I will be listening to music on the Fm, then turn it over to charlie and notice that the volume level is a lot lower on Charlie than on other statuions. The station just doesnt sound as loud as the other stations. I have to turn my volume knob up when it lands on Charlie. Why is this? Just curious!

It sounds like the processing is more conservative on Charlie.

I like it that way actually. The station sounds really good.

Just turn it up a little and enjoy the sound. The others are pushing it to the max, and that's more tiresome on the ears than what we hear on Charlie.

Some of the PDX FM's are like the old days of 60's-70's AM...loudness wars...and I hear real distortion on FM...not good.

Doesn't 97.1 have the same "level" as 94.7? I can't really compare levels from my location in Eugene, due to the weak reception.

They sure sound similar. I like that station too. Neither has that tiring "brick wall" sound.

107.5 has the most overdriven, distorted sound in Portland. The Clear Channel engineer really needs to adjust it, or install a new Omnia.

Let's give him a full 24 hours, at least.

Charlie, Jack in Seattle and Bob FM in Denver all of them I noticed have lower levels then the rest. I was just wondering if that was a package set up deal to run the levels lower. Sure can here the music better then being crammed and pushed into high volume levels.

BUT It doesnt sound good when you are scanning the dial. All the stations are at the same level and than you come to charlie and the noise level is really low. It really doesn't "Catch your ear" like the other stations do.

Yesterday, I did a very informal comparison of 97.1 versus other commercial music stations, and I don't notice much of a difference in the perceived loudness levels. I will try again tonight, using other radios and my Heathkit FM deviation monitor.

Oh no. There it goes!

Justin has started the next round of the loudness wars.

(please guys, leave those two alone! They sound good.)

I checked the deviation monitor. Mind you, the selection of radio stations that I can pick up on this is limited because this is a very low-sensitivity receiver with no preselector.

I found that if you were to listen to KUFO and then you flipped to KYCH, you might come off thinking, "gee, 97.1 sounds quieter." KUFO is deliberately using limiting (and probably clipping--I would need to get my oscilloscope to verify) to achieve a loud on-air sound. The meter on the deviation monitor just hovers around 60kHz deviation*. On KYCH, the needle moves around more, say 40-55kHz.

Now, if you were listening to KGON and you flipped to KYCH, you might think the opposite, that is that KGON is quiet and KYCH is loud. On KGON, I was seeing the needle move more, say 30-55kHz.

In all of these cases, I think that the amount of dynamic range being put on the air is reasonably small, so you should not have problems listening to these stations in noisy surroundings like a car, a commercial kitchen, etc. I think that striving for the level of loudness of KUFO brings with it diminishing returns in that getting that loud comes with the penalty that such a sound is more annoying to listen to for extended periods of time (audio processing literature uses the term "ear fatigue" to refer to this phenomenon).

* I am not assuming that the deviation meter is calibrated. I am more interested in how much the needle moves (indicating the relative amount of dynamic range) than in the exact values.

I may not be well calibrated either, but I get:

92.2 KGON 55-80 Khz, pilot 7.0khz, rds 5.5 khz, RF 78dbu
97.1 KYCH 60-78 Khz, pilot 7.0khz, rds 5.8 khz, RF 83dbu
101.1 KUFO 78-82 Khz, pilot 6.8khz, rds 3.8 khz, RF 88 dbu

Using an Audemat FM 100 Navigator.

Not much dynamic range on 101.1!

Now, take a look at 107.5 KXJM!

107.5 KXJM 75-85 Khz, pilot 6.8khz, rds 5.3khz, RF 82 dbu.

Note on this meter the "red zone" starts just below 80Khz.

Not much dynamic range on 101.1!

101.1 has the worst range in stumptown!

Since the deviation numbers that I posted above were jumping all over the map, I made some longer term measurements (15 minutes on each station) of left plus right modulation levels. Here are the results:

107.5: 1% min, 119% max, 73.4% avg
101.1: 1% min, 120% max, 91.2% avg
97.1: 4% min, 105% max, 76.4% avg
92.3: 1% min, 112% max, 75.5% avg

clearly 101.1 is the "compression king"

When did KGON start not being loud?

I think they may have changed their processing around the time that they started simulcasting in HD. When I first heard KGON some ten years ago, they were loud, and they had a slightly distorted sound.

What time of day did you listen. Live 5 am to 7 p.m. enco from 7 pm to 5 am. weekdays. and all otto the weekend. This could affect level when not live.

most stations got processing upgrades along with the HD.

KGON probably made the most dramatic change in terms of the comparative age between the old processing and the new.

I think they did a great job of using the modern gear to get a sound similar to the old but without the distortion.

"What time of day did you listen."

I just took the L+R modulation data again (15 minute average) to compare to last nights data:

107.5: 1% min, 111% max, 73.8% avg (RF= 82dbu)
101.1: 1% min, 122% max, 85.2% avg (RF= 88dbu)
97.1: 1% min, 106% max, 69.2% avg (RF= 82dbu)
92.3: 1% min, 112% max, 77.0% avg (RF= 81dbu)

Interesting topic...

I would be real curious jr_tech if you could take a quick reading on some of the translators too, specifically 102.7 K274AR. 73's

Sure... My signal strength is only about 47dbu on 102.7 so measurements may not be super accurate.

Again, a 15 minute average, L+R modulation level:

102.7: 32%min, 150% max, 115.1% avg (RF=47dbu) YIKES!!!

102.9: 1%min, 100% max, 32.6% avg (RF=39du)... Nice broadcast of "War of the Worlds"!

Wow...why am I not surprised at what you found. I had a feeling it was bad. But, 150 max is a bit overboard and not much of a minimum either!

Thank you Jr_tech for the snapshot on that and on KQSO. Looks like we're in the dirt...lol

What did you mean to say instead of 102.9? The only thing I know on that frequency is KNBQ Centralia-Chehalis.

I think he measured the LPFM on 102.9.

From the Hillsboro area 102.9 is also KQSO-LP if my APS-9 is pointed south:

http://www.fcc.gov/fcc-bin/fmq?state=&call=kqso&city=&arn=&serv=&vac=&freq=0.0&f re2=107.9&facid=&class=&dkt=&list=1&dist=&dlat2=&mlat2=&slat2=&NS=N&dlon2=&mlon2 =&slon2=&EW=W&size=9

Pretty low power...only .001KW erp!

It's a terrible thing, getting old, especially for a radio guy. The first thing to go is the frequency.

I think that might be the second to go... but I don't remember what was the first!

Gettin' old sucks.

Thank God for highly compressed FM stations then! You can put off that hearing aid purchase for a few years, maybe even longer if you're listening to 101.1. (I haven't been there much since it flipped away from KB.)

Gettin' old sucks.

It beats the alternative, though!

I hear a BeeGee's song on Charlie now...."Stayin...

001kw_erp:

I re-measured 102.7 today and got very different results:

102.7: 14%min, 98% max 73.8% avg (RF=36dbu)

Perhaps I have a local pirate that sometimes uses 102.7 ?? I will keep checking.

Ahhh thank you Jr_tech, it sounds like some quick adjustments may have been made....perhaps. Maybe not.

Feel free to email me with any fun findings that you come up with. I wasn't aware of a pirate in the area.

I assume the RF dBu number is your received signal strength. That really went down too from your previous reading. Did you swing your yagi in a different direction when you took the latest reading?

"Did you swing your yagi in a different direction when you took the latest reading?"

Bingo! Yes, it was still pointed toward Astoria... I listened to KMUN last night.



When I turned the antenna east, I repeated the awful data that I first presented. It appears that the FM Navigator perhaps becomes overloaded, and produces a "spur" right on the top of 102.7

With an attenuator in the line I just measured:

107.7: 14% min, 120% max, 85.9% avg (RF=34dbu)
This probably as good of a measurement as I can obtain on this weak signal in a forest of powerhouses.

It sounds like you put about a 10 dB or so pad in line with your antenna when you took this last reading. Even your previous reading of 47 dBu isn’t really what I would think to be strong enough to overload your unit. That is only about a -68 dBm signal.

I am not familiar at all with the FM Navigator. The front end could get overload sucking in all the Class C stations pointing to the east as you’re doing depending how selective it is. Oh well, I think you hit the nail on the head stating that it’s probably “as good of a measurement as you can obtain on a weak signal in a forest of powerhouses”.

I am curious if the FM Navigator can do any measurements relating obtaining the modulation index of a signal?

Thanks for the impromptu analysis…..

"The front end could get overload sucking in all the Class C stations pointing to the east as you�re doing depending how selective it is."

Yes, I believe that that is what is happening, From my Hillsboro location, only the very best FM tuners can handle the signal from the APS 9 pointed toward the Portland towers, without showing some signs of overload.

"modulation index of a signal? "

I see no indication that the Audemat FM 100 can directly make that measurement.

107.5's processing has changed, since Clear Channel took over. It now sounds better!