[mikethedruid]

The plate of the '71A will be hooked to the speaker. You will need an old fashioned high impedence magnetic speaker, the horn kind, or a modern speaker with an output transformer, anywhere from 2000 - 5000 ohm primary (tube side), and the output matched to the speaker. This will have to be one of the tube type output transformers, of course, with a high enough voltage rating, and at least 5 watt power rating. If you are only running the tubes at 3 volts you may not get much. 01As and 71As are designed to run with 5 volts on the filaments. Try the set with full voltages on the various connections. These very early sets are pretty rugged that way. If still no luck, next check the audio interstage transformer. Try ringing it out for resistance. or try injecting a signal at the secondary, and primary of the transformer. with the set on you should hear it .. just trace it back as you would with a modern set. Here are the ratings for the '01A and '71A tubes :
http://www.nostalgiaair.org/tubes/01a.htm
http://www.tubezone.net/pdf/71a.pdf
Looking at the bias needed for the 71A with 135 V on the plate, you will need about -17 volts to get efficiency out if it, so you may need that for your C voltage.