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WMBI

Posted by detectivetom <iframe src='https://members.boardhost.com/chicagomediachat/info/user=detectivetom' width='330' height='300' border=0 style='border:none;'> on March 14, 2026, 9:45 pm

Periodically I look to see area FCC applications. Nothing really new in these parts except an STA filed by WMBI. Here is link:

https://enterpriseefiling.fcc.gov/dataentry/views/public/fmDraftCopy?displayType=html&appKey=25076f919cae4329019cbf44698006bc&id=25076f919cae4329019cbf44698006bc&goBack=N

Re: WMBI

Posted by WYTZZ95FM <iframe src='https://members.boardhost.com/chicagomediachat/info/user=WYTZZ95FM' width='330' height='300' border=0 style='border:none;'> on March 15, 2026, 9:14 am, in reply to "WMBI"

Good find, interesting. Enjoyed reading it.

The FCC and FAA requirements can be different. The FAA (most of their systems are really antiquated) has been tightening standards especially concerning 5G, as the US can never logically follow the rest of the normal world. The 5G we have ratified here, has risk to interfere with plane communication and traffic.

The WMBI STA is for FM spurious emissions @ 130Mhz, top end of the civil aviation communication or "Air Band". They need time to mitigate this, hence reduce their power, so they can choose a vendor to suppress them and go back up to their maximum power level.

Wonder how this will affect their HD signals, if at all? Like EMF they utilize 4 HD sub channels.

Z

Re: WMBI

Posted by Jeremy Andrews <iframe src='https://members.boardhost.com/chicagomediachat/info/user=Jeremy+Andrews' width='330' height='300' border=0 style='border:none;'> on March 15, 2026, 1:22 pm, in reply to "Re: WMBI"

Their HD and everything is on. It's just at lower power.

Re: WMBI

affect their HD signals

I should have been more clear. I was wondering if it will affect the coverage area of their HD signals.

Z

Re: WMBI

Posted by detectivetom <iframe src='https://members.boardhost.com/chicagomediachat/info/user=detectivetom' width='330' height='300' border=0 style='border:none;'> on March 15, 2026, 3:53 pm, in reply to "Re: WMBI"

Yea, I never thought about those HD channels. Good thinking!

Re: WMBI

Posted by PhilJSmith <iframe src='https://members.boardhost.com/chicagomediachat/info/user=PhilJSmith' width='330' height='300' border=0 style='border:none;'> on March 15, 2026, 11:02 pm, in reply to "Re: WMBI"

I wonder if WMBI’s HD sidecars, which are well below & above the carrier frequency + FM stereo + RDS/RBDS ensemble, are making the airband emissions worse. Filtering a signal that spans roughly 300 kHz is more challenging than notching out a non-HD ensemble half as wide. Nonstop OFDM “noise” sounds really nasty on receivers detecting AM, too.

Re: WMBI

I wonder if they have a tube or a solid state transmitter. Tube transmitters are always more prone to spur. WIIL, WJZQ always spit spur on the entire lower end of the dial. They finally installed filters on it, was good for awhile then they did some work on the site and they failed. It started with spur on 100.4, so they pretty much replaced the transmitter with a new Gates Air solid state. That was a few years ago. It was otherwise the original 1983 Harris tube unit that went in with the current tower site. It was really obnoxious on the FM band. Not sure about the aircraft band.

As for WMBI, the transmitter is simply on reduced power. Nothing out of the ordinary. Just not as strong

Re: WMBI

Phil, possible. FCC recently authorized the FM stations using HD on the lower end of the band to voluntarily increase power. The upper part of the band can't at this time, due to the Air Band. I also believe this is one reason why the FAA is enacting tighter control of spurious emissions.

Z

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