25-06-2015, 07:54 PM
I built one about 40 years ago; it's described in my book on test gear but also shown in this discussion in the Antique Radio Forum:
http://www.antiqueradios.com/forums/viewtopic.php?f=8&t=276600
There are other suggestions in that thread too.
http://www.antiqueradios.com/forums/viewtopic.php?f=8&t=276600
There are other suggestions in that thread too.






