UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Defiant transistor radio

AC/HL · 10th Aug 2007, 10:32 pm

PP11 sets have the speaker connected between the battery centre tap and the (otherwise normal) output stage centre point, thus saving a capacitor. When PP11s became obsolete the standard mod was to replace the connector with press studs for 0v and 9v & use a PP9, which is the same size. This powered the radio as before. The centre tap was disconnected & removed, and the speaker connected via a suitably polarised 100mFd capacitor to 0v or 9V. Note the term mod, not bodge, as such mods have been an essential part of everyday radio maintenance from the early days.

10th Aug 2007, 10:32 pm	#4
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: Defiant transistor radio - model ? battery ? PP11 sets have the speaker connected between the battery centre tap and the (otherwise normal) output stage centre point, thus saving a capacitor. When PP11s became obsolete the standard mod was to replace the connector with press studs for 0v and 9v & use a PP9, which is the same size. This powered the radio as before. The centre tap was disconnected & removed, and the speaker connected via a suitably polarised 100mFd capacitor to 0v or 9V. Note the term mod, not bodge, as such mods have been an essential part of everyday radio maintenance from the early days.