fcc – Page 2 – Engineering Radio

Filing an STA

FCC rules stipulate that when a station is operating at variance from its licensed parameters for more than 10 days, Special Temporary Authority (STA) is required. The reasons for requesting an STA are varied but could include things like:

Damaged transmission equipment
Loss of transmitter site or building use
Loss of tower
Eviction
Facilities upgrade or renovation
Natural disaster

The loss of the transmission tower at WUPE-FM falls into one of those broad categories. Thus, we have filed an STA with the FCC for temporary transmission facilities while a new tower is being constructed. Since the old tower is completely lost, we specified a new tower location, new height above average terrain (HAAT), new ERP, and environmental certification. To gather that information, several steps were needed:

Obtain a new tower location. This was done with a GPS receiver and verified on itouchmap.com. Once the NAD83 position was obtained, it needed to be converted to NAD27 for the FCC filing. The FCC has a conversion tool on its website.
HAAT calculation is fairly simple, use the HAAT calculator tool on the FCC website. For this, the antenna radiation center height Above Mean Sea Level (AMSL) is needed. Using a topographical map, find the ground level AMSL, convert it to meters, then add the radiation center height above ground level (AGL).
The Effective Radiated Power (ERP) calculation is also simple; Transmitter Power Output (TPO) minus system losses (transmission line and antenna gain). It is easiest to do this in dBm, e.g. convert the TPO from Watts to dBm, then add or subtract the gain or losses in dB, and convert the final product back to Watts.
The environmental statement is slightly more tricky. Basically, the filer is certifying that the STA complies with all environmental regulations including OET-65 (RF exposure limits). Since the temporary antenna is significantly lower than the original, some investigation is required. For this, there are two methods to demonstrate compliance; ground measurements with a NARDA meter, or RFR worksheets which are a part of the broadcast station renewal form, FCC-303s.

I have taken the RF worksheet sections out of the 303s and separated them into the FM RF Worksheet and the AM RF Worksheet. These worksheets are not effective for large tower farm-type sites where there are too many variables and RF contributors to be accounted for. The calculations on the worksheets are not conclusive, however, if the facility in question falls under the limits, it is generally accepted as being in compliance. Taking ground measurements with a NARDA meter is the definitive method for determining RFR compliance. Since this is a relatively simple site, the worksheet calculations should be sufficient.

The worksheet calculations show that the RFR is within both the controlled occupation limits and the uncontrolled general population limits.

The position of the new temporary pole was verified on itouchmap.com:

It is never good to be operating at a varience from licensed parameters without notification of the FCC. Such things could lead to fine or other problems for the broadcaster.

AM revitalization comments

I have been reading the comments regarding the FCC’s NPRM (13-249). Clearly, many people are interested in keeping the AM broadcasting band both active and relevant. Some of these suggestions have merit but are unlikely to be adopted by the FCC. Others are viable and could alleviate at least a few of the technical shortcomings of the AM band. The rest fall along expected positions. Here is a brief rundown:

Clear Channel, iBiquity: Allow stations to transmit in all digital mode. Likelihood: Possible. The hybrid version of AM HD Radio has been a failure on several fronts; added interference to adjacent channels, self-interference, poor adoption, wonky CODECs, etc. However, letting stations choose to broadcast in all digital AM HD Radio may decide the issue once and for all. As long as the all-digital carriers fall within the current analog channels, this would be fine. Actually, I would add that stations transmitting in all digital be allowed to choose DRM as well as HD Radio
REC Networks, MMTC: Move AM stations to former TV channels 5 and 6. Likelihood: Unlikely. It would be a neat solution, however, there are currently many full and low-power TV stations still using those frequencies.
Clear Channel, SBE, MMTC, Crawford, et al: Allow AM stations a special translator filing window. Likelihood: Almost assured. This has been broached by the FCC itself. I would add that Class D and Class C stations be given priority.
SBE, du trial, Lundin and Rackely, MMTC et. al: Remove the “ratchet rule,” reduce antenna efficiency requirements and city of license contour requirements. Likelihood: probable. Over the years, the FCC’s rules and regulations designed to help AM broadcasting’s technical product have done the opposite in many cases. This is especially true of the “ratchet rule.”
SBE, du Trial, Lundin and Rackely, MMTC: MDCL (Modulation Depended Carrier Level) Likelihood: Possible. MDCL does not do much to improve AM signal quality, but it can save the station owner some money on the electricity bill.
Alabama Broadcaster’s Association, et al: Better FCC enforcement. Likelihood: Not very. This is another area where interference and AM noise problems can be fixed. Given Ajit Pai’s desire for “non-regulatory” relief, stepped-up enforcement seems to be a non-starter.
Hatfield and Dawson: Eliminate substandard AM stations. Likelihood: Not very. Getting rid of substandard stations and letting the remaining AM stations enjoy a little breathing room is actually a big step in the right direction. H&D notes that the FCC should petition congress for tax relief for those stations that choose to surrender their licenses. Unfortunately, it does not appear likely that the FCC, congress, and the current station owners would go for it.
du Treil, Lundin, and Rackely: Do away with skywave protection for class A stations Likelihood: Possible. The argument goes; skywave listening represents a very small number of mostly hobbyists (AM DXers) as other, better methods for program distribution exist for serious listeners. Sad but true.
du Treil, Lundin, and Rackely: No more new AM stations. Likelihood: Possible. There is a cogent argument to be made regarding the overcrowding of the AM band. Stopping any further crowding is a good idea.
SBE, Cohen, Dippell, and Everist, et al: Tighten regulations on electrical noise emitters. Likelihood: Unlikely. The FCC does not have the mettle to tighten regulations against powerful manufacturing and technology lobbies.
iBiquity: Do not let anything get in the way of the HD Radio rollout. Likelihood: Is it possible to get in the way of something that is standing still?

Talking amongst engineers and AM broadcasters, many of these ideas have merit. The real question is, will any of this bring more listeners?

Pai says “No fighting!”

In the putsch to revitalize AM, FCC Commissioner Ajit Pai advises that it would be best if we did not argue about solutions. Actually what was said was this:

On the other hand, if too many broadcasters allow the perfect to become the enemy of the good, our efforts could be doomed by infighting.

That is well and good, so long as the proposed solution does not make things worse. I would posit that worse is already the enemy of the good, so any proposal that would make things worse should be protested vigorously.

I have written quite a bit about AM, its relevance, and possible revitalization. There is no size fits all solution to the problems facing AM broadcasters. In the final equation, stations should be judged on their viability as a business and service to the community. Those that fail to measure up should turn in their licenses.

Update: And so it begins. The narrative is already being shaped, as Darryl Parks (original post has been removed) has found out. After posting in his blog a few comments on the FCC’s revitalization efforts, he was excoriated by several high-profile broadcasters calling his comments “Beyond not helpful.” For those not versed in double speaking, that means it is harmful. While Parks may not have gotten all the technical jargon exactly right, his points are valid and are in agreement with the widely accepted laws of physics. I know, I know, quoting science is dull and boring, something that conspiracy theorists are well practiced with.

Now, SHUT UP AND GET BACK IN LINE

Stay sharp, do not be fooled

I am wondering what is going on with the HD Radio rollout these days. Particularly the all-digital AM conversion scheme being bantered about so often last spring. Not much is being discussed publicly about that or the AM revitalization. I have found FCC Commissioner Clyburn’s remarks at this week’s NAB Confab interesting. HD Radio is paid lip service here:

There are hurdles: if broadcasters do not broadly embrace the HD technology and the multicasting and other enhancements that it makes possible, listeners will have few incentives to buy digital receivers. Likewise, if no consumers own digital receivers, then there is no reason to broadcast in digital.
But I’m not worried. More than 15 million digital receivers have been sold so far, and that number will only rise. Thirty-three auto manufacturers include or plan to include digital receivers in their cars, and those receivers are standard equipment in over 80 models. This will dramatically increase the number of digital receivers in the coming years.

But in the solutions for AM broadcasters, HD Radio is not mentioned at all. What is put forward as a six (actually five) step plan to revitalize AM radio turns out to be some rearranging of the deck chairs and a little more. Cliff notes version for the FCC’s AM revitalization:

Open a one-time filing window for AM license holders to acquire an FM translator
Relaxing community coverage rules for AM licensing allows greater flexibility for transmitter siting
Eliminating the “Ratchet Rule” used in nighttime allocation studies for new facilities
Permitting more widespread use of MCDL technologies by eliminating STA requirements
Reducing minimum field strength requirements by twenty-five percent allowing the use of shorter towers

While those options may save an AM license holder some money, none of them do anything to improve the technical quality of AM broadcasting. Several of them (#2, 4, and 5) will, in fact, if widely implemented, reduce signal levels over cities of license, making electrical noise and interference problems more prevalent. This is a step in the wrong direction.

These points are basically a rehash of some of the MMTC’s (Minority Media Telecommunication Council) ideas for a radio rescue first bantered about in 2009.

This demonstrates that the NAB and the FCC are not at all serious about revitalizing the AM band but merely marking time and making it look good until the final transmitter is switched off.

AM licensees are on their own, but all is not lost. I have noticed several successful stand-alone AM stations that are not only surviving but thriving. The common thread in this station is good local programming. On the technical side of things; a well-maintained plant with good quality audio feeding a properly operating transmitter and antenna array will go a long way to providing good service to the city of license.