Don’t be too fast at not looking at the contactor. I had a BE 4MX-25 where the contactor failed entirely. Turned out that the contactor coil is powered from
an internal switching power supply that could take in anywhere from 80 to 250 volts AC or DC and drive the contactor’s coil with its output. The entire contactor would have been expensive to replace, but I was able to buy the internal power module for about
Michael W. Price
Manager, Technical Services
Salem Radio Network
6400 Belt Line Rd., STE 210
Irving, TX 75063
From: Nathaniel Steele [mailto:firstname.lastname@example.org]
Sent: Wednesday, June 06, 2018 8:22 AM
Subject: Fwd: Transmitter down ! !
Anyone here had this problem?
Hi guys....if you know anybody that knows the control circuits for this transmitter, bounce this problem off them:
BE FM-30 the control system for the 20 and 25 is likely the same.
Problem: 3 phase main contactor in the power supply drops out, then immediately re-latches.
It may not do it again for a few minutes, or it may do it 3 or 4 times in succession.
Again: picture the TX in standby. All blowers on, filament on the PA.
The main contactor drops out, shuts everything off for a second, then latches back up.
May not do it for 5 minutes or so, from a cold start. Very intermittent.
Talked to BE tech service last night...." Mike" gave me a list of maybe 20 possibles. That's great.
I'm doubtful it is the contactor itself. Something in the control to it is likely making it drop momentarily.
I am going to pull the front panel off the 30 today to access the OCR's and controls. Or try to.
Uncle G. in Lawrence.
There is no backup for it here. Nada. Their money maker is down.
I'll open up the transmission line today and see if I can get a spare 250w exciter into it with a reducer.