[TowerTalk] US Tower Local Control problem

[NPAlex at aol.com]

John,
Based on your comments below that it works both UP and DWN from the REMOTE  
position would indicate that the UP/DWN relays and limit switches are  
okay.  This leaves two possibilities, one is when you switch from Remote to  
Local that you loose power to the Power Relay located in the tower box.   Check 
to see if that relay is closed.  However the most likely issue is a  faulty 
UP/DOWN LOCAL switch (it is a SPDT switch) -  Check to see if there  is 
115vac at  the center lug (reverenced to common), (there should be  as long as 
the remote box control is in the LOCAL position).  Next switch  to UP and 
check for voltage at one of the other lugs, and then DWN checking  again for 
voltage at the other lug.  The UP side should fail the voltage  test.  Look 
for a loose wire/lug at the switch.
 
I will send you a direct email with a schematic of the RM-1000 control  
system
 
GL
Norm W4QN

=====================================================
Date: Tue, 27 Apr 2010 06:45:48 +0000
From: John Farber  <kg6i at hughes.net>
Subject: [TowerTalk] US Towers 472MDP won't raise  from the LOCAL (base
of  tower) location
To:  towertalk at contesting.com
Message-ID:  <4BD6881C.1000607 at hughes.net>
Content-Type: text/plain;  charset=ISO-8859-1; format=flowed

Works fine from the remote unit in the  shack. At the tower base (LOCAL 
switch position on the remote box in the  shack), it will lower but not 
raise. Anyone been through this scenario and  found the fix? Thanks, John