Russell Senior, Secretary of Portland’s Personal Telco Project, writes up the club’s field day this August 26th, in News For Neighbors.

The Field Day has been an annual event of Seattle Wireless.

Portland’s field day was a two-hop affair, connecting one group on Portland’s 1,000 foot high Council Crest park, overlooking the West side of town (left), and one group on Mt Tabor, on the East side of town. Then the signal was relayed down to a youth Hostel on Hawthorne Blvd, about 2 miles below Mt Tabor.

The Hostel’s access point, it was hoped, would provide the internet connection for the relay network. It worked!

Here’s (part) of Russell’s report:

When I arrived on Saturday morning at about 11 am, Tom Higgins, Tamarack and Don Park had set up near the reservoir on Mt Tabor and were scouting out signals from a vehicle-mounted yagi.

Meanwhile, I set about configuring our Metrixes to make sure we had them working correctly at close range before attempting the longer shot to Council Crest.

Tom Higgins had brought a nice marine battery, from which he operated an inverter which allowed me to keep my laptop charged up, as well as supplied the Power-over-Ethernet injectors to energize the Metrixes.

After about 90 minutes of fiddling, during which Sam Churchill arrived, we had the Metrixes ready to go and configured for the most interesting Mt Tabor-Council Crest link.

Tom and Don took their Metrix, Sam’s tripod-mounted 24 dBi dish antenna, and an omni with them to Council Crest, while Tamarack departed for the Ondine and Sam and I headed for the top of Mt Tabor.

Don had brought along FRS radios for the event, and we were able to maintain voice contact between Mt Tabor and Council Crest while we were getting set up.

At the Mt Tabor end we attached two panel antennas to the mast. One was a 19 dBi loaned by Sam Churchill, pointing at Council Crest. The other was a 13 dBi, pointing at the Hostel.

All this activity, with the odd, un-park-like gear, attracted a fair number of questions from passersby. One gentleman approached and started to ask some questions, and it soon became apparent that he was there “on purpose”.

Jay was in town from his home in Seaside for another event. He’d heard about our Field Day from a friend of his who lives in Arizona, who had suggested that our thing might be worth checking out. While Jay got filled in on some of the details, he pitched in and helped as we assembled the final bits.

On Mt Tabor we didn’t have a nice marine battery and inverter to use with the PoE injector, so after mounting the Metrix to the mast, we opened the enclosure and applied 12V to the internal power jack and device sprung to life.

We used channel 1 on the longer link, since the Hostel’s node operated on channel 11. I had configured the Mt Tabor node radio to AP mode with an SSID of: www.personaltelco.net/tabor. I logged into the local Metrix from my laptop via ethernet.

Right away, we had a solid signal to the Hostel, and I was seeing what our driver (madwifi-ng) reported as “associations” from the Council Crest Metrix and one other, which turned out to be Tamarack’s Apple laptop from the Ondine. However at first, neither of them were _actually_ associated.

Then, ultimately, the Council Crest crew decided to try flipping polarity of the antenna. We’d set up vertical polarity at Mt Tabor, and Council Crest initially thought they had as well (I think they were just confused). They flipped the tripod over 90 degrees, and BAM, association!

We spent another 15 minutes or so getting some minor NAT issues and a little local DNS problem worked out, until I was able to authenticate with the NoCatAuth captive portal software at the Hostel node, and then Council Crest was online! Tom got on the IRC channel, made a Skype call over the link, and was generally just pleased.

The link to Council Crest was about 5.6 miles (9 km), according to our GPS coordinates and an online calculator. The radios at either end were ~19 dBm, with 24 dBi and 19 dBi antennas at the end points. We had some modest Fresnel zone interference at the Council Crest end.

The link to the Hostel was about 2.0 miles (3.2 km), which we connected to with a 19 dBm radio and 13 dBi panel. The Hostel’s gear consists of an unspecified Cisco outdoor AP and antenna originally donated by Intel and installed about 4 years ago.

We were pleased with our success, modest though it was, and resolved to try something slightly more ambitious next time: perhaps an additional link to Rocky Butte, and/or (if we can do it before winter weather sets in) a longer link to the top of Larch Mountain, about 25 miles to the east.

NOTES:

[0] http://wiki.personaltelco.net/index.cgi/FieldDay2006

[1] /www.seattlewireless.net/FrontPage

[2] http://wiki.personaltelco.net/index.cgi/NodeHawthorne

[3] These were Metrix Mark 2 devices, borrowed from the Mississippi Grant Project for the day. They are waiting to go on yet-unidentified roofs in the Boise Neighborhood of North Portland. One of the devices we used was recently reconstructed from surviving parts of our vandalism incident early this month.

[4] http://www.personaltelco.net/gallery/missipcommons/DSC01030

– Russell Senior, Secretary russell@personaltelco.net”

Posted by Sam Churchill on Sunday, August 27th, 2006 at 8:07 pm.