Uniden Digital Scanners – Search Options for Decoding Digital Signals

Over the past few months, I have been running my Uniden BCD325P2 in AutoStore mode, allowing it to search through sections of the radio spectrum and automatically save the active frequencies it finds.

Reviewing the results has revealed some interesting patterns. In particular, I started noticing that sometimes the scanner would identify CTCSS or DCS tones, while at other times those details were missing. At the same time, I have noticed an increase in the use of DMR and NXDN locally.

The problem was that the local digital activity has generally been too intermittent to spend the time needed to properly test exactly how the scanner's different search settings affect what is decoded and logged.

Recently, however, our local 70 cm DMR amateur radio repeater (VK7RJG) has been active during the evenings. The longer QSO sessions provided a perfect opportunity to sit down and systematically test the different search options.

My initial test was fairly simple. I manually entered the repeater frequency using the familiar:

HOLD → FREQUENCY → HOLD method, however, the DMR signal wasn't being decoded as I expected.

That led me back to the excellent Easier to Read Uniden BCD325P2 Scanner Manual, specifically the section covering Tone/Code Search.

The manual explains that Tone/Code Search determines whether the scanner searches for codes in Search and Close Call modes. It provides three options:

• Off – the scanner does not search for or display tones.
  
  
  
  
  
  
• CTCSS/DCS – the scanner searches for and displays CTCSS/DCS tones.
  
  
  
  
  
  
• NAC/CC/RAN/Area – the scanner searches for and displays NAC, Colour Code, RAN and Area information.
  
  
  
  
  
  

The manual also notes that this setting is ignored in AM, WFM and FMB modes. What I hadn't appreciated was just how much this setting could affect digital signal decoding.

Using the active DMR repeater as my test signal, I tried each of the three settings.

Tone/Code Search: Off

With Tone/Code Search set to off, the scanner decoded the DMR signal. However, no additional digital information was displayed. In other words, I could hear the decoded DMR traffic, but I wasn't getting the useful identifying information that I was looking for.

Tone/Code Search: CTCSS/DCS

This produced a very different result. Instead of clean DMR audio, I was greeted with what can best be described as "machine gun" audio. The scanner was effectively looking for analogue CTCSS/DCS information rather than the digital information associated with the DMR signal. For someone trying to identify digital activity, this is obviously not particularly useful.

Tone/Code Search: NAC/CC/RAN/Area

This was the interesting one. With NAC/CC/RAN/Area selected, the scanner successfully decoded the DMR signal and displayed the Colour Code. This is exactly the sort of information I want when investigating an unknown digital signal. It gives me both the decoded audio and an additional piece of information that can be used to identify and document the transmission.

The unexpected part: this also affects manual frequency entry. The biggest surprise from this testing was that these settings aren't just relevant when performing a traditional Search or Close Call operation. They also appear to affect what happens when using the: HOLD → FREQUENCY → HOLD method, to quickly enter and monitor a frequency.

That means the scanner's Tone/Code Search setting needs to be correct before entering the frequency, if I want the best chance of getting useful information from a digital signal.

This is an important distinction, as it would be easy to assume that manually entering a frequency bypasses the search configuration. My testing shows that it doesn't.

If I am investigating DMR or NXDN and have the scanner configured for CTCSS/DCS searching, I can end up with an entirely different result from what I would get with NAC/CC/RAN/Area selected.

Another limitation is changing the mode from the keypad

Another interesting observation was that, from the keypad, I can change the mode between options such as:

• AM
• FM
• WFM
• FMB

However, I don't appear to have the same direct control over the more specific digital/analogue decoding behaviour from the keypad.

This makes the global search configuration more important than I had previously realised.

It is very easy to change a frequency and start listening without necessarily realising that another setting is influencing what the scanner is actually looking for.

This has changed how I approach spectrum searches. Previously, I had assumed that running a search across a band segment would give me a reasonably complete picture of what was there. My recent testing suggests that this isn't necessarily the case.

If the scanner is configured to look specifically for CTCSS/DCS, I may miss useful digital information.

Likewise, if I configure it specifically for digital code information, I may not get the analogue tone information I was originally looking for.

That creates an interesting problem for anyone trying to document an unknown section of spectrum. Based on this testing, I think I will need to run two separate searches of each band segment.

The first search will use:

CTCSS/DCS: This should allow me to identify analogue FM activity and capture CTCSS/DCS information.

The second search will use:

NAC/CC/RAN/Area: This should give me a better chance of identifying digital activity and capturing information such as:

• DMR Colour Code
• NXDN RAN
• P25 NAC

The exact information available will, of course, depend on the signal type and what the BCD325P2 is capable of decoding.

One of the reasons I enjoy running the scanner in AutoStore is that it produces a large amount of data that can be reviewed later.

In this case, the AutoStore results were what initially made me question why some signals were being logged with useful tone information while others weren't. What I had originally considered to be inconsistent results now appear to have a much more logical explanation.

The scanner wasn't necessarily failing to detect the information, I was simply asking it to search for the wrong type of information. That's an important distinction. This little experiment has changed the way I think about searching for digital signals with the BCD325P2.

The Tone/Code Search setting isn't something I would normally think about when manually entering a frequency, but my testing indicates that it can have a significant impact on what the scanner actually decodes and displays.

For analogue monitoring, CTCSS/DCS is useful.

For digital signal hunting, NAC/CC/RAN/Area is the better choice.

And if I'm trying to comprehensively survey a section of spectrum, I don't think one search configuration is enough.

For my own monitoring, that means running the band segment twice, once looking for CTCSS/DCS, and again looking for NAC/CC/RAN/Area.

It's another reminder that modern digital scanners are considerably more complicated than the old analogue scanners I started with.

Loggings - 23/08/2026

RadioFreakDB Export

Generated: 24/08/2026, 8:58:24 am

Frequency	Callsign	Mode	Service
118.7	TOWER-LTON	AM	Airband
123.8	ATC-LTON APPROACH	AM	Airband
126.5	ATC-NORTH	AM	Airband
129.5	QANTAS	AM	Airband
131.15	AIR UNKNOWN	AM	Airband
132.3	AIR UNKOWN	AM	Airband
146.4	VK7RAA INPUT	FM	Amateur Radio
147.000	VK7RAA 2M Repeater	FM	Amateur Radio
157.775	RAILSWITCH	FM	TasRail
158	TASRAIL SIMP VHF	FM	TasRail
162.375	TASRAIL-MILLERS BLUFF	FM	TasRail
162.525	TASRAIL	FM	TasRail
162.550	TASRAIL	FM	TasRail
163.075	LCC FREELANDS(D)	DMR	Councils
407.950	UNKNOWN	FM	Business
413.35	LGH SECURITY(D)	DMR	Business
414.025	TASRAIL UHF LINK	FM	TasRail
414.26875	METRO UHF LINK	FM	Business
414.425	TASRAIL UHF LINK	FM	TasRail
438.4125	VK7RJG(D)	DMR	Amateur Radio
438.550	VK7RJG 70CM Repeater	FM	Amateur Radio
439.200	70CM SIMPLEX C4FM	FM	Amateur Radio
439.775	VK7RDR-DAZZLER	FM	Amateur Radio
450.68125	TASRAIL	FM	TasRail
454.275	METRO (TX)	FM	Business
463.025	LCC QVMAG(D)	NXDN	Councils
464.275	METRO ABLES	FM	Business
464.375	METRO FREELANDS	FM	Business
474.775	UNI SECURITY (DMR)	DMR	Business
494.925	LAUNCESTON AQUATIC CENTRE	FM	Councils
495.0625	VIZPIX	FM	Business
509.875	OFFICE OF RACING INTEGRITY	FM	Business

Exported from RadioFreakDB by VK7AAL

Video - 17/08/2026 - Launceston Approach

 

Loggings - 17/08/2026

RadioFreakDB Export

Generated: 18/08/2026, 9:10:09 am

Frequency	Callsign	Mode	Service
73.13	B W MANION	FM	Business
118.7	TOWER-LTON	AM	Airband
123.45	AIR SIMP	AM	Airband
123.8	ATC-LTON APPROACH	AM	Airband
125.55	ATC HOBART	AM	Airband
126.5	ATC-NORTH	AM	Airband
126.7	CTAF	AM	Airband
126.9	CTAF NW	AM	Airband
129.5	QANTAS	AM	Airband
130.300	ATC Mt Tassie (Vic)	AM	Airband
130.35	VELOCITY	AM	Airband
146.4	VK7RAA INPUT	FM	Amateur Radio
147.000	VK7RAA 2M Repeater	FM	Amateur Radio
156.425	MARINE WEATHER	FM	Marine
156.6	MARINE VHF 12		Marine
156.7	MARINE VHF 14	FM	Marine
156.8	MARINE VHF 16	FM	Marine
157.9	BORAL - INPUT	FM	Business
162.15	TASRAIL	FM	TasRail
162.375	TASRAIL-MILLERS BLUFF	FM	TasRail
162.500	BORAL	FM	Business
162.525	TASRAIL	FM	TasRail
162.6125	TASRAIL MT ARTHUR	FM	TasRail
163.575	LCC MT ARTHUR(D)	DMR	Councils
413.35	LGH SECURITY(D)	DMR	Business
414.26875	METRO UHF LINK	FM	Business
438.4125	VK7RJG(D)	DMR	Amateur Radio
438.550	VK7RJG 70CM Repeater	FM	Amateur Radio
462.325	SPOTLIGHT LAUNCESTON	FM	Business
464.275	METRO ABLES	FM	Business
464.375	METRO FREELANDS	FM	Business
471.7	PFEIFFER CRANES	FM	Business
473.500	TASRAIL UHF	FM	TasRail
474.775	UNI SECURITY (DMR)	DMR	Business
476.425	UHF CB CH 1	FM	UHF CB
476.5	UHF CB CH 4	FM	UHF CB
476.575	UHF CB CH 7	FM	UHF CB
476.5875	UHF CB CH 47		UHF CB
476.65	UHF CB CH 10	FM	UHF CB
476.75	UHF CB CH 14		UHF CB
476.8	UHF CB CH 16	FM	UHF CB
476.850	UHF CB 18 (TIP)	FM	UHF CB
476.95	UHF CB CH 22		UHF CB
477.05	UHF CB CH 26		UHF CB
477.075	UHF CB CH 27	FM	UHF CB
477.15	UHF CB CH 30	FM	UHF CB
477.1625	UHF CB CH 70		UHF CB
477.225	UHF CB CH 33	FM	UHF CB
477.25	UHF CB CH 34	FM	UHF CB
477.325	UHF CB CH 37	FM	UHF CB
477.375	UHF CB CH 39	FM	UHF CB
477.4	UHF CB CH 40	FM	UHF CB
477.4125	UHF CB CH 80	FM	UHF CB
494.925	LAUNCESTON AQUATIC CENTRE	FM	Councils
509.8875	UHF SIMPLEX	FM	Business

Exported from RadioFreakDB by VK7AAL 

30 Years of Scanning - My Radio Journey

September 2026 marks 30 years since I first started in the radio hobby. Three decades is a long time in radio, and when I look back, the hobby I started with is almost unrecognisable compared with what I do today.

What began as an interest in listening to radio transmissions has developed into a much broader fascination with radio systems, frequencies, antennas, digital modes, spectrum hunting, amateur radio and documenting what I hear.

When I first started
I started in the radio hobby in 1996. Back then, radio scanning was a very different hobby to what it is now in 2026. There was no online frequency database, no easy way of looking up a system on the internet, and very little of the information we take for granted today. We did have some printed books, which I purchased from my local Dick Smith store but these only painted some of the picture.

A lot of the fun was discovering things for yourself. You would find a frequency, listen, try to work out who was using it and write it down. Back then, before the Internet, forums and other online resources had really taken off, other enthusiasts and word of mouth were important sources of information.

Those early experiences were enough to turn radio from something I was simply interested in into a hobby that has stayed with me for three decades.

The first things I monitored
My early interest was primarily in listening to local two way radio communications and trying to understand what was happening around me through the radio spectrum. The first frequency I logged was a local construction / delivery company in the VHF high band, 30 years later, they are still on the same frequency.

The attraction was never simply hearing a voice. It was working out what I was hearing.

Who was transmitting?
Where were they?
What frequency were they using?
What was the purpose of the transmission?

That curiosity has probably been one of the constants throughout my entire time in the hobby.

Early antennas
Like for many scanner enthusists, the antenna became an important part of the hobby.

There is something particularly satisfying about improving an antenna and suddenly hearing stations that were previously weak, noisy or completely absent. I used various discones for many years and have recently been focusing mostly on the VHF airband and high band, so have found a VHF Marine band aerial, mounted on our second story roof is the best I can get for my monitoring needs. The antenna is still one of the most important parts of a monitoring station and it is often overlooked.

My first amateur radio experiences
Amateur radio eventually became another important part of my relationship with radio. I started in 2006 with getting my foundation licnece (VK7FPGB). In 2025, I changed to my new callsign of VK7AAL, this has become closely associated with my radio activities, and amateur radio gave me another perspective on the spectrum.

Radio scanning and amateur radio overlap, but they are also quite different. Radio scanning is often about discovering what other people are doing. Amateur radio gives you the opportunity to actually participate. Over the years, that combination of listening, experimenting and transmitting has helped shape the way I approach radio.

Equipment I've owned
My equipment has changed dramatically over the years. My first scanner was a Pro 25, which was a 100 channel VHF / UHF scanner, it cost me $100 from our lcoal second hand dealer. One of the most significant developments has been the move from conventional analogue scanners to modern receivers capable of handling a much wider variety of digital systems.

Over the years I have owned and used a large mix of equipment, both scanners and wide band recivers. The Icom R8500 was the centre piece of my monitoring station for a while. I also foudn the AOR 8600mkii to be useful, if very complex to use. I have been a fan of the Uniden range, I imported a BCD396T from the USA, prior to the Australian UBCD396T being released. One thing I have found is that the equipment is only part of the puzzle, knowing how to use it to get the most out of it is also very important.

Today my equipment includes receivers such as the Uniden BCD325P2, which has become particularly useful for portable monitoring and Close Call work.

I've also increasingly used computers alongside my radios. Radio monitoring is no longer just about having a scanner sitting on the desk. It can involve databases, logging software, programming files, digital systems and custom tools that I have developed myself. That has led to projects such as my own radio databases, frequency management tools and scanning software. RadioFreakDB has become the centre piece of my monitoring record keeping and it now runs on both my laptop and phone, giving me access to my loggings and other information no matter where I am.

It is difficult to pick a single favourite because different radios have served different purposes. The BCD325P2 is particularly useful for the way I monitor today. Its portability makes it ideal for getting out of the shack and taking the radio to where the signals actually are.

That is important because some of the most interesting monitoring I have done recently hasn't happened sitting at home.

For example, I have taken the BCD325P2 on drives around Tasmania, including a trip to Deloraine, running it in Close Call mode and seeing what signals appeared around me. That style of monitoring, taking the receiver to the signal rather than simply waiting for signals to come to me, has become a major part of my hobby. I often make sure I have this with me in one of the Auto Store modes, so I can review what is received later.

The Icom R20 was also a favorite of mine and I made good use of the audio recorder. I would often leave it setup and recording, espically on unkown frequencies, to review the recording later, this helped me with being able to ID a number of frequencies over the years.

How scanning has changed over 30 years
This is probably the biggest change of all. When I started, scanning was predominantly about analogue voice communications, FM on the buisness bands and AM for aircraft. Today the spectrum contains an enormous mixture of:

• Analogue FM
• P25
• DMR
• NXDN
• Data transmissions
• Telemetry
• Paging and other signalling

Some services have disappeared completely. Others have moved to digital systems. Some systems are now encrypted, making them effectively unavailable to the hobbyist listener.

In Tasmania, the TASGRN system is a good example of how things have changed. Large communications networks have become increasingly sophisticated, while encryption has also changed what can realistically be monitored.

The challenge today isn't necessarily finding a signal. It's understanding what the signal is.

How my interests have evolved
This is where my hobby has probably changed the most. I started as someone who wanted to listen to radio. Over time, I became interested in finding radio signals, then identifying them, then documenting them. Now I am increasingly interested in understanding the technology behind them.

I've also become interested in creating resources for other enthusiasts, including FreeScan configuration files and databases.

I enjoy the process of taking something I have personally discovered and turning it into something useful that somebody else can use.

For me, it is now less about the content and more about what frequencies are in use, where, when and by who.

What I'm monitoring today
Today my main focus is UHF band monitoring, searching for new users and signals and documenting this, Rather than simply programming a list of known frequencies and leaving the scanner running, I enjoy getting out and actively hunting for signals.

I'll take a portable scanner into an area, listen to the spectrum, watch for signals, investigate frequencies and then try to work out exactly what I've found. That might be UHF CB, a data transmission, a digital signal, a TASGRN control channel or something completely unexpected.

And that's still what makes scanning exciting after 30 years. You never quite know what the radio is going to find.

Where I think the hobby is heading
I don't think scanning is disappearing. I do think it is changing. The traditional idea of sitting beside a scanner listening to analogue conversations is becoming less representative of modern monitoring.

The future is likely to involve more digital systems, more data, more encryption, software-defined radio, computer-assisted analysis and increasingly sophisticated methods of identifying unknown signals.

The moment when you discover a signal you've never heard before is still just as exciting as it was when I started 30 years ago.

Looking back, I find it remarkable that something I started in 1997 has remained such a significant part of my life. Radio has gone from being something I listened to into something I research, document, write about, develop software for and actively hunt.

My interests have changed enormously, but the underlying curiosity that first got me started hasn't.

Photo Dump

Since the early 2000's I have keep a large number of radio related photos. Below are some, that show my journey over this time.