary are swapped but it's a 1:1 turn ratio.
For TX however, the '2' turn ratio should be on the line side and instead it's on the LIU side, so the pulses will end up being 1/4 amplitude of what they should be.

Subtasks 2 (0 open2 closed)

Bug #3270: Fix T1094NL symbolResolvedmschramm05/15/2018

Bug #3271: Fix T1094NL footprint in libraryResolvedmschramm05/15/2018

Actions #1

Updated by laforge over 3 years ago

  • Assignee set to laforge

I'm sorry for the fuckup :( I guess we could do some new boards and re-cycle the magnetics and LIU, as those are the expensive parts.

Actions #2

Updated by tnt over 3 years ago

I don't think that's necessary.

(1) it might just work since the pulse are just attenuated by 1/4 and for short distance it's fine
(2) You can rework to connect one of the pin on the LIU side to the center tap instead, this would bring in a 1:1 ratio. Not the expected 1:2 but it means the pulses are only 1/2 instead of 1/4 which is already much better.

Since the board is only for experimentation I think the existing one will be good enough for that purpose. Of course still worth fixing the footprint for future use :p

Actions #3

Updated by laforge over 3 years ago

  • Assignee changed from laforge to mschramm
Actions #4

Updated by mschramm over 3 years ago

  • Status changed from New to In Progress
Actions #5

Updated by mschramm over 3 years ago

  • Status changed from In Progress to Resolved
commit 00ebf25701b56d68a74c90c9afd7e1c6ff67fd61
Author: Martin Schramm <>
Date:   Tue May 29 19:52:28 2018 +0200

    replace old PULSE_T1094NL footprint, repair pin assignment (solves OSM#3269)

Also available in: Atom PDF

Add picture from clipboard (Maximum size: 48.8 MB)