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How?: AM as good as FM

AM can absolutely sound better than FM...I recently rebuilt the entire CRL stereo processing and CQUAM exciter at WPAX. Over the course of a few nights, I calibrated and adjusted everything...when I was working on the processing, I would remove the NRSC filtering...and transmit a wideband signal into the dummy load...and listen with the Motorola CQUAM mod monitor...I could not tell the difference between the off air and the program audio...and I'm pretty picky about audio...was a very eye-opening experiment.
 
Why, naturally AM can sound better than FM. It's hard to quantify, but the inherent nature of audio detected from FM is somehow
not as full and round in the lower audio frequencies. Then too, while the high frequency response in FM radios is far more
uniform than AM radios, these high frequencies never seem as pure as AM or like sounds from an actual musical instrument physically present. I'd describe it as sounding like the music is beautiful, but it's contained inside a plastic presentation box.
I prefer listening to music that sounds like the it's been taken out of the box for bettter appreciation.
AM, when done right, is much more intimate sounding than FM. It's wet vs dry, and I'll pick wet every time.
 
The two AM Stereos I built in the late 90's sounded awesome. And, in the mid-2000's, WOKY in Milwaukee sparkled in stereo on the Chrysler/Dodge radios of that era.
 
level42 said:
AM can absolutely sound better than FM...I recently rebuilt the entire CRL stereo processing and CQUAM exciter at WPAX. Over the course of a few nights, I calibrated and adjusted everything...when I was working on the processing, I would remove the NRSC filtering...and transmit a wideband signal into the dummy load...and listen with the Motorola CQUAM mod monitor...I could not tell the difference between the off air and the program audio...and I'm pretty picky about audio...was a very eye-opening experiment.

Right Chris, I'm totally with you.
Now, if we could only clean up the band by eliminating half the channels so we could get rid of the need for the NRSC filter, and then get some DSP guru to invent an effective noise/interference elimination algorithm for receivers...

And then I woke up. LOL!

Kind Regards,
David
 
Could awesome sounding AM stations nationwide "save" AM radio or at least stop its decline, or is it too late? If "done right" as referenced in these posts, coupled with an aggressive "Awesome AM sound" promotional campaign do the trick?
 
In the rush to make space on the dial for more and more stations... what, maybe 30 years ago.... the NRSC filter mention above by David Reaves was put into place by the FCC.

Because it was no longer legal to tweak your AM for "awesome" sound quality.

Guess what the manufacturers of receivers have done: You cannot buy an awesome receiver that would give you awesome sound even if someone decided to once again operate an awesome station.

Nobody is going to spend the money to create an awesome radio station sound (including the money to lobby the FCC to permit it) if no one can run to the store and buy and awesome receiver.

Second bad news of the day: Ford will probably not re-introduce the "Little Deuce Coupe" either.
 
johnbasalla said:
Could awesome sounding AM stations nationwide "save" AM radio or at least stop its decline, or is it too late? If "done right" as referenced in these posts, coupled with an aggressive "Awesome AM sound" promotional campaign do the trick?

But how to convince listeners to search out radios which reveal this? AMAX campaigns and PSAs were all but non-existant, and manufacturers
completely ignored it. I recently was called on to provide 3 hours of music for a house-warming party. I put together a 3 hour segment on my AM part
15, airchecked it, and made 3 1 hour CDs. No one at the party could believe that it was AM radio audio. In their experience, it CAN'T sound that good.
I won't say it can't be done, because as it turns out the coolest thing to have in college now is a real turntable, records, and a tube amp.
I agree it's cool, and approve, but can't figure out but that such technologies are surviving, and retain coolness on actual merits.
There's no advertising for these things, but kids are still finding them.

Figure out how to show off the superior AM sound to the masses, somehow make it magic, so they'll care, and you'll be rich indeed.

GRC, there's a huge market in AM radio widening. We'll open up kiosks, and wideband your radio in 2 hours on the spot. 39.95 for a new world of enjoyment.
We'll add 1khz tuning steps, 3-step delayed AGC, DSP noise reduction and monkeychatter eliminators, we'll add tuned RF stages so you can listen to
Seattle or Miami. Q-multipliers, we'll have 'em. Shortwave? No Problem.
 
The real key is the receivers. Most AM stations will sound good on a good receiver. Stations with a well tuned broadband AM antenna systems will sound great. Somebody mentioned a TRF (tuned Radio Frequency) receiver. There are monolithic AM receiver chips (MK484 or ZN414) that require very few external parts. A small, inexpensive portable TRF receiver that can be powered by a single AA battery. That unit can drive a headphone or an external powered speaker system.

Then independent AM station operators need to form a group to promote AM radio. Get it back into the public awareness and save themselves. Perhaps find a manufacturer in china that will knock out cheap TRF receivers. It is an uphill battle both ways, but with the decline of the FM band, it might be the last radio standing.
 
Randal Marshall said:
Most AM stations will sound good on a good receiver.
As long as the definition of "most" precludes those broadcasting in IBOC. NRSC dropped AM frequency response from 15khz (or greater) to 10khz...IBOC drops the analog audio to 5-6khz. I can see how NRSC can come close to FM with well under 1 octave of high end missing. 5Khz audio on the other hand is going to sound like , well, 5khz audio--at it's best. If all AM's were offered a protected FM translator (assuming a freq can be dropped in) in exchange for shutting down their AM transmitter permanently, the AM band would be cleaned up almost overnight, the dial could be refarmed to allow full AM fidelity for the strongest players that remain and with that full AM fidelity, the need for "HD Radio" on AM is suddenly gone. Sweet....
 
IBOC analog bandwidth isn't limited to 4.5 / 5KHz. Take a listen to KOA and KNX on a wideband radio.
Not sure what they're running but it sounds close to NRSC.
Have been running 7.5 KHz with IBOC (no secondary carriers) on a station myself.

Want to listen to a full fidelity AM? Try 1010 CBR Calgary!
 
I was in Denver a little while ago, and immediately knew KOA were running IBOC. I thought it sounded awful, and the programming wasn't much better.
 
There's the biggest problem though. Most programming on AM these days is throw away. Yes there are several great operators in the band that aren't, but enough of the band's programming is poor enough that peoples' preception of it is as bad as iboc stations sound... Lousy at best.
 
boiseengineer said:
Want to listen to a full fidelity AM? Try 1010 CBR Calgary!
Or 740 in Toronto.
 
A third vote for CFZM 740. I compare some of the exact same songs to my part 15 AM response on the air monitor, and I
am very impressed with their processing and audio response. It simply can't get any better than it is.
I recall a few years back they sounded very good, but they've improved. When they play a song with heavy reverb built into the song,
it sounds like the 60's.
 
PTBoardOp94 said:
I was in Denver a little while ago, and immediately knew KOA were running IBOC. I thought it sounded awful, and the programming wasn't much better.

It's only been a short time that I noticed the big improvement of KOA audio.
 
radiorob2.0 said:
A second on 740, they sound amazing on any AM radio able to replicate quality. Does the CRTC require NRSC-2?
Yes... I believe they actually required it years before the USA did. However, Canada also requires NRSC pre-emphasis for all AM stations, both mono and Stereo, while the USA only requires the NRSC curve for AM Stereo stations. As a result, many U.S. mono AM stations use a more aggressive "Optimod" pre-emphasis curve, which often produces a strident, midrange-heavy sound on a wideband receiver (although many FM stations sound just as bad these days!).
 
satech said:
radiorob2.0 said:
A second on 740, they sound amazing on any AM radio able to replicate quality. Does the CRTC require NRSC-2?
U.S. mono AM stations use a more aggressive "Optimod" pre-emphasis curve.....


Oww, Owwww, OWWWWW! ( As Jerry G Bishop used to say)
As if modern reciever design didn't already put enough (too much) weighting on 1000-3000 hz.
 
I had, and traded, a 2004 Mustang with the best AM radio I have heard since the modulation monitor at WJDX back in the 70's. When you tuned into an AM station, it would take a few seconds to determine the signal strength, then for stations that surpassed the threshold, it would open up the bandwidth. Unfortunately, the only remaining local music station was Music Of Your Life, but I enjoyed hearing cymbals, tinkly piano, vocal presence, and all those other upper frequency things you know are there, but don't make it through the keyhole on a normal AM radio. The AM HD I have now seems a poor substitute. IMHO, most AM HD music stations I have heard sound like either a poor mp3, or like an AM base with a tinny layer "tacked on". Of course, your mileage may vary.
 
robgrayson said:
IMHO, most AM HD music stations I have heard sound like either a poor mp3, or like an AM base with a tinny layer "tacked on". Of course, your mileage may vary.
Dittos...very unnatural sound...far inferior to what a mono wideband GE Superadio sounds like on a full 10khz mono station. Whoever claimed that AM HD sounds like analog FM should be ashamed of themselves. There is NO benefit to this worthless technology & much downside. There are some really gullible AM owners out there who frankly deserve the bankruptcy that's in their future.
 
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