[Elecraft] RS-232 Problem

[Jerry]

Bob,

Here is a list of just a few of the possible causes.

1. The computer has an actual problem with the com port. 
2. The cable between the K2 and the computer has developed a bad connection
or short. 
3. The K2 or KPA-100 serial interface has failed. 
4. Your computer has some other software locking up the com port. 
 
To troubleshoot this, first I would inspect the cable.  Next, if you have a
laptop, or if a friend has a laptop, you could install your K2 control
software on another computer to test out the serial interface inside the K2
along with the cable.  You may also be able to take your K2 to a friend's
house and test it on another computer.

Another suggestion would be to use a different com port.  Plug the K2 into a
different com port if one is available.  You will then have to change the
com port in the software you are using.  If you have another device that
runs on a serial port like an old printer that runs on a com port, you could
use a device other than the K2 to test out your computers com port.

Another possibility is that another software package is locking up the com
port.  If you have some software on your computer that uses the com port,
and does not release it, then other programs can not use that com port.

Let me know if these suggestions help, and what results you come up with.

I am interested in how you resolve your problem, and if any of these
suggestions help.

73's Jerry KC4YDP

K24U Software   http://www.kc4ydp.com

-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Bob Whitaker
Sent: Monday, May 31, 2004 11:33 AM
To: elecraft at mailman.qth.net
Subject: [Elecraft] RS-232 Problem

Started getting prepared for the CQ WW WPX and discovered that my K-2 would
not communicate with my PC.  I have K-2 with KIO2 and a separate EC-2 with
KPA-100 & KAT-100 installed in it.  Last time I checked, a week or so ago,
everything worked.  No problems communicating with the separate KPA-100 &
KAT-100, so problem has to be with cable or RS-232 circuitry.

 

I've checked the following:

 

1.	Changed ports on PC & control software.-------No Go
2.	Checked connectors & measured continuity on cable-----Found shield
wire on K-2 end loose, resoldered----No Go
3.	Moved KPA-100 back into K-2 & used RS-232 in KPA-100------No Go
4.	Checked voltages on P-4 on Control Board with eight pin cable
disconnected.  Everything normal except for Pin 1 (TXD->1.64 V vs req 5.0) &
Pin 3 (RXD--->.06V vs req 5.0) 
5.	Checked  voltage around MCU RXD & TXD inputs & outputs.   5+V on pin
3 of RP7 & 0.06V on pin 4 of RP7, Also 0.06V on pin 26 (RXD of MCU)
6.	Reset MCU & went through the woes of resetting filters and other
parameters.---Everything works except RS-232.

 

I had already ordered KV-60 upgrade with new MCU and it should be here next
week.  While control board is out should I check C20 & RP7 or could this be
an MCU problem?   

 

Suggestions please.    I worked a little bit of the contest, but without
radio control & readout, it's not fun!

 

Bob

W5RW

 

 

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