The AOR ARD9800 SSB DIGITAL VOICE MODEM
DIGITAL SSB WITH ANY
Reviewed 4.5 out of 5 on eham.net Sept 2006
Come back here when done
1. The ARD9800 provides NEAR FM QUALITY audio using SSB.
2. The digital signals may require LESS SIGNAL than analog throughput making operations possible under adverse band conditions.
HOW DOES IT WORK?
Understand that this is a greatly simplified explanation: the ARD9800 digitizes the signal and divides into 36 PSK sub-signals in the bandwidth occupied by a normal voice audio signal.
IS IT LEGAL?
The ARD9800 uses an open published digital protocol (G4GUO) per FCC rules. In the USA, you may identify in digital or analog mode.
DOES IT WORK IN OTHER MODES?
Yes! The ARD9800 can be used in AM or FM modes, however, FM mobile operation could be prone to "picket fencing" which could result in the loss of data.
IS THERE A MARKET FOR THIS?
The ARD9800 was demonstrated for audiences at Dayton and Friedrichshafen.
HAMS LOVED IT! The most asked question was, "When is it available?"
WHAT ELSE DOES IT DO?
With the optional memory board, images can be easily transferred, similar to SSTV but we believe the ARD9800 sends a higher quality image. You can also send file transfers.
Owner can use ARD9800 mic, or a mic of their choice (wired for ARD9800 input).
WHAT MUST I DO TO GET ON THE AIR WITH THE ARD9800?
The ARD9800 package includes, modem, mic, cables and manual.
1. You must build (or buy) a cable that interfaces from the rear panel of the ARD9800 to the mic input of your transceiver, similar to a packet radio connection between a TNC (modem) and your radio. Then simply connect the mic input cable, the "speaker out" from your transceiver to the "audio in" on the ARD9800 and connect the power cable to the ARD9800.
2. It is suggested that you power the ARD9800 from a well regulated DC power supply. The use of "wall cube" and some "switching" power supplies is not recommended.
3. Be sure your mic and audio output settings are OK.
4. Make a test transmission in the analog mode prior to operating in digital mode.
ARE THERE OPERATING SUGGESTIONS?
1. Try to coordinate your frequencies as closely as possible.
(Some Activity Daily 17:00-18:00 UTC)
Main Frequency 7.296 USB
(Westen U.S. Group Activity 23:30 UTC Saturdays & Sundays)
There is some small margin for error, but best results are obtained when both transceivers are exactly on the same frequency.
2. Be sure your audio filters are about 3KHz or wider.
3. Don't "overdrive" your ARD9800 with too much audio from your transceiver.
4. Don't transmit using "compression" (also known as a speech processor).
5. Be sure your ALC is within its specified operating region. If in doubt, lower audio output seems to work better than a higher setting.
6. Be mindful of your bandwidth when selecting a frequency on which to transmit. Be sure you will not interfere with operators on adjacent frequencies.
WHAT ABOUT DUTY CYCLE?
Your duty cycle will be more intense. This is important to users of amplifiers. Because the digital signal makes full use of the SSB audio bandwidth, you should consider that you will be transmitting at the maximum power output you have selected. At maximum power settings, this will likely result in your transmitter consuming more power and generating more heat. If you transmit images or large data files, your "key down" time could be three minutes or more.
ARE THERE OTHER SOURCES OF INFORMATION?
Below please find web sites that are NOT affiliated with AOR.
AOR takes no responsibility for their content.
|Band width:||300 Hz - 2500 Hz, 36 carriers|
|Symbol Rate:||20 mS (50 baud)|
|Tone steps:||62.5 Hz|
|Modulation method:||36 carriers: DQPSK (3.6K)|
|AFC:||+/- 125 Hz|
|Error correction:||Voice: Golay + Hamming|
Video/Data: Covolution + Reed-Solomon
|Header:||1 Sec. 3 tones + BPSK training pattern for synchronization|
|Digital voice:||AMBE2020 coder, decoder|
|Signal detection:||Automatic Digital detect, Automatic
between analog mode and digital mode
|Video Compression:||AOR original adaptive JPEG|
|Power requirements:||10 ~ 16 V DC, Approximately 200 mA Typ(@ 12 V
6 V DC by internal jumper setting
|Serial port:||RS-232C, 9600 bps, Asynchronous|
|Dimensions (w, h, d):||100 x 32 x 158 (mm)|
or 3.94 x 1.26 x 6.14 (inches) (Projections excluded.)
|Connectors:||Radio: Microphone output (level
Speaker input (500 mV ~ 5 V p-p), PTT (Push To Talk)
Video IN/OUT: NTSC 1 V p-p (75 ohm)
|MIC:||Microphone input, Speaker output, PTT input|
|Others::||Signal Encryption for commercial
(where permitted; special commercial version required)
Analog/Digital mode selector
Video capture/transmit switch
|Specification & price subject to change without notice due to continuous development of the receiver. E & OE.|