Datasheet of This battery powered intercom was found on a January 1947 Radio Craft. |The circuit is 4-way but can be modified by changing the key.
This circuit was found in English documentation from the 90's. Transistors are general purpose types....
This instrumentation circuit is from the June 1986 issue of Radio Electronics magazine. Equivalent...
This is an interesting idea that we found in the May 1971 issue of Radio Electronics magazine. It can...
