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AM Day/Night Pattern Change as Part of Automation Log?

S

spinjector

I'm thinking of implementing our AM day/night power/pattern changes as part of the programming log instead of a Burk Autopilot scheduled macro.

Is there any reason not to do this?

As per the FCC, do the pattern changes have to occur exactly at the specified times, or is it ok for switches to "spread a little wider" so the switch took place a little before night, and a little after dawn, so it fell with the appropriate commercial set in the hour?
 
I have always understood it to be within 5 minutes of the assigned time. Some automation systems will allow you to execute a script at a specific time regardless of what the system is doing.

If you already have a procedure set up to change power/pattern, why change it?
 
Don't most remote control systems have this capability?
 
More of a legal answer than a technical one. An FCC attorney told me to include in the log ONLY THAT INFO REQUIRED. In case of technical problems, what do you not want is a logged verification/paper trail that your pattern failed to shift or shifted at the wrong time. You may help the FCC place the rope around your neck.
 
The reason I'd like to do this is so it sounds smoother on the air. I was talking to the PD ab out it, and he said he's heard it on other stations. The play an ID, then you hear silence-fizzle-pop, and it rolls into a spot or other such thing. I was thinking during satellite programming, it could be timed over the network fill music.
 
spinjector said:
The reason I'd like to do this is so it sounds smoother on the air. I was talking to the PD ab out it, and he said he's heard it on other stations. The play an ID, then you hear silence-fizzle-pop, and it rolls into a spot or other such thing. I was thinking during satellite programming, it could be timed over the network fill music.
Click to expand...

I would be willing to bet that most listeners don't even notice it. I have my directionals set for a very short mute time. From the time the Sine sends the command, they are back on in 3 seconds.
 
Bill Wolfenbarger said:
Don't most remote control systems have this capability?
Click to expand...
Yep.
 
I'm with Bengal on this. Most people don't even notice it if it's done right. Use PDM kill if available so that off time is minimum and there is no relay closure to make noise. Two of my AM's are on the Burk's and they just do a lower command that trips two relays in sequence, with no particular time delay between the first that kills PDM and the second that switches the relays, then both are released to release PDM kill. Takes no more than about 2 seconds. My third AM uses a Davicom that sequentially kills PDM, Switches the pattern and releases the PDM all in about 2 seconds. I suppose no-one at the FCC would compalin about your going to lower power SLIGHTLY early in the evening or staying on lower power SLIGHTLY after you could have gone high power in the Morning, but do it the other way around and expect the fury of the FCC and maybe the co-channel station you are protecting.
 
PDM = what? Carrier mute? We have Harris DX's and Nautel, so they go up & down like a lightswitch.

Unfortunately, on two of our stations I'm limited by the timing sequences that are built into the custom Kintronics switching controllers. I've never attempted to tighten up the switching cycles.

As for the timing, if the legal expectorations specify a window of five minutes, that's what I'll go with.
 
spinjector said:
PDM = what? Carrier mute? We have Harris DX's and Nautel, so they go up & down like a lightswitch.

Unfortunately, on two of our stations I'm limited by the timing sequences that are built into the custom Kintronics switching controllers. I've never attempted to tighten up the switching cycles.
Click to expand...

without getting too technical PDM kill mutes the carrier without turning off the transmitter. Makes it easier on the transmitter to just kill the RF without a complete shutdown. It also comes back faster once the switching is complete. Most antenna controllers allow you to set the delay time that the array is switched after the kill signal is sent. For solid state transmitters, this does not need to be more than a second or two. It's adjusted in the antenna controller. Depending on what model of Nautel transmitter you have, look for a remote connection labled "PDM Inhibit" or just 'inhibit' (I can't remember which). I have not had the pleasure of installing a DX yet, but it's noted in the manual on the remote control wiring diagram which connection you need to mute the RF.
 
Again, Bengal has it on the mney. PDM is Pulse Duration Modulation or also called pulse width modulation. PDM kill forces the transmitter to 100% negative modulatio and holds it there. that = 0 output power. SInce there ar no clunky relay's just a loic state change in the pdm modulator it occurs pretty quick. I use it in all of my AM transmitters, Continental, Nautel, and have used it as long ago as 25 years in a Harris MW5, so it's nothing new.
 
Hit the wrong key before I could spell check the previous. My 4 tower 20kw/2KW has a custon Kintronics switcher that takes only an instant to change. My duplexed two AM's on three towers also has a custom Kintronics on one of the transmitters and an ancient Harris on the other. Switching time is neglible and I use PDM kill on all three Nautel mains and the Continental and Nautel backups.
 
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