Narrowband/Wideband measurement (Unable to detect a difference in transmitting with UV-5G Plus)

[dosw]

I have a Baofeng UV-5G Plus. I set it to channel 15 / 462.5500 and tested it in narrowband mode, as well as in wideband mode. I've been able to observe bandwidth using a TinySA with other radios (Retevis RA87, Baofeng UV-5G --not "plus", and MXT275). But with this radio I don't see a difference in transmissions between a narrowband and wideband setting.

The test setup:

Baofeng UV-5G Plus -> 10w 40dB attenuator -> 10w 20dB attenuator -> TinySA

TinySA is set to center frequency of 462.5500, span of 12kHz, -61.5dB attenuation offset*.

Here are a couple pictures of the TinySA:

Narrowband setting for the UV-5G Plus:

And by comparison, here is wideband:

 

See the difference?  I don't.

* (At 12kHz it still shows a broader band, because there's room on the screen. At 25kHz span, it's still identical).

* (-61.5dB, because my NanoVNA says that my total attenuation is -61.5dB, not "40+20=60".)

 

Is the radio just not switching to narrowband?

 

[SteveShannon]

2 minutes ago, dosw said:

I have a Baofeng UV-5G Plus. I set it to channel 15 / 462.5500 and tested it in narrowband mode, as well as in wideband mode. I've been able to observe bandwidth using a TinySA with other radios (Retevis RA87, Baofeng UV-5G --not "plus", and MXT275). But with this radio I don't see a difference in transmissions between a narrowband and wideband setting.

The test setup:

Baofeng UV-5G Plus -> 10w 40dB attenuator -> 10w 20dB attenuator -> TinySA

TinySA is set to center frequency of 462.5500, span of 12kHz, -61.5dB attenuation offset*.

Here are a couple pictures of the TinySA:

Narrowband setting for the UV-5G Plus:

And by comparison, here is wideband:

 

See the difference?  I don't.

* (At 12kHz it still shows a broader band, because there's room on the screen. At 25kHz span, it's still identical).

* (-61.5dB, because my NanoVNA says that my total attenuation is -61.5dB, not "40+20=60".)

 

Is the radio just not switching to narrowband?

 

That’s what it looks like.
Try changing to one of the channels where narrowband is required. What does it look like on that channel? 

[dosw]

Tested again in the 467 0.5w channels, also didn't see a difference.

Then I switched to the RTL-SDR because the software is easier to take a screenshot of. Also this time I spoke into the mic rather than just keying up. I think that was where my previous measurements fell down.

 

Within the waterfall (the lower section of the screenshot) there are two transmissions. The top transmission (more recent in time) was narrowband, the bottom transmission (more distant in time) was wideband. You can see the bandwidth peaks are wider. 

 

The red shading above is a 20kHz span, 10kHz deviation. The actual deviation of the radio is supposed to be around 2.5kHz in narrowband, and up to 5kHz in wideband. I see some difference when measured this way.

 

In this example I fed the radio on low power mode into the 61.5dB attenuation, and then into the RTL-SDRv4 on channel 19, and used SDR++ to observe the waterfall.