On Monday, 27 July 2020 08:57:29 UTC+1, wrote:
Anyway, I used to play 45s and later LPs on this.
I imagine the radio was probably just post war.
Would this have had RIAA Compensation circuitry built in?

RIAA became standard about 1954 on LPs

Accoustic 78s were made without equalisation; electrical 78s had varying equalisation curves depending on company (and year of production)

http://www.shellac.org/wams/wequal.html
and
http://midimagic.sgc-hosting.com/mixphono.htm

RIAA seems to be about average, if you have nothing else.

"the majority of all 78 rpm records can be equalised within a 2dB of the nominal (or alleged) curves claimed, using 4 low and 5 high frequency ranges - including flat and true RIAA for both."

Multi standard equaliser circuit

https://sound-au.com/project91.htm

Now it can be done in software
https://www.tracertek.com/cms-display/newway.html

Owain