Dual-purpose reflector for modular M4/GH driven element swapping? - Canadian TV, Computing and Home Theatre Forums

peano · 2009-07-06, 12:36 PM

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.

stampeder · 2009-07-06, 12:42 PM

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.

peano · 2009-07-06, 01:27 PM

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/show...0&postcount=52

300ohm · 2009-07-06, 02:03 PM

Quote:

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)

peano · 2009-07-06, 05:08 PM

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?

300ohm · 2009-07-06, 05:22 PM

Quote:

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.

peano · 2009-07-06, 06:02 PM

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

300ohm · 2009-07-06, 06:05 PM

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

peano · 2009-07-07, 09:49 AM

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

300ohm · 2009-07-07, 09:52 AM

Better than 16 ga stuff, heh.

peano · 2009-07-07, 10:11 AM

They also have .097" and .128"

Which would be best for gain or would it matter?

300ohm · 2009-07-07, 01:47 PM

Quote:

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.

peano · 2009-07-07, 07:05 PM

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?

300ohm · 2009-07-07, 07:20 PM

Quote:

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

That will be fine.

peano · 2009-09-01, 12:44 PM

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"?

2009-07-06, 12:36 PM	#1
peano Veteran Join Date: Dec 2002 Posts: 3,586	Dual-purpose reflector for modular M4/GH driven element swapping? 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.

2009-07-06, 06:05 PM	#8
300ohm Veteran Join Date: Mar 2008 Location: Somewhere in Delaware on the flat side Posts: 7,011	Yep, thats the one. Much prettier than my orig drawings, heh. __________________ My builds/plans (not the latest models) are located here.

2009-07-07, 09:52 AM	#10
300ohm Veteran Join Date: Mar 2008 Location: Somewhere in Delaware on the flat side Posts: 7,011	Better than 16 ga stuff, heh. __________________ My builds/plans (not the latest models) are located here.

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2009-07-06, 12:42 PM	#2
stampeder OTA Forum Moderator Join Date: Jan 2005 Location: North Delta, BC (96Av x 116St) Posts: 23,338	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.

2009-07-06, 01:27 PM	#3
peano Veteran Join Date: Dec 2002 Posts: 3,586	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/show...0&postcount=52

2009-07-06, 05:08 PM	#5
peano Veteran Join Date: Dec 2002 Posts: 3,586	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?

2009-07-06, 06:02 PM	#7
peano Veteran Join Date: Dec 2002 Posts: 3,586	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

2009-07-07, 09:49 AM	#9
peano Veteran Join Date: Dec 2002 Posts: 3,586	I found some 1" x 2" welded galvanized mesh that is 14 gauge. Is 14 gauge thick enough for the reflector?

2009-07-07, 10:11 AM	#11
peano Veteran Join Date: Dec 2002 Posts: 3,586	They also have .097" and .128" Which would be best for gain or would it matter?

2009-07-07, 07:05 PM	#13
peano Veteran Join Date: Dec 2002 Posts: 3,586	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?

2009-09-01, 12:44 PM	#15
peano Veteran Join Date: Dec 2002 Posts: 3,586	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"?