A Dedicated Interface … (/cont)

The passive bit …

The RF (Aerial) and 100KHz feeds are coax cable, whilst the DSB audio feeds are ‘twisted pairs’.

The audio amplifier …

‘Borrowed’ from the RA117 …


The RA218 provides two resolved audio outputs at SKT3 on the rear panel. I considered using a 6AQ5 to drive the loudspeaker but opted to use the Russian 6P1P which is ‘listed’ as an equivalent to the 6AQ5 despite the fact that it (the 6P1P) is a B9A device. I figured that the larger valve would be more robust.


SW2 selects the desired audio feed.