STR18 Tx

[David Simpson]

Does anyone have a copy of just the STR18 Tx Unit Circuit Diagram please. I understand that the whole AP is in the VMARS Archive. I'm enquiring on behalf of a vintage radio chum up here who is a VMARS member, but he says there isn't a proper circuit diagram in VMARS' AP. He's just back from Hack Green's sale and eager to get stuck into his purchase, (With my help - but I haven't touched an STR18 Tx since 1965 !).

Regards, David

[trh01uk]

David,

if that's the T4188 then yes I do have a copy of the schematic - see attached.

Richard

[David Simpson]

Thank you Richard for the pdf.
'Fraid I cant remember the individual designation for the STR18's Tx unit. The whole aircraft installation was a thumping great rack system :- PSU, Rx, Tx & ATU with a heavy loom of interconnectors terminating in big Plessey-like connectors. I only ever was acquainted with them whilst training at RAF Cosford as a young teenage airman. Thank God I never had to work on them in real life. STR18 replaced the old 1154/1155 in the 50's, and was itself replaced by Collins 618 in the late 60's.
I know of only one other Forum contributor - Olly Holbrook, who was planning to rebuild a complete STR18, but I haven't been able to contact him.

Regards, David

[trh01uk]

David,

its not a system I am familiar with - except for seeing bits of it for sale here and there. Lots of people have bits of it, but the racks I have never seen. I only have a few sheets relating to it - though I am sure a manual will be kicking about somewhere.

Here's a picture of the system, which may jog your memory. As I recall it has an autotune system, which arrived about a generation after the Americans managed it with their ART-13.


Richard

[David Simpson]

Thanks Richard for the picture. Yes, it brought back memories of my times in training. 1965 was the last time I saw one of these. Thumping great coils in the ATU, I remember.
I think most folk in the vintage radio fraternity have avoided these beasts - due to their sheer size. Also, 1154/1155 has a lot more chrasima about it due to it's association with the Lancaster Bombers.
Some guys in VMARS have had a big Collins618 project going. Good luck to them.

Regards, David

[Herald1360]

Originally Posted by David Simpson

Also, 1154/1155 has a lot more chrasima about it due to it's association with the Lancaster Bombers.

Love it! It sort of fits the 1154/1155 just so

[David Simpson]

Moderators, this thread can be closed now. Circuit diagram just the ticket.

Thanks, David