Thanks Andy for taking the effort to demonstrate that the key to clear reception is firstly, digital is obviously better than analogue. Secondly, the types of antennae chosen will yield different results. So, besides the design of the radio circuitry, what matters is the clear line-of-sight between receiver and transmitter and the appropriate antennae. Much appreciated for this demonstration. Fascinating.

2.4 gig isn't particularly useful for urban use, as it is quickly attenuated by almost any object, building, or even trees. If you went with two very directional antennas lined up and a clear line of sight, you might be upwards to 4 or 5 kms. But as soon as anything is in the way (even rain or fog) it's done for.

Bought a set of 4 of those 2450's 2 yrs ago and never got the chance to play with them. Would be interesting to see if they tx with that small patch antenna you have on your next video... Thanks for making this one really enjoyed it! You've got a new sub in the U. S. :)

Really enjoying watching the vids😎, looking forward to see the return of the radio stuff😆😉👍

Like the different topics and random ones you post. Maybe a video integrating all your favs: car, ebike, music, drone, solar and radio?😀 Always interesting!

Good to see you back doing radio videos

The radio looks almost identical to early 2000's Nextel phones but without the number keypad. Even the sounds it makes is exactly like the old Nextel phones. I wish they could bring them back.

We have some very similar radios at work. They work on the 902-928 MHz band, which is a license-free band here in the US. They do work quite well. I also think it's important to point out that the only "security" these offer is security through obscurity. Radio hobbyists have gotten pretty good at reverse engineering fairly sophisticated radio protocols and a determined attacker probably could do so with these. It would definitely be non-trivial, though.

Very interesting video Andy. Keep them coming

wow that was a really interesting video 0n 2.4Ghz digital, the two experiments i would love to try out on those hand sets is 1, try out making some circular polarization antennas they should at least give better range or maybe not that would be the experiment, and 2, go down to the edge of the sea where there is an inversion layer just above the sea a few feet. and get some one else in another country to do the same with the same hand set to see if it is possible to make contact there might even be an ability to go round heads of land due to the nature of the inversion layer at sea.

I just like how enthused you are with the subject!

Thanks, for the video. I'll be testing the dtr2430 in the next days hopefully. I'm so curious to explore 13cm.

Quite amazing how far you can get on such a high frequency. Maybe try some tests with 23cm sometime ? There's ATV repeaters on there also of course. Btw you have the same Bluetooth back-lit keyboard as me. Unfortunately battery life isn't great with the light on all the time

Interestingly they still sell a modernised DTR line in the USA, but using 1 Watt on the 900MHz ISM band.

That was an interesting video Andy! the best from LB1NH

I get well over 1 mile with my UHF transmitter and its RF power is 15mw, I have and many others have tested our 15mw transmitter with amazing results and it runs for a week in 2 AA batteries.

Blast from the past.. Great video. I think Lewis from the @RingwayManchester channel also had some of these.

Very clever radio experiment and video production!

Great video Andy. I have some of these too and they're good fun to play with and try a different band out. It's surprising how far you can get on 2.4 GHz

I have the models DTR 410, 550, and 650 which operate on the 900mhz spectrum. From where I live, I can get about a 1.5 to 2 mile range on these (approximately 3 to 3.5 km maybe) and they work well. I have the long whip antennas on mine and I love to listen with the scan option on these radios to other businesses and warehouses around my house. These radios also offer over the air cloning to program channels to other radios.

Great content interesting stuff

Bought back memories of using nextel back in the 2000s

Great video and nice tests! I love CB, that's why I have cars CB radio in my home.. 😂 Sometimes, cool to listen truck drivers..

Them radios look like the one's we used on the NEXTEL NETWORK IT WAS CALL PUSH TO TALK,BUT IT REALLY WORKED...

Nice work. Have always been interested in radios but never owned anything more than walkie talkies. If you have got nobody to talk to then you can only listen. So whats the deal with the scanners, what is the most reasonably priced scanner that picks up the most in urban area?

Very similar to what kind of distance you can get with the DJI Mini drones. Good stuff Andy. 👍🏽

Another great video, but I had trouble listening with the distraction of the music in the background. Is this really necessary? Thanks once again for all your stuff.

My record on 70cms ssb is 2700kms, 50w in to a yagi, contact from Ireland to Canary Islands, under tropospheric bands conditions.

What a lot of fun - it just shows what a curious mind can do

There are other DLR and DTR radios that operate in the 900 MHz ISM band, which is 900-928 in the US, or 915-928 in AU/NZ and parts of Asia.

They used 2 ghz for communications with Apollo on the moon. But they used 200 ft ground based dishes to do so. Amateur radio operators have used 2.4 ghz for moon bounce, but not with a wifi antenna:-)

We have the Retevis RB615 set for CTCSS and we've not actually ever heard anyone else on them. Mostly the kids use them because I got them really cheap for camping / hiking so the kids use them the rest of the time.

in the USA they are in the 900 mhz range transmits range is about one mile.

Ahh beautiful Hertingfordbury

I got a couple GMRS handheld radios that I can hit a repeater that's like 20 miles away. For those that lives across the pond that's 32km away. Which I'm kinda shocked I can hit the repeater cause there is plenty of trees, houses and stuff in between.

I've heard a lot of people saying that Pringles cans don't work at 2.4GHz, but I'm here to tell you THEY DO. Build a good antenna out of two of those things and you too, could easily get 7.5km with a pair of standard output wifi dongles (working on the assumption that you have line of sight from point to point).

Are there any radios like this one the 800mhz band? Isn't that band free to use and shouldn't it penetrate obstacles better than 2.4ghz?

Oh boy am I surprised to see a video on the DTR radios! I scored a couple DTR620's a few years ago on eBay and loved them so much I wanted to get a few more.. but realized I had a problem. I'd inadvertently gotten the DTR620 which was sold in the latin american market, instead of the US market DTR650. They appear to both use roughly 900MHz but are different enough that they won't talk to each other evidently. Supposedly there's a version of the firmware that allows the DTR620 to operate as a 650, but I have been looking for probably dozens and dozens of hours on the internet, and I cannot find such firmware or even the basic configuration software except for version 1 and 2 for the 620, and only two of my radios have old enough firmware to work with those earlier versions of the Motorola CPS software. If *anyone* happens to read this and has a newer version of the 620 CPS (remember these radios are not license restricted and the CPS was also similarly freely available back when these were in production!) or perhaps any cool or unique moto software, firmware or the like for these DTR radios, let me know! I've got both programming and flashing cables for them (the one that requires frankenstein 12V injection lol), just need some software to play with! 🤪

According to specs sheet RF output is only 100mW, works great with such tiny power.

Wow 2.45ghz!! Thats cemetery frequency, we could hear them below! So technically if i was using a portable radio AM radio transmitter that runs in the KHz range, i could reach further?

Isn't the window blocking the signal? Maybe on windowsill it's gonna be better?

9:27 Totally legal unless you use the 'secret sauce' software and programme them for 2W

Those are just like my DTR-650’s. They run 900mhz in the same manner as these.

is that a roland fantom 07 behind you ?

Are you going thru a repeater?

Are your windows double paned? The argon gas in a window makes LOS less effective.

I don't think DSSS inherently adds security in a modern SDR world. Back when it was narrowband scanners only sure, but that was 20 years ago.

Love it randers

The glass holder worked better than the cotton bud box

Definitely Andy enjoyed it

I’m planning to buy a couple of DTR 650s, are they worth it how many kilometres can they reach?

Nice device with impressive Motorola features. Too bad it has not external connection for telemetry

I know this is totally.off the topic Andy, but noticed you make your own music just wondered if youd ever consider making a video on your hardware...how to get started etc?

Amazing to think that voyager 1 transmits successfully over 14.6 billion miles on 2.4 GHz or higher. Helps that there's no churches or trees in deep space I guess 🙂

Music was cool by the way!

Very interesting. Lots of possibilities. 73 M7TUD

Hey mate, why not pick up a couple of Pringles cans on your way back home? 😄

Sounds line old school nextel

This technology is replaced by DMR. It is equally secure and can be connected to the internet for VoIP through a modem. There are roughly around 200,000 members using it including myself.

With the right antenna, low power is not an issue.

If you have a hundred of them in an area, they will use the other to retransmit the signal, the other radios, although not montoring, they don't hear you, just auto repeat ypur signal. They form a net. There are a few differnet manufacturers doing this. They are horrible expensive new. That is why the were discontinued. It is secure between two radios, although other radios retransmit your signal.

that was interesting, so why was it discontinued ?

This is what I come here for 😁

Andy, I liked this video.. Callum.

Take mine when I go fishing with a mate. He can wander off down the bank, and I can call him back if I need a hand. I'm disabled so a big beastie fish can be difficult for me to land.

does it have snake game from nokia...that screen reminded me of old nokia phones...

The reason why it had such long range was because of the cotton box under it.

I invented the cheap powerful reliable walkie talkie multipack just before cell phones came out

If you had 5 radios at various location along the way, you would be able to communicate very far.

👍👍

an AES encrypted radio transceiver might be better.

spoil the vid with background music...

I just can't believe how your interest has changed a lot since you stopped your e biking, what mey u stop Great riding videos Your friend make good ebike, where your content with excellent it a shame I was really shocked the e-bike community facebook All talking about just realise by the messages on Facebook what happened to Andy Kirby Hope get well soon stay positive

I don't know I haven't really alpha😊

I cant believe he just showed a modified 891 That's a big no no

Sound quality is like DMR, so you'd be better off with a Baofeng DMR on 446

2.4 GHz - that nice microwave oven frequency?

There was a V-Link by V-Tech, back in the day. It operated on 902 to 928 megahertz. It offered a half watt. It was supposed to cover an entire city block. It was quite interesting. It operated on FM narrow. I rather liked them. But V-Tech was making them without consent of the CRCT, nor the FCC. They were ordered to stopped being produced. Then V-Tech got the licenses needed and started marketing them again. But, it was too late. Everyone had lost interest in them.

Redoing old content worth it if you can add something, youtube likes next video next video... your enthuisiasm is catchy

There is no such thing as private radio communications.

the lower the frequency - the wider the range... the lower the frequency - the higher the tx- power..

Great in USA in 900Mhz using FHSS digital voice and text messaging with Private channels (Frequency Hopping Spread Spectrum) easy to program in CPS. Requires no license. 🎉 We call them DTR 410 500 650 700/600... all the same. 902-920mhz 90ms hops in 50 frequency channels. No decode possible with scanners nor like model radios when using private digital voice or text messages. VSLEP modulation in the USA ISM 900 mhz Business license free

900mhz, not 2.4 ghz...

I have the US versions of these, the DTR650, and the new DTR700, which is still produced. One thing to note, if you are on the public channels, any other DTR radio on that channel can hear you if they are in range, and you will hear them. If you set up a private group, and only assign your radios to it, no one else would hear you. It's not true encryption, but there aren't any scanners that can hear it, even the new digital scanners. You'd need an SDR, and a program that could follow the frequency hopping. Even then, the actual signal is a proprietary Motorola format called VSELP, which there are no software decoders for. If/when someone figures out how to demodulate the VSELP digital signal, and follow the frequency hopping, they could listen in. I have no doubt that Motorola has test equipment that can do just that, but it's unlikely it will be publicly released. For true encryption, something that offers AES256 with a strong key is about as unbreakable as you will get on the civilian market

Sounds like they don't work to good..

Did you make sure the one you gave me was Covid Free 🤣🤣

Yer in a graveyard... of course the radios dead !! .... duh 🙄😂

They're 900 mhz, not 2.4 G

how about parabolic antennas

I want to ask if China made radios is are bad as people say because I want to buy beofang 😊

I Bet These Radios Are Best Friend For Drug Lords And Kingpins!

Get to the point!

I use one of those to rebroadcast my scanner traffic just like a repeater would only the scanner is the receiver and the DTR radio is the transmitter and I'm not doing any harm and it cannot be used dropped on so nobody would ever know that I'm doing that how wonderful technology ended up so now I got myself a nice Wireless transmitter so I can use it like a speaker basically whatever the scanner hears the portable DTR will hear out in the field or even throughout the whole city after pumping 50 Watts out of it using an amplifier

Cool digital Motorola I use dlr1020 2.ch fshh900mhz? Happy Halloween.

I don't think DSSS inherently adds security in a modern SDR world. Back when it was narrowband scanners only sure, but that was 20 years ago.