{"id":2160,"date":"2019-11-23T14:56:46","date_gmt":"2019-11-23T12:56:46","guid":{"rendered":"http:\/\/racov.ro\/?p=2160"},"modified":"2020-03-31T13:35:59","modified_gmt":"2020-03-31T10:35:59","slug":"circuit-vox-pentru-statiile-radio","status":"publish","type":"post","link":"https:\/\/racov.ro\/index.php\/2019\/11\/23\/circuit-vox-pentru-statiile-radio\/","title":{"rendered":"VOX circuit for radio transceivers"},"content":{"rendered":"

<\/p>\n

VOX<\/strong> (voice activated transmission) activates the station’s transmission (press PTT<\/strong>) when it detects sound (modulation signal) at the microphone or (if the transceiver has one) at the <\/span>audio input.<\/span>
\nThis circuit is useful when, say, you drive (car or motorcycle) and you can’t use a hand to press PTT to talk. You speak directly and the VOX automatically activates the broadcast.<\/span>
\nFor radio amateurs it is useful in digital modes, when you connect the radio to the sound card of the computer, but not the PTT (you cannot, do not want, the software <\/span>does not have<\/span>). Newer transceivers have such audio interfaces (including vox).<\/span><\/p>\n

My YAESU FT-2400 (VHF-FM-50W) has no VOX or audio interface, so I made one earlier, presented here<\/span><\/span>.<\/a><\/span>
\nBut that VOX circuit didn’t work so reliably. Either it kicked in or out in the middle of the transmission, or it never disconnected the transmitter, I found the station once on Tx after a quarter of an hour, that you could boil an egg on it.<\/span><\/p>\n

In short, here is the new work:<\/span><\/p>\n