How to Skin a Cat

I dont’ want to cause any undue alarm to animal lovers amongst you, nor to risk a boycott by PETA when this title shows up in the search engines. So I’ll say right off that this is an allusion to the pre-Political Correctness saying “there is more than one way to skin a cat”. No animals were killed or harmed in this production. With that reassurance out of the way I want to tell you a story of old fashioned ham ingenuity.

Over the past year an increasingly larger proportion of the fine presentations at club meetings have needed Internet access. Our first attempt to skin this cat was the direct approach. We asked how we could connect to the Internet at Crandall House. Somewhat to our surprise we learned that there was no provision for guests of the facility to connect. Some discrete inquiries made it clear that trying to change this policy was unlikely to succeed.

Our next approach was to schedule meeting at members’ houses when we just had to have Internet access. This works but leads to confusion about where we are meeting. Also some members are set in their ways and don’t want to move around. I know this doesn’t apply to you or me but to those other guys.

Many would give up at this point. Our president, John Spigel, W1AN, is not one of those. He reasoned that the judicious application of some ham ingenuity should be able to solve this problem. This is basically a communication problem. We are hams. Communication is what we do, by HPM!

During a lull in a contest John and I speculated that it ought to be possible to connect wirelessly, either by eavesdropping on an unlocked wireless net at a neighbor’s building or some more upstanding approach that used RF to connect. John researched the issue and came upon some devices that might permit a radio link from Crandall House to the QTH of Bill, N1HRA, a straight line distance of about a mile. Bill has broadband Internet in his shack. What we needed was to build a “bridge” from his shack to the Crandall House over which could flow the bits.

Now anyone who lives in New England, particulary Rhode Island, knows that building a bridge is a decades long affair. After all there are two nearby bridges that have been undergoing just painting for more than five years! Imagine what would happen to emergency communications if hams took that long to build a bridge. We do things faster, better, and cheaper!

John found some used equipment (of course) that looked promising. It seemed to function in a test across about 500 feet. Would it work over ten times that distance? Less than a month from concept we were ready to try it out.

The nearby illustration shows the hookup. At N1HRA we would connect a Wireless Router & Switch operating at 2.4GHz. Attached to that would be a Wireless Bridge operating at 900MHz. Up twenty-five feet on one of Bill’s towers we would mount an eighteen element yagi pointed at the Crandall House a mile away to the North East. Although the illustration shows the Crandall House with an antenna mounted on the roof we didn’t want to raise that issue, so the antenna was mounted on the top of John’s truck which was parked next to the Crandall House.

 

There was a matching 900MHz Yagi positioned to point at N1HRA when John’s truck was properly oriented. The antenna was connected to another 900MHz Wireless Bridge jumpered to be a “child” device which feeds a Wireless Router and Switch at 2.4GHz. The Router establishes a link with any nearby computer equipped with a wireless adapter. In this case the computer will be inside the Crandall House in the basement meeting room where we have met for some years.

So much for theory. It was time to smoke test the lash up, err… Bridge.

W1AN, N1HRA, and W1PN met on Sunday at 1300 at Bill’s QTH and began installing the antenna and “Parent” side equipment. It was a nice day and the antenna work went quickly. After a few moments confusion over which Bridge was which, the equipment was installed in the shack and tested ‘locally’. That is, from the tower to the driveway.

Just as we were preparing to drive to the Crandall House for the other side of the Bridge, Bill got a call on his EMT HT and had to rush off to save someone’s life. John and I proceeded to Crandall House stopping midway at the Ashaway Post Office for a trial run. John positioned the antenna and I attempted a connection. Two seconds later the home page of WA1RR.org was on the screen and we had a half-mile connection operating at broadband speeds!

Flushed with success John and I drove on to Crandall House and set up near the building. Again I attempted a to make a connection with the club website.

Nothing heard.

We were crestfallen.

“Gimme a minute,” John said as he climbed on the roof of the truck and proceeded to swing the antenna back and forth. After a few repositionings we found a bearing that would work and again we had high speed connectivity.

So, now we have not only proof of concept but a workable solution to the problem as is. It would be convenient to have a permanently mounted antenna on the building but it isn’t required so we may just continue to operate with a half-fixed and half-mobile approach. Either way it’s great to have Internet access at our regular meeting room.

If you want to see all this in operation you’ll have to come to the April 16th meeting.