RPTR CLAIMS XMITTER HAS AUTO TERMINATION PROB IF KEYED FOR MORE THAN 28-30 SECONDS. RPTR CONSIDERS IT AN UNSAFE SIT.

Narrative

ON OKC-LO SECTOR; FREQ 128.4/290.2; IF THE XMITTER IS KEYED CONTINUOUSLY FOR MORE THAN 28-30 SECONDS; A CHAIN OF EVENTS IS INITIATED WHICH ULTIMATELY UNKEYS THE XMITTER EVEN WHILE THE CTLR IS STILL ISSUING CTL INSTRUCTIONS. ON JAN/XX/97; XX18 PM LCL; I WAS GIVING AN ACFT THE ADS WX; FOLLOWED BY DFW LNDG CONDITIONS. IN THE MIDDLE OF THE DFW CONDITIONS; MY XMITTER BECAME INOP. HAD THESE BEEN CTL INSTRUCTIONS; THE CONSEQUENCES WOULD HAVE BEEN MORE THAN JUST THE INCONVENIENCE OF READING BACK THE WX. THIS XMITTER 'AUTO-TERMINATION' PROB HAS EXISTED SINCE VSCS WAS INSTALLED. MY SUPVR SAYS 'IT'S ALWAYS BEEN THAT WAY.' I CONSIDER IT AN UNSAFE SIT. THIS 'AUTO- TERMINATION' FEATURE EXISTS ON AT LEAST 4 OF OUR 6 SECTORS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT HE WAS TOLD BY THE FACILITY MGR THAT AUTO TERMINATE OF THE XMITTER HAS ALWAYS BEEN THAT WAY IN ORDER TO PREVENT OVERHEATING OF THE XMITTER EQUIP. RPTR STATED THAT PRIOR TO THE VSCS EQUIP; THERE WAS NO INDICATION THAT THE XMITTER HAD SHUTOFF AND INDICATED THAT THERE IS AN AURAL ALARM AS WELL AS A SCREEN PRINTOUT SHOWING A LOSS OF THE XMITTER. RPTR STATED THAT IT OCCURS DURING LENGTHY XMISSIONS SUCH AS WX OR FLT PLAN INFO AND THAT ONCE THE XMITTER IS UNKEYED IT IS AUTOMATICALLY RESET FOR OPS.