Geotool Hf1 User manual

Thank you for purchasing our GeoTool Model HF-1 Mount!

You will need a soldering gun or iron, some electrical tape and 13/16”, ½”, 9/16”, and

5/8” wrenches, and screwdrivers. You may also need a rat-tail (round) file to enlarge the

hole in the bottom of the stake pocket, or a 5/8” wood drill (like the one in the photo to the

right) to make a hole in the bottom of the stake pocket if there is none. Read all

instructions before proceeding. The basic installation concept is uncomplicated.

However, the actual installation can be relatively easy to moderately difficult

dependingt on your truck. The instructions below are a little long winded, but I want to

provide you with the basics of the installation process, plus additional suggestions and

helpful hints which may pertain to individual trucks.

1. Select the stake pocket - The mount will generally fit into the front and rear stake pockets of trucks without double wall

construction. Pre-2000± long bed trucks (particularly Fords) may have tapered pockets in the center of each side, but the mount can still

be installed in the front or rear pockets. Some Toyota Tundra stake pockets are smaller inside than at the top opening. Newer trucks

generally have straight pockets all around. Double wall construction, or bed liners, can make installation more difficult because it may

be harder to access the bottom of the stake pocket to tighten the anchor bolt . Rear stake pockets may be easier to use by removing the tail

light for access. On Chevy’s, the tail light may be removed by unscrewing two Phillips head screws, accessible when the tailgate is

lowered. Other trucks may have similar fastenings.

2. Adjust the height of the mount in the stake pocket- Begin the installation by checking the height of the mount block in the stake

pocket. It is easier to do this before installing the coaxial cable onto the mount. Measure the depth of the stake pocket. If it is longer than

the mount body, determine how many of the 9/16” flat washers to put in the bottom of the stake pocket to raise the mount to the top of the

stake pocket. If you don’t have enough washers, the mounting bolt is too short, or the mount is too long, contact GeoTool for assistance.

3. Attach the coaxial cable to the mount - We recommend that you DON'TINSTALLTHE PL-259 on the radio end of the coax until

the mount installation is complete and the coax is routed inside cab. The largest diameter coax that will fit through the hollow 9/16”

anchor bolt, or into the slots in the side of the mount, is 1/4". Accordingly, only RG-8 Mini Coax or LMR-240 Ultra Flex are

recommended. Route the coax through the bottom of the mount, or out the side of the mount using the slots in the body of the mount to

allow inserting the mount into the stake pocket. The 3/8”-24 mounting hardware is shipped with the components connected in the

recommended installation order. Attach the solderless connectors to the coax as shown on Figure 1, and SOLDER THE COAX

CONNECTIONS.

Our new mounts have a Chemfilm conductive coating where the ground ring attaches inside the top of the mount. Afew older mounts

may not have this, and the anodizing should be carefully sanded or scraped away to provide a good ground contact under the top of the

mount. Using an ohm meter, check that there is good conductivity between Chemfilm (or cleaned surface), and the threads inside the

bottom anchor bolt hole. The anchor bolt hole was threaded after anodizing to ensure that the bare aluminum provides a good ground

connection (anodizing is non-conductive) The 3/8-24" antenna connector hardware should be tightened snugly to prevent it from

working loose. Be sure the lower nylon washer extends into the mounting hole if possible, and that you insert the 3/8”IDx1/2”OD nylon

spacer inside the top mounting hole. This is because only a small portion of the lower nylon washer extends beyond the ground lead

solderless connector fitting. Tighten the assembly securely. If not sufficiently tight, the nylon shoulder washers may loosen up and

require retightening in a couple of days. Keep an eye on this part of the assembly for a few days. Following installation of the coaxial

cable on the mount, be sure to CHECK ALLCONNECTIONS FOR PROPER CONDUCTIVITY AND SHORTS.

4. Prepare the mount block and stake pocket for installation - Refer to Figure 1 for the location of parts. You will need a 5/8”

diameter hole in the bottom of the stake pocket to install the hollow 9/16” anchor bolt. If not already there, you will need to drill a hole.

Follow the instructions in item 3 in the ‘Troubleshooting’ section on Page 2, and drill a 5/8” mounting hole. Using emery cloth,

sandpaper, or other scraping tool, REMOVE PAINT FROM THE OUTSIDE BOTTOM OF THE STAKE POCKET to ensure a good

ground. The ground connection is probably the most important part of the entire installation. If the ground is not good, the antenna will

not resonate. The flat washers included with the mount are only for adjusting the height of the mount inside the stake pocket. They

should be used inside the stake pocket only. If placed between the lock washer and the stake pocket, the star washer will not dig into the

body of the truck, and the ground connection will not be adequate. Next, route the coaxial cable into the stake pocket, through the 9/16”

flat washers, and out the hollow anchor bolt, or out the side of the stake pocket.

Installation Instructions - Models HF1 & Hf2

For using any standard mobile antenna with a 3/8”-24 style screw base.

Pick-Up Truck Antenna Mount

P.O. Box 10822

Newport Beach, CA 92658

GeoToolGeoTool

GeoTool

Phone: (949) 548-8885

E-mail: [email protected]

http://www.geotool.com/antmount.htm

U.S. Patent No. 5,995,053

Drill bit and extension for cutting 5/8” anchor hole.

Page 1

CONTUNUED FROM PAGE 1

5. Shim the top of the mount - Place the antenna mount body inside the stake pocket and check for space between the top of the mount

and the stake pocket. All trucks require some shimming at the top of the stake pocket. Pre-1999 Chevy and GMC trucks, and all Mazda

and Ranger trucks need only a small amount of plastic electrical tape wrapped around the top of the mount to obtain a snug fit at the top

stake pocket opening. The tape now comes in many colors, so if a little bit shows, it will not detract from the looks of the truck. The tape

need not protrude from the top of the stake pocket to work properly. Most other trucks have larger spaces at the top of the stake pockets,

and require additional shimming material (using sticky-back linoleum), which is provided. Shimming will include one or more layers of

the sticky-back linoleum, which is held in place with electrical tape. Cut each shim to slightly less than the length of the side of the

mount, and check for fit before sticking it in place. The shim material can be installed on only one side, or thicker on one side, to adjust

the mount so the antenna sits more vertical. (Vertical alignment of the antenna can also be modified by filing out the anchor bolt hole in

one direction, and using offset shims.) Use a small amount of plastic electrical tape to hold the shims in place, and to take up the last bit of

looseness at the top. Refer to the attached SHIM INSTALLATION DIAGRAM for additional help.

5. Secure the Mount - Secure the mount into the stale pocket with the 9/16" hollow bolt. The lock washer goes between the head of

the anchor bolt and the clean bottom of the STAKE POCKET to ensure a good ground connection. Check to be sure that the top of the

mount does not wobble in the stake pocket. If it does, loosen the 9/16" bolt and adjust the electrical tape part of the shim. When the

anchor bolt is tightened, use an ohm meter to CHECK ALLCONNECTIONS FOR GOOD GROUND AND SHORTS.

6. Route the coaxial cable to the radio location - Route the coax along the top of the truck frame, or any other convenient path to the

cab. I recommend trying to protect the coax from scraping by brush or other off road stuff. Secure it with zip ties. The cable can enter the

cab through a hole drilled in the floor, or by removing the plug from one of the existing holes in the bottom of the truck cab. These are

readily opened by removing the metal plug that you will see from the bottom of the truck. Rubber caps, or grommets, are available at

most hardware stores that will fit this opening, and the coax can enter the cab through a hole cut in the cap or through a grommet. One or

more coax cables can be routed into the truck through a hole cut in the same hole cap. You may be able to use a simple paper punch for

making the hole in the hole cap. When you have determined the final location of the radio and have routed the coax into the cab of the

truck, install the appropriate connector for your radio to the end of the coax.

Potential Problems

1. The stake pocket will not accept the antenna mount body - Try bending the interior flanges of the stake pocket opening slightly to

allow the mount to drop into place, or try another stake pocket. A piece of wood will minimize the potential for chipping paint. Stake

pocket dimensions vary a lot, as you may see if you place the antenna mount in each of the openings on your truck. If the mount will not

fit in any opening easily, you may not be able to use this mount without modification. Call us to see if there is a mount that will fit better.

Or, a metal shop may be able to mill a few thousandths off the body of the mount. The latter method will also remove the anodizing.

2. The stake pocket will not accept the 9/16" hollow anchor bolt - Use a round file, drill, or reamer to enlarge the hole so the bolt will

fit. Be sure to protect the paint on the upper part of the hole while filing.

3. The stake pocket has no anchor bolt hole - As mentioned in section 4 on page 1, you will need to drill a hole 5/8” diameter or larger

to accept the mount. Carefully mark the location of this hole with the antenna mount in place, prior to installing the 3/8”-24 connector in

the mount. One method of determining the location of the hole is to simply eyeball it to the center of the bottom of the stake pocket. If not

perfectly aligned, the hole can be enlarged later on, or drilled slightly larger to allow alignment of the antenna. Another method - I

recommend aligning the top of the mount parallel to the top of the stake pocket in the front to back direction. Then, I would suggest

sighting from the back of the truck toward the front, to align the antenna vertically from side to side. Trucks normally have a slight

forward slant to the top of the bed rail, the forward lean of the antenna when the truck is not moving compensates for the backward bend

of the antenna when the truck is moving. To mark the location of the anchor bolt hole, park the truck on a level surface and adjust the

mount so that the top of the mount is level from side to side using a hand level. You could also use a triangle or perfectly square object on

top of the mount to sight a vertical building or other vertical object. Carefully mark the center of the hole using a pencil or other

instrument and drill a 5/8” hole. Actually, a flat bladed 5/8” wood drill, like the one shown on Page 1, is pretty inexpensive and will cut

the 1/32” soft steel. These will easily survive cutting a few holes in the soft sheet metal of your truck. Extensions (as shown) are aksi

available, and will enable you to reach down to the bottom of the stake pocket. A5/8” chassis punch may also work.

4. Difficult access to bottom of stake pocket - Installation may be possible if you use a socket or ‘crow-foot’ wrench with several

socket extension sections (you may need to borrow from your friends). Also, it will be easier to install the anchor bolt using a socket

wrench if you route the coax out the side of the stake pociet. Most trucks have holes in the side or near the top of the stake pocket. This

will enable you to use a standard socket wrench without the coax running through the hollow anchor bolt.

5. No access through tailight opening - See item 4. Same techniques are recommended.

6. Alternate coax routing - If you don't want to use the hollow mounting bolt for routing the coax out of the stake pocket, you can use

the slot in the side of the mount to allow you to insert the mount with the coax exiting out an alternate opening, either existing or user

drilled, in the stake pocket. I recommend using additional chafing protection for the coax because of the sharp edges of the sheet metal in

the stake pocket openings.

Instructions for Installation - Model HF-1 & HF-2

For using any standard mobile antenna with a 3/8”-24 style screw base.

Pick-Up Truck Antenna Mount

P.O. Box 10822

Newport Beach, CA 92658

GeoToolGeoTool

GeoTool

PAGE 2

Phone: (949) 548-8885

E-mail: [email protected]

http://www.geotool.com/antmount.htm

Figure 1 - Model HF-1&2 Antenna Mount Schematic

Antenna

Coupling Nut - 3/8-24x1.5

3/8" Flat Washer

Nylon Insulating Washers

(Shoulder Washers)

Be sure nylon Washer extends into

top of mount. It will just lock in place.

3/8" Solderless Connector

3/8"-24x1.5” Bolt (or 1.75”)

Coax. Center Conductor

½” Solderless Connector

Coax. Braid

Coax. Center Insulation

Insulation

Coaxial Cable

Coax routing access slots for alternate

coax routing through side of stake pocket

9/16" Flat Washer(s) (1 or more)

(Optional for Height Adjustment.)

Bottom of Stake Pocket

9/16" Inside-Star Lock Washer

(Against Stake Pocket)

9/16"x18x1.25" Anchor Bolt (Drilled)

Coaxial Cable

3/8" Split Lock Washer

Antenna Mount Body

U.S. Patent No. 5,995,053

NOTE: It is now easier to install the anchor bolt if you route coax out the side, front, or back, of the stake

pocket. Place the coax into the side channels to allow the mount to slip into the stake pocket. A socket

wrench can then be used on the anchor bolt since the coax does not exit through the bolt.

Instructions for Installation - Model VHF-1

Fits Most Pickup Trucks

SO-239 Pick-Up Truck Antenna Mount

P.O. Box 10822

Newport Beach, CA 92658

Phone: (949) 548-8885

E-mail: [email protected]

http://www.geotool.com/antmount.htm GeoToolGeoTool

GeoTool

U.S. Patent No. 5,995,053

Thank you for purchasing our Model VHF-1 pickup TruckAntenna Mount. You will

need a soldering gun or iron, some electrical tape and 13/16”, ½”, 9/16”, and 5/8”

wrenches, and screwdrivers. You may also need a rat-tail (round) file to enlarge the hole

in the bottom of the stake pocket, or a 5/8” wood drill (like the one in the photo to the

right) to make a hole in the bottom of the stake pocket if there is none. Read all

instructions before proceeding. The basic installation concept is uncomplicated.

However, the actual installation can be relatively easy to moderately difficult

dependingt on your truck. The instructions below are a little long winded, but I want to

provide you with the basics of the installation process, plus additional suggestions and

helpful hints which may pertain to individual trucks.

1. Select the stake pocket - The mount will generally fit into the front and rear stake pockets of trucks without double wall

construction. Pre-2000± long bed trucks (particularly Fords) may have tapered pockets in the center of each side, but the mount can still

be installed in the front or rear pockets. Some Toyota Tundra stake pockets are smaller inside than at the top opening. Newer trucks

generally have straight pockets all around. Double wall construction, or bed liners, can make installation more difficult because it may

be harder to access the bottom of the stake pocket to tighten the anchor bolt . Rear stake pockets may be easier to use by removing the tail

light for access. On Chevy’s, the tail light may be removed by unscrewing two Phillips head screws, accessible when the tailgate is

lowered. Other trucks may have similar fastenings.

2. Attach the coaxial cable to the mount - Important note here, DON'T INSTALLTHE PL-259 ON THE RECEIVER END OF THE

COAX UNTIL YOU HAVE COMPLETED THE MOUNT INSTALLATION AND HAVE THE COAX ROUTED TO THE INSIDE

OF THE TRUCK CAB. The largest diameter cable that will fit the hollow 9/16” anchor bolt is 1/4".Accordingly, RG-8 Mini Coax or

LMR-240 Ultra Flex are recommended. Do not use RG-58 because of high losses and size mismatch at the SO-239 adaptor. Route the

coax up through the bottom of the mount, or through the side of the mount if you don’t plan on using the hollow opening in the anchor

bolt. Strip the coax as shown on the diagram on the following page. Refer to the diagrams on Figure 1 for details on installing the coax

into the coax connector. Lightly tin the baid before inserting in inside the coax connector sleeve. Insert the coax into the connector, and

solder the braid to the inside of the connector, keeping the center conductor aligned so that it does not short out if the insulation in the

coax melts during soldering (a very common situation). When cool, screw the braid/connector assembly into the SO-239 base, and

check for length on the center conductor wire. It should reach over the center conductor terminal inside the SO-239, but not extend past

it. Using a small soldering iron, carefully solder the center conductor wire to the center terminal. If all connections are good and there

are no shorts, attach the heat shrink tubing and shrink around braid and the end of the coax. Place the Allen head screw in the hole in the

side of the adaptor and tighten about ½ turn after it snugs. It has a different thread than the hole and will not go in too far. However, it is

possible to force it in and it may short out the center conductor.A 1” diameter area on the underside of the top of the mount block has been

treated with Chemfilm, a conductive coating, to allow the SO-239 to have a good ground. Using an ohm meter, check that there is good

conductivity between the bottom of the mounting hole where the SO-239 connector will be grounded, and the threads inside the bottom

anchor bolt hole. The anchor bolt hole was threaded after anodizing to ensure a good ground connection. Recheck the SO-239 connector

for shorts. Install the UHF adaptor into the top mounting hole. I recommend using the hex nut only if necessary to adjust the height of the

SO-239. The SO-239 should sit as high as possible, while still allowing the antenna base to contact the wide flange nut firmly. If

necessary, you should use the thin nut inside the mount block to adjust the height of the antenna. Tighten the top flange nut securely,

leaving the coax extending out the bottom of the mount. Following installation of the coaxial cable and SO-239 connector, be sure to

CHECK ALL CONNECTIONS FOR PROPER CONDUCTIVITYAND SHORTS.

3. Prepare the mount block for installation- Refer to Figure 1 for the names and locations of parts. You will need a 5/8” hole in the

bottom of the stake pocket to accommodate the hollow 9/16” anchor bolt. If not already there, you will need to drill one. Follow the

instructions in item 3 in the Troubleshooting section on Page 2 to drill a 5/8” mounting hole. Using the emery cloth provided, REMOVE

PAINT FROM THE OUTSIDE BOTTOM OF THE STAKE POCKET to ensure a good ground. The flat washers included with the

mount are for adjusting the height of the mount in the stake pocket hole. Place the antenna mount body in the stake pocket and check for

looseness at the top of the mount. After installing the SO-239 antenna adaptor, place the antenna mount body in the stake pocket and

check for looseness at the top of the mount.

Page 1

CONTUNUED FROM PAGE 1

4. Shim the top of the mount - All trucks require some shimming at the top of the stake pocket. Pre-1999 Chevy and GMC trucks,

and all Mazda and Ranger trucks need only a small amount of plastic electrical tape wrapped around the top of the mount to obtain a snug

fit at the top stake pocket opening. The tape now comes in many colors, so if a little bit shows, it will not detract from the looks of the

truck. The tape need not protrude from the top of the stake pocket to work properly. Most other trucks will have slightly larger spaces at

the top of the stake pockets. I recommend using the linoleum shim material included with the mount only if it will fit snugly in the stake

pocket when you install a shim (sometimes only 1 side need be shimmed), and still wrap about 2 turns of electrical tape around the

mount. Shimming may require one or more layers of the sticky-back linoleum material. Cut each shim to slightly less than the length of

the side of the mount, and check for fit before sticking it in place (it comes off easily, so don’t worry if it is not in the proper location on

the first try). Use a small amount of plastic electrical tape to hold the shims in place, and to take up the last bit of looseness at the top.

5. Secure the Mount - Secure the mount with the 9/16" hollow bolt, with the lock washer between the head of the anchor bolt and the

bottom of the STAKE POCKET (to ensure a good ground connection). Check to ensure that the top of the mount does not wobble in the

stake pocket. If it does, loosen the 9/16" bold and adjust the electrical tape shim. Using the ohm meter, CHECK ALL CONNECTIONS

FOR GOOD GROUND AND SHORTS.

6. Route the coaxial cable to the radio location - Route the coax along the top of the truck frame, or any convenient path to the cab.

Secure it with zip ties or wire. The cable can enter the cab through a hole drilled in the floor, or by removing the plug from one of the

holes already drilled in the bottom of the truck cab. These are readily opened by removing the metal plug that you will see from the

bottom of the truck. Rubber hole seals, or gromets, are available at most hardware stores that will fit this opening. One or more coax

cables can be routed into the truck through a hole cut in the seal. When you have determined the final location of the radio and have

routed the coax into the cab of the truck, install the appropriate connector for your radio to the end of the coax.

Potential Problems

1. The stake pocket will not accept the antenna mount body - Try bending the interior flanges of the stake pocket opening slightly to

allow the mount to drop into place, or try another stake pocket. Apiece of wood will minimize the potential for chipping paint. Stake

pocket dimensions vary a lot, as you will see if you place the antenna mount in each of the openings. If the mount will not fit in any

opening easily, you may not be able to use this mount without modification.A metal shop may be able to mill a few thousandths off the

body of the mount. This will also remove the anodizing, reducing the protection it provides.

2. The stake pocket will not accept the 9/16" hollow anchor bolt - Use a round file or drill or reamer to enlarge the hole so the bolt

will fit. Be sure to protect the paint on the upper part of the hole while filing.

3. The stake pocket has no anchor bolt hole - As mentioned in section 3 on page 1, you will need to drill a hole 5/8” diameter or

larger to accept the mount. Carefully mark the location of this hole with the antenna mount in place, prior to installing the UHF

connector in the mount. The location of the hole will control the vertical alignment of the antenna, and is somewhat critical. Park the

truck on a level surface and make the top of the mount level using a hand level, or use a straightedge to align the side of the mount

vertically sighting on the side of a building or other vertical object. Carefully mark the center of the hole using a pencil or other

instrument and drill a 5/8” hole. Actually, a flat bladed 5/8” wood drill, like the one shown on Page 1, is pretty inexpensive and will cut

the 1/32” soft steel. These will easily survive cutting a few holes in the soft sheet metal of your truck. Extensions (as shown) are

available for them also, to enable you to reach down to the bottom of the stake pocket. Also, a 5/8” chassis punch may work.

4. Front stake pocket installation - Front installation, is possible but may require a socket or ‘crow-foot’ wrench with a long

extension. Also, you may be able to route the coax out the side of the mount if your stake pocket opening is greater than 1.75” wide.This

will enable you to use a standard socket wrench without the coax exiting the hollow anchor bolt.

5. No access through tail light opening - You will have to access the bottom of the stake pocket from under the truck using a crow

foot wrench or an end wrench. If you cannot use a socket wrench with the coaxial cable extending from the drilled anchor bolt, the

method described below may work.

6. Alternate coax routing - If you can’t use the hollow mounting bolt for routing the coax out of the stake pocket, you can use the

slot in the side of the mount to allow you to insert the mount with the coax exiting out an alternate opening, either existing or user drilled,

in the stake pocket. I recommend using additional chafing protection for the coax because of the sharp edges of the sheet metal in the

stake pocket openings.

If you have questions, contact us at the address, phone, or E-mail location shown below. Best to call in the evening Monday through

Friday, and on weekends.

Instructions for Installation - Model VHF-1

”Fits Most Pickup Trucks

Pick-Up Truck Antenna Mount

P.O. Box 10822

Newport Beach, CA 92658

Phone: (949) 548-8885

E-mail: [email protected]

http://www.geotool.com/antmount.htm GeoToolGeoTool

GeoTool

U.S. Patent No. 5,995,053

Page 2

Coaxial Cable

Center Conductor

SO-239 Connector

Coax Braid

Inside Adaptor

Heat Shrink Tubing

LocationBefore

Shrinking

Foam Insulation

Inside Adaptor

Foam

Insulation

Flange Nut

UHF Adaptor

Allen Plug

9/16" Flat Washer(s)

(Optional for Height adjustment.)

9/16" Lock Washer (Against Stake Pocket)

9/16"x18x1.25" Bolt (Drilled)

Coaxial Cable

Antenna Mount Body

Flange Nut

The braid should extend just past the solder holes, and then

be soldered in place inside the adaptor. Tin the braid carefully

before installing it inside the fitting.

Solder the braid inside the coax connector

before screwing the connector into the UHF adaptor body. It

may be necessary to make several tries to get the center

conductor the correct length. First leave about ¼ inch of

center conductor beyond the end of the fitting, and then trim

as needed (about 1/16 inch average). Screw the coax

adaptor, with coax attached, firmly into the SO-239 connector.

Solder the center conducter wire carefully to the center

conductor inside the SO-239 connector. Do this through the

hole where the Allen head plug is installed.The Allen plug has

a different thread than the body of the mount, so it will not go in

too far. It uses a 4mmAllen wrench. Heat shrink tubing is then

installed from coax to the flange on the coax connector.

Leave the foam insulation

inside the fitting, and trim it to the end of the fitting after

soldering the braid.

U.S. Patent

No. 5,995,053

Bottom of Stake Pocket

NOTE: It is now easier to install the anchor bolt if you route coax out the side, front, or back, of the stake

pocket, using the side channels to allow the mount to fit into the stake pocket. A socket wrench can then

be used on the anchor bolt since there is not coax running out of it.

Figure 1 - Model VHF-1 Antenna Mount Schematic

Figure 1. Guide for stripping coaxial cable.

0.350”

Coax

Connector

0.365”

0.013”

Thank you for purchasing our Model VHF-2 pickup Truck Antenna Mount. The

following instructions will help you install the antenna on your truck. Installation is can

be relatively simple to moderately difficult depending on your vehicle. Most necessary

parts, including shims for the top opening, are included. You will need tools including a

soldering gun or iron, some electrical tape and a few wrenches. You may also need a rat-

tail (round) file to enlarge the hole in the bottom of the stake pocket, or a 5/8” wood drill

(like the one in the photo to the right) to make a hole in the bottom of the stake pocket if

it is not there already. Read all instructions before proceeding with the mount

installation. Some parts of the installation may require knowledge of later steps.

The followingare suggestedsteps ina normal installation: Drill bit and extension for cutting 5/8” anchor hole.

1. Select the mounting hole. Trucks without double wall construction can generally accept the mount in the front and rear stake

pockets. Pre-2000± long bed trucks often have tapered pockets in the center of each side, but the mount can be still installed in either the

front or rear pockets. Newer trucks, with the exception of some Toyota Tundras and Fords have straight pockets. On some trucks,

double wall construction makes installation in front pockets more difficult because it is harder to access the bottom of the stake pocket.

It is recommended that the rear pockets be used on these trucks. On many trucks, the bottom of the stake pocket is easily accessed by

removing the rear tail light assembly, which is held in place by two Phillips head screws, accessible when the tailgate is lowered. Others

are accessed with more difficulty from under the rear fender behind the rear wheel.

2. Attach the coaxial cable to the mount - Important note here, DON'T INSTALLTHE PL-259 ON THE RECEIVER END OF THE

COAX UNTIL YOU HAVE COMPLETED THE MOUNT INSTALLATION AND HAVE THE COAX ROUTED TO THE INSIDE

OF THE TRUCK CAB. The largest diameter cable that will fit the hollow 9/16” anchor bolt is 1/4".Accordingly, RG-8 Mini Coax or

LMR-240 Ultra Flex are recommended. Route the coax up through the bottom of the mount, or through the side of the mount if you

don’t plan on using the hollow opening in the anchor bolt. Bend the ground connector on the lower half of the NMO mount so that it

is directed downward as shown on the diagram on the Figure 1. Strip the coax as shown on the diagram, and carefully tin the braid

lightly. Insert the coax into the ground connector, and solder the braid to the connector. When cool, solder the center conductor to

the center conductor of the mount. Test for shorts between the center conductor and the braid!!! A1” diameter area on the underside

of the top of the mount block has been treated with Chemfilm, a conductive coating, to allow the NMO connector to have a good ground.

Using an ohm meter, check that there is good conductivity between the bottom of the mounting hole where the NMO connector will be

grounded, and the threads inside the bottom anchor bolt hole. The anchor bolt hole was threaded after anodizing to ensure a good ground

connection. If there are no shorts, insert the nylon spacer (5/8” OD x 3/8” ID) into the top opening of the mount. It is a tight fit, and

may require tapping the assembly gently on a bench or table to get it started. Next, install the lower half of the NMO adaptor into

the top mounting hole. Place the ‘O’ ring inside the grooves in the upper part of the NMO connector and being careful not to over

tighten it, (the bottom half of the mount may bend if over tightened) secure it to the top of the mount body. Leave the coax

extending out of the bottom or side of the mount, depending on the method of routing the coax once installed. Following

installation of the coaxial cable and NMO connector, be sure to CHECK ALL CONNECTIONS FOR PROPER CONDUCTIVITY

AND SHORTS.

3. Prepare the mount block for installation - Refer to Figure 1 for the names and locations of parts. You will need a 5/8” hole in the

bottom of the stake pocket to accommodate the hollow 9/16” anchor bolt. If not already there, you will need to drill one. Follow the

instructions in item 3 in the Troubleshooting section on Page 2 to drill a 5/8” mounting hole. Using the emery cloth provided, REMOVE

PAINT FROM THE OUTSIDE BOTTOM OF THE STAKE POCKET to ensure a good ground. The flat washers included with the

mount are for adjusting the height of the mount in the stake pocket hole. Place the antenna mount body in the stake pocket and check for

looseness at the top of the mount. After installing the SO-239 antenna adaptor, place the antenna mount body in the stake pocket and

check for looseness at the top of the mount.

4. Shim the top of the mount - All trucks require some shimming at the top of the stake pocket. Pre-1999 Chevy and GMC trucks, and

all Mazda and Ranger trucks need only a small amount of plastic electrical tape wrapped around the top of the mount to obtain a snug fit

at the top stake pocket opening. The tape now comes in many colors, so if a little bit shows, it will not detract from the looks of the truck.

The tape need not protrude from the top of the stake pocket to work properly. Most other trucks have larger spaces at the top of the stake

pockets, and require additional shimming material, which is provided. Shimming will include one or more layers of the sticky-back

linoleum material. Cut each shim to slightly less than the length of the side of the mount, and check for fit before sticking it in place.

Use a small amount of plastic electrical tape to hold the shims in place, and to take up the last bit of looseness at the top.

P.O. Box 10822

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Phone: (949) 548-8885

E-mail: [email protected]

http://www.geotool.com/antmount.htm

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U.S. Patent No. 5,995,053

Page 1

Instructions for Installation - Model VHF-2

Any Size Pickup Truck

NMO VHF-UHF Pick-Up Truck Antenna Mount*

CONTUNUED FROM PAGE 1

5. Secure the Mount - Secure the mount with the 9/16" hollow bolt, with the lock washer between the head of the anchor bolt and the

bottom of the STAKE POCKET (to ensure a good ground connection). Check to ensure that the top of the mount does not wobble in the

stake pocket. If it does, loosen the 9/16" bold and adjust the electrical tape shim. Using the ohm meter, CHECK ALL CONNECTIONS

FOR GOOD GROUND AND SHORTS.

6. Route the coaxial cable to the radio location - Route the coax along the top of the truck frame, or any convenient path to the cab.

Secure it with zip ties or wire. The cable can enter the cab through a hole drilled in the floor, or by removing the plug from one of the

holes already drilled in the bottom of the truck cab. These are readily opened by removing the metal plug that you will see from the

bottom of the truck. Rubber hole seals, or gromets, are available at most hardware stores that will fit this opening. One or more coax

cables can be routed into the truck through a hole cut in the seal. When you have determined the final location of the radio and have

routed the coax into the cab of the truck, install the appropriate connector for your radio to the end of the coax.

Potential Problems

1. The stake pocket will not accept the antenna mount body - Try bending the interior flanges of the stake pocket opening slightly to

allow the mount to drop into place, or try another stake pocket. Apiece of wood will minimize the potential for chipping paint. Stake

pocket dimensions vary a lot, as you will see if you place the antenna mount in each of the openings. If the mount will not fit in any

opening easily, you may not be able to use this mount without modification.A metal shop may be able to mill a few thousandths off the

body of the mount, but this will also remove the anodizing.

2. The stake pocket will not accept the 9/16" hollow anchor bolt - Use a round file or drill or reamer to enlarge the hole so the bolt

will fit. Be sure to protect the paint on the upper part of the hole while filing.

3. The stake pocket has no anchor bolt hole - As mentioned in section 3 on page 1, you will need to drill a hole 5/8” diameter or

larger to accept the mount. Carefully mark the location of this hole with the antenna mount in place, prior to installing the NMO