Finally built and tuned my new inverted-V fan dipole #antenna for #POTA #SOTA #WWFF. It's three 40m, 20m and 10m dipoles fed in the middle from the same box. I hang the feed point box from a rope I throw over some trees, or from my 10m #Spiderbeam, and then tie the antenna wires down with some pegs.

40m/20m/15m/10m/6m don't need a tuner.

60m/30m/17m work very well with a tuner.

The whole construction is ultralight, it's basically just the weight of the wires and ropes.

#hamradio

Shark’s Teeth and Canadian Jam – a tall story

I recently purchased a Spiderbeam mast from a vendor in the United States. The list price was US$78 – a great price for a high quality product. But the story didn’t end there – not by a long shot. The cost for shipping via courier was an additional US$44. I expected there would be more to pay once the product crossed the border into Canada and that expectation couldn’t be more true. There was plenty more to pay! I received an email from the courier telling me I owed them a further CDN$90 and that to expedite delivery would I like to send them the loot in advance. I paid the ransom and received another email saying thanks for the cash, now your delivery is going to be delayed by three days!

I began to feel that I was being treated like a sucker; I was charged brokerage fees, handling fees, processing fees and, of course, taxes owed to the Canadian government. Then along came the credit card bill from the bank advising me of their extortionate exchange rate to convert US dollars into Canadian dollars. In the end my US$78 mast cost well over CDN$250! I am going to take very good care of this most precious piece of ham radio gear.

What did I buy with that small fortune?

I chose the Spiderbeam 7m (23ft) mast, primarily because it collapses down to a very manageable 28 inches and, although heavier than most, is still light enough to backpack into a field operating location. Is 7m tall enough? Well I thought about that for a while and decided it would be quite sufficient for my needs. Spiderbeam masts are built from heavier gauge fiberglass tubing than other similar products. Many telescoping fiberglass poles – especially those intended for fishing – are very flexible. When deployed for ham radio purposes they tend to bend which reduces their effective height. Spiderbeam masts remain fairly straight – a 7m mast supports a wire at 7m; it doesn’t bow down under the weight of the wire.

Crash prevention

Many years ago I invested in an MFJ 31ft telescoping fiberglass pole. One day, while testing an antenna in my yard, a gust of wind blew the mast over. It crashed against the wall of my house destroying several sections near the top of the mast. Fortunately I was able to restore it to a shortened length of 29ft by replacing the broken sections with those scavenged from a Crappie fishing pole. It has served me well since but it is heavy and collapses to a length of around four feet.

My new Spiderbeam mast is going to be very well protected – it cost far too much to replace if it became damaged. So here is a short account of what I have done to protect it during transit and while in use out in the Big Blue Sky Shack.

First, in transit, I pack it inside a length of 2-inch (50mm) PVC plumbing pipe. That all goes inside an expanding document tube which, in turn, goes inside a carry bag previously used for a camping chair. The bag is also used for packing tent pegs and guy lines.

What is the plumbing pipe for?

Well I guess I could just set the Spiderbeam mast down on the ground and guy it in place. However, by slipping it inside the plumbing pipe it can be easily removed for adjusting the antenna wire when needed.

Shark’s teeth?

Experience has taught that tall masts have a tendency to slip at the bottom. It is simple physics; 23 feet of mast supported 2 feet from the base provides enough leverage to topple the mast in windy conditions, or when a long wire under tension is attached at the top.

In the past I have dug a small divot to hold the base in place – effective but with a tendency to generate disapproval from park wardens. Now, to protect my precious Spiderbeam from catastrophic collapse I cut a set of “shark’s teeth” at the base of the support tube. It works and, if I ever encounter a growling bear on the trail, I can show it my shark’s teeth to intimidate it into retreat.

The top of the support tube has a small section of enhanced diameter created by slipping several strong rubber bands covered in electrical tape. It’s purpose is to prevent the guy lines from slipping – simple and effective. The guy lines made from 550 paracord are secured using Canadian Jam knots. I have no idea why Canada is credited with this particular style of knot, but it is a very secure way of tightening a guy line around the support tube. Canadian Jam knots are also very easy to release when it is time to pack up the station.

At the other end of the guy line I use modified taut line hitches to create an adjustable loop around lightweight “aircraft grade” aluminum tent pegs. The modified taut line hitch involves a couple of extra wraps of cord to make it more secure. I have found standard taut line hitches tend to loosen a little when tied on paracord.

Finally, at the top of the pole, I attached a small loop of very thin, but strong, cord. I took a few inches of cord, formed a loop and tied a simple knot at the end. The knot was fat enough to fit tightly in the top, hollow section of the Spiderbeam mast. It was secured with hot melt glue and is very secure. I don’t think it could be dislodged even if I wanted to remove it.

The loop can be wrapped around an antenna wire, then slipped over the top of the mast as seen in the picture. To remove the wire I simply lift the wire above the top section of mast to release it quickly and easily.

So far, all is well. The small fortune I have invested from my meager retirement savings into this excellent Spiderbeam mast is going to be very well protected!

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#AmateurRadio #Antennas #OutdoorOps #Portable #Spiderbeam

The mast and #spiderBeam are ready for their marriage. #E13 #fieldday #hamburg

#amateurradio #hamradio