I actually found a good reason to shut off our HD service!

[Ralph Martin]

This Wednesday May 27th at 12:00 we're shutting off our HD system including all side channels for three hours!

The school asked us to cover our 8th grade graduation ceremony live. It'll be a "drive-in" ceremony where everyone will be in their cars listening to the officials speak. So, everyone will be watching the event from inside their car live while listening to their car radios. It'll have to be broadcast in "real-time."

To make this work, I'll have to temporarily turn off the HD service and go all analog to prevent the almost nine-second delay needed to accommodate the digital encoding process.

So here, in this COVID-19 world, is an example where analog beats digital. Odd how things work sometimes

Ralph
KVCB- not HD
(Well, for three hours, anyway.)

 

[Kelly A]

You could have also just bypassed the analog delay and let the HD streams run 6-8 seconds late during the ceremony.

8th Grade Graduation?? Is that a thing?

 

[Ralph Martin]

You could have also just bypassed the analog delay and let the HD streams run 6-8 seconds late during the ceremony.

To do that, everyone at the event would need to know how to deactivate their HD to prevent their radios from automatically locking onto the delayed digital signal. That would probably not work out for everyone. I suspect this is the best way. It's just a few hours.

I suppose this could be a problem for live sports Broadcasting for those who want to bring their radios and follow a game with their favorite sportscaster live.

At least we know they won't be rolling down their car windows. It's expected to reach 104° today!

8th Grade Graduation?? Is that a thing?

Yes it's the promotion to 9th grade. It's been a tradition for decades here, just not as a "drive-in" event.

 

[Kelly A]

Yes it's the promotion to 9th grade. It's been a tradition for decades here, just not as a "drive-in" event.

Recognizing this is completely off topic...but:

Graduating from High School is a defining right of passage into adulthood. Graduating Middle School, or even more strange; Kindergarten? I suspect these sorts of ceremony are more for the parents than the student.

 

[davideduardo]

Recognizing this is completely off topic...but:

Graduating from High School is a defining right of passage into adulthood. Graduating Middle School, or even more strange; Kindergarten? I suspect these sorts of ceremony are more for the parents than the student.

I also found that graduation from 8th grade being considered a major life event to be strange.

I agree with you that for most, ending High School is the point when kids become adults... are able to leave home for a distant college... enter trade school or getting a job. Almost all my friends from High School still talk about graduation, the parties and the like...

... I missed my graduation as it happened the same week my first radio station went on the air. So the strange kid could not make it and get his diploma. But I am still kidded by friends from the class about it... the event was so important.

But I can't see it for 8th grade.

 

[Ralph Martin]

I also found that graduation from 8th grade being considered a major life event to be strange.

I don't think it's that strange in our case. Many years ago, our school only went from preschool to 8th grade. After that students left and went to other schools. I could see after 11 or 12 years at the same school, they would have a nice "send-off." When our school added grades 9 through 12, the tradition of the 8th grade promotion stayed and is still a big thing for the parents.

What made it special this year was the circumstances under the pandemic. Everyone stayed in their cars in a parking lot with their windows rolled up. They listened to the outside event on their car radios. They applauded by honking their horns. It was somehow a good representation of what we've been through these past months. it was surreal.

HD had to be suspended to remove the approximately 8 seconds of audio delay that would have been a bit strange when watching the event through their windshield.

Anyway, that was my main point

 

[Ralph Martin]

Haha, and for the record:

I said approximately 8 seconds of delay. To be exact, I currently have the delay set at exactly 8.694 seconds

Add the 6 seconds of profanity protection, and the latency of remote to studio over IP and it becomes harder to call something truly "live." I was lucky to get the final delay to just under a half of a second. It worked out fine.

 

[gr8oldies]

Some stations (one being WLW), turned off their HD during baseball games for the benefit of those listening on portables in the stadium.

 

[Kelly A]

Some stations (one being WLW), turned off their HD during baseball games for the benefit of those listening on portables in the stadium.

That was because they had one of those old AM-re-transmitters in the stadium for those in the stand who want to listen to the broadcast on their 'transistor radio'. Those old re-transmitters don't like digital sidebands.

 

[DaveBayArea]

Some stations (one being WLW), turned off their HD during baseball games for the benefit of those listening on portables in the stadium.

Not sure if it's in the newer versions of the software, but there used to be a "ball-game mode" that set the diversity delay to zero. I always thought this was odd - that they would sacrifice the listening experience for HD radio users in favor of the ones in the ballpark with portable radios. Much better to follow Ralph's lead and turn HD off.

Dave B.

 

[KB1OKL]

You gotta be kidding me! There are actually stations still broadcasting in IBOC?

 

[TheBigA]

Look who's back...after how many years?

Most of these threads are not about AM HD, btw. AM is almost as dead as HD.

 

[KB1OKL]

I know I just saw your name, what's up?

 

[Ai4i]

...I'll have to temporarily turn off the HD service and go all analog to prevent the almost nine-second delay needed to accommodate the digital encoding process.
(Well, for three hours, anyway.)

I have been trying to set an audio processor at a studio while there is another one at the transmitter site which seems to be fighting it constantly AND I dare not touch the second one because the mod monitor broke.
The problem is that the station uses a web-based STL which introduces so much delay that it takes me about half a minute to hear the result of anything I do.
I really do wish that I still had my old oscilloscope.

 

[Kelly A]

I have been trying to set an audio processor at a studio while there is another one at the transmitter site which seems to be fighting it constantly AND I dare not touch the second one because the mod monitor broke.
The problem is that the station uses a web-based STL which introduces so much delay that it takes me about half a minute to hear the result of anything I do.
I really do wish that I still had my old oscilloscope.

Wait..you have an audio processor at each end of an STL? Why? Maybe an audio leveler/AGC at the studio to prevent overloading your STL, but two full-boat audio processors? No wonder you're chasing your tail.

An oscilloscope will help you keep the negative limit for an AM from closing the envelope, but setting asymmetrical modulation with an oscilloscope would be difficult, if not impossible. Trying to set modulation on an FM with an oscilloscope is also very difficult. Especially if you're running stereo or subcarriers. Finding a detector that you can rely on, also difficult.

Do yourself a favor. Get a working modulation monitor.

 

[Ai4i]

Do yourself a favor. Get a working modulation monitor.

I just volunteered to fix an audio problem because I could not stand the way it sounded on the air, but I told them to either send it in to be fixed and aligned or just get something from this century.
You are right about the purpose of the unit at the studio, I refuse to touch the full processor at the transmitter without being able to keep the negative peaks under 99%.
I never worry about positive peaks because 125% is an arbitrary commission figure and would not bother anyone even in the highly unlikely event that the equipment could produce them.

 

[davideduardo]

Wait..you have an audio processor at each end of an STL? Why? Maybe an audio leveler/AGC at the studio to prevent overloading your STL, but two full-boat audio processors? No wonder you're chasing your tail.

The classic example from "back in the day" was an Audimax at the studio and a Volumax at the transmitter. The gear has evolved, but the idea of an AGC at one end and a compressor-limiter at the other goes back to the late 50's and hollow state devices.

 

[Ai4i]

...hollow state devices.

I never heard that term but I like it,
hollow as in a vacume.

 

[Kelly A]

I just volunteered to fix an audio problem because I could not stand the way it sounded on the air, but I told them to either send it in to be fixed and aligned or just get something from this century.

Depending on what processing it is; I'd start with bypassing or eliminating that processor at the studio.

You are right about the purpose of the unit at the studio, I refuse to touch the full processor at the transmitter without being able to keep the negative peaks under 99%.
I never worry about positive peaks because 125% is an arbitrary commission figure and would not bother anyone even in the highly unlikely event that the equipment could produce them.

I wouldn't call positive modulation peaks arbitrary, because depending on the transmitter, excessive peaks could be causing severe distortion or even carrier shift.

Doesn't matter if AM or FM, there are so many variables that can affect the sound of a station. I've heard two stations with the exact same processor and presets that sound completely different. I've been called into FM stations with the latest, most expensive audio processor that still sounds like garbage. Come to find out, their tube-style FM transmitter had a tuning problem and did not only have constrained bandwidth and excessive AM noise, but their FM exciter had issues (dried-out capacitors in the modulator stage).

For AM, if the transmitter doesn't like the load, tubes are soft, caps are dried-out (Harris DX-series), or the audio processor they're using has dried-out capacitors, it will sound bad. In either case, processor settings will have limited improvement, if not make things worse.

 

[Greg Goodfellow]

Recognizing this is completely off topic...but:

Graduating from High School is a defining right of passage into adulthood. Graduating Middle School, or even more strange; Kindergarten? I suspect these sorts of ceremony are more for the parents than the student.

Our school system in Tyler County, West Virginia abandoned 8th grade graduation decades ago.