[R-390] Sp-600 Product Detector

[Steve Hobensack]

Here is a product detector circuit using an LM1496  
http://www.electroniq.net/radio-frequency/product-detector-using-lm1496.html
There was a construction article in Electric Radio magazine sometime back in the 1990s
By Bill Klernomos(sp) I built it and it works good. You must hit the chip with low Z signals.
As I remember, the bfo amp tube converts to a cathode follower then injects the beat osc signal. The IF output is already a cathode follower to a connetor on back of the chassis. The chip doesn't like too much signal, therefore a pot is inserted in each input for adjustment. The sp600 AM detector remains intact and a spdt toggle switch selects either the AM detector or SSB product detector. 
Steve N8YE