The unfortunate & epic saga of the perfect military radio

The long awaited but ultimately unwanted GMR radio

As my day job starts to include more long term projects & project management I was particularly intrigued by an article in arstechnica.com. The article is, "How to blow $6 billion on a tech project", although the title may be more inflammatory than technically accurate.

The article covers the 15 year development of an advanced & unified military radio communications system that suffered from multiple issues including scope-creep & a rapidly changing underlying technology.

If you are involved with a group that is working to develop a product or service you'll really get something from this article. If you interested in radio systems, military or otherwise, you'll find this interesting as well.

Its hard to image the frustration people suffer when contributing to a project that is mismanaged unless you have been there yourself. I hate to think of the wasted effort that resulted when people found out How to blow $6 billion on a tech project

Ham Radio and Mesh Networks

Lately I've been fascinated by the capabilities of mesh networks. The ability to quickly create ad-hock computer networks could be an invaluable resource for amateur radio operators in general and particularly for emergency communications (EMCOM)

The particular device and software I have been experimenting with is the Linksys WRT54G router and HSMM-MESH firmware from http://hsmm-mesh.org/.

Installing the HSMM-MESH firmware changes the way the Linksys router functions and allows it to automatically connect to other HSMM routers in a mesh network. No special configuration is required after setting your callsign. All TCP/IP configuration is pre-configured, even down to automatically assigning addresses to connecting clients.

Mesh networks are highly fault tolerant. Every router in the network is aware of every other router and has the ability to move network packets through from one unit to another provided there is a link, or chain of linked routers, between them.
In the diagram to the right each router is represented by a numbered circle. If router number 6 were to fail then network packets that needed to move between router 1 and 7 would travel through routers 2 & 3 or 5 & 10 until 6 was repaired. All this happens automatically and quickly enough so that there is no disruption to the traffic.

Anything you can access on a normal computer network can be made to work on a mesh network. Some of the services that have been demonstrated include email, voice over IP (VOIP), video conferencing, file sharing, web servers & groupware applications.

With simple modified antennas the modest output power from the WRT54G (100 to 200mW) can be used to reach distances of many miles or tens of miles with directional antennas. Mounting the router on a mast in a sealed enclosure can reduce losses from long cable runs while running off 12V power makes them compatible with ham radio power sources including solar and wind power.

The example to the left is from NG5V located on hsmm-mesh.org and consists of an omni-directional external antenna and a lawn sprinkler controller box from a popular home improvement store.

Did you know that ... Frequencies used by channels one through six of 802.11b and 802.11g fall within the 2.4 GHz amateur radio band. Licensed amateur radio operators may operate 802.11b/g devices under Part 97 of the FCC Rules and Regulations, allowing increased power output but not commercial content or encryption.

I hope to acquire a few more WRT54G routers and put together a mesh network in the Katy TX area as a resource for experimentation and education in an area not normally touched upon by regular amateur radio operators. Who knows what the future holds & it behooves us to investigate this technology and bend it to our own needs.

The Amateur is Progressive ... He keeps his station abreast of science. It is well built and efficient. His operating practice is above reproach.

The KN-Q7A - A new 40M SSB 10W transceiver kit

Amateur radio kit builders have had greater opportunities to construct high-end equipment thanks, in part, to more economical production processes. Online services allow kit manufacturers to farm out circuit board production to large workshops where jobs are batched together into larger production runs with significant cost savings. A number of suppliers are now willing to sell in smaller amounts while maintaining low costs due to automated on-line processing. The end result has been an increase in the number of kits available of significant complexity including rigs with using sideband, digital signal processing and software defined radio.

One new SSB rig kit is the KN-Q7A available from Adam Rong BD6CR/4, designed by Shi Ke BA6BF. The KN-Q7A is a 40M SSB transceiver in a compact case with VXO tuning and 10W power out. This style of rig would be ideal for back-packing, camping or as a compact emergency transceiver.

It would be interesting to see how this would pair with the NUE-PSK Digital Modem for a ultra-compact portable PSK31 station if the VXO could be made to tune to 7.035 MHz

The KN-Q7A - 40M with VXO SSB 10W

The KN-Q7A is available directly from http://crkits.com/ or from their US distributor http://www.qrvtronics.com/HAM-Radio

Price for the KN-Q7A kit is $125 USD, a suitable microphone is available for an additional $25 USD.

Specifications

• Dimension: 153 mm x 97 mm x 40 mm, not including protruding features
• Weight: 500 g or 1.1 lbs
• Power Supply: 12~13.8 V, 3 A
• Current consumption: 30 mA in RX and about 2 A in TX @ 13.8 V
• RF output: about 10 W PEP @ 13.8 V
• Spur suppression: better than -43 dBc
• Sensitivity: better than 0.5 μV at 10 dB SNR
• IF filter: 6 pole crystal ladder filter + 1 pole post IF amplifier crystal filter
• IF bandwidth: about 2.0 kHz
• IF frequency: 8.467 MHz or 8.192 MHz, depending on the selected tuning range
• Frequency tuning range: about 20 kHz in VXO type. Five options: 7.050~7.070 MHz,
7.080~7.100 MHz, 7.145~7.165 MHz, 7.200~7.220 MHz, or 7.280~7.300 MHz
• Connectors:
• Speaker output: 3.5 mm connector, mono output
• Microphone input: 8-pin, can be configured to be compatible with electret
microphones
• Antenna connector: SL-16 type (M or SO-239 type equivalent), rear panel mount
• Controls:
• IF Gain Control: act as volume control
• Tune Control
• On board RF Attenuator trimmer to eliminate broadcast interference