Some rigs are difficult to key this way. For example, I and others have had
trouble getting various optos to pull low enough to key the PTT line of the
FT-1000MP. I've tried 4n25 and a couple of other commonly-used optos,
including a Darlington pair - all to no avail, and I've seen similar posts
from others. It's a cleaner way, but might not work with all rigs.
----- Original Message -----
From: "Costas Krallis SV1XV" <sv1xv@eexi.gr>
To: <writelog@contesting.com>
Sent: Thursday, May 29, 2003 11:43 AM
Subject: [WriteLog] Re: CW Keying Interface
>
>
> > That's what I use. Some recommend a 3-4K resistor instead of the 1K
> > - won't hurt, might help. 2N2222 is fine. I key CW with DTR on the
> > COM port, thru resistor to base of 2n2222. Ground the emitter.
> > Emitter and collector to key rig. I think you have it.
>
> You may also replace the transistori with an opto-isolator (4N28 etc).
> This way you can get ground isolation between the computer and the
> RF equipment.
>
> 73 Costas SV1XV
>
>
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> | Costas Krallis, SV1XV |
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