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26 November 2009

3-element 2 meter quad takes shape

A view of the partially assembled 2 meter quad. Construction is all hardwood which presented advantages and disadvantages. Advantages: light weight, inexpensive, easy to cut and drill.

Disadvantages: tendency to warp, need to weather-proof for outside use.

In future, I think I would opt for all-PVC construction.

Wood was purchased at a local hardware store for about USD $15.


This view shows detail of method used to join the end of the 12-gage stranded wire used for the elements. This is a simple male-female connector crimped on to the ends of the wire. It slides together and apart. One alternative: use crimp-on closed loops that can be joined with a soldered-on jumper, allowing for easier length adjustments.


This view shows the nearly-completed 3-element quad on the floor of my "shack." Look closely to see how the twist and bend of the boom has caused the elements to be out of alignment. Not sure yet how this will impact antenna performance.



This view shows how the elements are wired. Instructions called for making slits in the ends of the spreaders, adjusting the depth of the slit to accommodate the wire. I chose to drill a series of 3 holes instead.

Here is a view detailing how the spreaders mount through the boom. I drilled half-inch holes, slipped the dowels through, centered them, then used small wood screws to affix the spreaders to the boom to limit slipping. Note how the mounting holes for the spreaders are drilled on either side of the line which represents the center of the wire for that element. I chose to use screws instead of glue so I could take the antenna apart as necessary.

Next steps: attach mast and feedline, and devise a method to mount the antenna on my porch that will raise it above the roof line.

21 November 2009

My next antenna project

A 2 meter 3 element direct coax-fed quad. Here are all the
pieces...now to build it.

17 November 2009

Ten-Tec 1340

I've decided to build a Ten-Tec 1340 QRP xcvr. Looks like a great kit that should be a good way for me to get back into kit building at a level where I can brush up my skills and challenge myself as well. Kit costs about $12o USD plus, Ten-Tec includes a free 2009 ARRL handbook, which I need anyway so that just sweetened the deal for me.

I chose the 1340 because 40m is such a reliable band for propagation even during the current sunspot minimum.

Ten-Tec's site has an amazing, free 330-page PDF provided by Chuck Adams, K7QO. Chuck's manual takes builders step-by-step through the process with excellent photos and insights to help you avoid making rookie mistakes along the way. Thanks, Chuck!

Not sure when UPS ground shipping will get the kit from Tennessee to Idaho but I'm hoping it will be no more than a few weeks.

Till then, Im studying K7QO's manual.

01 November 2009

40m opening today

1130Z: No 20m propagation this morning but there was light DX activity on 40m. Heard JA8BM and K2IX (NC).

Motorcycle battery is really inadequate for my station operation. Run time is just a couple hours, much less if transmitting, even at QRP. Time to upgrade to a power supply and keep a deep cycle battery for emergency.