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Davicom Climbs a Mountain

User Report: MiniMAC saves on visits to remote transmitter site

KELOWNA, B.C. — Over the years, Vancouver,-based S.W. Davis Broadcast Technical Services, the contract engineering firm for which I work, has installed a variety of transmitter remote control systems. Of course some of them have turned out better than others. One our most gratifying installations was just a couple of years ago, in Kelowna, B.C., for K963, CKKO(FM).

FM site selection in British Columbia’s interior can be a trade-off involving expense, difficulty and performance.The mountainous terrain guarantees that you will have multipath; it’s just a question of how much and where. And a site that is way, way up and offers great overall coverage may not serve your core market as well as something more modest, especially if you’re worried about stereo performance.

Mountaintop Tx

All of this is by way of explanation: K963’s transmitter site is on an isolated ledge on the north face of Okanagan Mountain, and offers better stereo coverage in Kelowna than most of the other mountaintops that have been tried over the years. But it’s difficult to get to at any time, especially in the winter: a horrible road, lots of snow and generally foggy conditions make it hard to access by truck or helicopter. And it’s a very long hike!

This was a site begging for a good remote control system, but there were complications.

There are no telco facilities available there, and we haven’t had very good luck in the past in these parts with the interface offerings from the wireless companies. Satellite phones remain an option, but the dollar signs involved would have our client reeling.

In this case, we decided to try a pair of the low-cost unlicensed 5.8 GHz outdoor wireless radio IP bridges that have become popular in recent years. At the site, we installed a Davicom MiniMAC II in the normal fashion, but with its Ethernet connection to the studios via the microwave radio, and no dialup connection at all.

The installation was straightforward, as we find it generally is. Davicom setup and calibration is a logical and well-thought-out process, and thankfully there are few surprises. We find the MiniMAC has ampleI/O channels for all but the largest installations (and the new expansion options increasingly make me wonder why we’d need to order one of the bigger units at all).

And luckily for us it can communicate in many ways: Whether you want to get your alerts via voice commands to your landline or cellular phone, numerically via pager, on your computer via modem or LAN or even if you want the details faxed to your office, it’s just a matter of configuration.

(I used to snicker about the fax option, thinking that it was primarily intended for those technicians that were very busy on the golfing green, but I must admit that it has come in handy at several installations over the years. And there’s nothing quite as convenient as a detailed fax printout of a log to help you analyze what really did happen on that mountaintop at 3 a.m.)

In this case, we had our studio engineering computer linked up to the Davicom over the radio link in no time, running the included MacComm software just as if we had dialed in via landline to any other site … MacComm presents the same look and feel, regardless of communications medium. That’s very comforting.

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Well, what about alert modes? The most practical approach seemed to be to connect our link up to the Internet via the studio’s office network, and use emails to alert our technical staff. It all looked straightforward, but for me this was untrodden territory and I didn’t have a helpful IT person on-hand to help with the details. I read the manual, plunked in the most likely numbers, and managed to get a “future” email account for our MiniMAC from the mail administrator. I couldn’t even test my results, because the new mail account wouldn’t be activated for a few days, by which time I’d be elsewhere, working on another project. Oh well! Maybe we’ll get this working next time I’m in town.

You’ve got mail

Imagine my surprise, just a week or two later, several hundred miles away in Vancouver, when the K963 MiniMAC started sending me unsolicited alert emails, in clear plain text, at 4:30 one morning. It looked like there was a problem with the main transmitter.

I called up the station’s technical person (he had also received this strange email) and we arranged for him to attend at the site.

I battled the elements and the fallen trees across the road, fought my way up the mountainside, arrived at the transmitter site, opened the door, and surely enough, one of the redundant power supplies has failed. The transmitter power was down by 40 percent or so.

I’ve seldom been so delighted by equipment failure. Here was our MiniMAC, unexpectedly but accurately reporting a problem that otherwise would not have been detected until the next site visit (and visits to this site are measured on one hand for a year’s worth).

In this case, the alert was the most important part. We had a replacement power supply sent by the transmitter maker and everything back to full power and normal parameters in short order. The toughest part was explaining to the station manager how we knew enough to install the remote control system just before something was going to break.

Frankly, wouldn’t all of our emergencies be so much easier to handle, if we could just schedule them for our convenience?

This was our first installation of a remote control system working solely with a private IP connection, but it won’t be the last. It’s plain to see that we’re going to be dealing more and more with this type of communication at our sites. And the little Davicom MiniMAC came right out of the gate, exceeding expectations.

Dan Roach is an engineer with S.W. Davis Broadcast Technical Services.

For information, contact Guy Fournier at Davicom in Quebec at (877) 282-3380 or visit