QEX

Efforts in the amateur packet-radio community are probably best described in terms of the International Standards Organization (ISO) Open Systems Interconnect (OSI) model. In general, we look at the communication task and relate it to the OSI model. A representation can be made between the functions of the radio controller and the OSI Reference Model. For the functions associated with the data link layer, almost all amateur packet-radio work is being done with what is commonly known as the AX....

Info

Any battles over the last meaningless 0.01 dB. For instance, how does one compare a Fujitsu FHX 16 with a waveguide input on 10 GHz with a SMA connect-ored NEC NE32684A Al's (WB5LUA) solution was just to make the waveguide-to-SMA-transition loss 0.11 dB, the difference in noise figures according to the readout of the Hewlett Packard 8970. A 50-mW, 13-cm amplifier using the MAV-1 l MSA-1104 MMIC from an MAR-8 MMIC amplifier on this band, many people don't like this device due to stability...

The American Radio Relay League

The American Radio Relay League, Inc. is a noncommercial association of radio amateurs, organized for the promotion of interests in Amateur Radio communication and experimentation, for the establishment of networks to provide communications in the event of disasters or other emergencies, for the advancement of radio art and of the public welfare, for the representation of the radio amateur in legislative matters, and for the maintenance of fraternalism and a high standard of conduct, ARRL is an...

Amateur Television

Made in USA Value + Quality from over 25years in ATV W6ORG Snow free line of sight DX is 90 miles - assuming 14 dBd antennas at both ends. 10 Watts in this one box may be all you need for local simplex or repeater ATV. Use any home TV camera or camcorder by plugging the composite video and audio into the front phono jacks. Add 70cm antenna, coax, 13.8 Vdc 3 Amps, TV set and you're on the air - it's that easy TC70-10 has adjustable > 10 Watt p.e.p. with one xtal on 439.25, 434.0 or 426.25 MHz...

Prescaler

Need to count microwave frequencies Heres a prescaler IC that will work up through the 3-cm band. Angel Vilaseca, HB9SLV and Serge Rivi re, F1JSR This article describes two applications a frequency counter and a phase-locked loop that make use of the Fujitsu FMM110HG, a 0.6-to-12-GHz prescaler IC that divides the Fig 1 shows the circuit used with the IC, and Fig 2 gives an etching pattern used to build the prescaler on a PC board. The circuit is based on a Fujitsu FMM110HG. It is a monolithic...

Coming Attractions

(Remember, software upgrades are free ) WEFAX and SSTV demodulators Commercial inquiries are welcomed. We offer rapid prototyping of custom commercial, civil, and government applications including intelligent radio, wireline, and telephone modems. DSP-12 Multi-mode Communications Controller 695.00 One Megabyte RAM Expansion Option 8-Channel A-To-D Telemetry Experimentation Option 00 Wall-Mount Power Supply for DSP-12 (110 We accept MasterCard & VISA and can ship C O D. within the USA. All...

SSB Receiver

Using the Weaver method in a receiver requires some care, This article describes an experimental 75-meter Weaver-method single-sideband SSB receiver built by combining parts of my previously described Weaver-method exciter with two of KK7B's R1 direct-conversion receiver boards.1'2-3 Although a first-try receiver rather than an optimized design, the SSB receiver works well. A Weaver-method SSB receiver offers advantages over filter or phasing-method receivers. Filter-type receivers tend to have...

Crc

Fig 4 Mapping of upper layers to data link layer DTM. have been developing HF ALE radi os for many years. There are many fielded radio systems across various government agencies, and the technology is maturing. It is in the area of automatic networking that development work is still being pursued. The architects of these systems are attempting to solve many of the same problems that developers of the Amateur Radio networking effort are experiencing. The functions and features of these ALE...

Weaver Method SSB Modulator Using DSP

Phasing Method Ssb

DSP eliminates the audio phase-shift and dc offset problems of analog Weaver-method modulators. Single sideband SSB remains the primary Amateur Radio HF communications mode. Of the three known SSB generation methods, the Weaver method has received the least attention. A recent design showed that a Weaver modulator can be readily built with current technology however, its prototype suffered from performance limitations arising from the characteristics of high-order switched-capacitor filters....