I remember there was a kit for something like the Don Bosco Stethotracer. there was also a cheaper version called the "Mosquito" these, as you know, where a signal tracers that where built into what looked like a fountain pen with a ear piece to listen with. The device I remember was built in a narrow circuit board that could be used as it or placed in some sort of home brew case. I cannot think of a search term that will get to it. Does anyone remember it? Hopefully it is still available. As a teenager in the late 1960's I remember Hamradio Gods of radio repair with these "pen things" in their shirt pockets. I would love to get something with the functionality of the Stethotracer, or the Mosquito originals are available but they have become collector's items and are worth more then I am willing to pay for one.

http://www.stevenjohnson.com/donbosco/stethotracer-kit.jpg

Found it: http://www.qrpkits.com/tracerinjector.html

http://www.qrpkits.com/images/injector1.jpg

I remember there was a kit for something like the Don Bosco Stethotracer. there was also a cheaper version called the "Mosquito" these, as you know, where a signal tracers that where built into what looked like a fountain pen with a ear piece to listen with.

IIRC, the "Mosquito" was not a signal tracer, it was a *signal injector* that could be used along with the "Stethotracer". It produced a rather "buzzy" (Mosquito sounding) raspy tone, rich in harmonics that could be injected into the circuit under test, while listening for output with the "Stethotracer".

jr

IIRC, the "Mosquito" was not a signal tracer, it was a *signal injector* that could be used along with the "Stethotracer". It produced a rather "buzzy" (Mosquito sounding) raspy tone, rich in harmonics that could be injected into the circuit under test, while listening for output with the "Stethotracer".

jr

I saw one of those Mosquito injectors over 50 years ago. I thought it was strange that the firm used the name of a Catholic boy's high school. It was on the south side of Milwaukee and most of the students were from Polish families. You were high-class, in those days, if you went there.
Of course, that wouldn't fly today. Even the trade schools have to be co-ed.

IIRC, the "Mosquito" was not a signal tracer, it was a *signal injector* that could be used along with the "Stethotracer". It produced a rather "buzzy" (Mosquito sounding) raspy tone, rich in harmonics that could be injected into the circuit under test, while listening for output with the "Stethotracer".

jr

Thanks for the clarification I only remember seeing them in the late 1960's being used by hamradio operators. I have no idea how they worked.