Monday, October 31, 2011

CisarNet: Italian Cisar Radio Amateur WiFi Network

This just in from IW0SAB, Renzo in Italy:



The National Digital Link Cisar CisarNet (http://wifi.cisar.it), is an ambitious project that is joining much of the Italian region via a backbone digital technology wifi connections to 2.4 and 5.7 GHz, which allows experimentation for radio amateur and any use if needed in an emergency to coordinate and support relief efforts.


They have a 304 km (world record) link on 5.7 GHz. And other impressive wireless links back to other parts of the Hamnet that I have blogged on before.

They have an English wiki that is worth taking a look at.

On the top of this infrastructure, CISAR is activating several services, from voice and video over IP, DSTAR support and conferencing systems.

Thursday, October 20, 2011

802.11 Digital Audio Repeater Linking






Some time back I planted the idea of linking analog repeater together using 802.11/HSMM.

Instead of dedicated link channels usually on 440 MHz, you'd put some of that microwave spectrum to good use.

Since most repeaters are on commercial towers, achieving the required line of site and fresnel zone clearance shouldn't be a problem.

Each repeaters audio would be converted to VOIP using an Asterisk solution or now the plug and play CL-100 controller from CAT. (As seen above)

The advantage is now that is a multi-use link. There will be plenty of bandwidth left over for APRS i-gate traffic, Winlink, etc. Not only that, but other repeater linking could be done on the same 802.11/HSMM microwave backbone.

High speed Multi-Media interconnecting backbones can support radio linking of today as well as of the future.

Large regional and statewide linked repeater systems really should give this idea some consideration.

Thursday, October 13, 2011

Motorola STF2520A 900 MHz Power Amplifier Modifications

In case you overlooked the latest documented GBPPR project. Here it is again.

Modifying a surplus Motorola STF2520A cellular-band RF amplifier for 150 watts in the 900 MHz ham band.