Got a new truck

[KG4LHQ]

Well new to me...

Picked up an 07 Chevrolet Silverado LTZ 4x4 and I want to drill the NMO hole but am scared to death in me doing it fearing I'll mess something up.

Anyone reputable around Louisville, KY that does this like tying their shoes every morning?

Thanks!

[d119]

Just drop the headliner, use a proper hole saw and make sure of where you're cutting. You'll be fine! Sure beats paying someone to do it... Otherwise, any reputable MSS should be able to perform that service.

[KG4LHQ]

I really have no problem paying a shop to do it since I know they screw it up its their baby.

I screw it up its my baby.

Whats the going rate for that kind of job.

[giguchan]

Drop the headliner and drill a pilot hole , then drop $25-30 and get a greenlee hole punch(since you will have the liner down anyway) you will have it forever and after your done you might be inclined to mount more antennas.I was the same as you are very nervous. after you get the Hole punch you can practice on a thin piece of cardboard or even a couple sheets of paper to see how it works. Gone are the days of jagged holes. here is how i did mine.. yes the VHF was a little off center.
well maybe for somepeople.
Good Luck

http://s872.photobucket.com/albums/ab28 ... 2QQtppZZ16

[FireCpt809]

Since your a Ham ask around on the local repeaters. Im sure someone knows how to or has a contact. Over all its not that hard to do. It looks intimidating.

[giguchan]

Thats a great idea.. I'll bet it would take longer to Drop the Liner than it would to mount the Antenna. I dont want to scare you, but if you have ANY plans to install more Radios NOW is the time to do it- while the Liner is down.
the very best of luck.. when it's done Snap up a few Pictures.

[Motoboy]

I work for a MSS, so this type of thing is like "tying my shoes in the morning", but I can offer some tips because it was only a few years ago that I was worried about something becoming "my baby". I would drop $25-$30 on an antenna holesaw that cuts very shallow-ly, and doesn't require you to drop the headliner. The Ripley HSK19 works as well as the MOT version. Just be sure you know what you are drilling into... Take the weatherstrip loose and look under with a flashlight, worst case scenario you will need to remove one of the visors (2-3 screws, no problem. If they aren't Phillips heads, they are Torx T-20) and the trim on the A-pillar (either just snap off with spring clips, or have an access panel you can gently pry off to access the 7, 8 or 10mm head screw underneath).

This truck, if I am thinking correctly, has a dome / reading light in the headliner up front. This can be removed taking the cover off the reading lights, and there are two screws underneath. Take them out, and pull to overcome the two spring clips. There is a space above this area where I usually mount the antenna. Behind this space is a channel that runs up the center of the roof to a beam that runs between the two B-Pillars. If you don't want the antenna that far forward, I would recommend going behind the B-pillars since (double check to be sure) that area is void of support structures until you get close to the rear window.

Also, if you are looking at getting through the firewall with your power cable, under the driver's side of the dash (around where the clutch would be if they still made pickups with them) there is a penetration behind the fuse panel. The fuse panel hinges out to give easy access. There is not much room around the grommet, but you should be able to squeeze another wire or two in there. A good power connection point is in the fuse block under the hood. There are two auxiliary power studs there, but they require you to go out and get a J-case fuse to provide power to them; I usually use a regular ATC fuse holder outside the block, and terminate to the male spade in the fuse block inside the J-case socket.

The first one is the hardest! It gets easier when you've done a few hundred of them. After you get comfortable on your own vehicle, you can volunteer your services to some of the Elmers out there that still have mag mounts!

[giguchan]

Moto,
Great post.! I had not thought of a lot of the things you said.When i installed my Frailblazer I tried and tried to find a way to get under the hood from the inside, but i could not. I had to use the Power source under the middle seat. I was told that this might not be a good diea, but it does work and i have not had any issues with the OBC. The next Vehicle i am due to receive is a Jeep Laredo. I have already had a look inside... I t does not look pretty. You are right though.. the First one is always the hardest!

[KG4LHQ]

Finished Product.

[tvsjr]

Have you swept that antenna? The lack of ground plane isn't going to be very kind to it - unfortunately, you're somewhat limited thanks to the sunroof.

[KG4LHQ]

Explain?

[tvsjr]

Explain?

A quarter-wave VHF antenna requires a ground plane to perform up to spec - basically, some nice flat roof underneath. Typically, the radius of the groundplane should be equal or longer than the length of the antenna. Lack of a proper groundplane can cause the antenna to exhibit some directionality, to provide less than expected gain, or to be detuned a bit. When compromising on ground plane, it's always a good idea to sweep the antenna with your favorite antenna analyzer just to see what's going on.

Your other option would be to look at a no-ground-plane antenna - like a 5/8-wave VHF. Although that may well be too long for you.

I'm not saying it's horribly bad - I have VHF antennas on my vehicle which are close to the rear edge of the topper and don't have the necessary ground plane... but it's a good idea to sweep the antenna to know for certain what's going on.

[giguchan]

Hey Great Job!!! it looks near Perfect.
I was going to mention the same thing about the ground plane as TVSJR SAID... but being so slow on te Keyboard he beat me to it. I know a lot of installs kinda go that way, this way you you have to Fuss with the headliner- to me that is an automatic. If i install the roof the HL comes with it fullstop.

TVSJR said it best... find someone with test set and see what you have.. if results are not Favorable... perhaps use a 5/8 wave but i dont because they for me are a bit too long...

But either way the job of mounting looks great! love the matching color too!
Great Job!

[KG4LHQ]

1:1 SWR @ 150mhz
1.1:1 @ 155mhz
1.2 @ 160 mhz
On a MFJ-259 Analyzer...

[Bill_G]

That's not bad. If you notice directionality, or odd vswr on specific freqs, wrap a quarter wave of rg-58 around your hand twice to make a balun. Tape it together so it makes a three inch circle with the coils parallel. Don't overlap them. Bury it in the headliner.

[KG4LHQ]

Can I ask the purpose of that?

Also I swept all the way from 146 to 160 on the analyzer and SWR was consistant with the frequencies with no odd SWR on certain freqs.

[giguchan]

Those are some pretty good numbers! nice going !

[Bill_G]

Can I ask the purpose of that?

Also I swept all the way from 146 to 160 on the analyzer and SWR was consistant with the frequencies with no odd SWR on certain freqs.

Flattens out antenna performance especially when you have insufficient ground plane. If you do not notice any degradation, then it's not necessary. Something to remember if you ever use a quarter wave on a TMB or a half wave in open air.

[giguchan]

Bil,
Thanks for the lesson.... that IS something for me to keep in mind too.. the next truck i will or will not be punching a hole through will be a Jeep grand laredo... no cabin room... for radios plenty of roof space but an install will be a night nare. i have seen some of the local govt using them i'll have to sneek a peek and see how they are being done.

[SlimBob]

Looks good. Very nice location, away from other antennas. I'm sure there's enough groundplane under the antenna to avoid issues.

[jhooten]

Been using the rear of the roof on trucks for going on 40 years without a problem. The channel in that area makes it so easy to slide the cable to either side pillar then drop down all the way to the floor of the cab without having to remove the head liner or trim. No directionality problems. No matching problems.

BTW, if there is a light bar across the middle of the cab it makes it a little harder to put the antennas above the dome light.

[giguchan]

I dont think it was the issue of Mounting the Antenna on the roof. It's pretty Practical really- best place as far as i am concerned. I think the issue was where on the roof it was mounted.. in regards to Groundplane and Proximity to other Antennas.