Category Archives: 700Mhz

The SDS-100 and why it is so revolutionary

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If you haven’t heard already, the new Uniden SDS-100 handheld digital scanner has taken the prize as the most desired scanner available. Introduced in the spring of 2018 and finally available in June, we sold every one we had and were promised and just now are able to keep them in stock for regular purchases.

What makes the SDS-100 so special? Why does it work so well? Why is it worth all the extra money it costs? Glad you asked!

The biggest advantage to the SDS-100 has over other scanners is it’s ability to monitor Linear Simulcast Modulation (LSM, also known as P25 Simulcast) systems. Traditional scanners do not work very well often with LSM systems but the SDS-100 handles them much better, almost as well as a regular system radio like the police use. Other scanners tend to break up, miss words or phrases or just not hear it al all.

Why, you might ask, does this happen? Simply put, a simulcast system transmits the same traffic on the same frequencies at the same time from 2 or more locations. A simulcast system would transmit from multiple sites to provide better coverage within its intended operational area. These signals then tend to arrive at your scanner with slightly different time delays. Even though these time differences are almost indescribably small, the fact that they are digital1’s and 0’s makes them interfere with each other. The 1’s from one tower tend to block the 0’s from another tower. This causes interference and sometimes the interference is so bad as to block the entire conversation.

The SDS-100 uses a totally different internal architecture than other scanners, basically using a Software Defined Radio (SDR) with True-IQ processing to more properly decode LSM transmissions. This means that the SDS-100 will receive these simulcast systems with little to no distortion or interference.

There are other advantages to the SDS-100 SDR-based architecture. It allows other features and capabilities to be added down the road. While Uniden has not announced any of these features yet the possibilities are endless.

The SDS-100 works much like the BCD436/536 series scanners, the interface is very similar and they use an updated version of the Sentinel software so you can share your Favorites Lists between them.

The other big feature with the SDS-100 is the color display. This display can be used in either a “Simple” or “Detail” mode. The Detail mode is entirely customizable. You can place any of dozens of different fields almost anywhere on the screen and assign any color to just about any item. You can switch back to Simple mode and just have the basics, still in color or even switch to a simpler black and white scheme that works better in bright sunlight.

The SDS-100 is an amazing radio. If you have simulcast systems in your area then it works much better than other scanners. While it is more expensive than other scanners it is well worth it!

Why does my Phase 1 scanner still work on a Phase 2 system?

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So you have had your trusty old BCD396XT or other Phase 1 scanner for years and it works great. You hear that your system has upgraded to a Phase 2 system but your old Phase 1 scanner still works? What gives?

Here is the skinny on that: Most “Phase 2” systems are actually operating in Phase 1 mode, at least partially. When a system upgrades to Phase 2 not only does the infrastructure have to be upgraded (base station repeaters, controllers etc.) but also all of the mobile and portable radios. Until ALL radios have been upgraded and reprogrammed the system will usually be operating in Phase 1 mode.

Many systems listed in the RadioReference database as “Phase 2” have been heard with Phase 2 operations but still operate as Phase 1, so in reality it is better termed as “Phase 2 Capable”.

Some wide area systems may operate in Phase 2 modes in one area and Phase 1 elsewhere. The huge StarCom21 system in Illinois is a good example of this. In the Chicago area some users use Phase 2 but others are on Phase 1 since the new radios are expensive. Until all those older radios are replaced or reprogrammed the system will operate in a mixed Phase 1 or 2 mode.

This makes your older Phase 1 only scanner usable for at least parts of the system and saves you from having to replace it right away. When they do switch entirely over to Phase 2 then you will need to replace your scanner.

Another question we often get here at the ScannerMaster International Headquarters is how one updates his older Phase 1 scanner to Phase 2. The answer to that is that you don’t. There is no update path for older scanners to Phase 2; you will have to replace it.

Most newer model digital scanners from Whistler and Uniden handle Phase 2, see them at https://www.scannermaster.com/Digital_P25_Phase_II_Scanners_s/708.htm

When the best scanner isn’t a scanner (Unication Receivers)

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Unication G5 Dual BandIf you live in an area covered by a Simulcast P-25 radio system you likely have suffered from Simulcast Distortion. This is the interference and missed calls caused by simulcast sites of these radio systems interfering with each other. All scanners have this issue and there are various things one can do to remedy the situation. This includes relocating or reducing the antenna, use of a directional antenna or turning on the attenuator.

Sometimes even this doesn’t help. If you really get in a bind there are other ways to get better reception. For some this means getting a specially programmed two-way radio set up on the system and using it as a monitor. While sometimes these can be programmed for receive only there are problems with this approach. First off is legality. Unless authorized by the system owner it may be illegal to have such a radio set up on the system due to the use of a “System Key”. Some states even This is considered to be intellectual property and restricted to authorized personnel. Even if you got past this hurdle two-way radios for these systems are expensive, sometimes over $5000. Add into that programming software ($300) and cables ($200) and pretty soon you are talking about real money.

The Unication receivers provide a possible solution that is much more reasonably priced, does not require permission or special codes or keys for the system but with reception rivaling that of the expensive radios at a fraction of the cost. The downside is that the Unication is not as flexible as a scanner and does not allow for field programming.

The Unication provides professional quality reception at a hobbyist price. While more expensive than scanners, it receives P25 Simulcast systems as well as the expensive two-way radios do at a much lower price.

ScannerMaster can program the Unication radio for you, be sure to select this option at the time of purchase if you want it. You can also do the programming yourself with a Windows computer, the software is free from Unication. Of course if there are any questions our knowledgeable staff is here to help!

The Unication G4 works in the 700 and 800 MHz. bands. The G5 works in these bands plus another, such as VHF or 2 different UHF bands. Currently they work on Phase 1 systems only but a Phase 2 upgrade will be available soon. This will be a paid update but pricing has not yet been announced.

Trunking System Types Glossary

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Earlier we discussed the differences between Type 1 & 2 and Phase 1 & 2 trunking systems. This week we will discuss some other formats of trunking. I choose to use the easier to understand mnemonics of 1 and 2 rather than the more correct I and II for some of these systems. These mnemonics are often interchanged.

“Motorola” trunking systems include Type 1, Type 2 and Type 2i systems. The original Type 1 systems used a 3600 baud control data signal and a Fleets/Subfleet programming style. In time it was found to be too limiting, it restricted the number of subfleets and radios that could be accommodated within the Fleets. Motorola developed what was called Type 2 trunking that used a similar 3600 baud control data signal but removed the restrictions about Fleets and Subflleets and removed many of the limits on radios. Type 2 systems could have more than 65,000 individual radio ID’s and thousands of Talkgroups.

Some Type 1 systems were upgraded, either to Type 2 or to a hybrid system that allowed both Type 1 and Type 2 radios, this was commonly referred to as Type 2i. A later version of Type 2 trunking, called APCO P16, used the same Type 2 control data but allowed either analog or digital modulation.

APCO P25, as we discussed last week, is an all-digital format sold by several manufacturers, including Motorola, Harris and others. The format was developed by and for APCO and is licensed from them. The system was designed to be interoperable between the several vendors but often they add features that only they can provide so as to rope in customers to continue buying their radios instead of radios from other companies. One way to tell a Motorola designed system apart is by the control channels. On Motorola systems the Control Channel rarely changes and there are only 2 to 4 channels that they would rotate to if one becomes unavailable. Harris designed systems can use any of the channels for control data and some of these rotate the control data regularly.

P25 voice is also commonly used on conventional (non-trunked) channels as well.

There are two main types of P-25; Phase 1 and Phase 2 (or Phase I and II). Phase 1 allows a single conversation on a voice channel while Phase 2, a form of TDMA, allows 2 on each channel, effectively doubling the capacity of the system.

Most scanners these days only require the current Control Data channel for many of the P25 and Motorola trunking systems to track them.

EDACS is a trunking system originally sold by General Electric as a competitor with Motorola Type 1 and later Type 2 systems. This comes in 2 different types, the 9600 Baud control data commonly used on 800 MHz. systems and 4800 baud control data mostly used on UHF and 900 MHz. EDACS systems can use either analog voice or digital voice, called ProVoice. While any trunking scanner can handle analog EDACS systems only certain Uniden scanners (BCD325P2, BCD996P2, BCD436HP and BCD536HP) scanners can monitor ProVoice operations and these require the ProVoice paid upgrade.

EDACS is commonly used for public safety and less often in business applications. It shares many features with the Motorola trunking formats but is not compatible with it. It can be used as Single Site, Simulcast or Networked or some combination of these.

After several years GE sold the EDACS product line and it bounced around to several companies before landing at Harris Communications. Since EDACS is no longer sold or supported by Harris many of the systems have been shut down or converted to other formats. At some point EDACS systems will all be shut down as parts become unavailable for repairs.

To program an EDACS system into a scanner one needs to put the channels in their proper assigned slots. This is called the “LCN” (Logical Channel Number). This is because the radio only sends the channel number, it is up to the scanner or other radio to match this with the actual frequency.

LTR (Logic Trunked Radio) is a popular format for business users and occasionally used for public safety. This format does not use a dedicated control channel like Motorola, EDACS or P25 systems do. Instead data is sent piggybacked onto the regular traffic on the channel advising specific radios to go to a channel for a message. While this allows all channels to be used for voice messages it is not as robust as other systems so is not often used for police and fire use.

One can tell is an LTR system is in us, there is a characteristic repeater key-up on most channels. This is sending data to radios assigned to that channel as it’s “Home Channel”. Most trunking scanners can handle LTR systems, the trick is determining the LCN slots properly.

DMR/TRBO/NXDN systems can be either conventional or trunked. Some systems can be trunked with a single channel, using sub-audible codes to separate the groups. These systems use TDMA for voice traffic so multiple conversations can be carried on one channel.

While used mostly for business activities these systems occasionally are used for public safety, especially in the SE states.

MotoTRBO is a brand name used by Motorola for it’s DRM offering. While there are slight differences a DMR scanner works fine for unencrypted TRBO systems.
DMR is available on certain Uniden and Whistler scanners.

NXDN trunking is very similar to DMR but just different enough to require a different mode. As of this writing (Spring 2017) NXDN was only available on the TRX-1 and TRX-2 scanners by Whistler.

Type 1, Type 2, Phase 1, Phase 2, what’s the difference?

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There is often confusion between different types of trunked systems. One of the most confusing things is the names of some systems. We get calls and letters all the time asking about Phase 2 and Type 2 systems and whether a particular scanner will work on them. They are different and the difference will determine if your scanner will work with it.

TYPE 2 (more accurately but less often written as TYPE II) systems are older Motorola trunking systems that use 3600 baud control data channels. These are commonly referred to as just “Motorola” systems when programming scanners. These were an evolution from the original Type 1 and Type 2i systems. The difference between Type 1, 2i and 2 systems is the way talkgroups are developed. Type 1 systems use a Fleet/Subfleet system that resulted in limited flexibility to assign talkgroups. Most of these systems have been shut down or updated and very few remain in use. Type 2 systems had a different method of assigning talkgroups and allowed greater flexibility. Some systems were called Type 2i, and were a hybrid between Type 1 and Type 2 systems.

Newer Type 2 systems, referred to as APCO P16 systems, allowed either digital, analog or both forms of modulation. There are still many of these systems in use all over the country.

PHASE 1 and PHASE 2 (more accurately referred to as Phase I and Phase II) systems are totally different than Type 1 or Type 2 systems. Phase 1 and 2 systems are forms of APCO P-25 digital systems that use 9600 baud control data channels and all digital modulation. Phase I systems have a single voice path per frequency while Phase II allows 2 voice paths per frequency, effectively doubling the amount of traffic a set number of channels can handle.

It gets even more confusing when programming some radios. Some scanner program the Type 2 and Phase 1 or 2 systems with the same system type, others have different selections. On the user end, most Motorola P25 (Phase 1 or 2) radios are also capable of being used on the older Type 2 systems.

Next week we will look at some of the other trunking systems like EDACS, LTR and TRBO.

Favorite Scanner: BCD436HP

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The BCD436HP (commonly referred to as the “436“) is Uniden’s premier handheld scanner. It takes the Location Based Scanning system from the HomePatrol and merges it with the huge feature set of the BCD325P2. You get the best of both worlds; easy ZIP code based scanning and the flexibility and functionality of a full featured professional scanner.

Remember the commercials for the candy where some guy got his chocolate into another guy’s peanut butter? Well, imagine mixing a HomePatrol 2 with a BCD325P2, instead of a tasty peanut butter cup the end result is a BCD436HP.

The HomePatrol’s ease of use required the removal of several key features that were present on other scanners, this included things like CloseCall, Limit Search, Fire Toneout and keyboard programming. While most HomePatrol purchasers do not need these features there are others that want them. The “436” restores all of these features and more and keeps the Location Based scanning of the HomePatrol. With Phase 2 capability, the 436 works almost everywhere in the USA and Canada, just by putting in a location.

The 436 also now allows one to listen to ProVoice. These are used in a few areas of the country and until recently could not be heard by any scanner. With the extra-cost ProVoice option you can now hear unencrypted ProVoice digital systems such as used in San Antonio or Oklahoma City among other areas.

The 436 also has the ability to record conversations heard on the scanner to it’s built-in SD Card, allows analysis of trunked radio systems and more. You can program it on the fly like you would older scanners, use a computer to program it or just let the radio use it’s internal database.

The 436 comes with the free Sentinel software to update the firmware and database (Windows only, sorry Mac dudes!) as well as rechargeable batteries, a USB cable and antenna. You charge the batteries with a USB charger, available at extra cost or just use the one from your cellphone or other USB device. It covers most scanner frequencies from 25 to 1300 MHz. and works on AM, FM, FMW, P25 Digital Phases 1 and 2 as well as ProVoice digital (requires extra cost key for ProVoice). Optional ARC software is also available for control and advanced programming.

The BCD436HP is available from ScannerMaster at BCD436HP or just call us at 800-SCANNER.

Uniden Scanners

The Digital Blues (or why does my local digital system sound like #$^?)

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So you bought that fancy new digital scanner and while it usually works great, sometimes on certain digital systems it doesn’t seem to sound right. Sometimes it just drops words or phrases but sometimes it drops the whole conversation.

You try moving the scanner around or connect to a better antenna and it doesn’t help or even gets worse. Before you throw the scanner against the wall in frustration read on:

We feel your pain! The problem isn’t you or in or the programming. It is called “Simulcast Digital Distortion” or more commonly “Bit Error”. Our friends at RadioReference have a great technical explanation of this in their Wiki at http://wiki.radioreference.com/index.php/Simulcast_digital_distortion

The 10 cent explanation of this is that you have signals from more than one tower arriving at your radio at ever-so-slightly different times. These signals compete with each other and tend to null each other out. This is why sometimes the radio will stop but you won’t hear any or part of it.

There are a couple things you can do to help get past this issue. If your radio has an attenuator function try that first. This reduces the signal and hopefully will force your radio to only be able to receive a single tower site. You can also try moving the antenna around the room to see if you can find a “sweet spot”. If you are using a telescoping antenna try adjusting it to different lengths or angles. Also try opening the squelch all the way. If all you are listening to is the digital system then this will not affect other channels.

If all of this fails then you may need to try a directional antenna. Commonly called “Yagi’s” these antennas will direct your reception in a single direction and hopefully force your radio to hear only a single tower.

This type of digital distortion usually is less prevalent with newer models of scanners and firmware updates usually reduce it as well. Make sure you have a current model scanner and that its firmware is up to date.

 

Scanner Tip: It is a Digital World!

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Many areas of the country have switched to “Digital”. What does this mean for the scanner listener? What is “Digital” anyway?

First, before we go any further, the number one question we get about digital scanners is whether they will also work on analog. The answer is YES. All digital scanners work just fine on analog channels, always have and always will.

Digital radio means that instead of using a regular AM (where the amplitude [strength] is changed) or FM (where the frequency is modulated or changed) signal , a digital signal type is used. This is a signal that is converted to the base 0’s and 1’s, compressed, and sent out on the airwaves. A digital receiver then converts it back and lets you hear it.

There are several types of digital that are of interest to scanner listeners. The most common for police, fire and other public safety use is APCO’s P25 system. This is widely used by both trunked and conventional (non-trunked) radio systems across the country. Several manufacturers, like Motorola, Harris and others sell P25 systems and equipment. While the P25 standards are supposed to ensure that any companies radios will work on the various systems, in practice some companies often add new “features” that tend to lock out other company’s radios from working with the system.

P25 comes in several flavors. “Phase 1” is the original single channel-per-frequency protocol used on conventional systems and most trunked P25 systems. “Phase 2” P25 effectively splits channels using TDMA (See technobabble below) to allow 2 simultaneous conversations on the same frequency, effectively doubling the capacity of a trunked system. If your system uses Phase 2 be sure to get a Phase 2 capable scanner!

Technobabble here: Phase 2 uses Time Division Multiple Access, more commonly known as TDMA. The radio system divides a radio signal into timeslots of tiny fractions of a second. In Phase 2 systems a certain time slot is assigned to the “0” channel and the other slots are assigned to the “1” channel. This allows 2 conversations to be held at the same time on the same frequency. The communications are restored at the receiver so it can be processed and heard by the user. Decoding software like UniTrunker or Pro96Com will show these sub-channels as “851.0375/0 and 851.0375/1”.

Some areas of the country have gone to a system called “OpenSky”, manufactured by Harris. While these systems have not been successful in many instances, the systems in place cannot be monitored by scanners. Harris has since dropped OpenSky from its catalog and is selling P25 systems now.

One trend that is growing in some areas is the use of various “DMR” systems. These are sold under various trade names like MotoTRBO, NXDN and others. They all use fairly similar digital protocols but current consumer scanners do not cover them. There are some SDR (Software defined radio) and advanced receivers (like the new AOR DV1) that will allow one to monitor these systems. The reason many agencies select these is usually cost, the radios are fairly cheap, especially when compared to P25 radios. While they may not be as durable, the replacement costs are often less than a repair would be. Businesses however have embraced these cheaper forms of digital radio and they are common on business channels. Railroads have agreed on using NXDN digital modes but implementation has been very slow. Ham radio operators use some of these also, as well as D-Star.

Do not confuse digital voice with encryption. While it is true that many digital systems are encrypted these days, most are not and these are perfectly legal to listen to. Also do not confuse digital voice with digital data. Most police and fire agencies use some sort of data systems for MDT’s or video, these systems cannot be monitored without huge budgets and massive computing power. Listening to digital transmissions on an analog only scanner will not work, you will just hear noise.

Some people hear and understand received digital communications better than others. The absence of background noise sometimes makes it uncomfortable for some users, since it can be mistaken for non-radio conversations. Digital certainly sounds different than analog but occasionally causes issues with things like firefighters protective gear. Usually it is just a matter of getting used to how it sounds. In addition, when digital signals are weak they tend to get garbled. Many agencies call this “going digital” since it makes a weird noise.

Digital scanners are more expensive than analog ones. This is mostly due to licensing requirements for the technology. While prices have gone down recently they still are usually about twice as expensive than analog scanners with similar features.

Will there be more scanners with DMR modes like TRBO and NXDN? We don’t know yet, but if and when they do become available we will be among the first to have them. The AOR DV1 is available now and does receive several of the digital modes.

Scanner Tip: Everything you need to know about trunking but were afraid to ask

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In the old days of scanning things were pretty simple, you put in the local police frequency to listen to the police. In many parts of the country however, this no longer works. Most cities, many counties and even entire states use Trunking Systems. What are trunking systems and how do they work?

The best way to explain how a trunking system works is the analogy of a set of bank teller lines. The bank has 5 tellers, you can line up at any of the 5 lines and hope your line goes faster than the others. Then you get stuck behind the lady that wants to have her penny jar counted by hand…

These days however, banks have a single queue and you go to the next available teller when you reach the head of the line. This is exactly how a trunked radio system works: All users are in one queue and get assigned the next available channel. Instead of having a separate frequency for the FD, one for the PD and another for the ambulance, they just go to the next channel that isn’t being used.

All this is controlled by a computer system called, appropriately enough, a “Controller”. The Controller watches the system and when a radio requests to talk it assigns that radio and any other radio in its group to a channel. All this happens in a fraction of a second.

Radios have all the frequencies used by the system programmed into them and the system is broken down into various virtual channels, called “Talkgroups”. Talkgroups are assigned to various uses like channels would have been before. For example, Mayberry PD might be assigned Talkgroup 101 for Dispatch, 102 for Car-Car and 103 for Detectives. Mayberry FD might be assigned Talkgroup 123 for Dispatch, 124 for Fireground and 125 for Tactical. If Mt. Pilot is sharing the system they might be assigned Talkgroup 287 for Police Dispatch and so on.

There are several types of trunking systems but they all work in much the same way. There are differences in the way they get programmed into scanners as well. The main types of trunked systems in use by Public Safety agencies in the USA include Motorola, EDACS, LTR, APCO25 Phase 1 and APCO25 Phase 2.

For scanner listeners these trunked systems add a layer of complexity to the programming. Depending on the type of scanner and the type of trunked system the method used to program differs. For newer Unidens you program in a “System” to identify the type of trunking, then “Sites” to put in the frequencies used and lastly “Groups” for the talkgroup listing. Whistler, GRE and Radio Shack scanners with Object Oriented programming work differently. On LTR and EDACS systems you have to identify the proper “LCN” channel numbers, these are usually well documented at www.radioreference.com. Motorola and APCO25 systems do not need the frequencies in any particular order.

HomePatrol and other scanners with the Database feature will have these Trunked System parameters already programmed so you can just select the Service and location to listen to them. They do all the heavy lifting for you.

Keep an eye on the ScannerMaster Blog for our explanation of Digital operations!