Deviation, step, channel spacing and narrow band/wide band

[archjeb]

Hello everyone.

I've googled and googled to try to find clarity on the title and it seems to be very unclear to me how to interpret the programming software for a lot of radios. Perhaps someone can clear things up for me.

So I understand the 5K deviation and the 12.5K channel spacing. But what I don't understand is what is the Narrow and FM option with Chirp software? Is the NFM really 5K deviation and 12.5K Channel spacing? I see the same config option with my UV-5R software (such Narrow/Wide) but what is their definition of wide or Narrow?

And then, I bought this Anytone radio, and the software doesn't even say Narrow or wideband. All it gives me is channel step and channel spacing. I'm assuming that if I set it to 12.5K channel spacing that it will set the deviate to 5K? Or am I assuming incorrectly?

It just seems that the manufactures / Software are inconsistent in nomenclature....or maybe its just me

If anyone can help on clarifying, it would be much appreciated.

-A

 

[W5LZ]

With FM deviation corresponds to microphone gain. That wide FM/narrow FM indicates that the radio is capable of doing either, wide means a 25 Khz wide FM signal bandwidth and narrow means a 12.5 Khz signal bandwidth. Channel spacing is a means of obtaining more 'channels' or usable frequencies. If tuning is possible using smaller 'steps' then you can have more usable frequencies per band than if the tuning steps were larger.Those narrower steps are for narrow FM, they typically are too small for separating the wider signals.
The amateur radio has not gone to the same degree of 'narrowness' as the commercial bands have. Wide FM is still legal, although it's sort of 'frowned' on. With typical narrow banding the trailing three digits after the decimal point for channelizing is just that, three digits long. Narrow FM is capable of steps making that figure after the decimal point have four digits instead of just three.
Confused yet??
- 'Doc

 

[archjeb]

ok. So set my channel memory with Chirp software to FM instead of NFM for 2m/70cm repeaters then.
And for the Anytone software, I guess I set the channel spacing to 25K as there is no other option to specify Narrow or wide?

-J

 

[W5LZ]

I don't know anything about the 'Anytone' radios or software, sorry.
- 'Doc

 

[Moleculo]

ok. So set my channel memory with Chirp software to FM instead of NFM for 2m/70cm repeaters then.
And for the Anytone software, I guess I set the channel spacing to 25K as there is no other option to specify Narrow or wide?

-J

I'm sure the Anytone does NFM, but I don't have one of the radios to check. Look for some other setting to set the TX bandwidth - I'm sure it's probably just called something strange in their software.

 

[archjeb]

I'm sure the Anytone does NFM, but I don't have one of the radios to check. Look for some other setting to set the TX bandwidth - I'm sure it's probably just called something strange in their software.

Via the front panel there is a wide,mid, and narrow option. That is documented in the manual.
Its the darn software tool that has no documentation....So its processs of elimination to figure it out.
If I set the channel spacing to 12.5khz in the software then narr shows up on front display for that channel memory (Which is indeed narrow band). If I set it to 25KHz in software and push it to the radio, then the 'narr' disappears.
So it looks like the Anytone software uses channel spacing to change to wide/narrow band.