VARA FM DEMONSTRATION AND DISCUSSION Merced County ARES

VARA FM DEMONSTRATION AND DISCUSSION Merced County ARES Stanislaus County ARES Adulterated by W 6 ABJ

WHAT IS VARA FM? VARA FM IS A SOUND CARD BASED HIGH PERFORMANCE MODEM UTILIZING OFDM MODULATION CREATED BY JOSE ROS EA 5 HVK. Orthogonal frequency-division multiplexing

ODFM

VARA FM is a derivative of VARA HF, which is optimized for data transmission with FM devices in the VHF / UHF range. It works in the mode “Narrow/1200" or “Wide/9600“. The designation Narrow/Wide refers to the connection to the FM device: Mode narrow/1200 is intended for the use of the normal audio path (as with Packet Radio 1200). Mode Wide/9600 can be used on equipment that utilizes a wider audio bandwidth. Newer Signa. Link sound card interfaces are capable of this, Along with DRA boards from https: //www. masterscommunications. com/

In narrow mode VARA FM uses up to 58 carriers which are modulated in an audio range of 300 - 2880 Hz with a symbol rate of 42 Bd. VARA FM uses 11 adaptive speed levels as follows: In wide mode VARA FM uses up to 116 carriers which are modulated in an audio range of 300 - 5800 Hz with a symbol rate of 42 Bd. VARA FM uses 13 adaptive speed levels as seen above

Audio Bandwidth of 2580 Hz In Narrow/1200 mode

Real world comparison 118 k picture AX. 25 Packet via KPC 3 AX. 25 Packet via Dire. WOLF Vara FM via Signalink 37 m 38 s 35 m 22 s 7 m 11 s A little over 4 times faster !!!! Vara FM via DRA-25 wide A little over 5 times faster !!!! Decoded Information from Radio Emissions for Windows Or Linux Fans Software based TNC 5 m 12 s

In the 9600 mode, you can work with greater LF bandwidth (4800 Hz NBFM)(5600 Hz WFM), so that there are more than twice as many carriers (116) in it. This results in the following 7 speed levels: Level Symbol Rate Carriers Mod. Bytes / Packets Net Data Rate 1 48 116 BPSK 2333 2 48 116 4 PSK 4768 3 48 116 8 PSK 7155 4 48 116 8 PSK 9540 5 48 116 16 QAM 11972 6 48 116 32 QAM 14966 7 48 116 32 QAM 17957 Speeds are approximate, compiled from various sources. User Data Rate 15300

NEW!!! VARA FM Digipeat Starting with VARA FM 4. 0. 1, VARA FM has the ability to digipeat.

Place your digipeater station sid here

AVAILABILITY OF WINLINK VARA FM NODES Currently We Have four Winlink VARA FM Nodes Here in The Valley

CURRENT WINLINK VARA FM GATEWAYS NAME FREQUIENCY DIGI / NODE USAGE Winlink RMS Servers Win. Link RMS / VARA MAR 5 FM LOCATION K 6 IXA - 10 144. 910 K 6 IXA - 11 Currently Down 145. 610 K 6 IXA - 12 145. 050 KBULN Win. Link RMS / VARA K 6 IXA-12 FM Mt. Bullion, Mariposa K 6 IXA - 13 145. 630 KOSO Win. Link RMS / VARA K 6 IXA-13 FM Mt. Oso, Patterson BEAR Win. Link RMS / VARA FM Atwater Bear Mt. Fresno

EQUIPMENT Signalink USB https: //www. tigertronics. com/ Available for about 139. 95 with all cables and accessories

Equipment DRA Series of Sound Card Interfaces DRA-30 https: //www. masterscommunications. com/products/radioadapter/dra 30. html Available as a kit for 30 dollars, usb cable is supplied, but you need to build your radio cable DRA-36 Similar to the DRA-30 but with a Mini-DIN-6 radio connector. Available as a kit for 36 dollars, usb cable is supplied along with 6 pin cable

Where Can I Get VARA FM? https: //rosmodem. wordpress. com/ In my opinion it is well worth the 65 dollars for the registered version, 50 if a club or organization gets 10 or more.