When I woke up shortly after 6am, I checked the transmitter, via a computer at home, and found there were once again no overnight cutbacks. I increased the modulation another 0.2dBU to 8.3dBu to see if I could induce a cutback. [If it would have cutback, I have the ability to remotely return it to full power] No cutback occurred, so will leave it at this level for tonight.

We managed to contact Nautel today and found that there are some adjustments, not mentioned in the set up procedures, that would bring the no modulation power level with AMC back up to 100kw, instead of 80kw. One of the setup procedures is to set the ‘gain balance’ so there are 0 volts between two specified points. We had done this procedure as explained in the manual. What was not mentioned, is that, after everything is set up and AMC switched on without modulation, this same ‘gain balance’ control can be adjusted, while switching between AMC and ‘standard AM’, so that the power levels are the same. This procedure must be done starting with low power, then repeated while increasing the power in steps to 100kw.

This afternoon, we followed these additional instructions. Now everything seems to function properly on AMC and when switched back to ‘standard AM’. We did some tests switching between the two and found that we could switch quickly from ‘standard AM’ to AMC. Switching from AMC to ‘standard AM’ resulted in multiple faults that shut the transmitter down and it could not be turned on again without shutting off the mains and turning them back on. I then carefully watched what was happening during the switching off of AMC and noticed that the power output would jump to over 130kw. I suggested putting a time delay before the transmitter was allowed to come back on after switching AMC off. This worked, if the delay was over 10 seconds. I then suggested an alternative to switch the transmitter power to 25kw at the same time as switching AMC off, waiting for about 2 seconds, then switching to 50kw. After another 8 seconds, then the switch could take place to 100kw. This way there is dead air for only one second instead of 10 seconds. Two macros, for 50kw and 100kw, was set up to automatically go through this process when switching dynamic carrier control (AMC) off.

Test programming was now successful run with AMC for about 30 minutes. We felt comfortable allowing AMC to be used for this evening’s broadcast. It is now after 10:30pm. The transmitter has been running for 5 hours and seems to be performing well. With this method of dynamic carrier control, AMC, the voltage peaks are considerably less than with ‘standard AM’, so I do not anticipate any problems with cutbacks.

We got our evening swim in tonight. We’ll have to make other plans for tomorrow because it is Friday night AND payday. We suspect there will be a BIG party!

Supper tonight was chicken strips on rice, with green beans, and the rest of the papaya for dessert.