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PTT
with Optocouplers
As described before keying the ptt line of the ft1000mp series is hard to pull
down.
The usual optocouplers such as the 4nxx series or others can not pull the PTT
line below 0.5 V.
I have used for years a 2n3904 transistor, others a 2n2222, to key the PTT line.
But I wanted to isolate the pc completely from the transceiver and a mosfet
optocoupler with low on-state resistance does the job.
I have used a TOSHIBA TLP227G with success, others has described the NEC
PS7141-a.
With thanks to JA1EOD Aki for his knowledge. ON4ADZ
Simple PTT Circuit

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