AR88 Control Unit Type 88 - UK Vintage Radio Repair and Restoration Discussion Forum

cougar_lou · 26th Jan 2010, 10:46 pm

Greetings to all.

The following comes from the Air Ministry document AP2567A,Receivers type R1556,R1556A,R1556B.

"One of the modifications to the standard AR88 or AR88D was the addition of a plug, type R to the rear chassis. This plug is connected in series between the resistor R55 (in the RF/IF gain control circuit) and earth. The control unit type 88 can be connected to this circuit by a socket type C; this arrangement provides sidetone in the receiver. A short circuited socket, type C is also provided so that when sidetone is not required, the normal RF gain control circuit can be restored".

Has anyone any information on the elusive Control Unit Type 88 or Soket type C etc?

Brian G.

GMB · 26th Jan 2010, 11:49 pm

You could always try the RAF Hendon archive.

They might have something on it.

Station X · 26th Jan 2010, 11:57 pm

I traced the wiring on my own AR88 which is the R1556A variant some time ago and have attached a rough sketch.

Socket type 'C' is a flat mains type two pin socket which mates with a similar plug screwed to the chassis of the AR88. I will take a picture some time and post it here.

cougar_lou · 28th Jan 2010, 10:32 pm

And you were kind enough to send me a copy back then. We were seeking info on the 88 control unit as well.

Thanks,Brian G.

Station X · 6th Feb 2010, 10:32 pm

Some pictures.

cougar_lou · 13th Feb 2010, 1:08 am

Ta muchly Graham,Brian G.

26th Jan 2010, 10:46 pm	#1
cougar_lou Tetrode Join Date: Dec 2007 Location: Melbourne, Australia Posts: 60	AR88 Control Unit Type 88 Greetings to all. The following comes from the Air Ministry document AP2567A,Receivers type R1556,R1556A,R1556B. "One of the modifications to the standard AR88 or AR88D was the addition of a plug, type R to the rear chassis. This plug is connected in series between the resistor R55 (in the RF/IF gain control circuit) and earth. The control unit type 88 can be connected to this circuit by a socket type C; this arrangement provides sidetone in the receiver. A short circuited socket, type C is also provided so that when sidetone is not required, the normal RF gain control circuit can be restored". Has anyone any information on the elusive Control Unit Type 88 or Soket type C etc? Brian G.

26th Jan 2010, 11:49 pm	#2
GMB Dekatron Join Date: Aug 2003 Location: near Reading (and sometimes Torquay) Posts: 3,099	Re: Ar88 control unit type 88 You could always try the RAF Hendon archive. They might have something on it.

26th Jan 2010, 11:57 pm	#3
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Ar88 control unit type 88 I traced the wiring on my own AR88 which is the R1556A variant some time ago and have attached a rough sketch. Socket type 'C' is a flat mains type two pin socket which mates with a similar plug screwed to the chassis of the AR88. I will take a picture some time and post it here. Attached Thumbnails __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

28th Jan 2010, 10:32 pm	#4
cougar_lou Tetrode Join Date: Dec 2007 Location: Melbourne, Australia Posts: 60	Re: AR88 control unit type 88 And you were kind enough to send me a copy back then. We were seeking info on the 88 control unit as well. Thanks,Brian G.

6th Feb 2010, 10:32 pm	#5
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: AR88 Control Unit Type 88 Some pictures. Attached Thumbnails __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

13th Feb 2010, 1:08 am	#6
cougar_lou Tetrode Join Date: Dec 2007 Location: Melbourne, Australia Posts: 60	Re: AR88 Control Unit Type 88 Ta muchly Graham,Brian G.