This is exciting. I made a very good build of the SBGH with the 8 co-linear rods.
I'm unable to insert photos directly so here's a link to the photos on FLIKR. Open a second browser window to look at photos when reading my mash of information here.
http://www.flickr.com/photos/thistlehead/
MATERIALS:
I tried to get almost all materials at Home Depot.
1). 1 -10' section of 1/2" PVC electrical conduit
2). 2 - Plastic faucet plumbing tubes (labeled photo)
3). 3 - 1" PVC conduit clamps (photo)
4). 4 - #10 nylon machine screws
5). 2 - 1/4" -20 x 2 1/2" nylon screws (photo)
6). 3 - 1/4" - 20 nylon nuts
7). 2- #8 brass machine screws (photo)
8). 4 - #8 brass machine nuts
9). 8 - #8 brass machine washers
10). 3 - 3/16" - 1 1/4" SS machine screws and nuts
notes:
item 2). has an ID of 1/4" and an OD of 3/8" and is just perfect - you'll see why
item 3). are 1" conduit clamps that you will flatten and cut for T-supports for elements.
item 4). are used to screw elements to upper and lower T supports
item 5). are glued inside T tube and are used to secure item 3).
item 6). are used to screw onto item 5). and hold item 3).
item 8). and 9). are used to secure elements to middle T and affix 300-75 ohm balun
item 10). is used to secure Ts to the 1/2" pvc conduit mast.
Not home depot:
There is a franchise called Metal Supermarket and another called Metal-Mart. Try to find a metal retail store. This makes all the difference in the world. No need to be straightening wire.
1 - 10' length of 1/8" Aluminum solid Rod (alloy T6061) or other alloy.
This is for the bent elements T6061 is nice because it doesn't corrode like other aluminum but it doesn't bend as easily as say T5052. You can bend the elements using something like the plywood and 2x4 in the photo. You'll have to do a couple of practice bends to figure out what you will have to do for layout marks and amount of material used in bend. A little black magic artistry is required to get the correct distances of element bends.
1 - 12' length or 1/4" Aluminum solid Rod (T6061). This is cut into the co-linear rod lengths. I used my table saw very carefully and got exactly the right lengths.
1 - scrap bit of plastic or polystyrene or something similar for spacer to hold elements apart and under machine screws. It should be 1/8" thick or a little less. About 4x6". I used 1/8" black styrene plastic that was in a dumpster.
TOOLS:
* Drill Press - almost mandatory. Handheld drill will give results that will work but not ideal
* Cordless Drill
* Drill bits - 1/16", 3/16", 1/4", 3/8", and others
* Olfa Razor knife
* Hacksaw
* Table Saw and the skill to cut aluminum. Not mandatory but real nice to cut co-linear rods.
* I used the Millimeter drawing so I had a good mm ruler. Millimeters was so much easier to work with for this project
* Bending Jig simple build (photo)
I laid out the measurements from the plans along the 1/2" PVC conduit and then used a tubing cutter (pipe cutter) to gently make a score mark at the layout locations. 8 marks for the co-linear rods. 3 for the T stand-off spacers. 2 more where the element bends would line up. You can see the score marks in the pictures.
I cut short lengths of the "faucet connector" tubing to use as spacers / holders of the co-linear rods. You'll have to do the math for the exact lengths. I inserted my co-linear rods 3/4" which I had carefully marked on the rods with the tubing cutter. The ID of the tubing is 1/4" so the rods themselves fight very tightly into the tubing. I even had to ream the 1/4" with a 1/4" drill bit to get the rods to go in. You need to file a slight bevel on the ends of the aluminum rods (just break the edge) so that the rods will slide in with a great deal of force. I then drilled 3/8" horizontal holes in the 1/2" pvc conduit at the proper locations. The plastic "faucet tube" fits perfectly into 3/8" holes. Pressure fit is sufficient from them to stay in place.
I made stand off Tee pieces to hold the 1/8" aluminum elements from 1" PVC conduit clamps/holders. I used a heat gun to heat the clamps until they were just pliable. I then pressed them down onto a flat surface and allowed them to cool. Cut off the ends (hacksaw) and you have perfect flat pieces. I drilled these and tapped them at the correct spacing for the elements. I laid my elements on a piece of paper at the correct spacing and used a pencil to mark where these holes need to go. I then transfered that measurement to the PVC strips. You don't need a tap. You can just use a steel machine screw to cut the threads into the plastic and replace with the nylon #10 machine screws.
I cut the 1/4" nylon bolt heads off and used cut lengths glued (epoxy?) into the end of the stand-off T 'faucet tube". I drilled a 1/4" hole in the center of the flattened conduit clamps and glued and the screwed a 1/4" nylon nut on the end. At first I thought that the PVC conduit and the "faucet tubes" were the same plastic and I would be able to use PVC glue. They are not and PVC glue doesn't work (wont stick to faucet tubing). I didn't try "model" glue or epoxy. I used "Gorilla" glue. I used #10 SS 1 1/4" bolt to hold the stand-off Tee securely in the 3/8" hole that I drilled in the PVC conduit. You can see in this in the pictures. Leave the tubes long and only trim to finished length (You'll have to slide them in and out to get your elements at the 100mm) once they are installed and secured with the bolt. I fabricated some spacers to go between the elements to keep the elements spread apart at the 44mm distance. They were slipping out from underneath the machine screws. So I used 1/8" thick black styrene plastic and a razor knife to fashion these spacers. They are just visible in some of the photos.
If this post is any good, perhaps Stampeder or someone else could scoop the photos from FLIKR and re-edit this post and insert them in. It's beyind me at the moment since I have no webspace to store them other than FLIKR. Thanks.
I'm unable to insert photos directly so here's a link to the photos on FLIKR. Open a second browser window to look at photos when reading my mash of information here.
http://www.flickr.com/photos/thistlehead/
MATERIALS:
I tried to get almost all materials at Home Depot.
1). 1 -10' section of 1/2" PVC electrical conduit
2). 2 - Plastic faucet plumbing tubes (labeled photo)
3). 3 - 1" PVC conduit clamps (photo)
4). 4 - #10 nylon machine screws
5). 2 - 1/4" -20 x 2 1/2" nylon screws (photo)
6). 3 - 1/4" - 20 nylon nuts
7). 2- #8 brass machine screws (photo)
8). 4 - #8 brass machine nuts
9). 8 - #8 brass machine washers
10). 3 - 3/16" - 1 1/4" SS machine screws and nuts
notes:
item 2). has an ID of 1/4" and an OD of 3/8" and is just perfect - you'll see why
item 3). are 1" conduit clamps that you will flatten and cut for T-supports for elements.
item 4). are used to screw elements to upper and lower T supports
item 5). are glued inside T tube and are used to secure item 3).
item 6). are used to screw onto item 5). and hold item 3).
item 8). and 9). are used to secure elements to middle T and affix 300-75 ohm balun
item 10). is used to secure Ts to the 1/2" pvc conduit mast.
Not home depot:
There is a franchise called Metal Supermarket and another called Metal-Mart. Try to find a metal retail store. This makes all the difference in the world. No need to be straightening wire.
1 - 10' length of 1/8" Aluminum solid Rod (alloy T6061) or other alloy.
This is for the bent elements T6061 is nice because it doesn't corrode like other aluminum but it doesn't bend as easily as say T5052. You can bend the elements using something like the plywood and 2x4 in the photo. You'll have to do a couple of practice bends to figure out what you will have to do for layout marks and amount of material used in bend. A little black magic artistry is required to get the correct distances of element bends.
1 - 12' length or 1/4" Aluminum solid Rod (T6061). This is cut into the co-linear rod lengths. I used my table saw very carefully and got exactly the right lengths.
1 - scrap bit of plastic or polystyrene or something similar for spacer to hold elements apart and under machine screws. It should be 1/8" thick or a little less. About 4x6". I used 1/8" black styrene plastic that was in a dumpster.
TOOLS:
* Drill Press - almost mandatory. Handheld drill will give results that will work but not ideal
* Cordless Drill
* Drill bits - 1/16", 3/16", 1/4", 3/8", and others
* Olfa Razor knife
* Hacksaw
* Table Saw and the skill to cut aluminum. Not mandatory but real nice to cut co-linear rods.
* I used the Millimeter drawing so I had a good mm ruler. Millimeters was so much easier to work with for this project
* Bending Jig simple build (photo)
I laid out the measurements from the plans along the 1/2" PVC conduit and then used a tubing cutter (pipe cutter) to gently make a score mark at the layout locations. 8 marks for the co-linear rods. 3 for the T stand-off spacers. 2 more where the element bends would line up. You can see the score marks in the pictures.
I cut short lengths of the "faucet connector" tubing to use as spacers / holders of the co-linear rods. You'll have to do the math for the exact lengths. I inserted my co-linear rods 3/4" which I had carefully marked on the rods with the tubing cutter. The ID of the tubing is 1/4" so the rods themselves fight very tightly into the tubing. I even had to ream the 1/4" with a 1/4" drill bit to get the rods to go in. You need to file a slight bevel on the ends of the aluminum rods (just break the edge) so that the rods will slide in with a great deal of force. I then drilled 3/8" horizontal holes in the 1/2" pvc conduit at the proper locations. The plastic "faucet tube" fits perfectly into 3/8" holes. Pressure fit is sufficient from them to stay in place.
I made stand off Tee pieces to hold the 1/8" aluminum elements from 1" PVC conduit clamps/holders. I used a heat gun to heat the clamps until they were just pliable. I then pressed them down onto a flat surface and allowed them to cool. Cut off the ends (hacksaw) and you have perfect flat pieces. I drilled these and tapped them at the correct spacing for the elements. I laid my elements on a piece of paper at the correct spacing and used a pencil to mark where these holes need to go. I then transfered that measurement to the PVC strips. You don't need a tap. You can just use a steel machine screw to cut the threads into the plastic and replace with the nylon #10 machine screws.
I cut the 1/4" nylon bolt heads off and used cut lengths glued (epoxy?) into the end of the stand-off T 'faucet tube". I drilled a 1/4" hole in the center of the flattened conduit clamps and glued and the screwed a 1/4" nylon nut on the end. At first I thought that the PVC conduit and the "faucet tubes" were the same plastic and I would be able to use PVC glue. They are not and PVC glue doesn't work (wont stick to faucet tubing). I didn't try "model" glue or epoxy. I used "Gorilla" glue. I used #10 SS 1 1/4" bolt to hold the stand-off Tee securely in the 3/8" hole that I drilled in the PVC conduit. You can see in this in the pictures. Leave the tubes long and only trim to finished length (You'll have to slide them in and out to get your elements at the 100mm) once they are installed and secured with the bolt. I fabricated some spacers to go between the elements to keep the elements spread apart at the 44mm distance. They were slipping out from underneath the machine screws. So I used 1/8" thick black styrene plastic and a razor knife to fashion these spacers. They are just visible in some of the photos.
If this post is any good, perhaps Stampeder or someone else could scoop the photos from FLIKR and re-edit this post and insert them in. It's beyind me at the moment since I have no webspace to store them other than FLIKR. Thanks.
