10 Nov 2012

10m Lesser Chirpy in a new box

Lesser Chirpy (should be No Chirpy!) 10m transceiver
At last I've got around to putting my Lesser Chirpy ultra simple 28MHz CW transceiver in a case. I've added an extra switch so I can listen on another RX if conditions are such that the internal RX struggles, although even with my 64 year old ears I can clearly hear better than -100dBm signals on Lesser Chirpy. Offset is set at about 700Hz between RX and TX. The FSK keying is a bit odd - there is only around 100Hz shift between carrier on and pseudo off (i.e. shifted) but there is zero chirp. This is now a seriously useful transceiver, albeit very very simple. Power out on this sample is around 80mW, so I believe this is certain to span the Atlantic in the next few days, if only to be spotted on the Reverse Beacon Network.
Lesser Chirpy cased
I have not got an internal low pass filter on this model. One should be added between the rig and the antenna to ensure low 2nd and 3rd harmonic levels.

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