I had a pair of Trr-Square 900 MHz Ht's like this in the US a while back, which frequency hop. I think in WWII, Heddy Lamar proposed Frequency Hopping for radios 📻 back at that time. Thanks again for a very interesting review. Ray, W2CH ex V25CH, WA2ZPD, WB7EGN, and WB1BTO.
I had a pair of tri square radios years ago. The tri square radios are frequency hoping spread spectrum but analog compressed audio. The tri square radios frequency hoping technology was flawed and the radios would become un synchronized and not be able to communicate at times. Tri square radios stopped factory production years ago.
@@davidmaclennan5252 great radios, picked up a pair on holiday. Shame about the battery and charging dock connections. Full of features, and in the 900mhz range if memory serves.
In my past I managed about 2 dozen of the DTR500 series radios that were used by an corporate event group. We'd get to a convention center or a hotel with multiple meeting rooms and I'd program and hand these out to the workers in my company. In the concrete and steel urban environments the 1 watt 900 MHz FHSS signals did a great job of penetrating multiple floors and covering a couple city blocks. Far better than any other simplex HT radio system we'd used before. In a suburban environment they would work up to about 2 miles away.
@@MotorsportsX, this guy (ruclips.net/video/OM-JgBISfw0/видео.html) claims 15 km w/ DTR700. In a city or on a highway (e.g. between two vehicles) 1-2 miles is more typical in my experience.
I've recently found your channel, and have been enjoying the vids! A few things I can add with my experience "across the pond" with the DTR650 and DTR700 radios: Anyone on a public group can be heard by any other DTR radio that is listening to that group, but setting up private groups virtually guarantees that only the radios with that group programmed in can hear it. Another thing to mention, they aren't truly encrypted, but it would take a lot of work to listen in for a few reasons: First, the FHSS, as you mentioned, makes scanners unable to listen in. Second, the digital codec "VSELP" is not supported by any of the digital scanners, nor is it currently supported by any of the SDR programs like DSD+ SDR#, etc. So even if you locked on to the FHSS, you wouldn't be able to decode the digital traffic, as it's a proprietary Motorola format, unlike P25, DMR, TETRA, NXDN etc. I figure Motorola engineers likely have special test equipment that can monitor these, and likely show things like radio ID, talkgroup ID, RSSI, etc. but it will likely not be released "into the wild" anytime soon.
Spread spectrum radio communication was invented by Hedy Lamarr (a famous film actress in the 1930s and 40s) and George Anthiel during World War II, as a technology for communicating with torpedoes to give them updated guidance information in a way that could not be intercepted or jammed.
FHSS is what we used on our SINCGARS radios back when I was on tanks in the U.S. Army. We'd load the encryption keys and "other data" into the radios using an ANCD or KYK-13 and away we'd go.
Interesting. But their range will be severely curtailed by rain, fog, or very humid air. 2.4Ghz is also used by microwave ovens since water absorbs at that frequency very effectively. Shame they're not on 5.8GHz. Could be interesting with a yagi though. As for detecting this sort of FHSS transmission, or CDMA, I can recommend the TTI 'PSA' series of spectrum analysers. They will catch everything, being ideal for very local txes, but with a good antenna a spectrum analyser will get signals from miles away. Thanks for the channel.
Hi Chris It's actually a myth that there's a water resonance at 2.4 GHz. Water has various vibrational modes over a wide range of THz (not GHz) frequencies out to far infrared . You can make a microwave oven to operate at any (microwave) frequency and large industrial ovens sometimes use 915 MHz. 2.45 GHz is popular for the mass market because a) it's license-free, b) the cabinet size is convenient for domestic use and b) magnetrons for this range are (relatively) easy to make and are also a good size and c) depth of penetration into most foodstuffs. The heating effect of RF is also used at much lower frequencies such as 27 MHz (!) for medical diathermy. The whole effect is due to dielectric heating which is caused by the electric field forcing the molecules from their normal somewhat genteel and ordered vibrational orientation to a more energetic and randomly aligned vibrational state - otherwise known as heat.
This vid prompted me to get down my box of radios from the loft. The 2430s were dead (now on charge) but surprisingly the Kenwood ProTalks still have a charge after at least 4 years up there.... The Nokia 3110 of the PMR world :-)
I use the Bowman PRR squad radios for short distance comms. They operate in the 2.4 GHz spectrum in the ISSM segment. If they are near any wiFi signals they will block them, same with Bluetooth signals. Using surplus connectors I have fashioned adapters for use with two or three wire Secret service style headsets. These are legal for use with the Ham bands in the USA since there is a portion allocated to ham use.
The Mil had the SINGARS - Single Channel Automated Radio system. I was trained on it while I was in the Guard. It does exactly what these do (with one major difference - SINGAR Radios use encrypted channels). You can set up either an encrypted com system or a plain text system. Once on an encrypted net, it is difficult for others to understand or even get into the com net (without the proper encryption key). A SINGAR radio does the Freq Hopping (it changes frequencies so that you may get one word on one freq and another word on another Freq). They are great radios.
SINCGARS waveform is also available on many platforms, from HT to Manpack to vehicle-mount. Accessories include 'high-power' amplifiers (I believe 25 or 50W). And it is Single Channel Ground and Airborne Radio System, I believe.
We had phones here in the states a ways back when I was a teenager that used similar technology it seems. Though, we had towers country wide, allowing you to ptt across the country. Basically civilian legal ham radio. I miss those..... Great video, brother.
Very good. The technology is very similar to that used in the British-designed Leonardo Personal Role Radio. This is a military platoon-level set actually designed in the 1980s when the compnany was still Marconi Communications (later became Selex). The PRR can be used on its own or jointly switched through a longer range combat net radio such as (originally) Clansman or (now) Bowman.
Really interesting video. I was always fascinated and really interested by these radios because of their unique operation etc. Where did you manage to get hold of them because I have been looking for some time now and have been unsuccessful? Love the work, keep it up!
USA models such as DTR700 DTR650 AND DLR1060 and other similar models operate on 900mhz fcc license free ism band which is shared with amateur radio 900 mhz band. You can easily purchase used DTR radios and use them to scan current DTR and DLR Radios .
@@christophep.8288 okay 👌🙂 I still receive plenty of conversations. I have never heard anyone say "let's talk on private channels" ... I believe that the vast majority of businesses using walkie-talkies stay on factory default public channels. There is Such limited use of these radios near Chicago (the headquarters of Motorola) and the radios are such short range ... it is unlikely that these radios get interference or cross talk from other users.. most of the communications I hear are on "public channel #1 " . I do have my DTR700 and DTR650 radios set to scan while I drive around Chicago often. Unfortunately the radios will not scan all possible public channels . They are limited to scan 10 to 20 channels... depending on model DTR650 or DTR700... I forget exactly... in order to scan all public channels you would need to set one radio to scan channels 1 to 10 and another radio 11 to 20 and so on ... for example... but I hear plenty on channel #1 .
I don't know how these radios work, but other radios that I am familiar with have a pre-defined hop-set (a list of usable frequencies). A 'key' serves as a seed for a psuedo-random number (PRN) generator. The numbers produced hash to a location on the list of frequencies. So long as the radios have the same key, and are synchronized, they will hop thru the same sequence of frequencies in unison. For example, lets say that the radio supports a hop-set of 32 frequencies. Each time interval (which may be anything from, say, 0.1 sec to, perhaps, 5 sec) a new PRN is generated. The modulo 32 of that number could be computed and used as an index into the list of frequnecies. The catch is that the radios need to be synchronized. I don't know how that is accomplished in this case. One technique would be to use GPS time and hop, for example, on the second-boundary. But the radio would need a GPS receiver to do this.
In the US fans of ISM 900Mhz license free the DTR series HT have FHSS, private calling, digital voice and built-in text messaging... easy CPS customizable. DTR 410 DTR 550 DTR 650
Is this one & the same radio/s my friend in the late 1980s used to say the FBI or some other govt. users nicknamed the "bubble machine" ? Your description of the technology used sounds exactly identical to what he told of, explaining exactly why hobby scanner users & others could not eavesdrop. This was when 800 MHz cell band was the mainstay in use, cordless house phones were still somewhat big, etc.
Frequency hopping and encryption are two difference concepts. Frequency hopping is a form of TRANSEC (Transmission Security) to make interception very hard. Encryption is the transformation of data content via a pseudorandom number (a 'key') and an encryption algorithm into something unreadable even if intercepted.
Great video. So the next 3 things that wouls be interesting to see / know is. Whats the range with a "better" dB portable antennas on the radios. Whats the base station to either bast station or base statiin to portable range using a medium to high dB base station 2.4Ghz antenna & a "better" dB portable dedicated 2.4Ghz antenna What's the mobile to mobile range again using an dd on medium to high dB mobile 2.4Ghz antennas. Rgs Wayne.
I wonder if there may be plans to 'network' the 2.4GHz version. That would be nice to connect multiple sites via WiFi and/or internet VPN tunnel (like DMR without a license??)
The first major popular CE product I fondly remember using spread spectrum was 2.4g Panasonic Gigarange cordless phones. This was back in the day of no wifi, nobody could eavesdrop on you & you could literally walk around the entire block talking, a good 20 houses away before it drops. Ridiculously resilient to unwanted interference. circa 1997.
I managed 2.5 miles from hilltop to ground level (on the 2.4 GHz versions). But where I live, surrounded by loads of wifi signals, it won't exceed 100m. Which means they are perfect for indoor use with privacy required.
MotoTalk used the same principal. iDEN was the network type for Nextel, but was different from MotoTalk. These use a more advanced version of what NotoTalk used.
I'm watching your videos from quit while. And i purchased 2 Baofeng uv5r just for starting up. Can you please tell me Which is best Antenna for medium to long range on VHF and UHF. i already have 2 Nagoya Na 771. Can you tell me which antenna is best is this Nagoya tactical abree or etc... Please dear reply me please Please
The Nagoya na-771 works alright for a baofeng. For 2 meters I like to use the mfj-1714. It comes in BNC, SMA-M and SMA-F connector variants. It’s collapsible and about 42 inches extended. Be aware it is only for 2 meters though. If you’re new, remember that the Baofengs can transmit outside of amateur frequencies, including FRS and GMRS frequencies. Transmitting on these is illegal in the US.
I was thinking Range wise line of sight for 100 MW wonder what the general Receivers are like be interesting to see or hear Lewis. Marc In Bletchley Towers G6XEG
These want be any good on sites or big hotels because the dam output power on 2.4ghz means a brick wall will stop them dead, they want work on ships . ...My mate bought two and they are a waste of time because the range is so poor ?
Frequency Hopping requires perfect timing. Without it you are receiving on a different frequency than the transmitter is transmitting on. Spread Spectrum is only dependent on timing of the spreading code is a function of time. In cheap SS systems the spreading code is time-invariant, a fixed "Psuedo-random" number. I don't know how these radios wotk.
An SDR receiver could see the waveform, but as it hops from one frequency to another (perhaps several times per second, I don't know the specs for these radios) it would be impossible for a human operator to follow the center frequency. Then, on top of that, it is spread-spectrum. You can't reconstitute the narrow band signal from the spread signal w/o knowing the spreading code and applying it to the perfectly-timed 'chips' (symbols) received. And then the signal is also encrypted. No SDR radio that I know of can decrypt the signal without knowing the algorithm (DES? DES3? AES128? AES256? ...) and the key. No average Joe, not even a very bright Joe, can "listen in" without a lot more capability.
I had a pair of Trr-Square 900 MHz Ht's like this in the US a while back, which frequency
hop.
I think in WWII, Heddy Lamar proposed
Frequency Hopping for radios 📻 back
at that time.
Thanks again for a very interesting review.
Ray, W2CH ex V25CH, WA2ZPD, WB7EGN,
and WB1BTO.
I had a pair of tri square radios years ago.
The tri square radios are frequency hoping spread spectrum but analog compressed audio. The tri square radios frequency hoping technology was flawed and the radios would become un synchronized and not be able to communicate at times. Tri square radios stopped factory production years ago.
She was brilliant
@@stevesmith8854 who ?
@@davidmaclennan5252 above. Heddy Lamar.
@@davidmaclennan5252 great radios, picked up a pair on holiday. Shame about the battery and charging dock connections. Full of features, and in the 900mhz range if memory serves.
In my past I managed about 2 dozen of the DTR500 series radios that were used by an corporate event group. We'd get to a convention center or a hotel with multiple meeting rooms and I'd program and hand these out to the workers in my company. In the concrete and steel urban environments the 1 watt 900 MHz FHSS signals did a great job of penetrating multiple floors and covering a couple city blocks. Far better than any other simplex HT radio system we'd used before. In a suburban environment they would work up to about 2 miles away.
how far you think they could work with elevation and line of sight?
@@MotorsportsX, this guy (ruclips.net/video/OM-JgBISfw0/видео.html) claims 15 km w/ DTR700. In a city or on a highway (e.g. between two vehicles) 1-2 miles is more typical in my experience.
I've recently found your channel, and have been enjoying the vids! A few things I can add with my experience "across the pond" with the DTR650 and DTR700 radios: Anyone on a public group can be heard by any other DTR radio that is listening to that group, but setting up private groups virtually guarantees that only the radios with that group programmed in can hear it. Another thing to mention, they aren't truly encrypted, but it would take a lot of work to listen in for a few reasons: First, the FHSS, as you mentioned, makes scanners unable to listen in. Second, the digital codec "VSELP" is not supported by any of the digital scanners, nor is it currently supported by any of the SDR programs like DSD+ SDR#, etc. So even if you locked on to the FHSS, you wouldn't be able to decode the digital traffic, as it's a proprietary Motorola format, unlike P25, DMR, TETRA, NXDN etc.
I figure Motorola engineers likely have special test equipment that can monitor these, and likely show things like radio ID, talkgroup ID, RSSI, etc. but it will likely not be released "into the wild" anytime soon.
Spread spectrum radio communication was invented by Hedy Lamarr (a famous film actress in the 1930s and 40s) and George Anthiel during World War II, as a technology for communicating with torpedoes to give them updated guidance information in a way that could not be intercepted or jammed.
Range will be pretty much line of sight over longer distances. Look forward to seeing what range you can get from some of the hills you visit.
FHSS is what we used on our SINCGARS radios back when I was on tanks in the U.S. Army. We'd load the encryption keys and "other data" into the radios using an ANCD or KYK-13 and away we'd go.
Interesting. But their range will be severely curtailed by rain, fog, or very humid air. 2.4Ghz is also used by microwave ovens since water absorbs at that frequency very effectively. Shame they're not on 5.8GHz. Could be interesting with a yagi though.
As for detecting this sort of FHSS transmission, or CDMA, I can recommend the TTI 'PSA' series of spectrum analysers. They will catch everything, being ideal for very local txes, but with a good antenna a spectrum analyser will get signals from miles away.
Thanks for the channel.
Hi Chris It's actually a myth that there's a water resonance at 2.4 GHz. Water has various vibrational modes over a wide range of THz (not GHz) frequencies out to far infrared . You can make a microwave oven to operate at any (microwave) frequency and large industrial ovens sometimes use 915 MHz. 2.45 GHz is popular for the mass market because a) it's license-free, b) the cabinet size is convenient for domestic use and b) magnetrons for this range are (relatively) easy to make and are also a good size and c) depth of penetration into most foodstuffs. The heating effect of RF is also used at much lower frequencies such as 27 MHz (!) for medical diathermy. The whole effect is due to dielectric heating which is caused by the electric field forcing the molecules from their normal somewhat genteel and ordered vibrational orientation to a more energetic and randomly aligned vibrational state - otherwise known as heat.
This vid prompted me to get down my box of radios from the loft. The 2430s were dead (now on charge) but surprisingly the Kenwood ProTalks still have a charge after at least 4 years up there.... The Nokia 3110 of the PMR world :-)
I must get a ProTalk.
I use the Bowman PRR squad radios for short distance comms. They operate in the 2.4 GHz spectrum in the ISSM segment. If they are near any wiFi signals they will block them, same with Bluetooth signals. Using surplus connectors I have fashioned adapters for use with two or three wire Secret service style headsets. These are legal for use with the Ham bands in the USA since there is a portion allocated to ham use.
The Mil had the SINGARS - Single Channel Automated Radio system. I was trained on it while I was in the Guard. It does exactly what these do (with one major difference - SINGAR Radios use encrypted channels). You can set up either an encrypted com system or a plain text system.
Once on an encrypted net, it is difficult for others to understand or even get into the com net (without the proper encryption key). A SINGAR radio does the Freq Hopping (it changes frequencies so that you may get one word on one freq and another word on another Freq).
They are great radios.
SINCGARS waveform is also available on many platforms, from HT to Manpack to vehicle-mount. Accessories include 'high-power' amplifiers (I believe 25 or 50W). And it is Single Channel Ground and Airborne Radio System, I believe.
@@joeb3300 thank you. It has been a while. That was 1998 since I last used it. God bless.
We had phones here in the states a ways back when I was a teenager that used similar technology it seems. Though, we had towers country wide, allowing you to ptt across the country. Basically civilian legal ham radio. I miss those..... Great video, brother.
Absolutely fascinating technology thanks for another great insight into PMR radio.
Very good. The technology is very similar to that used in the British-designed Leonardo Personal Role Radio. This is a military platoon-level set actually designed in the 1980s when the compnany was still Marconi Communications (later became Selex). The PRR can be used on its own or jointly switched through a longer range combat net radio such as (originally) Clansman or (now) Bowman.
Really interesting video. I was always fascinated and really interested by these radios because of their unique operation etc.
Where did you manage to get hold of them because I have been looking for some time now and have been unsuccessful?
Love the work, keep it up!
USA models such as DTR700 DTR650 AND DLR1060 and other similar models operate on 900mhz fcc license free ism band which is shared with amateur radio 900 mhz band. You can easily purchase used DTR radios and use them to scan current DTR and DLR Radios .
You would only get public group calls, not private calls.
@@christophep.8288 okay 👌🙂
I still receive plenty of conversations. I have never heard anyone say "let's talk on private channels" ... I believe that the vast majority of businesses using walkie-talkies stay on factory default public channels. There is
Such limited use of these radios near Chicago (the headquarters of Motorola) and the radios are such short range ... it is unlikely that these radios get interference or cross talk from other users.. most of the communications I hear are on "public channel #1 " . I do have my DTR700 and DTR650 radios set to scan while I drive around Chicago often. Unfortunately the radios will not scan all possible public channels . They are limited to scan 10 to 20 channels... depending on model DTR650 or DTR700... I forget exactly... in order to scan all public channels you would need to set one radio to scan channels 1 to 10 and another radio 11 to 20 and so on ... for example... but I hear plenty on channel #1 .
AWESOME. Thanks for this review Lewis, I'll be on the hunt for these now!
Cheers mate. Curious to know how each radio identifies the exact frequency patterns between them when receiving/transmitting 😁
I don't know how these radios work, but other radios that I am familiar with have a pre-defined hop-set (a list of usable frequencies). A 'key' serves as a seed for a psuedo-random number (PRN) generator. The numbers produced hash to a location on the list of frequencies. So long as the radios have the same key, and are synchronized, they will hop thru the same sequence of frequencies in unison.
For example, lets say that the radio supports a hop-set of 32 frequencies. Each time interval (which may be anything from, say, 0.1 sec to, perhaps, 5 sec) a new PRN is generated. The modulo 32 of that number could be computed and used as an index into the list of frequnecies.
The catch is that the radios need to be synchronized. I don't know how that is accomplished in this case. One technique would be to use GPS time and hop, for example, on the second-boundary. But the radio would need a GPS receiver to do this.
In the US fans of ISM 900Mhz license free the DTR series HT have FHSS, private calling, digital voice and built-in text messaging... easy CPS customizable.
DTR 410 DTR 550 DTR 650
i bought a pair of Trisquare TXS300 from walmart on holiday in 2010. cheap as chips!. then a second pair off ebay UK IN 2013.
I have a few of these I bring to camping! they work great with the digital communication and I love how you can put a custom name which I did
LoRa is also a low power spread spectrum low data rate technology which achieves some impressive ranges.
Is this one & the same radio/s my friend in the late 1980s used to say the FBI or some other govt. users nicknamed the "bubble machine" ? Your description of the technology used sounds exactly identical to what he told of, explaining exactly why hobby scanner users & others could not eavesdrop. This was when 800 MHz cell band was the mainstay in use, cordless house phones were still somewhat big, etc.
In a simplified sense, FM frequency hopping is how military radio encryption works on many FM military radios.
Frequency hopping and encryption are two difference concepts. Frequency hopping is a form of TRANSEC (Transmission Security) to make interception very hard. Encryption is the transformation of data content via a pseudorandom number (a 'key') and an encryption algorithm into something unreadable even if intercepted.
Looking forward to the next video testing the range!
We use these when we set up drug pickup locations. So far no cop problems at all!
why do you think motorola make their speaker grills look like a QR code? I wonder if it's a hidden message. 🤔
Great video. Is it easy to program manually or is it better with the cable? If by cable where to buy one please or is there a diagram to make one?
Didn't know about this. Cool fo sure
Great video.
So the next 3 things that wouls be interesting to see / know is.
Whats the range with a "better" dB portable antennas on the radios.
Whats the base station to either bast station or base statiin to portable range using a medium to high dB base station 2.4Ghz antenna & a "better" dB portable dedicated 2.4Ghz antenna
What's the mobile to mobile range again using an dd on medium to high dB mobile 2.4Ghz antennas.
Rgs
Wayne.
I still have a pair at my mums I going to pick them up on Tuesday and test them with my friend
I had a pair of these about 10 years ago. The range was appalling. 200 metres at most. I therefore sold them.
These DTR's have been in the states for 10 or 15 years. Very limited range...
I wonder if there may be plans to 'network' the 2.4GHz version. That would be nice to connect multiple sites via WiFi and/or internet VPN tunnel (like DMR without a license??)
I believe they have an extender unit, but that's it.
Another good informative video. Thanks Lewis.
The first major popular CE product I fondly remember using spread spectrum was 2.4g Panasonic Gigarange cordless phones. This was back in the day of no wifi, nobody could eavesdrop on you & you could literally walk around the entire block talking, a good 20 houses away before it drops. Ridiculously resilient to unwanted interference. circa 1997.
The phones ALREADY do that! Seriously.....
The Public doesn't know so we will sell them something they already have.
These are enhanced walkie talkies. And these don't require a radio tower to work.
I have got a pair of these that I bought out of Canada. Great idea but the range even in open countryside is absolutely awful...!!!
I managed 2.5 miles from hilltop to ground level (on the 2.4 GHz versions). But where I live, surrounded by loads of wifi signals, it won't exceed 100m. Which means they are perfect for indoor use with privacy required.
@@christophep.8288 That's way better than I ever achieved although I was out on the flat.
I’m interested in your distance test. Thanks.
Pushing These Secure High Frequency Radios To The Limit!
ruclips.net/video/bAx98Jvc7Z8/видео.html
Thanks Lewis
100mw at those freqs... You will be lucky to get a mile.. line of sight
One watt limits you unless you get a different and better antenna.
How do the radios maintain synchronization with each other?
Hey joe, watch the videos I linked at the end, I explain it in detail there. It’s kinda complicated to type here :)
Got a pair of these at work
Link to these?
They were called Nextel, and used Motorola tech
MotoTalk used the same principal. iDEN was the network type for Nextel, but was different from MotoTalk. These use a more advanced version of what NotoTalk used.
I'm watching your videos from quit while. And i purchased 2 Baofeng uv5r just for starting up. Can you please tell me Which is best Antenna for medium to long range on VHF and UHF. i already have 2 Nagoya Na 771. Can you tell me which antenna is best is this Nagoya tactical abree or etc...
Please dear reply me please Please
The Nagoya na-771 works alright for a baofeng. For 2 meters I like to use the mfj-1714. It comes in BNC, SMA-M and SMA-F connector variants. It’s collapsible and about 42 inches extended. Be aware it is only for 2 meters though. If you’re new, remember that the Baofengs can transmit outside of amateur frequencies, including FRS and GMRS frequencies. Transmitting on these is illegal in the US.
I was thinking Range wise line of sight for 100 MW wonder what the general Receivers are like be interesting to see or hear Lewis.
Marc In Bletchley Towers G6XEG
100 Mega Watts?
These want be any good on sites or big hotels because the dam output power on 2.4ghz means a brick wall will stop them dead, they want work on ships . ...My mate bought two and they are a waste of time because the range is so poor ?
I'd be curious to see if Unitrunker worked on these. Works great on other frequency-hopping systems.
Very interesting.
Is this a satellite phone? i want one please
Did you watch the video?
Yessss finally
5 watt is for line of sight
What’s your point
@@RingwayManchester im a ham - line of site is 5 watts usualy / less unlees good ant is less then 5 watts
are their walkie talkie any good and how many watts are they
trunk tracking scanners can still be used to track them
No they can’t at all!
How are they timed? Spread spectrum requires perfect timing. 50 pseudo-random freqs? Nice.
Hey tj I couldn’t find the timings anywhere unfortunately
Frequency Hopping requires perfect timing. Without it you are receiving on a different frequency than the transmitter is transmitting on. Spread Spectrum is only dependent on timing of the spreading code is a function of time. In cheap SS systems the spreading code is time-invariant, a fixed "Psuedo-random" number. I don't know how these radios wotk.
Bluetooth and Wifi are also on 2.4 Ghz it's very line of sight and extremely short distance.
It's all about LOS. AREDN mesh networks can get several kilometer links out of 2.4GHz off-the-shelf gear, if placed in the right location.
@@rkaag99 thanks for the education.
These are hella expensive
Motorola does make great products, but they know you'll pay a pretty penny too.
👍👏👏
High price
Made in China?!!
ലോകത്തിന്റെ എവിടെയെങ്കിലും ഉള്ള മലയാളികൾ ഇത് കാണുന്നുണ്ടോ👍🇮🇳
I guess not 🤷🏼♂️
@@digitalchaos1980 🙏
The average joe can use SDR to listen in. In this modern time there is no real scurity by using this.
Trust me, no SDR will decode these
An SDR receiver could see the waveform, but as it hops from one frequency to another (perhaps several times per second, I don't know the specs for these radios) it would be impossible for a human operator to follow the center frequency.
Then, on top of that, it is spread-spectrum. You can't reconstitute the narrow band signal from the spread signal w/o knowing the spreading code and applying it to the perfectly-timed 'chips' (symbols) received.
And then the signal is also encrypted. No SDR radio that I know of can decrypt the signal without knowing the algorithm (DES? DES3? AES128? AES256? ...) and the key.
No average Joe, not even a very bright Joe, can "listen in" without a lot more capability.
You're forgetting that audio is encoded by the vocoder to digital. So you might be able to see the hops, you still need to decide the data.