Programming NFM vs. FM

[bonus1331]

Is there any steadfast rule as to what is to be programmed NFM versus FM? I.e. trunked versus conventional. What would be the result by programming incorrectly?

 

[Voyager]

Is there any steadfast rule as to what is to be programmed NFM versus FM? I.e. trunked versus conventional. What would be the result by programming incorrectly?

There is no real hardfast rule, but...

If it's low band, it's likely FM (NBFM)

If it's high band (150 MHz) and ends in xxx.xxx5, it's likely NFM (SNFM). If it ends in xxx.xxx0, it's likely FM (NBFM), but could be NFM (SNFM).

If it's UHF (below 470 MHz) and ends in xxx.xxx0, it's likely FM (NBFM). If it ends in xxx.xxx5, it's about 50/50 as to which it is. Older portable-only licenses will likely be FM (NBFM). Newer high power repeaters will likely be NFM (SNFM).

If it's 470-512 and ends in xxx.xxx0, it should be NFM (SNFM). If it ends in xxx.xxx5, it's likely FM (NBFM) but could be NFM (SNFM).

800 is likely FM (NBFM)

900 should be NFM (SNFM)

That said, you can sometimes tell be the license emission designator. If it starts with 11, it should be NFM (SNFM). If it starts with 16 (or higher), it will likely be FM (NBFM) but could be either.

Joe M.

 

[INDY72]

And 700 is supposed to be NFM (SNFM) for conventional, and can be analog for non PS trunking, but MUST be digital for PS trunking.

 

[BANDIT]

I just use NFM for most all of my frequency's. If you take a look at the receive test when the BC785D first hit the market, it was more sensitive in NFM than FM.
Just open the squelch turn down the volume and listen to the noise background and notice the difference between NFM and FM. Also select a distant signal and do the same, it sounds better on NFM. Just my 2 cents worth.

 

[Voyager]

Is there any steadfast rule as to what is to be programmed NFM versus FM? I.e. trunked versus conventional. What would be the result by programming incorrectly?

There is no real hardfast rule, but...

I forgot to add my third test. If in doubt, program it as FM (NBFM). IF the audio sounds low compared with other users on other frequencies, you likely have the setting wrong - change it to NFM (SNFM) and see if they sound better balanced. If they do sound better balanced, NFM (SNFM) is likely the correct setting.

Joe M.

 

[loumaag]

There is, of course, the way we have it posted here in the DB. There is probably some chance of error there though.

However, in the US, if you look at the FCC license, it will tell you what the frequency is licensed for and that is a pretty good indication of how you need to program it.

 

[Julian1]

NFM

8)

On my Uniden 780 & 785 I program everything as NFM. I listen to
VHF, UHF, and 800.

I tried FM on 800 for scan/trunking a Motorola system. NOT. Did not work.

I have found VHF, UHF, and certainly 800 work best in the NFM mode.


Take care,
Julian

 

[rasputen246]

Is there any steadfast rule as to what is to be programmed NFM versus FM? I.e. trunked versus conventional. What would be the result by programming incorrectly?

There is no real hardfast rule, but...

I forgot to add my third test. If in doubt, program it as FM (NBFM). IF the audio sounds low compared with other users on other frequencies, you likely have the setting wrong - change it to NFM (SNFM) and see if they sound better balanced. If they do sound better balanced, NFM (SNFM) is likely the correct setting.

Joe M.

Thank You,

This old post helped me solve a low volume issue I had with my PD being very low volume compared to my Sheriffs Office.

BTW: it's Murfreesboro,TN.

Both are published as FM in all listings I have seen! :roll:
The PD @ 460.3750 gets much better recption/volume as NFM.
The SO @ 460.2000 works fine either FM or NFM.

Thanks, my 3 other scanners have only AM/FM but my new BC246T is my first with NFM option.

Great info for lurkers!