I had some time today since I couldn't find any bars showing my Raiders getting their butts kicked by the Ravens so I worked on the antenna a little more. I cut the PVC and drilled the remaining holes and assembled the rest of the hardware. When I stripped some of the coil wire I saw that that wire was a smaller diameter than I thought. I was fooled by the size of the insulation! Well, that means it might actually be closer in size to the antenna I patterned this after. Since the insulation is so much thicker, that means the spacing between wires is going to be a little more than there's also. Well, I guess we'll find out how much of a difference it makes, but I don't think I'll really care since I can just adjust the tag ends after the coil.
Next I measured out the wire and attached it to the PVC. The math says for an Inverted V for 7mhz it should be about 32.5 feet. So I cut each one 33'. In retrospect, I wish I had left a little more to play with just in case. What's odd is that I calculated that the 40m segments on Alpha Delta's antenna are about 35'. I got to this number by taking their stated overall length of 82', then subtracting what I physically measured as the 80m tag + coil length. Take off a few inches for the center insulator and you come up with 35'. I can't explain an extra 2' unless it has something to do with the coil. If I end up needing 2' more on each leg, I'll have to solder some back on
You can see in the attached pic that I didn't attach the wire to the coil itself, just the PVC for now. I want to take a measurement of the wire by itself, then attach the coil and see what affect it has on 40m. Then I'll attach the tag ends of the wire and see what that does also.
The rest of the afternoon was spent wasting a lot of time with stuff that didn't work. I thought it would be a good idea to use some sort of glue to keep the coil wire from moving around or accidentally getting abused, I got out some contact cement glue and brushed each coil liberally with it. Nice idea except that I found out that the contact cement never really hardens up like some glues. After the dry time elapsed, I still found it to be nice and tacky. Yuck!
So out came the adhesive cleaner and I had to soak the coils to get the glue off. Some gently rubbing and wiping got it all back off after about 20 minutes.
Next I got all my tools and stuff and put it in the bucket to head across the street to the park to try this antenna out. Photo of bucket of antenna stuff attached. (BTW, whoever swiped my good pair of dykes and good needle-nosed pliers, please put them back in my tool box!!
) I found the only tree that looked like it might work and got out the home-made fishing reel slingshot, took a couple of shots into the tree to get the distance down and also get it where I wanted. Then I got the perfect shot over the branch I wanted, but the lead sinker broke off on the tree and went flying off the swivel-snap, fishing line falling down.
Oh well. So I attached some 100 pound dacron line to a tent post and threw it up into the tree. That worked after a couple of tries. I raised up the antenna using the dacron, answered the same question about 3 times to passer-bys about what I was doing
and tied it off to the bucket to hold it. After uncoiling the wire I realized that the tree wasn't tall enough. DOH!
I packed everything up and came back home after an hour of messing around in the park. Now I have to find a bigger tree.