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Neil Purling · 5th Sep 2010, 9:57 am

A 3 transistor regenerative TRF: OC45 & 2x OC71.
A fellow constructor made the same circuit & introduced two changes: OA79 instead of OA91 diodes and also substituting OC81D for the pair of OC71's.
His effort sounded great & I wondered if this was due to the OC81D having greater gain than a OC71. Or maybe the diode swap had some effect?
Can anyone tell me what the gain of a OC71 and a OC81.OC81D should be from data sheets?

5th Sep 2010, 9:57 am	#1
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,087	Transistor Choice in radio project A 3 transistor regenerative TRF: OC45 & 2x OC71. A fellow constructor made the same circuit & introduced two changes: OA79 instead of OA91 diodes and also substituting OC81D for the pair of OC71's. His effort sounded great & I wondered if this was due to the OC81D having greater gain than a OC71. Or maybe the diode swap had some effect? Can anyone tell me what the gain of a OC71 and a OC81.OC81D should be from data sheets?