[RTTY] ptt keying the mark V

[ON4ADZ]

Dear

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 succes, others has described the NEC
PS7141-a.

With thanks to JA1EOD  Aki for his knowledge.


I have some Toshiba TLP227G left, if you are intrested give me personal
mail.



73
DIRK
on4adz at pro.tiscali.be