Any ideas on temporary mast to attach to satellite j mount?

I

IDRick

DTVUSA Member
#1
#1
Spring has arrived and it's time to get ready for some antenna testing on my roof. I was given a used satellite j-mount and plan to purchase a non-penetrating roof mount as the base (j-mount attaches directly to it). I would like to attach a 5 ft tall mast to the j-mount. The internal diameter of the j-mount is 1-9/16 inches. Can I buy a swagged antenna mast that will fit in the j-mount? Will 1-1/2" EMT fit inside the j-mount? Other ideas? Please note, this is for temporary use only, not a permanent mount.

Thanks!

Rick
 
T

Tower Guy

DTVUSA Member
#3
#3
IDRick said:
to it). I would like to attach a 5 ft tall mast to the j-mount. The internal diameter of the j-mount is 1-9/16 inches. Will 1-1/2" EMT fit inside the j-mount?
Click to expand...
1 1/4" EMT is rated for an OD of 1.510.

Calpico - Pipe Linx Sizing Chart

It's the closest available pipe size for what you want to do. You would have .0525" of clearance. To clamp the two pipes together without slipping, slit the J-mount with a hacksaw and use one or two muffler clamps.
 
SWHouston

SWHouston

Moderator
Staff member
#5
#5
Rick,

The 1.5 EMT certainly will fit inside the J-Mount, but not the Swaged end, the straight end will. So, you could just use a plane piece of EMT, and not have to go to the expense of buying one with a Swage. I don't think the Swage part of the EMT will fit over the J, unless you heat it and get it to relax a little. The OD's of the J and ID of the Swage of the EMT will be almost identical.

If you put the EMT inside the J...
And found that to be a little too loose, you could drill the J and use a couple or three Sheet Metal Screws like Set Screws to tighten the EMT up inside it.

Some of those J's are pretty tall, nearly 40", if yours is tall like that, you sure you can't get it on the peak of your roof, and not use the EMT?

Thought about putting it (EMT) on your Chimney (if you have one). I've used a couple pieces of Rope, with twist type turnbuckle/tensioners. That was really shabby, but it was temporary like you say now. Just thinking out loud here.

Hope this helps, and UOO it feels good to turn some help like you've given me around, and hand it back in some modest way. Thank YOU !

Have a good Day ! :)
S.W.
 
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I

IDRick

DTVUSA Member
#6
#6
Great idea, S.W.! Using the same priniciple as a christmas tree stand. I like it! :) My j-mount is only 18 inches tall. Based on previous testing, I need to have the bottom of the 4-bay antenna at least 3 feet above the ridge. It's easy to accomplish this with a tripod mount at the ridge but I'm not sure how to set it up for a portable/temporary mount. Any thoughts?

Best,

Rick
 
SWHouston

SWHouston

Moderator
Staff member
#7
#7
Tripod Roof Mount - Temporary Mounting

Rick,

Okaaa..... If I understand that right...
Use a Tripod but make it portable, right !

Use a couple pieces of Plyboard.
Straddle the Roofline (peak), and mount the Tripod on them.
One post on one board, the other two on the other board.
Might run a couple straps across from one board to the other to keep distance right.
Just set it on the roof and it should adjust it's self to the pitch.
If your boards are big enough, you may not need any "mounting" down to the roof, it may just sit there and deal with a little wind for you.

This what you meant ?





Have a good Day ! :)
S.W.

PS:
Don't get too tight on the Tripod to Board bolts. Let um kinda float where the Boards will lay flat.
Might put a couple Sand Bags or Bricks on the Boards, to add weight to the assy.
Might add a couple pieces of old Carpet UNDER the Boards, to add traction to the assy. Tack um to the underside of the Boards.
I'm thinking that the Boards need to be a mimimum of 24" x 36", but then, they don't really have to be the same size ! ;)
 

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I

IDRick

DTVUSA Member
#8
#8
Nice drawing! Excellent discussion and great food for thought! I have some carpet samples that would work very well for this application and a spare piece of 3/8 plywood (40" x 40"). I'll give it a go! :) Thanks SW!
 
SWHouston

SWHouston

Moderator
Staff member
#9
#9
Rick,

I am VERY pleased to be able to help you out !
You get this done, and Don and I will sign your Shadetree Mechanic's Permit. :D

Have a good Day ! :)
S.W.
 
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