Designs Department Technical Memorandums

DDTM

Technical Memoranda (DDTM) were written and issued by Designs Department to fulfil one of the following major needs:

1. To describe the functioning and maintenance of a piece of equipment designed in the department, and thus act as a provisional handbook for the equipment.
2. To give a factual report on commercial components or apparatus which may be of interest to the BBC generally, or describe modifications to commercial equipment.
3. To describe the performance of communication circuits.
4. To describe-system tests carried out with independent observers.

Usually the best way to find the number of a DDTM on a specific topic is to do a search in this list of DDTMs. 

Very few DDTMs presently appear on BBCeng, but some are available on request.  Here are a couple, but they are not very representative:

DDTM 2-439(78) Improvements to Pye UHF77 Drive

DDTM 6-134(76) OB Comms, Notes on DDTM 6.134(76) OB Comms