From deep within the dark recesses of the darkside...I am installing a stereo head unit with NAV capability. Instructions call for mounting the GPS antenna on the dash below the windshield where it has a good "look" at the sky. On most new vehicles this is easily achieved since most new windshields have one helluva slant on them. Our trucks have almost none so mounting a GPS on the dash is worthless. That said, there is plenty of real estate on the cowl vent AND it has an unobstructed view of the sky...I just can't bring myself to mount that black cube there (and they are not waterproof).
This brings me to my next point...why not mount it UNDER the cowl vent??? Well the cowl vent is metal so that is a pretty good "why not" but what if the vent cover were a non-metallic material, kinda like the radome on a satellite dish? Tomorrow I am off to the Ridout Plastics store to buy a sheet of some sort of fiberglass and test it out...not only can I fit the GPS antenna under the vent cover but also the cell and radio antennas. I got the idea watching videos of A/V systems installers mounting GPS antennas inside the dashes of new cars...if the satellite signal can pass through 8 inches of plastic, ducting, wiring, etc into the inner bowels of a new dash then surely it will work through a sheet of plexiglass.

 

one caution Charlie.... they do have to see the sky. Had a friend park his truck and 24' boat/trailer under a service station canopy, left the keys in the ignition and wife in passenger seat...car was running to keep her cool. She jumps out, hits the door lock out of habit and heads inside to get a Diet Pepsi. When he realized it he thought "no problem, call On-star... the canopy blocked the signal and they couldn't unlock.. couldn't push it..., called a Lock-pop guy and 60 bucks and 45 minutes later they were headed home... and the interior of the truck was way cool

have you thought about getting a newer exterior one from the junk yard and mount it in the cowl vent ?>

You probably won't do that... but remember the sky when you park.

john

 

Now that's funny! Along with my GPS,etc I am installing a Digital Guard Dawg Keyless Pushbutton ignition. If you lock the RF keyfobs in the car (or elsewhere) you can resort to the digital card in your wallet to open the car. Lots of cool stuff out there these days...don't get me started on the E-stop brake system.

 

I have my Sirius antenna against my defroster duct in my '56 and have never had issue.

 

Interesting. How much metal is between the antenna and free space?

 

Could it see enough sky from behind the grille?

 

I have Speedhut gauges in my 52, speedometer is determined by the GPS antenna on the dash close to my windshield. So far it works fine, also tells me the elevation and the time. I haven't noticed that it doesn't pick up, except when in the garage.

 

shouldn't be a problem Moo.... if you're like me, you don't drive very fast in the garage

 

I watched some new videos on the subject and learned that the latest GPS antennas have more advanced signal processing software in them...bottom line, they aren't quite as finicky about having line of sight to the satellite. When I get back from Ridout today I will try some different materials to cover the antenna and see which ones work the best. If it all goes as things usually do...I'll find the perfect material, get it shaped to the size of the cowl vent, and then either not be able to get it sealed or getting working perfectly and have the sun warp it in six months.

 

You are correct Charlie. The new radios are much better at obtaining satellite signals. Jeep Wrangler has a much more vertical windshield like our trucks. Here is a video on installation. Skip to the 7:40 min mark for the GPS antenna.
Also here are some GPS antennas. GPS Antennas


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