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After being out of Amateur radio for awhile, i'm getting back in.
I've always been intrigued by digital formats and was wondering if anybody here is using D-Star??? I know that Icom has a D-Star repeater on the air in Bellevue but how widespread is the use by local hams?? Any nuggets of wisdom???
Groups i should check out(any local clubs with this format in king county/north pierce county)???

The D-Star system is a nice arrangement. Unfortunately it's out of bounds price wise for most in the area allowing it's implimentation to stagnate. It's also a proprietary format which closes out others from developing further to reduce the over all cost.
Maybe Icom will re-evalute this in the future and provide a better cost effective means for digital communications.

73's de KG7HQ

_________________
Thank You,

Michael
ARS - KG7HQ
Assistant Director/Technical Specialist/VE
Northwestern Division
ARRL
kg7hq@arrl.net
http://www.kg7hq.wetnet.net

Since the US is mostly going to Project 25, I think Icom's going the wrong way. I've got no interest in a digital system that's not compatible with my existing (type-accepted) handheld or my scanner. Beta vs. VHS again.

Flash

It's too bad that Icom tried to monopolize the market in this area instead of making it open source. I recently saw where they upgraded the firmware for addtional and improved features. But since the price is still up there, most hams will just thumb their nose at it and maintain normal FM communications with the continuious experimentation using sound card interfaced systems for digital support.
I'm seeing the Terminal Node Controller (TNC) communities take a hit as more look for a less expensive means of facilitating digital comms.
Open source software defined systems are the new rage... I hope the big "3" amateur radio companies pay attention and get invovled soon.

73's

_________________
Thank You,

Michael
ARS - KG7HQ
Assistant Director/Technical Specialist/VE
Northwestern Division
ARRL
kg7hq@arrl.net
http://www.kg7hq.wetnet.net

Now that Sprint has over air the internet for 50 dollars a month why bother with DStar. ICOM does not understand that DSTAR takes up more bandwidth and will not work on an anolog repeater. See what ICOM Says

ICOM SNIP

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
http://www.icomamerica.com


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

Hello Matt,

Great input. There are many asking hat very question. Thank you for sharing.

Michael - KG7HQ

_________________
Thank You,

Michael
ARS - KG7HQ
Assistant Director/Technical Specialist/VE
Northwestern Division
ARRL
kg7hq@arrl.net
http://www.kg7hq.wetnet.net

My name is not Matt. I did however think that the information would be interesting to you.


Ham Hog

P25 is the way to go (as far as inexpensive Digital voice)

Mixed-Mode repeaters allow BOTH analog and Digital modes. Gear can be found pretty cheap these days in both UHF and VHF.

Multiple vendors now produce P25 equipment:

Motorola (VHF, UHF, 700/800)
EF Johnson (VHF, UHF,700/800)
Kenwood (VHF, 800)
M/A-Com (VHF, UHF,800)
Icom (VHF)
Yeasu/Vertex (VHF)
Datron (VHF)
Thales/Racal (VHF)
Relm/BK (VHF)
Tait (VHF, UHF)
Daniels (repeaters only)


I'm a Motorola Nut, so I might be biased a bit ;-)



-Mike

_________________
flickr | mikegilbertphotography.com

Who's missing the point? Certainly NOT me.


Huh?

I think you're using the term "digital" a little loosely. ALL P25 gear is compatible. No matter what brand you're using, as long as it's on the same band (obviously) and conventional.



Have you done any research to back this statement up?
If you define "the market" as the local swap meet, you may be right. (things are changing faster than you might think)

I see THREE Quantars on ebay right now. Most can be had for a bit more than a comparable analog repeater. (meaning not some hamtronics crystal-controlled job)

Come by my table in Puyallup- It will be an Astro paradise.



Don't you mean

D-Star and P25 will NOT work together. D-Star uses AMBE, while P25 is IMBE.

Bottom line here folks:

P25 IS the way to go if you're looking for an open standard for digital voice. With so many vendors out there, prices WILL fall. heck, they've been falling since 1996 when IMBE hit the market.

Hell, I pick up 1-year-old radios for pennies on the (taxpayer's) dollar.

I'm done.

-Mike

_________________
flickr | mikegilbertphotography.com

Just a bit of info on P25 in the ham bands in the area. Here in the Willamette Valley we have 4 Motorola Quantars running mixed mode P25, and analog, and 3 more to be up very soon. Four on 2 meters, and three on 440.

Also in the Vancouver area on Larch Mt, there is Moto Micor that has been modified to PASS digital modes, and BOTH D-Star, and P25 will work just fine. The repeater has a new owner, and he has the repeater in PL sql most of the time. When the PL decoder is inline it will not work with the digital modes. With this method the repeater will only pass the signal, and you don't have any FEC at all.

Anyone coming to Rickreall with P25 (or without) drop by my table and say hi. I'm the one with the Quantar on the table. Same thing goes for Puyallup. The yellow XTS’s will be hard to miss.

For Rickreall 442.025 + with a NAC of 293, and PL of 123.0 for analog. It is not on the hill yet, so I don't know what we will have for coverage, but it should work well at the fairgrounds.

Simplex on 147.540, and 446.025 NAC 293


Jim

Hey Jim... will you have anything Astro up at Puyallup? I'll make sure to program up an Astro Saber so I can play on IMBE. ;)

446.025 NAC 293
147.540 NAC 293
464.500 NAC 293 W/encryption