"Dump AM IBOC, Move the AM Band"

[dbdigital]

Undoubtedly there is some truth to what you say. How else would you explain a $25 million price tag for a station that has so few listeners it isn't even listed in the Arbitron book. Such is the case with Los Angeles AM station KMPC.

That LA station could be used for an Asian format, and produce $2 to $4 million in BCF with no trouble, and with no ratings. Many stations with no ratings are very profitable... ask Art Lieu, a master at making loads of money with less than competitive stations and signals.

KMPC bills slightly over a million a year. Using your figure of 12 X for an AM that means the station is worth a little over half of what they're asking. Perhaps being in the #2 market makes it more valuable but it would take quite a bit of work to bring it back to a profitable business.

db

 

[OldGringo]

KMPC bills slightly over a million a year. Using your figure of 12 X for an AM that means the station is worth a little over half of what they're asking. Perhaps being in the #2 market makes it more valuable but it would take quite a bit of work to bring it back to a profitable business.

db

Actually, it bills over $3.5 million.

But it is just a stick since it will loose its Sporting News radio format. An AM with no cash flow in LA has a wide range of stick values. If someone wanted KTNQ or KHJ to go Asian, they would pay around $50 million. lesser facilities go for less, down to things like the 900 or 1430 facilities that are probably worth under $20 million.

If KMPC bills just under $4, they may cash flow a million if lucky... so the multiples don't work since it is worth more dead than alive.

 

[dbdigital]

KMPC bills slightly over a million a year. Using your figure of 12 X for an AM that means the station is worth a little over half of what they're asking. Perhaps being in the #2 market makes it more valuable but it would take quite a bit of work to bring it back to a profitable business.

db

Actually, it bills over $3.5 million.


If KMPC bills just under $4, they may cash flow a million if lucky... so the multiples don't work since it is worth more dead than alive.

That's not what I've heard from someone who works there. KMPC bills 100K a month on average.

db

 

[OldGringo]

That's not what I've heard from someone who works there. KMPC bills 100K a month on average.

I sense you are not distinguisning between billing and profit (or BCF.... Broadcast Cash Flow).

Billing is what the total invoices go out for. BCF is after all expenses before interest, taxes, amortization and depreciation. Prices are based on BCF if the format is viable. In this case, it is not and the $25 million asking price is based on stick value or market value (both terms being the same).

The gross billings per BIA are over $3 million.

 

[Tom Wells]

Bruce Carter's suggested AM 3 part band-plan is the only way I can see to let ibiquity have its own pig-sty, while not trashing the whole band. It will still hurt to lose the value (fidelity) in the middle section.

However, the major AM band shuffle of March 1941 was not without headache.
Many stations found their stick not so easy to tune to a new assignment, just as many found out their stick
didn't like operating at 640 or 1240 during the Conelrad tests.

At least in those days, your tube output would just groan a little bit, semiconductors having a way of checking out unexpectedly when SWR rises.

And many listeners did not like trying to find where "their" station went on the dial, despite most stations having
spent $$ to inform listeners where their new assignment would be.

This inconvenience would be far preferable to having the whole AM band turned into a open sewer.

 

[rbrucecarter5]

Most sticks are too short these days anyway, but it does present some very interesting loading challenges to solid state transmitters to change frequencies.

I think reverting to omnidirectional in as many cases as possible would end up saving a lot of stations money. If a re-allocation is made, intelligent separation rules could be enforced. And I think many more stations could be put on the band if more frequencies were relegated to local only, no extended skywave guaranteed. If the IBOC don't want skywave, let them pack a section of a band with 2 megawatt monsters every 30 kHz in every city over a section of the band. Digital would take care of skywave at night, although with nulling you could perhaps nab some interesting catches from a nearby city.

The only problem with this idea - it basically tells the rest of the world go to ____ we are going to saturate the band with super power digital.

Of course, Mexico and Cuba saturate our band with their stations operating daytime power at night, so what is the difference?

 

[OldGringo]

Most sticks are too short these days anyway, but it does present some very interesting loading challenges to solid state transmitters to change frequencies.

The FCC has minimum height/efficiency requirements for each class. There are very few at variance with this, and the FCC will only consider them due to hazards, lack of available sites, etc.

Nearly all AM transmitters output to 50 ohm coax, and that is terminated at the Antenna Tuning Unit (ATU) which presents a 50 ohm load and matches it to the tower, whatever its impedence. The ATU compensates for -/+ j (reactance) and tower impedance that is almost never 50 ohms.

I think reverting to omnidirectional in as many cases as possible would end up saving a lot of stations money. If a re-allocation is made, intelligent separation rules could be enforced. And I think many more stations could be put on the band if more frequencies were relegated to local only, no extended skywave guaranteed. If the IBOC don't want skywave, let them pack a section of a band with 2 megawatt monsters every 30 kHz in every city over a section of the band. Digital would take care of skywave at night, although with nulling you could perhaps nab some interesting catches from a nearby city.

It would be very hard to pack all the stations on anohter band and keep them non-D, since there are just too many and they would interfere.

Of course, Mexico and Cuba saturate our band with their stations operating daytime power at night, so what is the difference?

Cuba can do whatever it wants. It is no longer following NARBA and none of the stations there are granted different day and night powers.

Mexican stations are as good as US stations about going to night power. The difference is that Mexico considers daytime to be 6 AM to 7 PM every day of the year, so power is not reduced until 7 PM local time.

 

[OldGringo]

However, the major AM band shuffle of March 1941 was not without headache.
Many stations found their stick not so easy to tune to a new assignment, just as many found out their stick
didn't like operating at 640 or 1240 during the Conelrad tests.

The NARBA reallocation was nowhere near as drastic. Stations up to 730 stayed on the same channels, and the rest moved 10 to 40 kHz up the dial, making thier towers electrically longer, not shorter. 740 to 880 nearly all moved just 20 khz up. From 890 on, the moves were 30 to 40 khz with a few exceptions.

Most stations just did a little tweek to the tuning and bought a new crystal and that was that.

And many listeners did not like trying to find where "their" station went on the dial, despite most stations having
spent $$ to inform listeners where their new assignment would be.

Since there were no digital dials, and the moves were so, so close, I doubt any listeners had to do much more than "fine tune" to find the stations they wanted to hear (and there were only about 900 or so stations then, anyway.

Examples of the moves: KGO from 790 to 810. WBAP form 800 to 820. WLS from 870 to 890. KPRC from 920 to 950. KOMO from 920 to 1000. KDKA from 980 to 1020. WSMB from 1320 to 1350. WEVD from 1300 to 1330. KSTP from 1460 to 1500.

Of course, in 1940 (per November Radex) there were no US stations above 1500. And 1500 was neatly moved to 1490, one of the Class IV channels post NARBA. 1310 became 1400, 1370 became 1400 and 1420 became 1450, three more of the Class IV channels.

 

[wnmb]

Please allow me to comment about IBOC. It is not the answer for AM. Instead, it is another inequity. AM IBOC is technically inferior to that of FM. While I will leave the specific tech specs to the engineers, the bottom line is that AM IBOC does not deliver the sound quality that FM gets from it. My station, WNMB, in North Myrtle Beach, South Carolina, broadcasts in C-Quam AM Stereo. The technical quailty is superb. For example, we have a plain Ford Expedition with a standard AM Stereo/FM Stereo radio in it. Our AM Stereo sounds better than any of the FM stations in our market. It is clean, bright, and of great fidelity. Now, granted, a lot of the FM stations play loudness wars and muddy themselves, but nevertheless, we sound better. If other AM station owners would implement AM Stereo, some nice things could happen for our industry. We can complain about the AM stereo standard coming late and how the band got in the shape its in, but we are where we are and we can only go forward.

 

[rbrucecarter5]

You are preaching to the choir as far as I am concerned. I have never really heard a good explanation as to why AM stereo sounds so good - even compared to FM stereo. But there are a lot of people making the observation. Unfortunately - "digital" is a buzzword and now everybody has to have it. This nonsense started with cell phones - the old 900 MHz analog cell phones sounded much better and were more robust than digital cellular - but you can't get service on 900 MHz any more. At least the cell phone companies are migrating to GSM which is more robust than DCMA, but the sound quality on both is terrible - over compression.

Then they botched up TV. Instead of opening up a new band with 30 MHz channels, they compress it into 6 MHz channels and I can tell you the results are suckish - digital artifacts all over the place. I'd much rather we stuck with NTSC with its color limitations than to see compression artifacts all over the screen near edges. My daughter's cartoons are almost unwatchable because the colors are supposed to be pure up to the edges.

Now that extend the digital madness to radio, and already many FM stations that took the easy way out with separate antennas are finding severe coverage issues, and of course AM is noisy - not just a little noise, a whole lot! And the limited bandwidth makes even talk and sports radio sound awful - radios still being sold for $300 won't penetrate the market.

My idea of making a graveyard for IBOC stations would destroy only a portion of the AM band, and leave skywave for the western 2/3 of the country and displaced sports fans untouched. Both sides get what they want. And I, for one, would love to give Castro back some of his own medicine.

 

[amfmsw]

In regards to Bill's comments on AM Stereo Fidelity...I had an '87 Cadillac with an AM stereo radio. When 1210Kc simulcast sister 98.1Mc WOGL in Philadelphia, I preferred the AM Stereo! It was smoother, spacial, and just more natural sounding than the FM.

The 600 pound gorilla in this room fella's, is bandwidth. The one thing AM needed to retain listenership was NOT addressing adjacent channel interference or heterodyning whistle. It was mandating wideband IFs and noise blanking. So what did the FCC/NRSC do? CUT the bandwidth to 9Kc. Rediculous! How STUPID.

When proofs were mandated, I know WMID 1340 Atlantic City had a perfectly flat (+/- 1db) audio response 80 to 12Kc. The xmtr was an RCA BT1 using a Derough triband processor. With a little tweeking, it would hit 13.8Kc. Who would ever notice the difference of 1.2Kc in Stereo if it played their music and served their community? Oh yeah, the poor saps with the Delco radios that limit AM to 3.5Kc.

 

[SUPERCASTER]

In regards to Bill's comments on AM Stereo Fidelity...I had an '87 Cadillac with an AM stereo radio. When 1210Kc simulcast sister 98.1Mc WOGL in Philadelphia, I preferred the AM Stereo! It was smoother, spacial, and just more natural sounding than the FM.

The 600 pound gorilla in this room fella's, is bandwidth. The one thing AM needed to retain listenership was NOT addressing adjacent channel interference or heterodyning whistle. It was mandating wideband IFs and noise blanking. So what did the FCC/NRSC do? CUT the bandwidth to 9Kc. Rediculous! How STUPID.

When proofs were mandated, I know WMID 1340 Atlantic City had a perfectly flat (+/- 1db) audio response 80 to 12Kc. The xmtr was an RCA BT1 using a Derough triband processor. With a little tweeking, it would hit 13.8Kc. Who would ever notice the difference of 1.2Kc in Stereo if it played their music and served their community? Oh yeah, the poor saps with the Delco radios that limit AM to 3.5Kc.

Or the i-Borg cartel who insist the way to save AM is to brick wall limit the audio bandwidth to 5kHz and then add horrible digital buzz to the adjacent channels. They have the audacity to claim this is a solution for interference, and the savior of AM!
Totally rediculous. What a super con-job.

 

[Chuck]

Or the i-Borg cartel who insist the way to save AM is to brick wall limit the audio bandwidth to 5kHz and then add horrible digital buzz to the adjacent channels. They have the audacity to claim this is a solution for interference, and the savior of AM!
Totally rediculous. What a super con-job.

Of course, after people get accustomed to that kind of audio quality, HD AM does sound like a huge improvement. The illusion is helped by the fact that most radios have had 3 kHz audio for quite some time. We all know that it doesn't have to be that way, but at the moment, it is.

IBOC is almost the "perfect storm." It allows improved AM audio while obliterating those pesky small stations. Nice work, if you can get it. As Cal Stymes has pointed out, this will probably end up as great drama in a courtroom.

I used to be mildly indifferent toward this technology, mostly dreading the cost my small station may have to incur. The more I learn (not just here - mostly talking with radio engineers who are charged with dealing with this) the less I like it.

 

[Tom Wells]

I installed -60 db 10khz notch filters in the low-impedance (speaker) circuit of all AM receivers I use regularly.
The 3 db loss nicely drops any residual hum or power amp transistor shot noise.
The difference is like being able to listen to the studio monitors.
When the whistle is gone, you wouldn't believe the high-frequency info present in so many stations.
OH, I forgot, we can't use any actual LRC passive components in receiver design.
That would cost actual money.......


Well, what is the least we can do to get by?

This is why AM receiver performance has been so miserable. Reduced expectations in someone's engineering department.
I blame Delco, mostly, for setting the stage for the "supposed problem".

 

[calstymes]

Chuck proclaimed:

The more I learn (not just here - mostly talking with radio engineers who are charged with dealing with this) the less I like it.

Nawww... impossible!

According to several posters here, HDradio this is the shot in the arm that over-the-air broadcasters need to survive in the modern world of satellite radio, internet radio and Ipod audio entertainment!

Over-the-air broadcast engineers should be grateful for the opportunity to participate in the installation of technology that will save their employment.

uBiquiLaw: They do it ALL for you!

Oh boy, the fireworks that are on their way will be spectacular!

 

[rbrucecarter5]

The difference is like being able to listen to the studio monitors.
When the whistle is gone, you wouldn't believe the high-frequency info present in so many stations.

I have an active circuit in a stand alone box. With the advent of 100 MHz op amps, it is now possible to implement an active low pass filter with astonishing results: http://focus.ti.com/lit/an/slyt230/slyt230.pdf (page 19). The nice thing about an active filter is that I can make the Q so high that it will barely affect frequencies other than 10 kHz. It is hard to get such a high Q with LC networks.

 

[Tom Wells]

Indeed, at high-to-medium impedances, the Q is not sufficient to give a sharp notch, and too wide a band is "tuned".
But at 16 to 4 ohm range, the Q is quite enough to give a very narrow notch.

I built a 3-frequency stereo active op-amp infinite notch filter like you describe in 1981.
I was collecting recordings, and needed to remove 60, 14,758, and 19,000.
The design allowed variable R or C, and the single turn trimmers made adjusting the high frequency notches touchy.

When monitoring a source with 60 hz in it, turning on the notch is unsettling, but only for second. Then you want to turn it on
and off, sayin "Goll-lllleee".

The passve notch requires only two .047 caps, a 25 ohm rheo, and approx 40 ft of No 20 wire on a form.

rheostat, adjustment will be critcal
------------------------vvvvvvvvvv-
| ^
| |
| |
out1-----------) (------------)(--------------------------------------sprkr1
.047 | .047
|
Q
Q
Q coil
Q
|
out2------------------------------------------------------------------spkr2

Set rheostat initially to same R as measure voice coil RESISTANCE, not just stated impedance.
Wind coil and after 20' begin pricking wire while audio with 10 kc present and the exact length to cut wire will be evident, as the average
"window" of wire length to hit this notch is about one foot. When you find the null, find its center, by gosh.
Then SOLDER WELL.
And using larger gauge wire in L makes a difference, so go as large as a given space available permits.
I hope someone tries this, it has made a big difference in my enjoyment of radio.

 

[hipporadio1]

I would suggest a mass shuffling of AM stations to make intelligent use of the spectrum, and its characteristics. Here is a plan:

All frequencies from 540 to 1000 kHz - clear channel, high power, spacing at least 1000 miles, absolutely NO IBOC, but Kahn and C-Quam allowed. Primarily serves sparsely settled Western 2/3 of the country with skywave. Daytime power unlimited to get some semblance of skywave ranges.

1010, 1020 - unused

1030 to 1470 - local use only - high power allowed - IBOC stations spaced at least 30 kHz (1030, 1060, 1090, etc). No skywave guarantee, no guarantee of reception at all outside the metro area, maybe less than 100 mile spacing, high enough power to cover metro area with 2 mV contour needed for IBOC.

1480, 1490 - unused

1500 to 1700 - regional, small rural towns. Frequent re-use of channels, some skywave possible, but NO IBOC. Replaces current graveyard channels like 1230, 1240, etc - and lets hundreds, maybe thousands of new stations on the band. More diversity.

A computer program could be employed to find the optimum location of the cutoff frequencies -

IBOC would become a band within the AM band, large cities that can benefit from digital could use it at whatever power it took for complete metro coverage, with no adjacent channel concerns, no skywave concerns.

Music formats not on the IBOC band could still use Kahn, C-Quam, or whatever they wanted. For this to work, the FCC would have to mandate both IBOC and stereo capability in all radios over $50.

Skywave would be preserved as a resource for isolate rural communities with no fear of eventual interference from IBOC. DX'ers would be happy to get back a band to DX.

Everybody gets what they want - the only inconvenience is a one time frequency shuffle which to the consumer would be no more upsetting than a format change on all the AM stations in their community. In days, it would be done, the band preserved, and everybody happily broadcasting in the format they feel they need to reach their intended audience.

Coordinate this with Canada, Mexico, Cuba - and nobody would have unwanted interference.

This is INTERESTING--considering. But could this be way to "cerebral" for the regulators? As media evolves--so MUST the AM band. AM (and even its skywave) is a NATIONAL RESOURCE... I'd think it MORE important NOW than at any time in a three-decade past. There's NOTHING "wrong" with AM--'just its mis-management by the FCC. Face it--it's a MESS now! IBOC "pretends" NOTHING to an analytical mind that understands the old margarine commercial that sings "you can't fool Mother Nature"... OK... Stop trying to fool her!