[1000mp] RS232 port repair

[J. C. Mc Laughlin]

Dear Zoli  HA1AG:

    You are correct.  I expect to use optical isolators as well as make the 
internal (very difficult to replace) chip as rugged as possible.

    Lower cost, self-powered, external isolators for 3 wire RS232 may be 
found here:

http://www.ascii-chart.com/RS232-RS485-RS422-Serial-Converters/RS232-Isolator-3-wire.htm

http://www.rs232-converters.com/rs232_surge_protector.htm

http://www.usconverters.com/index.php?main_page=product_info&products_id=187

http://www.sel-com.com/sel-2910.htm

    Please suggest lower cost, packaged, 3-wire RS232 isolators.

    Newer IC are available that contain all except four or five capacitors 
and that provide optical isolation.

    Does anyone know of  pin-for-pin chips to use inside of FT1000 that are 
more rugged than original equipment?  Part numbers?

73,   Mac   N8TT

J. McLaughlin;  Michigan, USA
Home:  JCM at power-net.net
----- Original Message ----- 
From: "Zoli Pitman HA1AG" <ha1ag at yahoo.com>
To: "J. C. Mc Laughlin" <jcm at power-net.net>; "All about Yaesu 1000mp" 
<1000mp at mailman.qth.net>
Sent: Saturday, April 04, 2009 4:54 PM
Subject: Re: [1000mp] RS232 port repair


>
> Hi Mac,
>
> I suggest to use an optical isolator pair in your cat line. There are 
> specific isolator IC's for this purpose.
>
> I use two optocouplers,  where the rig tx side is fed by it's internal 13V 
> (available on backplane connectors), and I instruct my pc to pull up DTR 
> to supply the PC TX side. It is build on piece of perfboard and sits in 
> the rig.
>
> 73, zoli ha1ag
>
>
>
>
> ----- Original Message ----
> From: J. C. Mc Laughlin <jcm at power-net.net>
> To: 1000MP Dec2001 <1000mp at mailman.qth.net>
> Sent: Saturday, April 4, 2009 10:31:46 PM
> Subject: [1000mp] RS232 port repair
>
> Dear Group:
>
>    A weak link with the FT1000 Mk V (and probably all of the other members
> of the family) is the CAT port.  The chip used is fragile.
>
>    The chip appears to be an Analog ADM232LJR for which a MAX232CWE is
> supposedly a pin-for-pin substitute.  Improvements have taken place in 
> such
> chips.  I propose to replace my defective chip with a ADM202EARWZ (the Z
> just indicates low Pb).  The ADM202EARWZ appears to be a pin-for-pin
> replacement, a chip with considerable resistance to ESD, and a chip with
> attention paid to EMC.
>
>    What experience have group members had with more rugged substitutes to
> the original RS232 chip?
>
>    Today, one would design using an optically isolated chip, but I did not
> find one that is a direct replacement.
>
>    73,    Mac    N8TT
>
>
>
>