More extreme stuff from VK3YE: decoding CW without a BFO
- Thread starter OC71
- Start date
Ham4CW
Administrator
The Pixie series of QRP transceivers use the same idea, plus a few others as well.
Seeing Peter using that QRP rig as an external BFO reminded me of the many happy hours I used to spend doing a very similar thing. External BFO units were very popular years ago, just a single transistor oscillator running at the I.F. frequency of the receiver used. Mine were pretty well always 455KHz, using salvaged I.F. transformers as the coil for the oscillator.
You would bring the the oscillator (usually on a small piece of Vero board) near to the radio until you had found the optimum distance t get just the right mixing level. The beauty was you could listen anywhere within the radios coverage range, since the I.F. frequency was always the same.
It worked great for CW or SSB reception.
The good old days! bd
73, Mark...
Seeing Peter using that QRP rig as an external BFO reminded me of the many happy hours I used to spend doing a very similar thing. External BFO units were very popular years ago, just a single transistor oscillator running at the I.F. frequency of the receiver used. Mine were pretty well always 455KHz, using salvaged I.F. transformers as the coil for the oscillator.
You would bring the the oscillator (usually on a small piece of Vero board) near to the radio until you had found the optimum distance t get just the right mixing level. The beauty was you could listen anywhere within the radios coverage range, since the I.F. frequency was always the same.
It worked great for CW or SSB reception.
The good old days! bd
73, Mark...