Unnumbered Page Advertisement 1

Radio Record, Volume V, Issue 10, 18 September 1931, Unnumbered Page

Voull find Hhis screen- gvid 'valve is beliter Jhe OSRAA AY 324 'MaDE IN ECLAAD Prneretzado detection is 2 matter of perfect valves: This new 2.5 volt; Osram is, like the entire 2.5 Osram series, definitely non-microphonic: Shocks or vibration do not affect it. It is the ONLY screen-grid valve that Is perfectly noiseless In operation: You can test Osram 2.5 at your Radio Dealer's. Ask to switch on_ any set, tune sqpecicriy out stations and tap the 224 OP 227 detectora If it is: microphonic the speaker will emit 2 Pinging nolse, indicative 0f imperfect reception: If the micro- Phonjc valves are replaced by" Osram 2.5s, tapping will result in silence: Ask your dealer also to show You the full range of Osram 2.5 Osrm vl 2alves MY.227 MX.245 & MX.280 250 valves MADE IN ENGLAND Advertisement 0f the BRITISH GENERAL ELECTRIC CO= LTDe 37 Taranaki Street; Wellington: Brunswick Bldgse, 49 High Street, Auckland: Hannaford Chambers, 145 Worcester Street, Christ- church;