SDS100 vs SDS150 reception issue

[KC8STN]

I just got my SDS150 and I wanted to compare it to my SDS100. I tried to compare them by tuning them into the same FM radio station (because I wanted something that is broadcasting continuously). I tried out both radios and used the same antenna on both. I found that my SDS100 is getting -40dBm for the station and my SDS150 is closer to -65dBm. I played around with attenuation and IFX but neither improved the reception.
Any thoughts on this? I know that listening to FM radio is far from an ideal test for the scanners, but these results surprised me regardless.

 

[rhodester]

Compare them on weather channels.

 

[KC8STN]

Compare them on weather channels.

Good idea, I just tried this. I found that the SDS150 is at least 8dBm better on the weather bands.

**EDIT**
I found that if I set my SDS100 filter to "Normal", I then get about 15 better dBm on the SDS100 actually. So my 100 is getting better reception on weather, depending on the filter I select. And I know that the 150 doesn't have a filter selection.

 

[Ubbe]

Good idea, I just tried this. I found that the SDS150 is at least 8dBm better on the weather bands.

Do the comparison when you have the Noise value being shown on the display and look at that in the pause between the announcements. Lower noise value means a better quality audio. The SDS100 are measuring RSSI over a very wide frequency range, including interference from all the weather channels and other transmitters. Then switch antennas between the two scanners.

/Ubbe

 

[KC8STN]

Ok, noise is better on the SDS150. I'm seeing the lowest level of noise at about 170 on the SDS100, but on the SDS150 I see it drop down to as low as 50.

 

[KC8STN]

What "units" is the noise value in, anyway? Just some kind of internal calculation?

 

[Ubbe]

What "units" is the noise value in, anyway? Just some kind of internal calculation?

It's probably only a simple audio level meter, the more audio, being it background noise or someone talking, the higher the value.

/Ubbe