SDS100/SDS200: RSSI

[Chris0516]

Below is Screen Capture of my SDS100



Below is a Screen Capture of my BCD436HP


Now, What potentially could be causing negative RSSI #'s on my SDS100, but. Very few on my BCD436HP.

Apart from Simulcast on the SDS100 and, NXDN-key activation on the BCD436HP, the are pretty much identical.

TIA

 

[rf_patriot200]

Is the Audio Quality the the same in Comparison to the S/N ratio ? On the same talkgroups, or frequencies ?

 

[GTR8000]

Yeah, so...the SDS shows RSSI in dBm, the x36HP uses Uniden's arbitrary scale. Apples and oranges.

 

[hazrat8990]

They are actually reading two completely different protocols. The SDS series actually displays the correct RSSI. The lower the number, the stronger the signal.

 

[dmfalk]

-60dBm is pretty strong! At least it's not reading -114dBm (noise floor).... I wouldn't complain.... 🙃

 

[Chris0516]

Is the Audio Quality the the same in Comparison to the S/N ratio ? On the same talkgroups, or frequencies ?

The Audio Quality sounds fine.

Yeah, so...the SDS shows RSSI in dBm, the x36HP uses Uniden's arbitrary scale. Apples and oranges.

Ok

They are actually reading two completely different protocols. The SDS series actually displays the correct RSSI. The lower the number, the stronger the signal.

I read, about. The RSSI levels. Before I asked the question. I needed clarification.

-60dBm is pretty strong! At least it's not reading -114dBm (noise floor).... I wouldn't complain.... 🙃

I did a sort in Proscan, of the RSSI data. On the 19th, it got -117dBm on one signal. By "(noise floor)', do you mean it can pick up the sound of me walking around?

 

[dmfalk]

The Audio Quality sounds fine.

Ok

I read, about. The RSSI levels. Before I asked the question. I needed clarification.

I did a sort in Proscan, of the RSSI data. On the 19th, it got -117dBm on one signal. By "(noise floor)', do you mean it can pick up the sound of me walking around?

No, the actual level of background noise, if you had the squelch set to 0. This would be the same as if the radio was missing a connected antenna......😶

 

[Ubbe]

The SDS100 shows the signal level below 0dBm, so all values will be more negative the weaker the signal and something like -120dBm will be no signal. The 436 shows instead a level above 0 that will be no signal and goes up higher to positive values the stronger the signal are.

Both have their signal bars calibrated pretty much equal. One bar are -115dBm and two are -110dBm and three are -105dBm and four -100dBm and five -95dBm.

One problem are that SDS100 also adds the measurements from adjacent channels and if the signal are strong enough it can add signal strength from signals even several MHz away. The 436 only measures from its own channel so are less inflicted from channel interference. If you try and get the strongest possible signal in a SDS100 by trying different filters you could actually be tuning to have the most possible interferences as possible. Always use the d-error bit error rate value from a digital channel to tune scanners to best performance.

/Ubbe

 

[nessnet]

By "(noise floor)', do you mean it can pick up the sound of me walking around?

I hope you were joking......(?)

Noise floor:
Sit in a quiet room, maybe a fan going and a TV going in the other room.
All of the background 'noise' combined is the acoustic (audio) noise floor.
Now a street corner.
All of the honking, traffic and airplanes - that is also the acoustic noise floor for that location.

In radio communication and electronics, the noise floor may include RFI (radio interference caused by anything emitting radio waves), thermal noise, cosmic noise as well as atmospheric noise from distant thunderstorms and any other unwanted natural or man-made signals.

Visually: (the green on the bottom is my current RF noise floor here in my office.
The 'spikes' are a couple of local trunking control channels.

 

[Chris0516]

No, the actual level of background noise, if you had the squelch set to 0. This would be the same as if the radio was missing a connected antenna......😶

Good point

The SDS100 shows the signal level below 0dBm, so all values will be more negative the weaker the signal and something like -120dBm will be no signal. The 436 shows instead a level above 0 that will be no signal and goes up higher to positive values the stronger the signal are.

Both have their signal bars calibrated pretty much equal. One bar are -115dBm and two are -110dBm and three are -105dBm and four -100dBm and five -95dBm.

One problem are that SDS100 also adds the measurements from adjacent channels and if the signal are strong enough it can add signal strength from signals even several MHz away. The 436 only measures from its own channel so are less inflicted from channel interference. If you try and get the strongest possible signal in a SDS100 by trying different filters you could actually be tuning to have the most possible interferences as possible. Always use the d-error bit error rate value from a digital channel to tune scanners to best performance.

/Ubbe

Good description

I hope you were joking......(?)

Noise floor:
Sit in a quiet room, maybe a fan going and a TV going in the other room.
All of the background 'noise' combined is the acoustic (audio) noise floor.
Now a street corner.
All of the honking, traffic and airplanes - that is also the acoustic noise floor for that location.

In radio communication and electronics, the noise floor may include RFI (radio interference caused by anything emitting radio waves), thermal noise, cosmic noise as well as atmospheric noise from distant thunderstorms and any other unwanted natural or man-made signals.

Visually: (the green on the bottom is my current RF noise floor here in my office.
The 'spikes' are a couple of local trunking control channels.

View attachment 173573

Another good description. I wished, I had been joking.