two tone

Maritime Mobile Service Network - Maritime Mobile Service Net for disaster help on high seas on foreign lands

CARMEN Caribbean Amateur Radio Meteorological Emergency Network - Volunteer amateur radio operators (Hams), have maintained a radio station WX4NHC at the National Hurricane Center (NHC) in Miami since 1980.

Pipo Communications - The highest-quality and most reliable Dual-Tone Multi frequency encoders.

Otto Engineering - OTTO Communications designs and manufactures audio accessories for two-way radios used in public safety, police, fire, retail, hospitality manufacturing and other markets.

Communications Specialists Inc. - Manufacturers quality tone signaling, wildlife telemetry,avionics equipment,video transmision modems.

EZMaster by HamRadioSolutions - EZMASTER the all mode all in one interface. USB/Parallel/Serial Device. Include 75 sec Digital Voice Keyer, K1EL Winkey CW Keyer, SO2R switching, two radio interface, two RTTY audio insulated ports, two flexible Antenna Switch control. Ideal for Contesting, SO1R, SO2R, field day and daily activity. Compatibile with all software on the market : CT, CTWIN, TR, NA, WriteLog, N1MM, WinTest, MMTTY, MIXW and more .

Greenstone USA Priority listing - Manufacturer & distributor of vacuum tubes for all applications, we guarantee best service,pricing & delivery and we also guarantee sameday shipping.

Mixed-Mode Operation on Voice Repeaters - Mixed-mode operation, where voice and digital transmissions are used in turn on the same frequency

USPacket - USPacket is dedicated to networked amateur radio.

An Introduction to FlexNet - Features and operation of FlexNet packet networking software are discussed. Details of the software architecture, RMNC and MS-DOS hardware platforms, applications, user interface, adaptive parameters, and routing techniques are presented.

Manualmall - Amateur Radio Technical, Operators, and Service Manuals. Commercial Two-Way, Test Equipment, and Military Radio Manuals, Owners Manuals

CutRate Batteries - CutRate Batteries supplies fully compatible, after market battery packs for two-way radios and barcode scanners. Our products are guaranteed to work with Motorola, Kenwood, Yaesu, Vertex, Icom, Telxon, Intermec, LXE and PSC two-way radios and barcode scanners.

TestParts Sales Company - TestParts.com carries RF Microwave WiFi Coaxial Attenuators Coax Adapters Dummy Loads Waveguide Oscilloscope Probe Leads DMM Manuals RF Switch Relay SurplusSales Bristol Spline Pocket Toner Tubes Digicon Heliax RF Parts Oldaker Test Leads Silver PL-259s

Groton Electronics - Repair all major brands of Amateur Radio Equipment, such as KENWOOD, ICOM, YAESU. We also repair vintage American radio equipment.

Test Equipment Depot - New and Pre-Owned Agilent, Avcom, Fluke, Hewlett Packard, Instek, Leader, LeCroy, Tektronix,and more ..Oscilloscopes, Spectrum Analyzers, Network Analyzers, Power Supplies, Video Test Equipment, Generators, Meters and more

AST Global Electronics - New and Pre-Owned Agilent, Avcom, Fluke, Hewlett Packard, Instek, Iwatsu, Leader, LeCroy, Tektronix, etc. Oscilloscopes, Spectrum Analyzers, Network Analyzers, Power Supplies, Video Test Equipment, Generators, Meters and tons more

MediaCorp Radio - Operates Singapore's largest radio network with 11 FM stations and 3 shortwave stations providing sound entertainment and up-to-the-minute news and information locally and internationally.

Israel Radio - Israel Broadcasting Authority guide to the IBA radio networks known in Hebrew as Kol Israel - the Voice of Israel.

Caracol Radio - One of several Colombian broadcasting networks heard on AM and FM and worldwide on 5076 kHz in the 60 meter band.

Democratic Voice of Burma - Democratic Voice of Burma is a multimedia organization focusing on Burma - Myanmar. We provide impartial news, information and analysis about Burma. We have two hour daily radio broadcast to Burma via short wave, promoting press freedom, democracy and human rights. Our news is available in Burmese, English, Arakan, Chin, Kachin, Karen, Karenni, Kayan, Mon and Shan languages.

GoSatWatch - Satellite tracking on the iPhone/iPod touch. Track and predict visible satellite passes. Touch a satellite in the map view to see it’s orbit path and location.

APRS on your phone - iBCNU is an APRS GPS position reporting and text-messaging application for the Apple iPhone. When position reporting is enabled, the application will periodically send out location of your iPhone using either 3G or WiFi network and iPhone's built in GPS receiver

Antenna Noise and Signal Cancelling at LF - By using the signals from two antennas, controlling their relative amplitudes and controlling the phase of one of them, unwanted signal or unwanted noise can be phased out. Circuitry is described which uses the signal from a wire antenna to provide selective cancelling against the signal output from an LF loop antenna.

Rig to Soundcard Interface by M0UKD - Practival project that contains two isolation transformers, one for AF from the tranciever to the line in on a soundcard, and one from the audio out of the soundcard back to the mic / data input of the radio. Both of which are variable inside the interface via two preset resistors.

VNA-dsp / Antenna Analyzer - This project is an attempt to build a portable standalone VNA (Vector Network Analyzer).