CB Goes FM

I would like to see some "skip" mitigation, but FM is just as annoying to hear when on AM.
Someone wants to make some money is all it is...

 

$$$$$ I believe it's the radio manufacturers mostly pushing FM. $$$$$

And a few bored radio enthusiasts looking for something new.

They're good for profits.

And fun too.

 

Not to bash you or slam you but you don’t know anything about fm.

fm is the same as dead keying the mic on am. It is a carrier with no modulation, the swr meter doesn’t care if it fm or am or transmitting Martian signals.

the way fm works is it shifts the carrier frequency as you talk into the mic, the shift is called deviation. The limits on fm has changed over the years, amateur radio excluded, the bandwidth used to be 25kc, then 12.5kc, now it can be as small as 2.5kc. The gmsr channels use what is now called wideband deviation - 12.5kc, while frs uses 5kc.

it is quieter because the circuits that are used to produce the audio in the receiver makes it very quiet,

11 meters is a shared band, there are business and military uses for the band, some areas of the country have activity outside the band. There is also a lot of activity (US military) on the band in other counties.

as I mentioned, the reason why there is and won’t be fm on the cb band is the National Telecommunications and Information Administration.

 

All the Military stuff is most likely Spread Spectrum, my guess is they could care less what analog mode the public is using on 27 MHz...

 

Yep, it's two manufacturers.. Cobra and President... They probably want something to compete with the FRS/GMRS sound quality, Narrow FM will have less noise..

 

I remember back in the old days the noise floor was S-2 to S-3 (That was a noisy day) on AM!!! And that was with a Starduster on the roof at 50ft!!!

 

It's all pretty much moot though, isn't it? I don't see all these truckers running out to buy a new radio when the old one still works. I've seen guys demure over paying $25 for a radio. Some of the 10 meter conversions out there now will already do FM (albeit not legally), but who uses anything but CB channel 19?

 

And here are the new Part 95 Rules regarding FM on the CB Band:

95.967 CBRS transmitter power limits. * * * * * (a) When transmitting amplitude modulated (AM) voice signals or frequency modulated (FM) voice signals, the mean carrier power must not exceed 4 Watts. * * * * * 5. Section 95.971 is amended by revising paragraph (a) to read as follows: § 95.971 CBRS emission types. * * * * * (a) Permitted emission types. CBRS transmitter types must transmit AM voice emission type A3E or SSB voice emission types J3E, R3E or H3E, and may also transmit FM voice emission type F3E. Federal Communications Commission FCC-CIRC2108-06 12 * * * * * 6. Section 95.973 is amended by revising paragraph (a) to read as follows: § 95.973 CBRS authorized bandwidth. * * * * * (a) AM and FM. The authorized bandwidth for emission types A3E and F3E is 8 kHz. * * * * * 7. Section 95.975 is amended by adding a new paragraph (c) to read as follows: § 95.975 CBRS modulation limits. * * * * * (c) When emission type F3E is transmitted the peak frequency deviation shall not exceed ±2 kHz. * * * * * 8. Section 95.979 is amended by revising the first row of the table in paragraph (a) to read as follows: § 95.979 CBRS unwanted emissions limits. * * * * * (a) Attenuation requirements. * * * Emission Type Paragraph A3E, F3E (1), (3), (5), (6). * * * * * * * * * * * * * * * * * * * 9. Section 95.1763 is amended by revising paragraph (d) to read as follows: § 95.1763 GMRS channels. * * * * * (d) 467 MHz interstitial channels. Only hand-held portable units may transmit on these 7 channels. The channel center frequencies are: 467.5625, 467.5875, 467.6125, 467.6375, 467.6625, 467.6875, and 467.7125 MHz. 10. Section 95.1787 is amended by revising paragraph (a)(1) to read as follows: § 95.1787 GMRS additional requirements. * * * * * (a) * * * Federal Communications Commission FCC-CIRC2108-0

It sounds like the Full Commission will vote on the changes August 5th, 2021...

 

I'm a firm believer in a good external swr meter. I still have a Radio Shack VHF/UHF swr/power meter that works great. This meter would work good on a FRS or GMRS radio.