[TowerTalk] Fw: [SteppIR] Re: 3 ELEMENT 180 DEG SWR PROBLEM

[Al Williams]

----- Original Message ----- 
From: Al Williams 
To: towertalk at contesting.com 
Sent: Thursday, June 18, 2009 9:37 AM
Subject: Fw: [SteppIR] Re: 3 ELEMENT 180 DEG SWR PROBLEM


Please provide us with as much detail info on those signals as you can:

1. Where do you connect the scope ground?

2. What is the time duration of the pulses?

4. Are those pulses only during switching from 20 to 10 meters?

5. What is the significance of the long vs short pulses?

6. What pulses occur during a change of freq within a band?

7. Is this kind of info available elseqhere>

Thanks

k7puc
----- Original Message ----- 
From: rstealey 
To: SteppIR at yahoogroups.com 
Sent: Thursday, June 18, 2009 5:06 AM
Subject: [SteppIR] Re: 3 ELEMENT 180 DEG SWR PROBLEM





One thing you can do, if you have a scope is to look at the signals on pins 5-8 of the RS232 connector. Those are the pins used to activate the director motor. Do this by removing the connector, opening it up. Compare the signals you see on those 4 pins to the ones you see on 1-4 (the driven element). Use extreme caution not to short pins together.
If you switch from 20 to 10 meters, you will see a couple long pulses, and then a bunch of short pulses, then some long ones again. About 20 volts peak. Look at pins 1-4 to see what they should look like. Any differences means your driver chip is probably bad.
I just did this on mine to isolate driver chips that I blew out through mis-wiring. All my fault, but I replaced two chips and all is FB now.
You can do this test with a spare unused male RS232 connector if you have one. You don't need to have wiring connected to the antenna. Measure between the pins and the shell of the connector.
You can do this test and put things back together in about ten minutes.
Rick K2XT



__._,_.___
Messages in this topic (3) Reply (via web post) | Start a new topic 
Messages | Files | Photos | Members 
 
Change settings via the Web (Yahoo! ID required) 
Change settings via email: Switch delivery to Daily Digest | Switch format to Traditional 
Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe Recent Activity
  a..  10New Members
Visit Your Group 
Give Back
Yahoo! for Good

Get inspired

by a good cause.

Y! Toolbar
Get it Free!

easy 1-click access

to your groups.

Yahoo! Groups
Start a group

in 3 easy steps.

Connect with others.
. 

__,_._,___