Description
P4dragon DR-7400
Use the Pactor modems to send wireless e-mail, transfer files, use real-time data links, and access weather information, all over your SSB or VHF radio.
The compact HF modem P4dragon DR-7400 offers a lower-priced entry to the P4dragon modem class. The DR-7400 has been optimized for use with the new high-end data transmission mode PACTOR-4. This allows unparalleled fast and robust data links via shortwave. Email almost like at home – from any point on earth. The DR-7400 is software compatible to the PTC-II series and to the DR-7800 so that existing PACTOR software (Airmail, RMS Express, Alpha etc) can continued to be used. The elegant design as well as the easy upgrade possibilities (free updates!) complete the concept of the “Little Dragon“. Of course, the DR-7400 also provides TRX remote control, a GPS input and an (optional) Bluetooth interface.
This unit is compatible with radios from manufacturers such as ICOM, Yaesu, Furuno,
Kenwood, SGC, etc. that have a transceiver switching time of 20 ms and adequate cooling for
sustained high power operation. The P4-Dragon is compatible with commercial service networks
such as SailMail (www.sailmail.com) as well as the international network of free Winlink
(www.winlink.org) amateur (ham) radio operators (MBOs) that support PACTOR modes.
Compatible with Microsoft operating systems XP, Vista, & Windows® 7 32/64-bit.
Special Features:
P4dragon modems use a very complex newly developed synchronization algorithm for the link initialization (both ”normal” and ”robust”). This allows that on receipt of a ”connect” request from a calling station, an immediate and loss free automatic frequency compensation of up to ±280 Hz! can be applied to the receiver. The receiver of the ”Connect request” e.g. the Winlink-RMS or similar base station corrects its own receiver frequency AND the transmit frequency of the short radiated acknowledgement directly after the FSK synchronization. The modem of the calling station must then only correct the small remaining error (max ±10 Hz) after the link initialization. Thus PACTOR-2 /-3/-4 connects start immediately with full speed, independent of the initial frequency error. Base stations which operate using DR-7X00 modems thus also allow users initiating a link with a frequency error of greater than 30 Hz immediate full speed operation, even when the user only uses a PTC-II. (PTC-II modems in contrast only have a capture range of ±100 Hz for the reception of a link request, and automatically reduce the PACTOR-3 throughput when frequency errors of greater than ±30 Hz are measured.)
A high Tolerance to frequency errors is especially useful on the ”higher” shortwave bands. A relatively ”normal” frequency error of only 10 ppm produces a frequency error on the 20 meter band for example of 140 Hz.
