[1000mp] MAX232 replacement.... not a big deal.

[Guido]

Dear Frans,
    it can be possible, but, actually, I never found a PC (Desktop or
Laptop) that fails to work with the interface.
With my circuit, even with a RS232 that can supply only 7mA at 8V and a 4N25
with its minimum CTR (20, but, at 99%, it is much higher) you will have
enough signal to drive the MAX232 receiver.
73 de Guido, ik2bcp


----- Original Message ----- 
From: PA5CA Frans
To: 1000mp at mailman.qth.net
Sent: Monday, August 28, 2006 11:14 PM
Subject: [1000mp] MAX232 replacement.... not a big deal.

Dear Guido,

Thanks for the excellent input for the CAT users however I need to make one
little remark on the schematics.

In your drawing you are feeding the OPTO"s from the RS232 port. we know from
experience that some RS232 ports do not deliver enough current, so I
designed an interface which ccan handle that phenomenon.

It is a pitty that I can not up-load schematics so I 'll  place modified
schematics on the PA6Z home page.

Please note that you may read the text at
http://www.pa6z.nl/PROJECTS/INTERFACE_v2/interface_v2.html first.

After reading this part go to the following link with the modified
schematics for the FT1000mp.xx

The URL will be www.pa6z.nl/ft1000mp.html

Good luck... and have fun.

De PA5CA Frans.......73