I am trying to build an optimum reflector using mesh that I can use for either a GH or Bowtie style by changing the elements out.

Interesting idea for a testing platform, but ya, I think you'll find that mclapp's reflector specifications are the only ones to use with an M4 and that the GH ones are equally specialized in 300ohms' and other peoples' designs.

I am going to try something similar to 300ohm's curved mesh reflector for both the GH10 and M4 (and perhaps M8):

http://www.digitalhome.ca/forum/showpost.php?p=782100&postcount=52

I am going to try something similar to 300ohm's curved mesh reflector for both the GH10 and M4 (and perhaps M8):
Yeah, that should work well for the M4 too, but dont cut the 1 inch gap in it for the M4. (a little bit larger than needed, and a bit too small for the M8) Sweep the whiskers a bit forward to match the reflector sweep. For the GH10, follow the element directions for Autofils GH10 gen2 and not JEDs GH10 rev2. (confusing I know, heh)

Thanks. That would have been my next question. Yes, all the versions are quite confusing.

Here's another question................if I make GH10 curved mesh style reflector long enough to turn it into an M8, will that screw up everything if I have the GH element on it?

if I make GH10 curved mesh style reflector long enough to turn it into an M8, will that screw up everything if I have the GH element on it?
No, it may even give it a hair more gain. I stopped at 4' X 4' because of practical size considerations. (a DBGH curved mesh would be 8 ft tall as is) Finding the 2 X 4 inch (or any) mesh running the 2 inch high way may be a problem for you now a days, but I know it did come in at least 6 ft high sizes.

Thanks. It looks like a dual purpose reflector will work decently for the SBGH10 and the M8.

This is the element I need for the SBGH10 curved mesh model correct?

http://www.asmordean.com/Gen2SBGH-GH10-Plans.pdf

Yep, thats the one. Much prettier than my orig drawings, heh.

I found some 1" x 2" welded galvanized mesh that is 14 gauge. Is 14 gauge thick enough for the reflector?

Better than 16 ga stuff, heh.

They also have .097" and .128"

Which would be best for gain or would it matter?

They also have .097" and .128"

Gain wise, not much at all, thicker would have a bit more gain, measured in 10ths of a dbi. And the thicker.128" (8gauge) is easier to keep straight.

Thanks. The thicker stuff comes 2 x 1 so I'd have to use two pcs. to get the most wires horizontally. I think I'll stick with the .063 stuff and make it one piece. Its quite a bit lighter anyway.

I plan to add two or three galvanized steel cross members approx. 3/32" thick x 1" wide behind the mesh, similar to the old CM4228.

I don't have to worry about funky gain effects when they are behind the reflector correct?

I don't have to worry about funky gain effects when they are behind the reflector correct?
That will be fine.

I have finally assembled the 300ohm SBGH GH10 curved mesh configuration.

The plans call for a 2" feed gap, but I have read here wider is better. Should I leave it at 2"?

Holy smokes ! Someone besides me built my curved mesh model ? ?

On the SBGH GH10 curved mesh model, 2 inches is best. You do realize it drops off after channel 42, but you do get better gain on the low channels. Ive confirmed that in real life testing. :)

Yes, I built it. :D Well, I changed the structure design, but the dimensions are all the same.

I'll post pics soon.

I made it so I can change back and forth from the GH10 to the M4 fairly easily.

Yeah, the curved mesh reflector will work well with an m4 too. Just sweep the bowties forward to match the sweep of the reflector.

Bending the plastic pipe was pretty easy once you get the hang of it, wasnt it ?

I think a lot of people are intimidated by it.

I actually think I could make a frame for a 10ft parabolic using the same technique, but would have no place to mount the monster, heh.

I used 1/2" EMT for the cross braces and 3/4" EMT for the spine.

Pics here:

http://www.digitalhome.ca/forum/album.php?albumid=211&pictureid=1445

http://www.digitalhome.ca/forum/album.php?albumid=211&pictureid=1446

http://www.digitalhome.ca/forum/album.php?albumid=211&pictureid=1444

http://www.digitalhome.ca/forum/album.php?albumid=211&pictureid=1449

The elements are 1/4" copper tubing which I will change to 6AWG solid. (I am not happy with the elements).

I bent the 1/2" EMT in a vice and used a template to check the shape. They are held onto the spine with U bolts.

The mesh is 1" X 2" galvanized 48" wide by 60" tall and is held by the U-bolts to the spine. I will also add some #8 x 1/2" zinc plated truss head screws to further secure the mesh to the cross braces instead of the temporary cable ties.

The same #8 screws secure the Tees to the EMT.

I drilled through the element and tee and mounted the balun with brass 4-40 machine screws, nuts and lock washers.

I can remove the Tees on the cross braces and add three to the spine to allow mounting the M4 elements.

Oh, you used metal EMT for the back curve, thats fine too, but isnt it a loose fit in the tee ?

With the 1 X 2 inch mesh, your high channel performance will be about a db better, while low channels, maybe .3 db. (wind and ice load, maybe 3 times as much as 2 X 4 inch mesh, so your mounting strength will have to compensate)