I'd like to make/put one into the radio case. 1. use the 115VAC in a transformerless rectifier ( IC package ) + 500Pf cap with B & C voltage divider; 2. use a 5 or 6.3 volt filiment xmfr with rectifier ( IC package ) + 500Pf cap for the A. Seems like it'd be cheap and small... Comments please, Steve T.