SNACC P25 Phase 2

[afchev]

I recently began scanning heavily again after about a year hiatus. Before the changeover to Phase 2, I seem to remember I used to be able use the waterfall feature or even just frequency search to listen to one of the site frequencies, the SDS200/100 would decode it no problems. Now when I try that, It's just static or silence although the radio does identify the frequency as P25 and provides a NAC code. Is this just something to do with how Phase 2 works vs Phase 1? It seems to still work when listening to a Phase 1 system like Nellis/Creech AFB so maybe I answered my own question.

Also my rooftop antenna has line of sight to the Angel Peak site, and my work issued APX6000 programmed for SNACC automatically switches to Angel while at home, so I'm using that as a metric to assume that Angel Peak is ideal for my location up in the far NorthWest. Is it logical to think that I would miss any traffic if I just listened to a single site like Angel or Apex? Does every site on a system talk to each other? Logic tells me that a unit on Potosi should be able to talk to a unit on Angel peak even if neither person is in line of sight of the other repeater.

I'm having a heck of a time trying to get good results on Simulcast with the SDS200/100 and I've been trying to use the waterfall feature to see if there is any major nearby signals screwing with my reception. Angel Peak is always pegged at -55dbm with little to no digital errors so I'd prefer to use that.

I know nothing about anything, so thanks in advance.

 

[afchev]

Trunking Basics - The RadioReference Wiki

wiki.radioreference.com

This actually mostly answered my question.

 

[es93546]

I recently began scanning heavily again after about a year hiatus. Before the changeover to Phase 2, I seem to remember I used to be able use the waterfall feature or even just frequency search to listen to one of the site frequencies, the SDS200/100 would decode it no problems. Now when I try that, It's just static or silence although the radio does identify the frequency as P25 and provides a NAC code. Is this just something to do with how Phase 2 works vs Phase 1? It seems to still work when listening to a Phase 1 system like Nellis/Creech AFB so maybe I answered my own question.

Also my rooftop antenna has line of sight to the Angel Peak site, and my work issued APX6000 programmed for SNACC automatically switches to Angel while at home, so I'm using that as a metric to assume that Angel Peak is ideal for my location up in the far NorthWest. Is it logical to think that I would miss any traffic if I just listened to a single site like Angel or Apex? Does every site on a system talk to each other? Logic tells me that a unit on Potosi should be able to talk to a unit on Angel peak even if neither person is in line of sight of the other repeater.

I'm having a heck of a time trying to get good results on Simulcast with the SDS200/100 and I've been trying to use the waterfall feature to see if there is any major nearby signals screwing with my reception. Angel Peak is always pegged at -55dbm with little to no digital errors so I'd prefer to use that.

I know nothing about anything, so thanks in advance.

What is the "waterfall" feature? I've never come across the term in my 50+ years of scanning.

 

[afchev]

What is the "waterfall" feature? I've never come across the term in my 50+ years of scanning.

 

[es93546]

The video is helpful if you know what function the "Waterfall" is performing. However, that is not explained.

 

[afchev]

Its a band scope/spectrum analyzer. What do you need me to explain?

 

[es93546]

Its a band scope/spectrum analyzer. What do you need me to explain?

What does a "band scope/spectrum analyzer" do?

 

[afchev]

What does a "band scope/spectrum analyzer" do?

A band scope (also called a panadapter or spectrum scope) is a visual display on a radio that shows radio signal activity across a range of frequencies in real time.
Instead of tuning blindly, you can see signals on the band.

What it displays
A band scope typically shows:
Horizontal axis (X-axis): Frequency
Vertical axis (Y-axis): Signal strength
Strong transmissions appear as peaks or spikes.

What it’s used for
Band scopes are useful for:
Finding active stations quickly
Detecting weak signals
Seeing interference or noise
Monitoring an entire band segment
Spotting digital, CW, AM, FM, or SSB activity
Hunting satellites, aircraft, or HF DX signals

On an amateur HF radio, a bandscope might show:
A cluster of SSB operators around 14.200 MHz
FT8 digital signals around 14.074 MHz
Empty sections with no activity
You can then click or tune directly to a visible signal.

Common types:

Basic bandscope
Shows only a narrow range around your current frequency.

Wideband spectrum scope
Shows large chunks of spectrum at once — sometimes several MHz.

Waterfall display
Adds time history:
New signals appear at the top
Older signals scroll downward
Persistent carriers become vertical lines
This is common on SDRs.

SDR connection
Software Defined Radios heavily rely on bandscope displays. Programs like:
SDR#
HDSDR
GNU Radio
show large real-time spectrum and waterfall views.

Practical analogy
A normal radio without a bandscope is like searching for stations in the dark.
A radio with a bandscope is like having a map showing where all the activity is before you tune.

 

[es93546]

A band scope (also called a panadapter or spectrum scope) is a visual display on a radio that shows radio signal activity across a range of frequencies in real time.
Instead of tuning blindly, you can see signals on the band.

What it displays
A band scope typically shows:
Horizontal axis (X-axis): Frequency
Vertical axis (Y-axis): Signal strength
Strong transmissions appear as peaks or spikes.

What it’s used for
Band scopes are useful for:
Finding active stations quickly
Detecting weak signals
Seeing interference or noise
Monitoring an entire band segment
Spotting digital, CW, AM, FM, or SSB activity
Hunting satellites, aircraft, or HF DX signals

On an amateur HF radio, a bandscope might show:
A cluster of SSB operators around 14.200 MHz
FT8 digital signals around 14.074 MHz
Empty sections with no activity
You can then click or tune directly to a visible signal.

Common types:

Basic bandscope
Shows only a narrow range around your current frequency.

Wideband spectrum scope
Shows large chunks of spectrum at once — sometimes several MHz.

Waterfall display
Adds time history:
New signals appear at the top
Older signals scroll downward
Persistent carriers become vertical lines
This is common on SDRs.

SDR connection
Software Defined Radios heavily rely on bandscope displays. Programs like:
SDR#
HDSDR
GNU Radio
show large real-time spectrum and waterfall views.

Practical analogy
A normal radio without a bandscope is like searching for stations in the dark.
A radio with a bandscope is like having a map showing where all the activity is before you tune.

Thank you, that is an excellent response. I now understand what I was looking at in the video.

 

[afchev]

Thank you, that is an excellent response. I now understand what I was looking at in the video.

You can thank chat GPT for that one my friend.