FM CB

[n1chu]

Wondering if Uniden will be including both CB AM and FM modes in their National listings? (I know it’s a simple matter to switch the CB band to capture both by selecting “Auto” in the Modes menu but just spitballing here!)

 

[gary123]

In my opinion I cant see this as practical. Or maybe not until there is a national consensus on FM mode only channels. The scanner will pick up FM mode signals while in AM. The audio just sounds really crappy.

 

[wtp]

the auto feature only uses the band defaults in the radio.
with some of them you can change the default in settings, but it is just one or the other.
it should have said "default" and not "auto".

 

[n1chu]

the auto feature only uses the band defaults in the radio.
with some of them you can change the default in settings, but it is just one or the other.
it should have said "default" and not "auto".

Ok. I want to run something by you. I attend military air shows. I believe the USAF Thunderbirds have used (on occasion) both AM and FM modes during their demo flights. I have set the mode to “Auto” on my SDS100 and BCD436HP without issue. I’ve listened to an AM signal while the scanners were set for FM and vice versa and have noticed a difference in intelligibility due to choosing an incorrect mode. I’ve also set the scanner to “Auto” and had no problems regardless of the actual modes. Does this sound like it agrees or disagrees with your take on the “Auto” setting?

 

[wtp]

from the manual,

When you select AUTO for a channel, modulation, or step, the above values are used unless you’ve edited the Band Defaults. Set Modulation Set the demodulation method to use for the range. AUTO uses default modes based on bands i too have heard AM/FM things and made out what was said. i have a long story about hearing a plane landing during and airshow that they did not hear because he was using FM. they told him to "land and bring your license to the tower" i called and told them what the problem was, my phone call was not well received. but it might have saved him. they seem to be harder to hear the farther away they are.

 

[n1chu]

from the manual,

When you select AUTO for a channel, modulation, or step, the above values are used unless you’ve edited the Band Defaults. What above values? Set Modulation Set the demodulation method to use for the range. AUTO uses default modes based on bands i too have heard AM/FM things and made out what was said. i have a long story about hearing a plane landing during and airshow that they did not hear because he was using FM. they told him to "land and bring your license to the tower" i called and told them what the problem was, my phone call was not well received. but it might have saved him. they seem to be harder to hear the farther away they are.

 

[wtp]

the word should have been default, as in band default like it says in the manual.
the same goes for step, there is also auto there too and it should have been band default.
it will not change step by what the radio hears.

 

[n1chu]

In my opinion I cant see this as practical. Or maybe not until there is a national consensus on FM mode only channels. The scanner will pick up FM mode signals while in AM. The audio just sounds really crappy.

Understood and agreed. While the successful push by the manufacturers to include FM Mode as an allowable mode (in addition to AM Mode) on any of the 40 CB channels, it is seen as an obvious marketing ploy to get CBers to buy new AM/FM radios, and then, if they care to, leave it up to the CBers to come to a consensus, a gentlemen’s agreement, as to which channels should be listed as FM Only and which to designate as AM Only. At least Uniden gives you the option of changing the mode from AM to FM as desired.

But another post points out… Of the three mode choices offerred, namely “Auto”, “AM” and “FM”, only “AM” and “FM” are available because the “Auto” choice only brings you back to whatever that band’s default modulation is set to in the radio… in the case of CB, the default band mode is AM. I believe the military aero bands are also defaulted to AM so if you are not sure what the Blue Angels or Thunderbirds use during their demos at the airshows, choosing Auto only assigns AM. If in fact this is true, the other post is correct when they suggest Uniden should be replacing “Auto” with “Default”, or more clearly, “Default to Band Mode” in the menu. I suppose the miss-labeling, using the term “Auto” instead of “Default to Band Mode” will become apparent soon enough when those that listen to the CB Band learn choosing Auto does nothing for them because the scanner can not differentiate between the two modes and pick the correct one in use, it only defaults to AM. Meaning until or if Uniden either allows for its SDR’s to have that capability to discern between the two modes automatically (which will allow Uniden to keep its “Auto” label), or lists the 40 CB channels twice, once as AM and again as FM, the end user will need to set up a FL that does the same thing.

Uniden said from the onset of their SDS line of scanners (Software Defined Radios [SDR]), that these type of changes would be forthcoming in the future. Let’s see if they can pull this one off.