[300ohm]

It has been a month or so since my last post. So far no replies

Oops, sorry about that. I must have skipped over it somehow. Yes, I built a SBGH 10 with the curved mesh reflector. I works fine, but its large, heh. A DBGH GH curved mesh reflector would be a monster.

I have eighth inch copper rod to cut and braze for the array. I wonder if that is OK.

Yes, that would be great but pricey. For curtain quads, you may want to consider using galvanized fence wire, sold in the fence dept at Home Depot or Lowes. The gain is only going to be a bit less, but its cheaper and stronger than copper.
Since you have brazing equipment, give the curtain quad a shot.

I've tried to figure out the nec modelling software but that has been a little of a challenge so far. If anyone could tell me the dimensions of the quad array and the details of the elements where the balun attaches I would be most appreciative.

For getting the dimensions, just follow my easy directions here :
http://www.digitalhome.ca/forum/showthread.php?t=107457

The balun connection point is where the wire with the red ball on it is at. (that wire is not a real physical wire. Its a source wire for modeling purposes)

 

[300ohm]

Yes, thats good antenna material too. But unless you have specialized heliarc welding equipment, you cant braze it together for a curtain quad.
I think it would be too thin for use with the alumi-rod stuff.

 

[300ohm]

I found some fencing wire but it was awful thin. If well supported can aluminum be soldered?

I think the fencing wire you were looking at in Tractor Supply was for electrical fencing, which now a days, is pretty thin. The 9 gauge stuff I was talking about is sold at Lowes and Home Depot, and is used with chain link fencing.

Aluminum can be brazed using the alumarod type stuff.
http://www.aluminumrepair.com/aluminum_repair.asp
Its also sold at Harbor freight in small pricey packets.
The trouble is, with 8 gauge wire, it may puddle and melt before you can attach a piece to it, making the job very tricky to do. Aluminum doesnt have a large temperature bandwidth to work with. One minute its solid and with more heat, it just colapses. Try putting the mapp gas on an empty beer can to see what I mean, heh.

I think the 9 gauge fencing wire with regular cheaper brazing rod would be the cheapest way to go for a curtain quad. I believe the 9 gauge fencing wire at Home Depot is less than $20 for a 170 ft coil of it.

But if youre building the 13 element curtain quad, and already have the copper rod, then go ahead and use it. (I just personally would save the copper for the GHs as copper is back up to around the $4 / lb range http://www.metalprices.com/ )

 

[300ohm]

Standard 5/8" dowels fit inside very snugly.

Putting some polyurethane construction glue in the pipe before inserting the dowels will snug it up even more as the polyurethane construction glue expands as it dries. Woodworking polyurethane glue does that too, but costs more than the construction stuff.
Polyurethane glue sticks to pretty much anything, as Ive used it to repair my sport type shoes at the rubber to leather contact points, heh.

My plan is to drill a tiny hole in the tension wire at the junctions and tie and wrap them with short lengths of thin fencing wire prior to brazing

Sounds good.

If I have time this weekend I may learn how to run the optimizer.

Before doing that, it would be worthwhile to you to explore all the great features of Geometry Edit and the Build feature, ie build and copy and paste and rotate and rescaleing and resegmentation etc of wires. Its a very powerful tool for free hand design of any antenna that you could think of, given the NEC2 engine limitations, which in designing a practical vhf/uhf antenna, arent limitations at all, heh.

 

[300ohm]

It would probably help if I could find a tilting rotor to install it on since angling my 91xg did improve reception considerably.

The curtain quad does have a much narrower beamwidth than a 4 bay, so aiming it properly is much trickier.