• To anyone looking to acquire commercial radio programming software:

    Please do not make requests for copies of radio programming software which is sold (or was sold) by the manufacturer for any monetary value. All requests will be deleted and a forum infraction issued. Making a request such as this is attempting to engage in software piracy and this forum cannot be involved or associated with this activity. The same goes for any private transaction via Private Message. Even if you attempt to engage in this activity in PM's we will still enforce the forum rules. Your PM's are not private and the administration has the right to read them if there's a hint to criminal activity.

    If you are having trouble legally obtaining software please state so. We do not want any hurt feelings when your vague post is mistaken for a free request. It is YOUR responsibility to properly word your request.

    To obtain Motorola software see the Sticky in the Motorola forum.

    The various other vendors often permit their dealers to sell the software online (i.e., Kenwood). Please use Google or some other search engine to find a dealer that sells the software. Typically each series or individual radio requires its own software package. Often the Kenwood software is less than $100 so don't be a cheapskate; just purchase it.

    For M/A Com/Harris/GE, etc: there are two software packages that program all current and past radios. One package is for conventional programming and the other for trunked programming. The trunked package is in upwards of $2,500. The conventional package is more reasonable though is still several hundred dollars. The benefit is you do not need multiple versions for each radio (unlike Motorola).

    This is a large and very visible forum. We cannot jeopardize the ability to provide the RadioReference services by allowing this activity to occur. Please respect this.

DLR Series.... Channel Pool?

Status
Not open for further replies.

CopperWhopper67

Member
Premium Subscriber
Joined
Mar 22, 2018
Messages
104
Location
Northern California
I have been trying to find the list of frequencies that Motorola DLR radios use in the 900 MHz ISM band. The user manual does not list the freqs unlike the manuals of other radios. Does anybody have a list or know where I can find one? Thanks
 
Last edited:

Will001

Member
Joined
Dec 1, 2016
Messages
506
Location
Pine Ridge, SC
I have been trying to find the list of frequencies that Motorola DLR radios use in the 900 MHz ISM band. The user manual does not list the freqs unlike the manuals of other radios. Does anybody have a list or know where I can find one? Thanks


They are frequency-hopping from what I’ve heard.


Sent from my iPhone using Tapatalk
 

n1das

Member
Joined
Feb 17, 2003
Messages
1,601
Location
Nashua, NH
I have been trying to find the list of frequencies that Motorola DLR radios use in the 900 MHz ISM band. The user manual does not list the freqs unlike the manuals of other radios. Does anybody have a list or know where I can find one? Thanks
The DLRs have 18 hop sets of 50 frequencies each. This is up from the DTRs having only 10 hop sets to work with. The first 10 hop sets in the DLRs match the 10 hop sets in the DTRs. Hop set #1 is the default frequency hop set in the DTRs and DLRs.

Digital modulation on a given hopping frequency is according to an 8-level FSK scheme. The vocoder used is VSELP.

I looked up the FCC test reports in the FCC's Equipment Authorization database for one of the DTR models a while back and happened to find the info you are looking for. It should be in the reports for the DLRs. For each hop set, the information is listed as a base frequency in the 902MHz range and follows a formula with a step size to calculate the 50 frequencies in the hop set. A frequency hopping spread spectrum (FHSS) device operating in the 902-928MHz band is required by FCC15.247 to use a minimum hop set of 50 frequencies. The DTRs and the DLRs spend no more than 90ms within a 400ms period on any given frequency in the hop set. The entire 902-928MHz band is used when these radios transmit.

DTR410 FCC ID = AZ489FT5842
DTR550/650 FCC ID = AZ489FT5852

DLR1020/1060 FCC ID = AZ489FT5870, AZ489FT5871

In case anyone is wondering, forget about trying to monitor these on any consumer grade receiver (scanner) because you can't.

:)

Sent from my XP8800 using Tapatalk
 
Last edited:

CopperWhopper67

Member
Premium Subscriber
Joined
Mar 22, 2018
Messages
104
Location
Northern California
The DLRs have 18 hop sets of 50 frequencies each. This is up from the DTRs having only 10 hop sets to work with. The first 10 hop sets in the DLRs match the 10 hop sets in the DTRs. Hop set #1 is the default frequency hop set in the DTRs and DLRs.

Digital modulation on a given hopping frequency is according to an 8-level FSK scheme. The vocoder used is
Can you explain in more detail what a hop set does and why hopping needed for this band?

Thanks
 

n1das

Member
Joined
Feb 17, 2003
Messages
1,601
Location
Nashua, NH
Can you explain in more detail what a hop set does and why hopping needed for this band?

Thanks
From the FHSS article on Wikipedia........
https://en.wikipedia.org/wiki/Frequency-hopping_spread_spectrum

A spread-spectrum transmission offers three main advantages over a fixed-frequency transmission:

1. Spread-spectrum signals are highly resistant to narrowband interference. The process of re-collecting a spread signal spreads out the interfering signal, causing it to recede into the background.
2. Spread-spectrum signals are difficult to intercept. A spread-spectrum signal may simply appear as an increase in the background noise to a narrowband receiver. An eavesdropper may have difficulty intercepting a transmission in real time if the pseudorandom sequence is not known.
3. Spread-spectrum transmissions can share a frequency band with many types of conventional transmissions with minimal interference. The spread-spectrum signals add minimal noise to the narrow-frequency communications, and vice versa. As a result, bandwidth can be used more efficiently.

In the US, FCC part 15 on unlicensed spread spectrum systems in the 902–928 MHz and 2.4 GHz bands permits more power than is allowed for non-spread-spectrum systems. Both frequency hopping and direct sequence systems can transmit at 1 Watt, a thousand-fold increase from the 1 milliwatt limit on non-spread-spectrum systems. The Federal Communications Commission (FCC) also prescribes a minimum number of channels and a maximum dwell time for each channel.

The DLRs and DTRs spend no more than 90 ms on any given hopping frequency in a 400 ms period. The hopset of 50 frequencies spreads the transmitted signal out over the entire 902-928 MHz band.

:)
 
Last edited:

n1das

Member
Joined
Feb 17, 2003
Messages
1,601
Location
Nashua, NH
The DLRs and DTRs spend no more than 90 ms on any given hopping frequency in a 400 ms period. The hopset of 50 frequencies spreads the transmitted signal out over the entire 902-928 MHz band.

:)
As a minor clarification, the DLRs and DTRs spend no more than 90 ms on any given hopping frequency before changing to the next frequency in the hopset of 50 frequencies. The radio may revisit a recently used hopping frequency one or more times during a 400 ms period. The accumulated dwell time on any given frequency in the hopset cannot exceed 400 ms per FCC 15.247.

I assume the OP wants to listen to DLR and DTR radios. I do too! The DLRs and DTRs are not monitorable on any consumer grade receiver (i.e., scanner) so don't even bother trying with these. The only inexpensive and practical way to monitor these is with another DLR or DTR radio, AND it has to programmed to the same frequency hopset and talkgroup ID. The DLRs also have a 4-digit Profile ID to enable another level of privacy. If using a DLR, the Profile ID also has to match in order to hear anything. DTR radios don't have the Profile ID feature. The Profile ID in a DLR has to be set to 0000 (Off) for a DLR to work with a DTR. All settings have to match in order to hear other traffic on a given hopset, group ID, and profile ID (DLR only).

DLR and DTR radios will talk to each other right out of the box at their factory default programming. They are usable without needing to program anything at all. Customization of settings and features and setting up private groups requires the CPS. I have monitored some DLR and DTR traffic when traveling through major urban areas. I am finding that most users simply use these radios as they come out of the box at their factory default programming, just like GMRS/FRS bubble packs. Users who have set up Private Groups won't be monitorable at all by a DTR or DLR that's not member of the Private Group. While technically not encrypted, these radios can be made very secure. It's essentially security through obscurity.

I have set up a Private Group in my own fleet of DTRs and DLRs and purposely kept the rest of the programming at the factory defaults so I can listen for activity on the default public groups. I do catch occasional local chatter on them from time to time.
 
Last edited:

n1das

Member
Joined
Feb 17, 2003
Messages
1,601
Location
Nashua, NH
The DLRs have 18 hop sets of 50 frequencies each. This is up from the DTRs having only 10 hop sets to work with. The first 10 hop sets in the DLRs match the 10 hop sets in the DTRs. Hop set #1 is the default frequency hop set in the DTRs and DLRs.

Digital modulation on a given hopping frequency is according to an 8-level FSK scheme. The vocoder used is VSELP.

I looked up the FCC test reports in the FCC's Equipment Authorization database for one of the DTR models a while back and happened to find the info you are looking for. It should be in the reports for the DLRs. For each hop set, the information is listed as a base frequency in the 902MHz range and follows a formula with a step size to calculate the 50 frequencies in the hop set. A frequency hopping spread spectrum (FHSS) device operating in the 902-928MHz band is required by FCC15.247 to use a minimum hop set of 50 frequencies. The DTRs and the DLRs spend no more than 90ms within a 400ms period on any given frequency in the hop set. The entire 902-928MHz band is used when these radios transmit.

DTR410 FCC ID = AZ489FT5842
DTR550/650 FCC ID = AZ489FT5852

DLR1020/1060 FCC ID = AZ489FT5870, AZ489FT5871

In case anyone is wondering, forget about trying to monitor these on any consumer grade receiver (scanner) because you can't.

:)

Sent from my XP8800 using Tapatalk
EDIT: The DLRs and the new DTR700 and DTR600 models have only 10 frequency hopsets available to work with, not 18 hopsets as previously mentioned. The 10 hopsets of 50 frequencies across the 902-928MHz band are the same hopsets used in the older DTR models. I was confusing the 18 Profile IDs for a channel in the DLRs with frequency hopsets. My bad.

:)
 
Status
Not open for further replies.
Top