[elmsley]

Hi everyone, I should have read more about this antenna class before. This site is very informative!

I built a db-4 antenna, then db-8 antenna using the coat-hanger design on some 2x4s. Although I don't get any better reception on the upper floor with the db-8 design (compared to the db-4) I surfed around for more ideas. I read more about this fascinating SBGH antenna, and will try and build this before going to do the install up in the attic.

I'm confused by the design listed on this site and maybe someone can help with some basic questions. (I should note that I'm looking for inexpensive solution that will blow the db-8 out of the water). I am also very new to all this physics talk, and I still can't understand a lot of it.. (Yes, I have an undergrad degree, but not in tinkering).

2) It looks like I need 3 meters of copper wire, will any do (eg. solid, thickness) or do I need a specific type?
3) I see some designs use some pvc tubing as a mast. Does wood not work well (eg. would reusing my 2x4 be a good idea?)
4) Some designs use a mesh screen, some have the 12 rods. Does a screen cover all my basis and I can do away with the rods?
5) The reflector rods, can it be just 6 rods, or do they have to be cut to be in pairs?
6) Does the plane distance from the front wiring to the back rods make a difference? (I see some people use 3/8 PVC, so I guess the distance is at least that far).

 

[jflarin]

2) It looks like I need 3 meters of copper wire, will any do (eg. solid, thickness) or do I need a specific type?

solid is required. I used 10awg the largest available in canada. 6awg is more rigid. but it is all ok. The result might not be exactly as predicted by the computer model, but real life result are always imperfect anyways.

3) I see some designs use some pvc tubing as a mast. Does wood not work well (eg. would reusing my 2x4 be a good idea?)

wood absorbs water and rot if put outside. wet wood conducts electricity=bad. I use wood but keep my antenna in the attic.

4) Some designs use a mesh screen, some have the 12 rods. Does a screen cover all my basis and I can do away with the rods?

search for sbgh10 gen2 plans.

5) The reflector rods, can it be just 6 rods, or do they have to be cut to be in pairs?

must be cut in 10 pairs for the gh10, 8 pairs for gh8, 6 pairs for gh6. gh10 has more gain.

6) Does the plane distance from the front wiring to the back rods make a difference? (I see some people use 3/8 PVC, so I guess the distance is at least that far).

the closer you are to the model, more your result will be like the optimized model. Do you need all the gain offered by the gh10? Only you can figure it out, but it's best to follow plan.

jf

 

[ScaryBob]

I should note that I'm looking for inexpensive solution that will blow the db-8 out of the water

The cost mainly depends on materials. #14 copper wire will work for an attic build and wood is Ok as long as it doesn't get wet. Using heavier copper and PVC will provide resistance to the elements for an outdoor placement but can increase costs significantly.

The SBGH is a good design but it won't do that, though it might improve on the current builds. Each antenna has it's strengths and each may perform better on some channels. If there are problem channels, try varying the design with different size elements or reflector parameters to increase performance on those channel. For a significant improvement in performance, placing the antenna above the roof is the best bet. For a dramatic improvement in performance, a tower, large yagi and rotor may be necessary.

 

[stampeder]

elmsley, comparing apples to apples is the first step: an SBGH and an M4 (4-bay) are quite close in performance, and both will easily trounce your utube 4-bay. Take a look at the many versions of each and pick the one that suits your requirements best.

It sounds like you want to roll out the big gun, though. Since you've build a utube 8-bay you would want to look at the DBGH as a replacement that will show the big performance breakthrough that you desire.

My suggestion is that you read through the reception thread covering Markham to see what others around you are successfully using (lots of happy CM4221HD 4-bay users there) and then base your DIY plans on that:

ON - Vaughan/Richmond Hill//Markham/North of 407 - OTA