Rogers/Sign DM344 Distortion Meter Information.

[chriswood1900]

I’m looking for information on the history of Sign Electronics who designed and possibly built a range of test equipment comprising a DM344 distortion meter, S324 audio frequency oscillator and an AM342 audio voltmeter. This was around 1968 to 1973 this range of products was then taken up by Rogers the same model numbers re-used.
Did Rogers buy out Sign, or subcontract them to produce the instruments?
There is a reference to this range of instruments in Gordon J Kings book Radio Television and Audio instruments 2nd Edition Page 181when they were credited to Rogers but show Sign branding on the front.
The only reference I have found in Wireless World was in July 1970 P358 when Sign Electronics were using Aveley Electrical as a Distributor and in Studio Sound where it appears as a Rogers Product in March 1973
https://worldradiohistory.com/hd2/ID...-09-IDX-29.pdf

I was wondering if any forum member has used one of these and does anyone know anything of the history of these Rogers/Sign products.
It seems as though many manufacturers dabbled in Distortion meters including Ferrograph, Sugden, Radford plus many more!

[chriswood1900]

Just a quick bump to see if anyone has any info on the Distortion Meter plus at Biggleswade on Sunday I bought the matching AM324 branded 'Sign' so I'm now also looking for some info and a schematic for this.