I think I know why your voltage readings didn't make sense to me. First I made a math mistake, but also I thought you built old_coot88's version and I guess you built vts1134's. In that version the collector voltage varies as you adjust the pot to change the AC gain. I think if you check, the pot was adjusted to about 1.6K. That would mean the AC gain is about 2 instead of about 4 with the pot at 3.3K. Anyway you can't argue with success!
More on that regulator; you can see the relevant data by clicking on the link on that page. The pages for the 9V version is on pages 4 and 9. You need at least a 0.33 uf on the input and at least 0.1 uf on the output. The regulator should be fed by at least 12 V.
03-13-2017, 11:04 AM
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