A10 Service Class

[Class A10 Upgrade/Impact Search Tool]

On June 13, 2024 Carl Haynes had filed a Petition for Rulemaking with the FCC to establish a new A10 (A-Ten) service class for full-service FM broadcast stations.  This would be a new intermediate service class placed between Classes A and B1 (for FM Zones I and I-A) and C3 (for FM Zone II).  The A10 service class has a maximum facility specified at 10 kW at 100 meters height above average terrain (HAAT) with a 60 dBu service contour of 32 kilometers.

The Federal Communications Commission has put the Petition up for public comment as MB Docket 24-183.  Comments are due on July 22, 2024 and reply comments are due to August 21, 2024.  We note, that this is not yet a Notice of Proposed Rulemaking.

The A10 proposal is an evolvement of the previously proposed Class C4 which proposed 12 kW at 100 meters HAAT only in FM Zone II.  The A10 petition does not include the substantial changes to §73.215 that were in the Class C4 petition and were a major point of contention at REC, NAB and other broadcast advocacies.  

REC Networks has performed several substantial studies regarding the upgradability of Class A facilities in the nonreserved band (92.1~107.9 MHz) as well as the potential impacts to LPFM and FM Translator stations. 

In summary, these studies have found that:

  • 1,414 (51.6%) of Class A facility records* are eligible for an upgrade to Class A10 using either §73.207 traditional distance separation or §73.215 contour-based short-spacing.
  • Of those 1,414 facility records, only 260 (18.4% of the subset and 9.5% of all Class A facility records) would be able to use the traditional §73.207 method, while the remaining 81.6% (42.1% of all Class A) would need to use the §73.215 method that involves directional antennas and/or reduced power.
  • 432 Class A facility records in 170 groups would be mutually exclusive meaning that not all of the upgrade eligible facilities will be able to upgrade if another upgrade eligible station also wishes to upgrade.  Some of these may be upgradable through a site change or through using the contour methods in §73.215. 
  • 382 facility records representing 377 unique Class B1 and C3 facilities would now fall into the technical parameters of A10 instead of B1 or C3.  A majority of these facility records are in the reserved band (88.1~91.9 MHz).  Overall, there are 2,026 Class B1 and C3 stations.
  • For LPFM with upgrade eligible Class A stations on co-channel and first adjacent channels, a simple distance separation study showed a potential impact of increased interference at various levels to 20.7% of all LPFM facility records.  A more granular contour study would show that 10.6% of all LPFM facility records would experience new or increased interference inside of the LPFM station's 60 dBu service contour.
  • For LPFM with upgrade eligible Class A stations on second-adjacent channels, Class A10 upgrades can create up to 13 new short-spacings which will not immediately impact the LPFM station but may make it more difficult to change facility locations in the future.  The study showed that 43 LPFM stations that are currently Class A short-spaced will receive a higher field strength from the Class A10 facility at the LPFM site.  This is actually a positive impact as it decreases the area surrounding the LPFM station that needs to be protected as part of a second-adjacent channel waiver.  This will make it easier for LPFM stations to change locations in the future.  7 short-spaced LPFM stations have another short-spaced short-spaced station with a weaker arriving field strength and therefore will have no impact, negative or positive. 
  • One LPFM station may be subject to displacement, pursuant to §73.809 if a certain Class A station upgraded to Class A10.  Five additional LPFM stations that have been previously identified as being in potential §73.809 displacement situations due to the Class A facility would have those situations aggravated further thus increasing the chance for displacement.  (§73.809 displacement only occurs when the primary FM station files a complaint.)
  • A contour overlap study shows that up to 12.7 percent of all FM Translator facility records may experience new or incoming interfering contour overlap thus resulting in increased interference on co-channel and first adjacent channels.
  • A contour overlap study for second and third-adjacent channels shows that 95 FM Translator facility records will receive first-time contour overlap as a result of Class A10,which is a negative impact.  366 facility records are currently Class A overlapped and therefore would receive an increased incoming service contour at the translator site, which is actually a positive impact. 
  • Figures provided assume that all upgrade eligible Class A stations upgrade to Class A10.  There are many reasons why an upgrade eligible Class A station may not upgrade, such as budgetary, radio frequency exposure, FAA related issues, market needs, topography of the station's service area or an unviable directional antenna arrangement under §73.215.  With that said, the actual impact figures from the A10 upgrade may be significantly lower than the "worst case scenario" results provided in these studies. 

Overall, REC Networks will only support the Class A10 upgrade if is coupled with the REC Networks Simple250 Petition for Rulemaking (RM-11909) also known as "LP-250".  If LP-250 is not a part of the equation, REC will oppose this Petition for Rulemaking.  

If the FCC was to adopt Class A10 and regardless of REC's position on its overall implementation, REC has the made the following positions regarding its implementation:

  • Split FM Zone I-A into two zones with Zone I-A being California south of 40 degrees latitude and a new Zone I-B being Puerto Rico and the Virgin Islands.
  • Oppose the implementation of Class A10 in FM Zone I-B (Puerto Rico and the Virgin Islands).
  • Oppose the §73.207 and §73.215 distance separation charts provided by the petitioner due to multiple technical errors and replace them with charts from REC.
  • Utilize the proposed §73.807 chart amendments provided by REC for LPFM protection to the A10 service class.
  • Until new international agrements can be negotiated, all Class A10 stations should be considered as international Class B1 for the purposes of the United States international agrements with Canada and Mexico.
  • Require the downgrade of Class B1 and C3 facilities that do not meet the revised minimum facility requirements for those classes but instead fall into Class A10.

REC Networks has established an Interactive Search Tool that permits the checking of Class A facilities for potential upgrades and for LPFM and FM Translator facilities to check for potential impacts from upgraded stations.  This search tool can be found at:

https://recnet.com/a10-search

Document Collection

Original Class A10 Petition for Rulemaking

6-22-2024 - REC Networks initial statement on Class A10 (includes the proposed §73.807 LPFM distance separaiton tables)

6-24-2024 - REC Statement proposing updated §§73.207 and 73.215 distance separation tables for Class A10

7-11-2024 - REC Networks Position Statements on Proposal for The Establishment of A New FM Service Class "A10"