I suspect the vast majority of listeners wouldn't notice the difference; more would notice a scratchy signal though.

I have a colleague in a medium market where one of their FMs was in mono for MONTHS and nobody noticed. You'd also be at an all time low for the number of people who even know what mono is.

It really makes sense on an underpowered signal, certain terrains, and certain formats.

Forward Power wrote:

I'm guessing the station was still feeding the transmitter with a mono audio line and/or the old AM audio processor which could not/cannot generate an FM-compatible stereo output.

I wonder if this is the case for CBC on 99.1.  Their sound has a very boosted and dynamically compressed upper midrange, akin to AM on a wideband tuner.  So I wonder if they perhaps have an AM audio processor and a limiter somewhere in the chain left over from their 740 KHz days.
 

RadioAaron wrote:

The "talk" presets on FM processors often do exactly that.
 

So the engineers I take it would rarely have to mess with threshold, attack and release settings?  That almost disappoints me, because I'd like to be the architect of my "own sound".  I know the Optimod has a signature sound, but I though there was still some old schoolers that did it the old fashioned manual way.

What I still have to learn.
 

The entire Radio I nedwork is mono and it is intentional. They say it's more efficient.

Last edited by turkeytop (August 25, 2022 8:36 pm)

kevjo wrote:

I did hear form someone who was there at the time that when CKLY flipped to FM the owners of the day did it on the super cheap. Instead of a new site, they put the FM stick on the same swampy site. It had worked well for the AM but was not conducive to FM transmission resulting in a signal that didn't get out much past the city limits.
As part of the major technical upgrades they found a proper site which allowed the signal to reach its full potential including (coincidentally?) reaching Peterborough.
 

I do excuse the original owner that made the switch to FM. 
First of all, being a little guy company, not some big guy with deep pockets.
Money wasn't just tight, it was a miracle the station ever managed to stay on the air in the first place.

I seem to recall hearing something like this while tuning in one time way back in the day:
(Before Chum Group took over)

"...and don't forget to thank Joe's Garage, because if it weren't for Joe's Garage, we wouldn't be here!! Thanks for listening to the music of 5 decades..." 


 

kevjo wrote:

I did hear form someone who was there at the time that when CKLY flipped to FM the owners of the day did it on the super cheap. Instead of a new site, they put the FM stick on the same swampy site. It had worked well for the AM but was not conducive to FM transmission resulting in a signal that didn't get out much past the city limits.
As part of the major technical upgrades they found a proper site which allowed the signal to reach its full potential including (coincidentally?) reaching Peterborough.

I was a teen in Omemee at the time, about 10 km LOS from CKLY's site, and the signal, roughly 14 kW ERP, was about as good as what someone in the north end of Lindsay would receive. CKLY-FM actually stayed at the ex-AM site and is still there to this day, but just before the change from "Y92" to "BOB FM" in the mid 2000s, a significantly taller tower was built, allowing CKLY to transmit more efficiently with more height and less power. There were plans a couple of years earlier to move 91.9 to a site in the hills near Bethany, but I believe those were shelved.

I agree with Radiowiz on the ownership group's financial situation... the place had been rather unprofitable for probably the entire time that Centario (a group of area investors) owned CKLY. I can only imagine what it cost for them to a) bring in automation in 1997, and b) set up the FM plant the following year. One jock's job had to be cut, and maybe a second employee as well, shortly before the conversion took place.

Isnt this kind of the same thing as those receivers when you can select stereo to be on/off which we used to push to get rid of the background "hiss"of a weak signal?  

markow202 wrote:

Isnt this kind of the same thing as those receivers when you can select stereo to be on/off which we used to push to get rid of the background "hiss"of a weak signal?  

Exactly. When mono is selected (or stereo isn't) the better receivers / tuners will shut off the multiplex circuit in the tuner resulting in less hiss or noise. You will notice the stereo indicator also goes off.

I've seen other (usually cheaper) receivers that don't disable the multiplex and when mono is selected, the noisy stereo signal is sent to the amplifier where it is changed to mono. The result will be a noisy stereo signal that comes out as mono. The FM stereo indicator will stay illuminated.

This can be easily demonstrated if you have a separate tuner and amplifier with a mono selector. Tune to a weak noisy stereo signal and switch the tuner to mono and noise will drop. Put it back on stereo and select mono or L+R on the amp and the noise will not be reduced.

Radio World, which originally published the commentary on turning off the stereo on FM to improve reception, has now put out reaction to the article. There's clearly a huge divide among radio professionals about this idea and you can read the wide variety of opinions here.