Removing Onstar Antenna and Rerouting Radio Antenna

This is a pretty simple modification I did on my Saab. I read that a couple of other people did this modification, but I was not able to find any picture instructions, so here’s a sort of how-to.

To give some background, when Saab got purchased by GM, some of them came with OnStar. As a result, there are two antennae on Saabs of that period (1999 to 2002 9-3s). The one one top is the Onstar antenna, while the extendable mast in the back is for the radio. The rubber used to seal the Onstar antenna, unfortunately, hasn’t weathered well, and most of them are pretty cracked and ugly. The nylon rack gear in my aerial also snapped, and they’re sort of a pain to replace, so I decided to remove the Onstar antenna and install a radio antenna in its place.

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Removed Onstar antenna and replacement antenna

The skirt on the Onstar antenna clearly wasn’t doing a great job of keeping stuff out. Years of dirt got under the antenna. Fortunately, the smaller grommet seemed to seal well against the car, so nothing got into the roof.

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Cheap antenna means low quality

I paid $11 for this Universal Shark Fin Antenna off Amazon. I definitely got what I paid for. The wire for the antenna ran out the back of the housing, which I didn’t really like, and the “antenna” part of the device wasn’t really much more than just a little wire sticking out. I might pick out a Windshield Antenna and stick it inside the housing if it proves to not have enough reception in the future.

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Rerouted wire in antenna housing

I drilled a a 1/2″ hole in the bottom of the antenna housing to pass the wire through the bottom instead of the back. This way, I could use the entire antenna housing to cover up the hole in the top of the car. I’m not really one for car washes, so I just spot cleaned the area using paper towels and break cleaner.

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Steel fish tape

One of these tools makes running the wire down to the rear quarter panel a little easier. They’re available for pretty cheap from Home Depot or really any hardware store.

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Fish tape got stuck

I couldn’t really feed the fish tape all the way up the rear strut, so I pulled of some of the housing to see what was going on.

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Antenna connector

I just had to unplug the antenna connector from the old assembly and link it to the new antenna connector. Pretty straightforward.

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Antenna stuck down

Tidy everything up, make sure the new antenna is properly aligned, and stick it down!

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It’s a little more bulky, but it’s not super noticeable.

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Making Walled Scales

So this is going to be a pretty long, sort of how-to post about how I make knife scales that have walls. Basically all scales come in two different forms. The easier scales to make are flat scales. The name is pretty self-explanatory. A flat scale is shaped to the knife, and just has the proper through holes and countersinks for the screws. The more difficult scales to make, however, are the walled scales. One method of making these scales is to start with a thicker piece of wood and to mill out or pocket the inside of the scale, but without a CNC mill, doing it by hand it both tedious and very time consuming. With the tools I have available to me, I decided to try and makes walled scales using a combination of a 3D printer and the rest of the handle-making equipment that I already have.

To start off, it’s always nice to have the project knife on hand. This allows me to check fitment every step of the way and also allows me to create a CAD model for the walls.

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Scanner image of pocket side of scale

Just for reference, the knife I am working on in this write-up is a Boker Plus Nano. It’s a pretty unique, compact knife that’s really quite affordable.

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Edited scanner image

I am really only interested in the walls of the scale and not so much the scale itself. Since on this particular scale, the screw holes don’t intersect with the wall, my task is a little simpler. The images was edited using GIMP.

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Vectorize in Inkscape

After editing the original scanned image, the image is then imported into Inkscape. Using the “Trace Bitmap” toll under the “Path” menu item, I created a vector of the inner and outer edges of the wall. Taking a set of calipers to measure the vertical dimension of the physical scale, I make sure that the vector in Inkscape has the same vertical dimension. Afterwards, I export the vector as a DXF.

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DXF imported into Solidworks

Upon importing the DXF of the scale wall into Solidworks, I again check the vertical dimension, making sure that nothing has changed between the two different programs. Once verified, I simply leave the sketch underdefined and extrude the sketch to the appropriate thickness of the wall. Finally, with a solid model in Solidworks, I can export the file as an STL and print it on my 3D printer.

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Scale wall glued onto scale

After the print completed, I glued the scale onto a rather thin piece of wood. Using the metal liner, I was able to transfer the hole pattern using two different sized drill bits that closely matched the clearance hole diameters on the original scale. Unfortunately, when I was drilling the more centrally located small screw clearance hole, the drill bit walked quite a bit. I had to use a small file to “fix” the hole and elongate it such that the screw would still fit through. The wood is Myrtlewood Burl. It’s not a very dense or strong wood, but as a sort of decorative part, it suffices.

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Countersinking the screw clearance holes

Using a belt grinder and Dremel, I was able to easily remove the extra wood that was outside of the scale walls. In order to size the counterbores, I first assembled the knife. The impressions left in the wood by over-tightening the screws that held the knife together gave me a good sense of how and I should make the counterbores and exactly where to place them. Using a mill end in a Dremel, I carefully enlarged the screw clearance holes. This process involves a lot of stepping down small increments and checking to see how far down the screw sat in the scale.

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Test fit before coating and sealing

Before sealing up the scale in acrylic spray, I had a quick test fit to make sure nothing was sticking out, everything was smoothed, and the knife still can open and close properly. With a couple passes of acrylic spray, the outside of the scale is sealed. I usually leave the inside of the scale untreated.

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That’s it! I hope this walkthrough was useful.