Hole Through the Roof Advice Needed

[crock]

We decided to permanently mount a Sirio 5000 antenna to the roof of my Fiat 500 (thank you board members!). The metal roof is not reinforced very well, so it "oil cans" (remember actual cans of oil? ). What kind of roof mount do you recommend? I was thinking of using a 3 inch Breedlove. Maybe there is something better. Also, need to get a good hole saw to go with the mount. I have seen some nice ones in videos, but nobody talks about where they get them.The standard holes saws sold by Sears and hardware stores come with teeth too coarse for cutting thin painted & unsupported sheet metal. I know somebody is making a hole saw specifically for drilling antenna holes through car roofs and it looked pretty cool. I don't know who the manufacturer/seller is.

[sonoma]

harbor freight sells a kit for 25.00 does 1/2 to about 1 1/4 holes.I have one I use to use for making nice neat holes. just drill a small hole then put the punch together and tighten it up to punch out the metal.

[MDYoungblood]

What you are looking for and what sonoma is describing is a "Unibit", excellent for drill holes in sheetmetal. The Breedlove mount would be a good choice, it offers a little more support, but the Sirio mount is good as well. If you want to add a little some support to the mount an old cookie sheet (with the rim removed) cut to fit the area would work.

3's

Greg

[sonoma]

if you can not find it on their site I will try to post a link to it here if MDYoungblood will say it is OK to list it. its not a radio. maybe he will. let me know MDY

[MDYoungblood]

I don't think this is an item carried by any of the forum's sponsors so a link to it would be okay, if not another mod can remove it.

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I have used these (the store is a mile and a 1/2 from my house) but they dull rather fast, guess that is why they are so cheap, you can look online at "Unibits" and find them cheaper too.

3's

Greg

[sonoma]

here is the hole punch I was talking about. it makes a nice clean hole for the antenna or what ever you use it for.I have had this for years and it still works good. the only time I had a problem with it punching out a hole was on a 1960 ford 1/2 ton pickup. the metal was so thick it did not want to cut it out. cars these days do not have the thick metal like they did back in the 60's. hope this will work for you.

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[jessejamesdallas]

I don't think this is an item carried by any of the forum's sponsors so a link to it would be okay, if not another mod can remove it.

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I have used these (the store is a mile and a 1/2 from my house) but they dull rather fast, guess that is why they are so cheap, you can look online at "Unibits" and find them cheaper too.

3's

Greg

Those step-bit's from Harbor Freight is what I've used..."Don't buy them at Sears!" Cost ya 3x as much for the same thing...

Northern Tool also has them at a decent price.
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[crock]

Okay, so once I do this deed and drill the hole through the roof, what do I need to do to ground the antenna?

[sonoma]

normally the antenna bracket grounds on the inside of the body. just make sure to clean off the paint and elpo from inside the roof where the bracket will ground at. I would not scrape the paint off the outside since the bracket does not ground there and it will help keep the body from rusting under the mount. just clean the inside to bare metal. then verify with a ohm meter the mount grounds good after you install it. the car goes through a phosphate and elpo dip before it gets primer and painted so be sure to clean it off good.

[MDYoungblood]

here is the hole punch I was talking about. it makes a nice clean hole for the antenna or what ever you use it for.I have had this for years and it still works good. the only time I had a problem with it punching out a hole was on a 1960 ford 1/2 ton pickup. the metal was so thick it did not want to cut it out. cars these days do not have the thick metal like they did back in the 60's. hope this will work for you.

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Cool, never knew they sold them. I've had the Greenlee brand at work but the cost was extreme.
The Harbor Freight Unibits like I said dulled quickly but one thing they do is exchange them for a new set just once, (within a couple days of purchase and receipt).

3's

Greg

[sonoma]

I bought mine from them a few years ago and it works just fine. the only time I was worried about it breaking was on the roof of my old 1960 ford pickup. they are not like the high dollar ones my buddy uses at his shop. but he paid over 100.00 for his. mine was about 20.00 when I bought it years ago. if a guy is not in a hurry wait until they have a 20% coupon and it will bring the price down about 5.00. I mainly bought this one to do a radio inside a aluminum case for truck drivers. it leaves a nice clean hole in the metal to install an antenna or antenna connector. they also sell a nice one .

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[crock]

Breedlove is offering their three inch puck in everal configurations.

First, I am looking for minimum clearance between the puck and the interior headliner under the roof. Does this mean that I should go with a ring terminal mount? If yes, then what kins of coax connector do I use?

Second, will the Sirio 5000 antenna screw into the flat 3 inch puck on top of the roof, or do I need to order the extra 3 inch standoff? I am assuming I do not need a standoff.

Third, what kind of coax cable is best for these mobil installations? I think a coax that resists pinching would be the best for car installations. What type of coax cable would that be? I will only be running 100-200 watts with my final installation. Is there a specific coax manufacturer or brand i should ask for?

Fourth, I would like to use a crimp style coax cable. Any recommendations for a quality crimp connector and crimp tool?