2020 Chevy Silverado install

[ems55]

Cutting the end off was all that was needed.

GREAT !!! t
THANKS AGAIN !!!!!!!!!!!!!

 

[n0xvz]

MMckenna, that nipple you cut to get wires into passenger compartment, when you cut it does that opening go right in or do you need to cut something else on the inside of car?

As @mmckenna said, It does go straight into the passenger compartment. I used the same pass-through and had trouble getting the wires routed through. I finally found success using a wire hanger and angling it down and slightly to the passenger side. If I ever get a free moment, I'm going to do a write up too.

 

[mmckenna]

I finally found success using a wire hanger and angling it down and slightly to the passenger side.

Yes, that would certainly help. I think I ran that through and used an inspection camera with the flexible pipe with a hook on the end. I can just scope up there and grab the wire. Great labor saving tool.

 

[K7HUT]

A bore cam (used with rifles) on a coat hanger would have been a great idea for me too, but I ended up taking down one side and the rear of my headliner, which first had the pre-requisite of taking off C pillar trim, which had it's pre-requisite effects of other trim removal.

To an earlier inquiry the NMO mount I used was a Laird NMO LL195 part number NMOHPCNUHFM518. Definitely I felt my hole saw traveled a smidge out of round and made the hole bigger than theoretically intended by the NMO design. I wonder if one of the actual NMO hole saw drills would have performed better than the Bosch drill I used. Quite possible. If I get motivated, I will pull that Laird assembly out and go with a Breedlove mount which seems the size of hockey puck almost, and ain't gonna come out easily at all.

That being said, the new NMO roof triband Larsen antenna I replaced the 2/70sh Larsen with is significantly more flexible, a tad shorter, and makes much less noise when it catches and flicks under my garage door every day. So the slightly out of spec NMO hole is not being stressed nearly as much as before.

 

[mmckenna]

A bore cam (used with rifles) on a coat hanger would have been a great idea for me too, but I ended up taking down one side and the rear of my headliner, which first had the pre-requisite of taking off C pillar trim, which had it's pre-requisite effects of other trim removal.

Harbor Freight sells an inexpensive bore camera. I've seen it on sale for $50 or so.
There are companies that sell some that will interface with your smart phone.
For most hobbyists, those are sufficient.

To an earlier inquiry the NMO mount I used was a Laird NMO LL195 part number NMOHPCNUHFM518. Definitely I felt my hole saw traveled a smidge out of round and made the hole bigger than theoretically intended by the NMO design. I wonder if one of the actual NMO hole saw drills would have performed better than the Bosch drill I used. Quite possible. If I get motivated, I will pull that Laird assembly out and go with a Breedlove mount which seems the size of hockey puck almost, and ain't gonna come out easily at all.

The hole saws sold at hardware stores are usually designed for wood. Yeah, they'll work on thin sheet metal. I think the very first NMO install I did was with one of those. The thicker kerf of the blade usually creates issues.
If you get one of the NMO hole saws, like the ones sold by Laird, they have a much thinner blade and kerf. They have a finer tooth saw, also. They tend to do a really good job.

I was in a jam once and did pick up a 3/4" hole saw at Home Depot. It was one specifically designed for drilling thin metal and had the fine tooth saw and thin kerf. I've used it a few times and it's been fine. But my preference is my Laird hole saw. It consistently does a good job.

Other option, if you want to go nuts, is get a 0.750" chassis punch. You can get them from places like McMaster-Carr and they do a really nice job. You do need access to both sides of the sheet metal, and you do have to drill something like a 3/8 pilot hole, but they make a perfectly round 0.750" hole. I have one that I occasionally use. At the time I purchased it, it was cheaper than the Laird unit and fit my needs. A good option to have in your tool box if you do a lot of these.

 

[KK6ZTE]

EDIT: I'm a moron and didn't read properly. Sorry.

 

[K7HUT]

@mmckenna Indeed this Bosch bit is for sheet metal, BUT the kerf/teeth are wide and the way the teeth are oriented and arranged I feel almost ensures a bit of run out. Yes, I was being cheap, and didn't want to pay 3x for the price of the Laird bit (like $45 iirc) just to drill one darn hole. I practiced on a piece of sheet metal before the actual truck ceiling and I had a bit of the same runout, but felt I could hold the drill better, and also I didn't quite st down to examine the NMO mount to see what would surfaces would mate in the mounting sequence. I didn't realize the different that a slightly large hole would make to the strength of the mount. I contemplated the chassis punch for all my efforts, I could NOT get the headliner all the way down, due to the rear overhead light plastic fixture not pulling down and free from it's receptacle fitting in the ceiling. Nor could I actually press it back in all the way ... it's sort of 1/3rd the way down right now, yet it looks OK with the way the Chevy headliner works. Thank goodness.

Anyway, yes, excellent advice. Always always get the right tool for the job. Especially when it comes to putting holes in a perfectly good truck ceiling.

 

[mmckenna]

I have no idea why Laird charges so dang much for their hole saws.
Replacement saw blades are also expensive. I think it's like $50 for two. I guess it's a niche tool and they can get away with it. For hobbyists, it's an expensive investment. For professional installers, it's a no-brainer.

I have seen Ripley brand antenna hole saws a bit cheaper, but they are harder to find. Every now and then they'll show up on e-Bay, often with a larger 1 1/8 or 1 1/4 saw for doing the old ball mounts. I think it was a Motorola kit.

 

[ems55]

As @mmckenna said, It does go straight into the passenger compartment. I used the same pass-through and had trouble getting the wires routed through. I finally found success using a wire hanger and angling it down and slightly to the passenger side. If I ever get a free moment, I'm going to do a write up too.

Thank you, Sir !!!!!

 

[K7HUT]

You can be sure I will get a true NMO hole saw for the next install.

Also a Breedlove 'NMO' mount: https://breedlovemounts.com/store/ols/products/nmo-roof-mount

 

[03msc]

the new NMO roof triband Larsen antenna I replaced the 2/70sh Larsen with is significantly more flexible, a tad shorter, and makes much less noise when it catches and flicks under my garage door every day.

Which Larsen did you go with?

 

[mmckenna]

Which Larsen did you go with?

I'd like to know, too.

I was placing a Tessco order and noticed that Larsen has a couple of new tri-band designs based off their latest model. Two of them had a higher flexibility whip. I ordered one of each to give them a try. Unfortunately won't be shipped until May, if our purchasing department doesn't totally $#^#it up.

 

[03msc]

I'd like to know, too.

I was placing a Tessco order and noticed that Larsen has a couple of new tri-band designs based off their latest model. Two of them had a higher flexibility whip. I ordered one of each to give them a try. Unfortunately won't be shipped until May, if our purchasing department doesn't totally $#^#it up.

Nice. I'll go check them out. I was thinking he meant the 'old standard' 150/450/850 tri-bander but was going to point out it's tuned for pub safety/commercial and not ham...of course, maybe he's using it for pub safety/commercial, I don't know...

 

[K7HUT]

I settled on this antenna:
NMO150/450/758SF Tri-Band Antenna For Motorola APX8500 & Harris Unity XG-100M (AN000131A0, 12099-0330-01, SKFN-TB-V/U/C-EAN-SP)

Yes it is a one of those tribanders for public safety ostensibly. Not for ham. But I tx/rx 140/440 bands and receive at GMRS 460-470 no problem.
I have tuned in a 147.120 repeater from Yuma while I was in Scottsdale AZ, maybe about 200 miles away, while i am in one particular higher spot in Scottsdale.

Anyway, it was recommended to me for ham radio operation, and I think it's at least as good as the Larsen 2/70sh for reaching my repeaters that I have experience with. It's not quite as good as my Comet 2x4srnmo for receiving GMRS, close but not as good. That Comet is hard to beat on all bands from what I have experienced, but it's a big long heavy beast. This tribander also tunes in the 120MHz band for aircraft tower traffic as good as the 2/70sh.

It's $59 this tribander, and in stock at arcantenna from what i saw pulling up my order.

As the description says, this new tribander is quite flexible, and goes under my raised garage door much easier than myu 2/70sh did, the latter which would 'twang' hard as it went under, and I could see the NMO hole metal flexing on the top of the truck.

 

[03msc]

Awesome, that's good to hear. I haven't ever put my Larsen 150/450/850 (the older one without a spring) on my antenna analyzer to see what it shows for ham bands; it may be better than I assumed. Of course, it's not that far out of range with 2m ham frequencies (repeaters up around 147MHz and it's 150 so that's close) so it's probably doing a respectable job. Obviously it's working for what you need it for. I may have to check into it...just what I need, another antenna...thanks a lot! haha Looks nice though!

EDIT: Is the whip black or stainless or what? I can't tell from the pics I've seen online...

 

[K7HUT]

Here is my pic, and it is darker than the shiny whip of the 2.70sh. This new triband doesn't impress me as perfectly matte black color... seems somewhere in between almost. Honestly I have to take another look at it and see if I can say what color it is.

note: the 2/70sh is the one towards the front of the vehicle and is not on the NMO mount, but just standing there for comparison.

 

[wa8pyr]

BlueSea Maxi-Fuse mount:


More to follow.

Do you have any issues with water infiltration on that fuse holder, or does it have a water-resistant cover?

 

[03msc]

Here is my pic, and it is darker than the shiny whip of the 2.70sh. This new triband doesn't impress me as perfectly matte black color... seems somewhere in between almost. Honestly I have to take another look at it and see if I can say what color it is.

note: the 2/70sh is the one towards the front of the vehicle and is not on the NMO mount, but just standing there for comparison.

View attachment 100591

Thanks. Almost has a dark silver tint to it, it seems.

 

[mmckenna]

Do you have any issues with water infiltration on that fuse holder, or does it have a water-resistant cover?

I'd have to check. Not my truck, it's my brother in law's. When I was helping him do the install, we looked at all the locations, and that was the one he chose. I do have the 'snow plow' fuse kit, so I may end up relocating it at some point for him. But so far, no issues that he's reported.

 

[03msc]

I'd like to know, too.

I was placing a Tessco order and noticed that Larsen has a couple of new tri-band designs based off their latest model. Two of them had a higher flexibility whip. I ordered one of each to give them a try. Unfortunately won't be shipped until May, if our purchasing department doesn't totally $#^#it up.

Matt when you get those in I'd like to see a SWR curve for like 146, 147MHz or so just out of curiosity if possible.