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
DSTAR will not work on an anolog repeater
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Hamradiostuffing
- Posts: 34
- Joined: Sun Apr 10, 2005 6:19 am
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Hamradiostuffing
- Posts: 34
- Joined: Sun Apr 10, 2005 6:19 am
above message
The message above is a snip from mods dk
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Hamradiostuffing
- Posts: 34
- Joined: Sun Apr 10, 2005 6:19 am
more DStar
another snip from mods dk
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.
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Matthew F. Yellen K7DN
Systems Engineer
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
D-STAR Digital Format
Okay, ICOM Has Digital capable transceivers and apparently repeaters too. Several items I've been wondering about the ICOM's Digital Mode / Format:
Does D-STAR use AMBE or IMBE in the Digital mode?
Are the ICOM Digital Repeaters capable of Mixed mode operation, Analog and Digital?
Is there a Priority as setable in the software for the repeater mode?
As far as Amateur Radio RF Channel Spacing: 25 kHz, 12.5 kHz and/or 6.25 kHz for Frequency Spectrum efficiency in crowded metropolitan cities?
Does the ICOM Digital Product have Network Access Codes the equivalent to /\/\otorola Astro Digital Products and are they compatible?
Does D-STAR use AMBE or IMBE in the Digital mode?
Are the ICOM Digital Repeaters capable of Mixed mode operation, Analog and Digital?
Is there a Priority as setable in the software for the repeater mode?
As far as Amateur Radio RF Channel Spacing: 25 kHz, 12.5 kHz and/or 6.25 kHz for Frequency Spectrum efficiency in crowded metropolitan cities?
Does the ICOM Digital Product have Network Access Codes the equivalent to /\/\otorola Astro Digital Products and are they compatible?
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Hamradiostuffing
- Posts: 34
- Joined: Sun Apr 10, 2005 6:19 am
it does not matter
it does not matter