Icom Dstar will not work on analog repeater

[Hamradiostuffing]

This is a snip from mods dk

If you try to talk through an analog repeater, in digital mode, it will not work. The repeater must be able to receive a digital carrier and re-broadcast a digital carrier.

Since a digital carrier is different than an analog carrier, a non-digital radio can not re-broadcast the digital carrier. It's not just digital data, it's an actual digital signal. If you try to transmit, in digital mode, into an analog repeater, all the analog radios on the repeater will simply hear white noise and a digital radio listening will hear nothing. The digital radio will see activity on the signal strength meter, as would be normal when there is analog activity on the frequency.

_____________________________

Kevin McClinton, W7JRL
Amateur Technical Trainer

ICOM America, Inc.
2380 116th Ave. NE
Bellevue, WA 98004
Ph. (425) 454-7619
Fax (425) 637-8417
www.icomamerica.com

 

[mam1081]

If you open the repeater up to pass more audio, I think it might work.

Users have gotten it to work in APCO-25 on a two-analog-mobile-radios hooked together set-up. They had to adjust the audio in and out to pass 12 kHz audio, with no filtering or other processing. No tone or tone squelch can be used either (opens it up to a lot of interferance).

See instructions: http://batboard.batlabs.com/viewtopic.php?t=45645

Again, this is no guarantee that it will pass D-start digital, but perhaps someone with this repeater and a pair of d-star radios can try it out!

 

[N_Jay]

Isn't this kind of a "Duh" issue?

 

[Hamradiostuffing]

The answer is, NO it will not work.

The reason is simple, the modulation scheme is not compatible, nor is the repeaters circuitry.

In a typical analog repeater, an FM demodulator is used to demodulate the FM signal, effectively "decoding" the voice signal imposed upon the carrier, by way of Frequency Modulation. The analog repeater then takes the analog audio, and passes it to the repeaters transmitter, where it is "re-encoded", by the FM modulator and sent over the air.

In a D-STAR repeater, an IQ demodulator is used, to "decode" the data imposed upon the carrier, by way of Gaussian Minimum Shift Keying. Once the digital signal, effectively ones and zeros, is extracted, it is buffered and regenerated. The regenerated signal is sent to the transmitter where it is "re-encoded" and sent out over the air.

As you can see, the operation is similar, up to the point where the signal is received, by the repeater, but after that, the process, and type of signal (one being audio and the other be data ones and zeros) is very different.

Any type of digital system, that uses tones, or audio, to represent data, can be passed through an analog repeater, because that’s what analog repeaters pass, Audio. Not all analog repeaters will pass that digital signal well, since there can be level and fidelity issues, but it should work. That’s also why D-STAR a "true" digital system will not go through any analog repeater.


_____________________________

Matthew F. Yellen K7DN
Systems Engineer

 

[MacombMonitor]

Why the need for the warning? I can't believe an licensed amateur radio operator would think otherwise.

 

[N_Jay]

Why the need for the warning? I can't believe an licensed amateur radio operator would think otherwise.

LOL, you have got to be kidding!

Don't you read some of the posts here by "licensed amateur radio operators"?:wink: :wink: :lol:

 

[Tweekerbob]

Okay, so I de-Gaussed my monitor and pressed the Shift key a minimum amount of times while doing so, and I still can't get D-STAR to work with an analog repeater!!! WHAT am I doing wrong???!!! I obviously have a defective unit so I will send it back to iCOM to rectify the problem.

Seriously, what was the point of this thread again? To read useless warning labels, like the one on my lawn-mower that STRONGLY advises me from servicing the blade while the motor is running? Kinda figured that was a bad idea. Also, don't look down the barrel of a loaded gun. "One-eyed Willy" taught me that one. OK, I promise not to get upset when my D-STAR doesn't work with an analog repeater! Promise!

 

[NeFire242]

Would a digital scanner like a pro96 be able to listen to the D-Star format?

 

[N_Jay]

Would a digital scanner like a pro96 be able to listen to the D-Star format?

NO.

The Pro96 is not a "digital Scanner".

It is a "P25 capable Scanner".
D-Star is NOT P25.

 

[NeFire242]

Yeah we know D-Star isn't P25.

Ok so the only way to monitor DStar is with another DStar radio. That would be ideal in some situations.

 

[n4voxgill]

The Icom DStar radios have the ability to operate in both digital and analog modes. If you want to transmit via an analog repeater, you put your radio in analog mode. To transmit in a DStar repeater, you put your radio in digital mode. I beieve the latest Icom mobile has an analog receive capability while in digital mode so that you can hear if someone is calling you via analog mode.

DStar is an open mode created by the Japan Amateur Radio League or club. Icom did participate with the Japanese government agency that help get an open standard. DStar is fully open. Icom doesn't own DStar.

P25 is certainly not a world standard. Just look at TETRA which has become the recognized mode in many countries. The FCC has only accepted P25 as a standard for interoperability in the 700 MHz band. This is why many large system are being built that will be either Provoice or OPen Sky with P25 only being included if it is required by the purchaser for interoperability.

Most ham radios are developed and built in Japan. With an open standard there for DStar it will be very easy for all of the manufactuers to concentrate on DStar.

 

[Grog]

Ok so the only way to monitor DStar is with another DStar radio. That would be ideal in some situations.

That's the real sprit of amateur radio :roll:

If you want to hide something, hide it well. That's where real encription is useful. Just do it outside of the amateur bands

 

[n4voxgill]

The FCC has stated the purpose of amateur radio in Rule 97, where they state:
The rules and regulations in this part are designed to provide an
amateur radio service having a fundamental purpose as expressed in the
following principles:

(a) Recognition and enhancement of the value of the amateur service
to the public as a voluntary noncommercial communication service,
particularly with respect to providing emergency communications.

(b) Continuation and extension of the amateur's proven ability to
contribute to the advancement of the radio art.

(c) Encouragement and improvement of the amateur service through
rules which provide for advancing skills in both the communication and
technical phases of the art.

(d) Expansion of the existing reservoir within the amateur radio
service of trained operators, technicians, and electronics experts.

(e) Continuation and extension of the amateur's unique ability to
enhance international goodwill.

Sections B & C encourage trying new things. Digital would certainly fall in that category. There has been a lot of interest in packet and APRS which are digital modes that have required using modems. Now with DStar you can send data messages at the same time you are talking. this can be valuable in emergency communictions.

 

[fineshot1]

The Icom DStar radios have the ability to operate in both digital and analog modes. If you want to transmit via an analog repeater, you put your radio in analog mode. To transmit in a DStar repeater, you put your radio in digital mode. I beieve the latest Icom mobile has an analog receive capability while in digital mode so that you can hear if someone is calling you via analog mode.

DStar is an open mode created by the Japan Amateur Radio League or club. Icom did participate with the Japanese government agency that help get an open standard. DStar is fully open. Icom doesn't own DStar.

P25 is certainly not a world standard. Just look at TETRA which has become the recognized mode in many countries. The FCC has only accepted P25 as a standard for interoperability in the 700 MHz band. This is why many large system are being built that will be either Provoice or OPen Sky with P25 only being included if it is required by the purchaser for interoperability.

Most ham radios are developed and built in Japan. With an open standard there for DStar it will be very easy for all of the manufactuers to concentrate on DStar.

Gill - I dont beleive the D-Star repeaters are configurable to both modes. When you set up and configure them for service they must be one or the other. The only way someone could be calling you via analog if the repeater is setup for digital is there must be a second repeater setup for analog. I am sure if I goofed on that one someone will jump in and correct me but the way I read the technicle info on the configurations I think that is correct.

 

[N_Jay]

. . .
P25 is certainly not a world standard. Just look at TETRA which has become the recognized mode in many countries. The FCC has only accepted P25 as a standard for interoperability in the 700 MHz band. This is why many large system are being built that will be either Provoice or OPen Sky with P25 only being included if it is required by the purchaser for interoperability. . . . .

P25 is a "World Standard", unlike TETRA.
Tetra uses proprietary technology licensed only for use in TETRA in certain regions of the world. All P25 technology is open for use in P25 equipment and systems worldwide.

I am not sure, but last I heard there were more P25 systems worldwide then there were TETRA systems.

Not only has the FCC selected P25 as the standard for 700 MHz interop channels, but many US federal government agencies have selected P25 as their land mobile digital standard.
In addition many states have selected P25 as their public safety digital radio standard.

I think you will find many more large systems operating P25 than the number that operate OpenSky and ProVoice combined.

And all this is off topic to the discussion of D-Star (Sorry, bad information hanging out there as "facts" bugs me)

 

[n4voxgill]

fineshot, I tend agree with you on the repeaters. I was addressing the mobiles and portables. They have the ability to work both analog and digital.

I do not know if the base stations have backwards capability or not so they can pass analog. I certainly would not disagree if someone has looked at the specs for the repeaters. I have only read up on the mobiles and portables.

If DStar repeaters can only pass digital, I don't see where that is a major drawback. Some of the older amateur mobiles and portables didn't have ctcss boards and could not work analog repeaters with tone control. But that didn't stop people from putting up repeaters using ctcss.

 

[NeFire242]

That's the real sprit of amateur radio

If you want to hide something, hide it well. That's where real encription is useful. Just do it outside of the amateur bands

That's what I have Nextel for.

The thing is, define encryption for me. If a person doesn't have a P25 scanner, but tries to listen to the hams talking in P25 or DStar, is that encryption because not everyone has the ability to monitor? What about speech inversion or other forms? You can purchase equipment and kits to make it where you can listen.

A lot of ideas and technology involved with radio today came from amateur radio. When does it cross the line of trying to further the art of radio into coming up with new standards, inventing a new form of "encryption" or some type of other new operating mode?

 

[N_Jay]

That's what I have Nextel for.

The thing is, define encryption for me. If a person doesn't have a P25 scanner, but tries to listen to the hams talking in P25 or DStar, is that encryption because not everyone has the ability to monitor? What about speech inversion or other forms? You can purchase equipment and kits to make it where you can listen.

A lot of ideas and technology involved with radio today came from amateur radio. When does it cross the line of trying to further the art of radio into coming up with new standards, inventing a new form of "encryption" or some type of other new operating mode?

You are confusing encryption and encoding.

If you don't know German, then German may sound "encrypted" to you, but in fact it is just a different way to "encode".

Encryption requires a coding method that includes a variable key without the proper key you can not decode or "unencrypt" the message.

Think of it as the difference between a latch and a lock.

If you don't know how to work a latch properly it may seem locked.

 

[Grog]

You are confusing encryption and encoding.

If you don't know German, then German may sound "encrypted" to you, but in fact it is just a different way to "encode".

Encryption requires a coding method that includes a variable key without the proper key you can not decode or "unencrypt" the message.

Think of it as the difference between a latch and a lock.

If you don't know how to work a latch properly it may seem locked.

I swear, most of the time you make me want to punch my computer screen. Then you make such a profound statement, and I want to buy you a beer

 

[N_Jay]

I swear, most of the time you make me want to punch my computer screen. Then you make such a profound statement, and I want to buy you a beer

Maybe you need to reevaluate the times you want to punch the computer?:twisted: :twisted: :twisted: