The following is excerpted from the Alabama Broadcasters Association's weekly e-newsletter, Monday Morning Coffee and Technical Notes. Thanks to Larry Wilkins, who puts together the content and has shared it with Radio magazine readers. To subscribe to the newsletter, send an email to email@example.com, and he will add you to the database.
BROADCAST LICENSE RENEWALS
All broadcaster licensees, AM, FM and television are granted a license for a period of eight years. The next cycle of renewals will begin next year (2019). Alabama Radio station licenses expire on April 1, 2020. Renewal applications must be file four months before expiration date, Dec. 1, 2019. To see a list for each state, click here.
It’s not too early to begin some "house cleaning". Engineers should take this opportunity to check the following documents for the correct information.
- STL Licenses: Verify that the transmitter location is correct. Sometimes a station will move the studio (including the STL) and forget to change the location of the STL transmitter. Also check that the frequencies and azimuth is still correct
- Antenna Structure Registration: Verify that the correct owner is listed on the ASR. When stations are sold or bought, a change of ownership for the tower structure(s) must be filed, it does not automatically change with station ownership.
- Translators: Verify that the correct "associated facility" is listed. This is the station that is rebroadcast on the translator, which may or may not be the owner of the translators.
- Station Licenses: Review all the information on the station license to make sure it is current. If you find on a FM license that the "transmitter output power" is blank, find the original station application or calculate the required TPO and post with station license.
- Review RF environmental effects: On the license renewal form there is a question that requires the applicant to certify that its facility complies with the Commission's maximum permissible radio frequency electromagnetic exposure limits for controlled and uncontrolled environments. More details are available on the FCC form 303-S page 10.
NEWS FROM THE SBE
The National Certification Committee has announced that the SBE is creating an ATSC 3.0 Specialist Certification with the help of the Advanced Television Systems Committee.
Ralph Hogan, Certification Committee chair said, "they are on track to release the Certification during the second quarter of 2019". An individual applying to take the exam must first hold a five-, ten- or 20-year engineering level certification as the host certification. Hogan added, "an SBE CertPreview update will also be released prior the first exams covering this field of specialization".
The ABA Engineering Academy is working with the IEEE to host a special ATSC 3.0 seminar during 2019. It will be presented by Gary Sgrignoli of Meintel, Sgrignoli & Wallace. Date will be announced soon.
AM BROADCAST “CRITICAL HOURS”
For AM broadcast stations, the term critical hours refer to the time periods of sunrise to two hours after sunrise, and two hours before sunset to sunset. During these periods, the ionosphere has commenced its transition from daytime to nighttime conditions (or vice versa), resulting in greater coverage than would be expected from a daytime-only analysis. But because the transmitting station operates with its daytime power between sunrise and sunset, the extended skywave signal can be strong enough to interfere with other stations.
The rule provides for operation at a lower power during critical time periods to limit interference from new or changed Class B or D stations (where the changes were made after 1959) operating on frequencies specified in Section 73.25, to Class A AM stations on the same frequency.
For an example if local sunrise is at 6:15 AM the station must operate with critical hour power until 8:15 a.m. If local sunset is 4:45 p.m., the station must operate with critical hour power from 2:45–4:45 p.m.
Not all AM stations have critical hour operation, check you license to see if your station is required to reduce power during these times.
This is acoustic volume or loudness of sound, measured in decibels. SPL is a function of a signal's amplitude. Aside from the usual (and justified) warnings about hearing damage from high SPLs, it is worth noting that because of the way our ears function, sounds will appear to have a different timbre (or tone) to us at different SPL levels.
This is important to keep in mind, especially when mixing in a studio environment. Be sure to check your mixes at a variety of volume levels to ensure that the mix is accurate. The old rule of thumb is that if a mix sounds good at a low SPL, it will sound great at higher levels.
ACRONYM OF THE WEEK: EPOCH TIME
As television moves closer to the next generation of delivery (ATSC 3.0) a word you will begin to hear mentioned is "Epoch Time". An epoch means an instant in time chosen as the origin of a particular era. The "epoch" then serves as a reference point from which time is measured. Time measurement units are counted from the epoch so that the date and time of events can be specified unambiguously.
In a computing context, an epoch is the date and time relative to which a computer's clock and timestamp values are determined. The epoch traditionally corresponds to 0 hours, 0 minutes, and 0 seconds (00:00:00) Coordinated Universal Time on a specific date, which varies from system to system. Most operating systems use Jan. 1, 1970 as the epoch date.
The date and time in a computer is determined according to the number of seconds or clock ticks that have elapsed since the defined epoch for that computer or platform. This number is limited by the word length, and also by the number of clock ticks per second. In a 32-bit computer with 1 tick per second, for example, the clock will wrap around (that is, reach its maximum numerical time) on Jan. 18, 2038. This is not likely to be a problem, because most computers are obsolete after a few years, and longer word lengths and/or new epochs will likely be defined before 2038.
If you interested to see what time it is (in epoch) go to the following web site: http://www.epochconverter.com/ and use the Epoch Converter. This converter will change the time stamp to human date. It can also do vice versa.