Engineering veteran (and past Radio World Excellence in Engineering Award recipient) Clay Freinwald raised a very real issue on the Broadcast.Net site recently.
As we enter colder months, Clay compiled a list of “must haves” for the transmitter site. His list was by no means exhaustive but will get readers to stop and think about their personal requirements, be it in the vehicle or at the transmitter building.
Topping the list is water. If you get stranded at a site, you’ve got to have water. I saw 36 bottles of water, wrapped in a plastic pack, on sale at Staples the other day for less than $5.
What to do with leftover Halloween candy? Take it to the site; and buy one of those hard plastic tubs, a Tupperware or other brand of food container to discourage animals from lunching on your food. Nuts are a good source of protein. “Meals Ready to Eat” and other sealed dehydrated camping food is available from military surplus stores as well as camping supply stores like REI.
Fig. 1: This emergency food kit provides freeze-dried meals for a single person for 72 hours and includes six entrees, three vegetables and three breakfast meals. It can last on the shelf for seven years.
In fact, REI sells a 72-hour emergency food kit for around $50. The dehydrated entrées sound pretty good — they do need hot water to prepare, though the instructions say that in a crunch they can be mixed with cold water, yuck! Consider the purchase of a coffee pot, or better yet a small fold-up camp stove.
The same company that packages the emergency freeze dried food sells a $12 flameless food oven “sleeve” that can be used five times. A chemical reaction generates the heat, preparing hot meals in just 20 minutes.
Clay’s suggestions include chemical light sticks, LED flashlights and plenty of batteries. If your budget permits, purchase a fold-up cot and sleeping bag; put both in a sealed plastic bin or trash bag.
Clay mentioned an emergency cell phone. But planning against a failure of cell service, he adds a 2 meter ham rig, perhaps an old base station that could be used to contact people should the cell phone fail.
He also recommends a set of snowshoes; and I’d add cross country skis, which are much more efficient than snowshoes if you need to travel any distance. But hopefully, you won’t be traveling; stay put! That’s the whole idea behind stocking these supplies.
We’ll touch on medical and health items in our next column. Meantime, if you have things to add to the list of emergency items to keep on hand at your transmitter site, please send them to me at [email protected].
Fig. 2: Check proper operation of deicer controls. It’s time well spent this time of year. * * *
Speaking of colder season prep, this is a good time to check the operation of your FM antenna deicers.
Radio World’s Buc Fitch wrote a thorough article in 2008 about deicers, how they work and how to keep them working. It is archived at rwonline.com/article/71554.
An example of deicer temperature controls is seen in Fig. 2.
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Greg Muir read here about Lincoln Hubbard washing his equipment after a flood, and adds a few pearls of wisdom.
Greg enjoys restoring and using older tube-type test equipment in his lab. Aside from his front-line solid-state equipment, Greg has some 400 vacuum tubes in his older inventory (plus 2,500 spare replacement tubes). It gives him plenty of heat to keep warm through the winter!
Part of his stock consists of several Tektronix 500 series tube-type oscilloscopes. Cleaning and restoring these can be a chore.
Many years ago, Tek published a service note explaining that its service department used to (carefully) wash their scopes using a light mixture of water and a mild cleaning agent.
Greg has found considerable success with this technique. He also uses the approach with newer solid-state equipment and finds that this equipment is considerably more resilient to the effects of water when it is applied properly.
A good discussion can be found at the website of U.K. Vintage Radio Repair and Restoration; link to it at tinyurl.com/rwbath. The thread explains some of the caveats, including possible recontamination of the equipment if you are using tap water.
As for using a car wash, Greg notes, you might want to be cautious about aggressive (and sometimes corrosive) soap solutions, as well as wash pressures that can force water into places it shouldn’t go. Even if you don’t apply soap, there may be residual amounts in the system as you wash.
For uncomplicated wash applications (printed circuit boards, small items), Greg uses a small amount of tap water and a small paintbrush to lightly scrub the dirt off, followed by a distilled water rinse and then low-pressure air to remove most traces of moisture.
He then places the clean board in a low-temperature (~100 degrees) source and lets it bake for an hour or so. Finally the cleaned item is left at room temperature overnight before energizing.
Of most importance is to keep water away from transformers, motors, relays, switches and other electromechanical devices. Greg recommends covering those parts and then cleaning them individually by other means on a per-item basis.
It’s important to treat high-voltage circuitry carefully, due to creation of possible leakage paths from residual contamination. The big thing to remember is that water can damage things as well as clean them.
The website www.vintage-radio.net/forum/index.php is a resource for those who need to repair or restore any type of equipment old or new. There also is a good vintage Tektronix scope forum on Yahoo referenced on the thread we mentioned earlier.
Greg Muir is a principal engineer with Wolfram Engineering Inc. in Great Falls, Mont.
Fig. 3: It only takes a few minutes to inspect the condition of site fence padlocks. * * *
What is the condition of your site locks? If they are rusted like the one in Fig. 3, the cold weather isn’t going to be a good time to find out.
Next site visit, check every outside padlock. If they are in working order, add some spray graphite lubricant and work it through the mechanism. The five minutes it takes can avoid an embarrassing situation later.
John Bisset marked his 40th year in radio in broadcasting recently. He works for Tieline Technology and is a past recipient of the SBE’s Educator of the Year Award. Reach him at [email protected] or (603) 472-5282. Faxed submissions can be sent to (603) 472-4944.
Submissions for this column are encouraged and qualify for SBE recertification credit.