In addition to Chris' excellent primer about WLLH/Lowell-Lawrence, thought you'd want to know that during the days that AM Stereo was being introduced, WLLH was ready to make "the plunge" to go to Stereo as well. I was told, by someone who was there at the time, that they even bought a new set of jingles to herald that fact and some new C-QUAM stereo exciters. BUT.... there was the issue of the outdated synchronous set-up with both transmitters fighting it out causing a phase distortion every 10 or so seconds in the areas when both transmitters' signals would be equal in strength. Never mind that C-QUAM stereo had a tendency to cause "platform motion" when the signals of two transmitters on the same frequency collided and the sound of the left and right channel information would move from side to side. Today, with GPS, this would not have been a factor as both transmitters would use the exact same frequency standard to stabilize the exciters. So, AM Stereo never flew at WLLH. Then again, AM Stereo never had a chance to grow at all (but that's for another posting).
-
Get involved.
We want your input!
Apply for Membership and join the conversations about everything related to broadcasting.
After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
If you use a disposable or false email address, your registration will be rejected.
After your membership is approved, please take a minute to tell us a little bit about yourself.
https://www.radiodiscussions.com/forums/introduce-yourself.1088/
Thanks in advance and have fun!
RadioDiscussions Administrators
I remember prepping WCCM for AM stereo. The board was already stereo, as was the jingle package...it was a matter of re-recording a ton of music and jingle carts in stereo. It was part of a plan to use a Unistar satellite format which was of course in stereo-in fact the jock liners were cut and carted but that deal died at the last minute- I don't know why. The stereo plan died as well shortly after when (as I heard it) Mr. Gowdy and his...well...interesting son Trevor found it would require a new exciter or transmitter (I forget which) and an extra STL loop so the project was shelved...but not after I and another employee re-recorded 500 or so carts on new Audiopak AA4's. Must've cost a mint in carts and payroll. Just as well, the old ones were in pretty bad shape and sounded terrible anyway. The new ones sounded far better than what WCGY was using.
Wasn't WBZ in stereo for a time?
Wasn't WBZ in stereo for a time?
WBZ was in stereo right up till they turned on IBOC for daylight operation. Was it last year or the year before they turned the AM stereo back on for the 4th of July Hatch Shell concert?
WLYN was in AM stereo until recently, WJIB still is, I don't know if WILD still is... the only AM stereo receiver I had was in a car I sold 5 years ago.
WLYN was in AM stereo until recently, WJIB still is, I don't know if WILD still is... the only AM stereo receiver I had was in a car I sold 5 years ago.
NHRadio said:
Yes, WBZ was in Stereo from 1982, until they dumped it for IBOC a few years ago. Other AM Stereo stations in the nearby markets included WJIB/740 (still running it), WORC/1310, WMEX/1150, WILD/1090, WICE/550, WOCB/1240 (really sounded good, too!), WTAG/580, WHEB/750 (now deleted) and "WNNNNNNN-B-C"/660 NYC. Virtually most of the clear channel (not the company) stations used Stereo at one time or another. Of course when Randy Michaels of CCI mandated all of the Clear Channel (the company) AM stations to stop using it, THAT pretty much sealed AM Stereo's fate. Now all of the IBOC stations sound the same...... muddy.
Oh I don't know about that, Peter. I find WMKI sounds pretty decent. WBZ does indeed sound pretty hideous, but that's partly the problem with the HDC codec having a much easier time with music than with voice at low bitrates (AM IBOC is limited to 32kbps in hybrid mode).
That said, while I think IBOC for FM is reasonably okay, I am no apologist for IBOC on AM...it's pretty much a disaster overall.
For some reason, this spontaneously posted all by itself when I hadn't yet completed the post.
I wish there was a user post delete function on this board, because it sometimes seems to have a mind of its own.
I wish there was a user post delete function on this board, because it sometimes seems to have a mind of its own.
Here's a list off the top of my head of local stations that I remember hearing in AM stereo in this area, NOT including distant skywaves at night.
550 WICE Providence - as oldies in the mid/late '80s, now WDDZ Radio Disney
740 WJIB Cambridge - THE ONLY ONE STILL SURVIVING IN ANALOG AM STEREO!!
790 WEAN Providence - as easy listening/standards, now WPRV oldies
830 WCRN Worcester - as Big Band/Nostalgia, now talk
1030 WBZ Boston - was still playing some AC music when they went analog stereo early '80s. Now all news/talk and IBOC stereo.
1060 WJLT Natick - for a brief period as "Jesus the LighT" mid/late '90s. Now WBIX, business news.
1090 WILD Boston - as urban contemporary, then urban AC/classic soul. No longer AM stereo. Was also briefly IBOC for a short time a couple of years ago. Now mostly syndicated talk.
(1120 WATD Concord - as "Walden 1120" folk music, had bumper stickers printed promoting AM stereo, but it never actually happened. Now WBNW, business news).
1150 WMEX Boston - as oldies 1985-1989, though it may have previously also been AM stereo as beautiful music WHUE. It remained AM stereo through a huge number of format changes until around the late '90s. Now WTTT, Spanish religion.
(1260 WMKI Radio Disney - currently in IBOC stereo. Was never analog stereo).
1310 WORC Worcester - as oldies (and country?) late '80s/early '90s, now Spanish
1330 WRCA Waltham (now Watertown) - went AM stereo in 1990 with flip to "show-biz", Broadway, and comedy format. Remained stereo for a few more years as brokered ethnic.
1360 WLYN Lynn - went AM stereo while temporarily rebroadcasting WUMB between ownerships around 2001. Remained stereo for a few more years as brokered ethnic.
(1430 WXKS Everett/Boston - some national AM stereo aficionado websites listed this as AM stereo. To the best of my recollections, it never actually was analog stereo. Now IBOC stereo only).
1440 WAAB Worcester - still had the AM stereo pilot on as WVEI with their current simulcast of mono WEEI as of a few years ago. I don't know if it's still on.
1470 WSRO Marlborough - as AC and local metro-west service programming '80s and early '90s. Now WAZN Watertown, brokered ethnic.
1510 WSSH (AM) Boston - soft AC - the ONLY Boston area station (that I know of) to broadcast in the Kahn AM stereo format, from the late '80s/early '90s. After a huge number of call letter and format changes and going back to mono, National Religious Broadcasters flipped it to C-Quam stereo in 1995 as Christian WNRB for a couple of years. The AM stereo was finally shut off about a year into the sports format as (briefly) WSZE, now WWZN.
At one time about fifteeen to twenty years ago, the AM stereo light lit up at about a dozen local spots on the dial.
550 WICE Providence - as oldies in the mid/late '80s, now WDDZ Radio Disney
740 WJIB Cambridge - THE ONLY ONE STILL SURVIVING IN ANALOG AM STEREO!!
790 WEAN Providence - as easy listening/standards, now WPRV oldies
830 WCRN Worcester - as Big Band/Nostalgia, now talk
1030 WBZ Boston - was still playing some AC music when they went analog stereo early '80s. Now all news/talk and IBOC stereo.
1060 WJLT Natick - for a brief period as "Jesus the LighT" mid/late '90s. Now WBIX, business news.
1090 WILD Boston - as urban contemporary, then urban AC/classic soul. No longer AM stereo. Was also briefly IBOC for a short time a couple of years ago. Now mostly syndicated talk.
(1120 WATD Concord - as "Walden 1120" folk music, had bumper stickers printed promoting AM stereo, but it never actually happened. Now WBNW, business news).
1150 WMEX Boston - as oldies 1985-1989, though it may have previously also been AM stereo as beautiful music WHUE. It remained AM stereo through a huge number of format changes until around the late '90s. Now WTTT, Spanish religion.
(1260 WMKI Radio Disney - currently in IBOC stereo. Was never analog stereo).
1310 WORC Worcester - as oldies (and country?) late '80s/early '90s, now Spanish
1330 WRCA Waltham (now Watertown) - went AM stereo in 1990 with flip to "show-biz", Broadway, and comedy format. Remained stereo for a few more years as brokered ethnic.
1360 WLYN Lynn - went AM stereo while temporarily rebroadcasting WUMB between ownerships around 2001. Remained stereo for a few more years as brokered ethnic.
(1430 WXKS Everett/Boston - some national AM stereo aficionado websites listed this as AM stereo. To the best of my recollections, it never actually was analog stereo. Now IBOC stereo only).
1440 WAAB Worcester - still had the AM stereo pilot on as WVEI with their current simulcast of mono WEEI as of a few years ago. I don't know if it's still on.
1470 WSRO Marlborough - as AC and local metro-west service programming '80s and early '90s. Now WAZN Watertown, brokered ethnic.
1510 WSSH (AM) Boston - soft AC - the ONLY Boston area station (that I know of) to broadcast in the Kahn AM stereo format, from the late '80s/early '90s. After a huge number of call letter and format changes and going back to mono, National Religious Broadcasters flipped it to C-Quam stereo in 1995 as Christian WNRB for a couple of years. The AM stereo was finally shut off about a year into the sports format as (briefly) WSZE, now WWZN.
At one time about fifteeen to twenty years ago, the AM stereo light lit up at about a dozen local spots on the dial.
ZRXOA 5248 said:
That fiasco was a few years ago now. They promoted heavily that the Pops would be in AM stereo that night, but it ended up not actually happening. It ended up staying in mono.
At WLYN, we pulled the plug on AM stereo about 1 1/2 years ago. At that point,
only a couple of hours per day were truly in stereo (only programs
originating from our studio), and there are so few receivers
out there, it made no sense to continue it...however, it did sound great!
only a couple of hours per day were truly in stereo (only programs
originating from our studio), and there are so few receivers
out there, it made no sense to continue it...however, it did sound great!
"In addition the rooftop shunt fed radiator was only 100' and did not have the
normal efficiency of a standard 200' vertical radiator which is now required for a station at 1400 Khz."
This was the only error I picked up in Chris's post. The only blanket requirement on antenna height for Class C AMs is that the antenna must meet a minimum efficiency of 241 mV/m/kW @ 1 km. The corresponding minimum for Class B and D AMs is 282 mV/m. If you look at the efficiency vs antenna-height curves in 73.190, you find that a remarkably short antenna (~0.07 wavelength or ~25 degrees or ~50' at 1400 kHz) is all that is required to meet the Class C minimum. In fact, as I verified by asking a friend who is an extremely knowledgeable consulting engineer and an expert on AM antennas, this value is WRONG! According to my friend, the FCC has known about this error for about 30 years but long ago chose to do nothing about it. And since nearly all Class Cs are ND, proofs of performance, which would demonstrate the error, are not required. So an applicant for a new or upgraded Class C on 1400 COULD get away with using an ~50' antenna, although the actual efficiency would be pathetically low. In fact, an antenna of ~0.15 wavelength (or ~100' at 1400) is required to meet 241 mV/m/kW @ 1 km, assuming a standard ground system of 120 1/4-wavelength radials. The height could be reduced to ~75' by use of guy-wire top loading. A 74' Valcom Fibreglass whip (and, at 1400, probably even the 62' version) could also be used, eliminating the need for guy wires.
normal efficiency of a standard 200' vertical radiator which is now required for a station at 1400 Khz."
This was the only error I picked up in Chris's post. The only blanket requirement on antenna height for Class C AMs is that the antenna must meet a minimum efficiency of 241 mV/m/kW @ 1 km. The corresponding minimum for Class B and D AMs is 282 mV/m. If you look at the efficiency vs antenna-height curves in 73.190, you find that a remarkably short antenna (~0.07 wavelength or ~25 degrees or ~50' at 1400 kHz) is all that is required to meet the Class C minimum. In fact, as I verified by asking a friend who is an extremely knowledgeable consulting engineer and an expert on AM antennas, this value is WRONG! According to my friend, the FCC has known about this error for about 30 years but long ago chose to do nothing about it. And since nearly all Class Cs are ND, proofs of performance, which would demonstrate the error, are not required. So an applicant for a new or upgraded Class C on 1400 COULD get away with using an ~50' antenna, although the actual efficiency would be pathetically low. In fact, an antenna of ~0.15 wavelength (or ~100' at 1400) is required to meet 241 mV/m/kW @ 1 km, assuming a standard ground system of 120 1/4-wavelength radials. The height could be reduced to ~75' by use of guy-wire top loading. A 74' Valcom Fibreglass whip (and, at 1400, probably even the 62' version) could also be used, eliminating the need for guy wires.
NHRadio said:
When the Class IV class was created (sometime in the early '30s, I think) it was supposed to be for stations in small communities that served those communities and not much more. The power levels were 100W and 250W, which, over the years, were increased to 1 kW. As with today's Class D AMs, Class IVs received no nighttime protection. The low minimum antenna efficiency allowed the use of shorter, and hence less expensive antennas, which were thought consistent with the smaller revenues such stations would generate.
Of course, some of the oldest Class IV stations wound up in the largest cities. Chicago had three that shared time on one channel. Such stations could not cover their entire communities of license at least at night, but that was unimportant because they were not required to do so. Then in the 80s, the Rio treaty required nighttime coverage of at least 80% of the CoL. The suddenly inadequate nighttime coverage of nearly all Class C AMs was thus grandfathered, but when a Class C wants to make any change in its operation, the FCC usually gives them a ration of you know what and generally holds up granting of a CP, sometimes for years. The Chicago three-way time-share arrangement existed until only recently, although the FCC allowed the station that acquired the other two (WSBC) to retain the facilities it had used for decades. Another major market Class C is in Los Angeles--geographically one of the largest cities in the US. It took years and years for that station, KYPA, to move from its rooftop L antenna to a diplex with a higher-power co-owned station. WWRL in New York City was a Class IV until shortly after World War II but it was licensed to Woodside, a neighborhood in Queens, which is one of New York's five boroughs.
As for Class A AMs, at least in the US, the minimum efficiency is 362 mV/m/kW @ 1 km. Using a conventional antenna, this efficiency requires a tower almost 1/2 wavelength high. Because of FAA restrictions, Class A stations at the lower (longer-wavelength) end of the AM dial can receive waivers of the 362 mV/m requirement if achieving 362 mV/m would require a tower or towers taller than 500'. Several Class A stations at higher frequencies also have received waivers; two of them are KGO and WBBR. KNBR which is in the glide path of San Francisco International Airport, uses a sectionalized tower that was supposed to achieve the required efficiency with a tower of less than 500'. I've heard that the proof of performance did not support the intended efficiency and that the data was then somehow lost. I have no proof of that but it is interesting that, officially, KNBR's efficiency is exactly the Class A minimum.
Since sometime on the '80s, US Class A AMs have been required to run 50 kW-U. One US Class A, KNZR, is grandfathered at lower power (25 kW-D/10 kW-N). KOA cannot officially run 50 kW at night because allocations on 850 are based on KOA using an antenna of exactly the minimum Class A efficiency and KOA's 200+-degree tower is too efficient. The problem could be solved, of course, by slightly reducing the transmitter power, but that would violate the requirement to run 50 kW-U. So KOA--allegedly at least--uses a resistor to waste ~10 kW of its transmitter output. Now that's only about seven toasters' worth, but in these days of energy conservation it still seems like a waste.
Speaking of which, anyone know if there's a Rochester or Finger Lakes-area AM station that still runs in C-QUAM AM Stereo? Scott?
It's not critical, I'm just writing a review of a particular HD Radio and many of them will decode C-QUAM but don't advertise it, so the only way to know for sure is to find an AM stereo station and listen.
It's not critical, I'm just writing a review of a particular HD Radio and many of them will decode C-QUAM but don't advertise it, so the only way to know for sure is to find an AM stereo station and listen.
aaronread said:
None left that I know of. WLGZ (now WRCI) 990 was the last in these parts, and they were still running the C-QUAM at night even when they went IBOC by day. Then they went IBOC at night, too (not that I can decode it in...ahem...Brighton!) and that was the end of the C-QUAM.
There were a bunch of C-QUAM AMs up in Canada, but most of them have gone to FM.
It may well be that the nearest C-QUAM AMs still operating are WIRY 1340 up in Plattsburgh (still running as of a few weeks ago when I visited) and WJIB in Boston (still running so long as Bob Bittner and Peter George draw breath...)
I'll never forget seeing old Bitty climbing that tower himself during a storm to fix it.Scott Fybush said:
As of eleven months ago (mid-August 2007) , I heard WREF 850 AM Danbury, CT running Scott Shannon's "True Oldies Channel" in full C-Quam AM stereo glory in the daytime when I was in Bridgeport.
At night they either go down to flea power, or go off the air. I couldn't hear them at night where I was.
I haven't been down that way since then, so I don't know if they're still in stereo.
Eli Polonsky said:
Oops, that should've read 1120 WADN Concord - that's what I get for listening to WATD while typing!
Well, I know I can't DX WJIB all the way out here in Rochester...
Wait a sec, aren't all the expanded-band AM's supposed to be in C-QUAM AM Stereo? I remember DX'ing WWRU 1660 up in Waltham, once...can you DX a C-QUAM signal? Or is that like DX'ing an HD Radio AM signal: possible in theory, and you'll even see flashes of it, but realistically it doesn't work.
aaronread said:
They were at one time, but I don't know if that mandate still holds. I doubt it, nowadays.
aaronread said:
You can certainly DX C-Quam stereo. The threshold required to decode C-Quam is MUCH lower than HD.
Skywave C-Quam reception was not always consistent though, just as skywave reception itself is not always consistent. Phase distortion and interference inherent in skywave reception at times also negatively affected stereo reception.
I used to get all of the 50kw NYC stations in AM stereo that were broadcasting in that mode here in Boston at night at least most of the time. If I remember correctly, those included 660, 1010, 1130 and 1560 (which was actually in Kahn, not C-Quam AM stereo).
Some others that I recall skywaving into suburban Boston in full C-Quam AM stereo at night at times included: 760 Detroit, 890 Chicago (before WAMG Dedham existed), 990 Rochester NY, 1190 Ft. Wayne (before their nighttime power reduction), 1210 Philadelphia, 1520 Buffalo, 1540 Albany, and I'm sure I'm forgetting a number of others.
Also, I should mention that I used to hear WBZ in full AM stereo at night in my travels from Detroit to Tennessee.
- Status