key to cathode of two diodes, first diode anode connects to Hermes keying input and pulls it low when key is closed. Anode of second diode goes to one side of piezo whose other connection goes to 12V. Piezo sounds when key is closed. 73, Bob GM4CID@@TheArtofEngineering
Glad to hear you're finding the KiwiSDR useful ... Andy VK2AAK
Yes ....it has been a great aid in testing rigs and at times getting thru due to QRM/QRN at my QTH. 73 and TU George VK2AOE
While I’m at it, maybe throw a diode across the coil of the relay to manage the back EMF
Got one internal…thought about double down on it but only risking the tank PSU!
@@TheArtofEngineering so the relay coil is polarised with built in back emf suppression??
How is the Hermes receive vs the venerable TS520 ??
Very good now can you tell me how you got the Aimos wheel to move the vfo please
Yes…. Go to this video
czcams.com/video/v0ZwnwG_QXw/video.htmlsi=ze_VRy7FId13LiK- 73
Two diodes and a piezo would have done the same job.
Would it present 12V to the piezo and isolate the input of the Hermes whilst still allowing the tip to sleeve to see earth? 73 de VK2AOE
key to cathode of two diodes, first diode anode connects to Hermes keying input and pulls it low when key is closed. Anode of second diode goes to one side of piezo whose other connection goes to 12V. Piezo sounds when key is closed. 73, Bob GM4CID@@TheArtofEngineering