GLA Systems

TEXAS BUGCATCHER


"The SERIOUS HF Mobile Antenna"
by Henry Allen, K5BUG's - GLA Systems
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The GLA Systems "Texas BugCatcher" antennas are constructed from the best materials available.
The coil center support rod is produced from 1-1/2-inch diameter "Delrin" rod with threaded inserts in each end for easy attachment to any mast or whip.
All coil end fittings are machined from 1 inch brass hexagon bar stock. The fittings are tapped with standard 3/8-24 threads to allow connection to mast or whip. Stainless steel machine screws are used to attach the coil wire to the head of the end connectors. This allows the coil to be tightened securely to the mast or whip without damage to the the coil end.
This construction insures the best possible mechanical and electrical connection between the coil and mast or whip.

The coil support frames are machined from clear polycarbonate (Lexan®) stock. Center coil form supports are used in all coils when needed for strength. No parts of GLA Systems "Texas BugCatcher" loading coils are made of PVC or phenolic, both of which become quite brittle with exposure to sunlight. Our coils are all of the large, open, air-wound type to minimize the buildup of moisture, dust and dirt between the coil and coil form and to insure the highest "Q" and best performance. All GLA Systems "Texas BugCatcher" coils are built with both top performance and durability as a top priority.

All GLA masts are constructed of 3/4 inch outside diameter stainless steel tubing with stainless steel threaded inserts pressed and welded into each end. All masts, coils and mounts have standard 3/8-24 female threads to fit most standard antennas and antenna parts. Stainless steel male threaded studs are provided for each end of our masts to allow connection to most any type mount or coil. The capacity hats are made from aircraft type 2024-T4 aluminum.

The GLA Systems "Texas BugCatcher" antenna can be assembled to meet almost any mechanical configuration necessary to fit a particular installation. Our masts are available in stock lengths from 6 inches to 5 feet, with custom lengths of up to 8 feet. However, it is important to remember that the center loaded antenna has the highest theoretical radiation efficiency (as much as 150% higher than a similar base loaded system).
With this in mind, we strongly recommend a base mast of 3 to 5 feet and an effective whip length of 4 to 8 feet. Variations from this range will generally give excellent results but should be used only when installation requirements prohibit true center loading.
When selecting mast length, consideration should be given to several factors:

  • A mast should be used that will allow the bottom of the coil to be at least 6 inches above the roof line of the vehicle.
  • This should be increased to 12 inches if the edge of the roof is close to the antenna as would be the case with vans, suburbans and other "sport utility" type vehicles.
  • When the overall length of the antenna becomes a problem, remember that, in most cases, the length of the whip (or effective length of the whip-hat combination) is more important than the length of the mast so long as the ratio of whip length to mast length does not exceed about two.
    For example, if an antenna consisting of a 5-foot mast, coil and 7-foot whip must be shortened by 12 inches it would be better to take the 12 inches off the mast (reducing the radiation resistance by 20%) than to take it off the whip (requiring an increase in coil inductance and losses reducing antenna current by as much as 14% and radiation efficiency by 26%) as long as the coil is kept above the roof of the vehicle. A better approach to this situation would be to add a capacity hat maintaining the effective whip length.
The important thing to remember is that the GLA Systems "Texas BugCatcher" antenna can be assembled to fit YOUR particular vehicle and when properly tuned will give excellent performance on all bands.
We have systems being used with great success from as short as 6 feet up to 15 feet on mobile installations and much longer in fixed use.

It is impossible for us to cover all possibilities in this limited space but we hope we can give you enough information to help you design your own "Texas BugCatcher" antenna.

If you have additional questions please feel free to call or E-Mail us anytime.


 

LOADING COILS


400 SERIES COILS * 600 SERIES COILS

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GLA Systems "Texas BugCatcher" coils are currently produced in two families, 4-inch and 6-inch. The 4-inch coils provide improved performance at a reasonable cost. Their large diameter allows for a coil with a near-ideal form factor. The 6-inch coils provide the top performance of any commercially available HF mobile antenna system, and with their greater turn spacing, allow operation at higher power levels. All GLA Systems loading coils now include our new heavy duty machined brass end fittings. Coils are currently available 40 thru 10 meters, 80 thru 10 meters and 60 thru 160 meter operation. The 80 meter coils can be used for coverage of the new 3200 kHz (94 meter) MARS frequencies as well. While our 80 meter coils will perform well on all frequencies from 3200 kHz thru 30 MHz, most installations are optimized for 75/80 meter operation and result in an antenna system which is too large for direct resonant operation above 22 MHz.

All GLA Systems coils are custom-built with support frame end caps of 3/8 inch thick polycarbonate "Lexan®" sheet and coil wire supports of 3/8 inch diameter "Lexan®" rod. Intermediate support plates are included where needed in the coil frame.

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4-inch COILS


400 SERIES COILS * 600 SERIES COILS

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All GLA Systems 4-inch "Texas BugCatcher" coils are 4-3/8 inches in diameter and are wound with 12 gauge wire at 6 turns-per-inch. This shorter and wider 4-inch coil form results in a more attractive installation while providing higher "Q" and excellent radiation efficiency for those desiring top signal performance. GLA Systems now produces three 4-inch "Texas BugCatcher" coils, the #480 for 80 thru 10 meters, the #440 for 40 thru 10 meters, and the new #480XL for "hatless" operation on 75/80 meters with short whip lengths (Similar to the earlier #88.)

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#480 COIL

The #480 coil has 85 microhenrys inductance and will load on 75 meters with a whip length of 6 feet without the addition of a capacity hat.

When using a capacity hat, approximate MINIMUM whip lengths for full US 'phone band operation will be as follows:

20 inch HAT - - - 36-inch WHIP
16 inch HAT - - - 48-inch WHIP
12 inch HAT - - - 59-inch WHIP

These whip lengths are intended as a reference only. The length of the whip should always be kept as long as practical to insure minimum coil losses.

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#440 COIL

The #440 coil is 4-3/8 inches in diameter but only 4 inches long. The #440 coil has the same mechanical and electrical advantages as the #480 coil. Because of its shorter length it is an excellent choice when 75 meter operation is not desired.
The #440 coil makes a neat, nearly square coil with 35 microhenrys inductance and works 40 through 10 meters with the standard 59-inch whip and a 30-inch or 36-inch mast. When used with a small (8-inch or 12-inch) capacity hat and proportionately shorter whip, the #440 makes up a truly great operating shorty antenna for 40 through 10 meters.

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#480XL COIL  

The new #480XL coil is an extra long version of the #480. It has fifty percent more turns giving it sufficient inductance to operate on 75 meters without a capacity hat and with a whip length of less than 42 inches, an ideal choice when mechanical restraints preclude the use of a capacity hat.
With a 59-inch whip, the #480XL also covers the new 3200 kHz MARS frequencies. The #480XL has 50% greater inductance with the resultant 50% higher coil loss resistance and about 1.5dB less signal compared to the same antenna configuration with the #480 coil, but will operate with a 33% shorter whip making them ideal for use on tall vehicles such as 18-wheelers which do not allow use of long whips and lack space for large capacity hats.

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6-inch Coils


400 SERIES COILS * 600 SERIES COILS

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The GLA Systems 6-inch coils are just over 6-1/4 inches in diameter and are wound with 12 gauge wire at 4.5 turns-per-inch, the optimum for this wire size. (An exception is the #6160 -160 meter coil- which is wound with 12 gauge wire at 6 turns-per-inch.) We currently have three 6-inch models, the #680 for 80 thru 10 meters, the #640 for 40 thru 10 meters and the #6160 for 60 thru 160 meters. In addition to improving coil "Q" and providing some signal improvement, the inter-turn gap resulting from the 4.5-turn-per-inch spacing is over 120 thousandths-inch providing for easier installation of the coil-tap clips and higher power operation.

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#680 COIL  
The #680 coil has a winding length of about seven inches, yielding a near square form factor and a calculated "Q" well in excess of 1000 at 4 MHz. The resultant lower loss resistance can yield as much as 2dB greater signal radiation than our most popular 3-inch coil on 75/80 meters. With the 75 microhenry inductance of this coil, a whip 6-1/2 to 7-1/2 feet long must be used to resonate on 75/80 meters when a capacity hat is not used.

Adding a capacity hat will allow approximate MINIMUM whip lengths as follows:

20 inch HAT - - - 36-inch WHIP
16 inch HAT - - - 48-inch WHIP
12 inch HAT - - - 59-inch WHIP

These whip lengths are intended as a reference only. The length of the whip should always be kept as long as practical to insure minimum coil losses.

The "Higher Q" makes our 600 series coils your best choice for 40, 60 and 75 meter operation.

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#640 COIL

The #640 coil has a winding length of just over three inches yielding a slightly over-square form factor. It is designed to give superior performance on 10 thru 40 meters. The #640 coil does not have sufficient inductance to resonate on 75/80 meters without using a whip much too large for mobile operation. The #640 resonates on the 40 meter US 'phone band with a 5-foot whip without the use of a capacity hat. Addition of a hat will, of course, allow the use of an even shorter whip in those installations where this is desirable.
The #640 will require a whip at least 72 inches long for full 40 meter band operation.

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#6160 COIL  

The GLA Systems #6160 coil is the Big Brother to the original #2-88 coil and is wound with 63 turns of 12 gauge wire at 6 turns-per-inch. This coil was designed primarily for 160 meter operation and will operate quite satisfactorily on 75/80 or 60 meters but tuning on the higher bands is not recommended because of the excessive shorted turns. A whip at least 7-1/2 feet long with a 20 inch diameter capacity hat is required to load this coil on the low end of 160 meters. If a whip at least 8-1/2 feet long is used, the 16-inch capacity hat may be used with this coil for 160 meter operation. For portable operation, a 10-foot whip, made up of a 102-inch whip and an 18- or 24-inch extender mast, may also be used to give full 160 meter coverage without a capacity hat. Adding a 20-inch capacity hat to this combination will extend operation down into the 1700 kHz experimenters band.

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"BANANA-PLUG" COIL TAP SYSTEM


400 SERIES COILS * 600 SERIES COILS
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The BANANA-PLUG coil tap system is our latest innovation in the quest to make band changing with the GLA Systems "Texas BugCatcher" easier and more convenient. The system consists of a NEWsix socket ring connector, NEW "BANANA-PLUG" coil taps and matching tap leads. The ring connector is mounted atop the coil and the NEW "BANANA-PLUG" coil taps are attached to the coil. The NEW "BANANA-PLUG" coil taps provide a hooked female banana jack tap. The tap leads are then connected from the appropriate "BANANA-PLUG" tap to the nearest ring connector socket. No more need to wrap the tap lead around the coil to get to some of the tap points. All GLA Systems "Texas BugCatcher" coils are shipped with the ring connector, a full length flex lead and one BANANA-PLUG coil tap for initially determining the tap points or for single band installations. Additional BANANA-PLUG coil taps and flex leads may be purchased separately.
The BANANA-PLUG coil tap system "Top Ring" piece is available for updating earlier GLA Systems "Texas BugCatcher" coils.

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COIL TAP KIT

The BANANA-PLUG Coil Tap Kit makes returning to tap points for various frequencies much easier. The tap kit includes five of the new BANANA-PLUG coil taps of our latest design that hook around the coil wire and are locked in place with a plastic knurled nut. Two jumpers with Banana-Plugs on each end are included. Both jumpers are long enough to reach all the way to the base of the coil. You will usually want to shorten one of the leads for using tap points near the top of the coil as for 75/80 meters. This is easily accomplished as the banana plugs are secured to the lead by clamp screws. The remaining long jumper is used for higher frequencies that require tapping farther down the coil.
Once the tap points are located and the BANANA-PLUG coil taps are in place, the frequency can be changed by simply plugging the jumper onto the proper BANANA-PLUG tap jack.

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IMPEDANCE MATCHING


400 SERIES COILS * 600 SERIES COILS
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As with all short, high "Q" mobile antennas (especially on 40, 60, 75 & 160 meters) the feed point impedance of the GLA Systems "Texas BugCatcher" antenna is quite low. This necessitates some method of feed point impedance matching whenever an antenna system tuner is not employed.
This matching can be done in one of several ways. An inductor, capacitor, toroidal transformer or other method can be used. Because of the ease of its use we recommend the shunt inductor. The GLA Systems Heavy Duty Matching Coil is easy to adjust and will match the GLA Systems "Texas BugCatcher" antennas in all cases. It can also be used to match other types of HF antennas with great success.

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HD80 MATCHING COIL

The HD-80 Heavy Duty Matching Coil is 2 inches in diameter and 2-1/2 inches long. The base of the coil is a solid piece of copper that is the full diameter of the coil. This copper plate has a 3/8 inch hole in the center that allows the stud of the mast to secure the coil to the mount.
The coil wire is wound on a solid machined CPVC form. The coil form has a 1 inch hole in the center to allow the mast to pass through and secure the coil to the mount. This greatly increases the strength of the coil and also reduces coil vibration.
The coil is connected to ground with a jumper and our special BANANA-PLUG coil taps, two of which are provided with the HD-80.

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CAPACITY HATS


400 SERIES COILS * 600 SERIES COILS
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As most of the loss in a short inductively loaded antenna system, such as the GLA Systems "Texas BugCatcher" antenna, is in the loading coil, it is important to reduce the amount of inductance (load) needed. The most effective method of doing this is by adding capacitive top loading. By adding a capacity hat the resonant frequency of the antenna will be lowered considerably without reducing the antenna current in the lower (mast) section or increasing the loss resistances. A sizable amount of the loading coil can then be removed, providing a substantial increase in antenna radiation efficiency while maintaining the short physical height necessary for mobile operation.
Another very important use for the capacity hat is to reduce the overall mechanical length of the antenna. When the length becomes a problem because of trees or other obstructions, a capacity hat can be added or enlarged and the length of the whip section reduced while maintaining the desired resonant frequency without sacrificing radiation efficiency. Through the use of capacitive loading provided by a capacity hat, 75 meters can be tuned with a whip no longer than 3 feet on any of our #x80 loading coils. Without a capacity hat, 75/80 meter operation requires a whip of from 6 to over 8 feet in length, depending on the loading coil used and the lowest frequency of operation desired. The alternative in those restricted height installations where a capacity hat is not practical would be to use a less efficient coil having considerably greater inductance (and losses), as with the GLA Systems #480XL coil.
Radiation efficiency is greatest when the capacity hat is located outside the field of the coil, ideally at the top of the whip! In practice, we have found that the signal loss which results from placing a capacity hat about one coil diameter above the coil is not more than 2dB from that "top-of-the-whip" ideal nor more than 1dB from the best practical separation of two coil diameters.
The center support post of the 4-inch GLA Systems "Texas BugCatcher" coils are designed to accomplish the "one diameter" minimum displacement. A spacer must be added to the 6-inch coils for even this "one diameter" spacing and for all coils when the preferred two-diameter spacing is desired. This can be easily accomplished by using a 6-inch, 12-inch or 18-inch extension mast on top of the coil. The capacity hat can then be placed on top of the short mast and held in place by the whip.

GLA Systems is currently offering four different size capacity hats: The 20-inch hat is primarily used with the 160 meter coil but will enable 75/80 meter operation with a whip of 36 inches or less with any #x80 coil. The 16-inch hat, along with a 59-inch whip, is the standard choice on 75/80 meters for the #680 coil, with the 12-inch hat and 59-inch whip preferred for the #480 coil. The 8-inch capacity hat was chosen in the design of the earlier #1012 antenna and either an 8-inch or 12-inch hat can be used to shorten the whip section when using an #x40 coil. Both these capacity hats make a excellant choice for reducing the whip length on "screwdriver" antennas.
We are now able to offer custom sized capacity hats at a reasonable cost. Hats up to 36 inch have been successfully used by our customers. Call or E-Mail us for a quote on your hat requirements.

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QUICK DISCONNECTS


400 SERIES COILS * 600 SERIES COILS
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GLA Systems currently offer several types of quick disconnects for use with the GLA Systems "Texas BugCatcher" antennas.

In a standard duty model, we offer the "External Slot" type (G-217) which has two "J" slots cut in the female piece with the locking pin in the male center piece.
For heavier loads, we offer the "Internal Slot" type (HDQDS) quick disconnect which is made of stainless steel and has the double "J" slots cut into the male center post with the locking pins in the outer female shell. The solid outer shell of this female piece insures a tight, strong fit.
Additionally, we offer the "Screw-Together" type (KDT) chrome plated brass quick disconnect which utilizes a knurled nut to couple the mating post and socket providing a "tight" connection with no play even when hand tightened.

We also have available the Hustler Model QD-2 quick disconnect. This is a HIGH QUALITY all stainless steel medium duty quick disconnect.

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ELECTRICAL MOUNTS


400 SERIES COILS * 600 SERIES COILS
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HEAVY DUTY MOUNTS

The GLA Systems Heavy Duty Mount is a heavy duty stud type mount using a 3/4 inch stainless steel hex top piece and a 3/8-24 stainless steel bolt for the stud.
Nylon washers of 1-1/8 inch diameter are used on the top and bottom of the mounting surface to give a larger load bearing surface. The GLA Heavy Duty Mount is recommended where a strong mount is needed on a flat surface. Coax connection is made using a lug that is furnished with the mount.

The NEW Super Stud Mount provides a similarly strong mount with an SO-239 connection. The SS-750 requires a 3/4 inch hole for mounting.
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STANDARD MOUNTS

Standard duty mounts are available in both stud type (G-200) and with an SO-239 base (G-201). As with all GLA Systems products these mounts are top quality but are not as strong as the "Heavy Duty Mount."
On the stud type mount, coax connections are made with lugs. A direct connection with a PL-259 can be made on the mount with the SO-239 base. The G-201 is supplied with GLA Systems' VAN, SUBURBAN, HITCH and TIRE-CARRIER Mounts.

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VEHICULAR MOUNTS


400 SERIES COILS * 600 SERIES COILS
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FOLD-OVER HITCH MOUNT

The FOLD-OVER HITCH MOUNTS are designed to be bolted directly to a trailer hitch draw bar where the hitch ball would normally be installed.
The GLA Systems FOLD-OVER HITCH MOUNT is constructed of 1-1/2 inch square steel tube 2 feet tall with a steel plate on the bottom to allow bolting to the trailer hitch. A plate with a 1/2 inch hole for mounting the antenna is provided 6 inches up from the bottom. A strong antenna support of 3/16 inch thick "Lexan®" is provided at the top. It has a pin that can be quickly pulled which allows the mount to fold away from the vehicle to enable a rear door or tailgate to be opened.
This combination provides a strong mount for the "Texas BugCatcher" or other large antenna without drilling any holes in the vehicle and does not require any additional support such as guy lines.
The GLA Systems FOLD-OVER HITCH MOUNT is ideal for many newer automobiles which do not otherwise provide mounting points as well as vans and sport-utility vehicles such as AEROSTAR - MPV - ASTRO VAN - VOYAGER - CARAVAN - PATHFINDER - TRANSPORT - APV - PREVIA - EXPLORER - CHEROKEE - PICKUPS - and many others..

A LONG version (3 feet tall) of the FOLD-OVER HITCH MOUNT is available on special order for Full-Sized vans and other tall vehicles. The antenna mount plate is located 18 inches up from the bottom of the LONG FOLD-OVER HITCH MOUNT and with a 5-foot mast raises the coil above the higher roof lines of these vehicles.

Both GLA Systems HITCH MOUNTS are constructed from steel tubing and have a gold irridite and black powder coated finish to give a surface which is durable and can easily be painted to match the vehicle while providing an extra strong antenna mounting.

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TIRE CARRIER MOUNT

The GLA Systems TIRE CARRIER MOUNT was originally made for mounting the GLA Systems "Texas BugCatcher" antennas on the spare-tire carriers of vehicles like the Bronco II, Nissan Pathfinder and others that have swing-away tire carriers. It can also be used on RV ladders and any vertically aligned parallel bar units and on single vertical bars, such as grab rails on trucks, from 3/4 inch diameter up to 1-1/4 inch diameter.These mounts are constructed of all stainless steel.
The GLA Systems TIRE CARRIER MOUNT brackets bolt to the lower and upper arms of the tire carrier, or other fixture, with the antenna mounted on the lower bracket and supported by the upper bracket / insulator. The brackets attach to the carrier arms with "U" bolts and require no drilling.

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VAN / SUBURBAN MOUNT

The VAN MOUNT is a special mount designed for full-size vans and other large utility type vehicles available on special order. The mount bolts to the rear door hinges or other substantial mounting points with special brackets and allows the "Texas BugCatcher" antenna to be well supported in the operating position and then moved down into the stored position with only a small part of the antenna higher than the top of the vehicle. Installation is particular to each vehicle but may require one 5/16 inch diameter hole to be drilled in each door hinge. Note that most newer full-sized vans and all mini-vans have recessed hinges and may no longer allow for hinge mounting. Special brackets can be fabricated for most of these vehicles.

The SUBURBAN MOUNT is a shorter version of the VAN MOUNT designed for Suburbans and other sport utility type vehicles. Special brackets are included to fit each type vehicle.
We have produced brackets for vans and Suburbans with swing type rear doors and vehicles with rear mounted swing-away type tire carriers. Brackets for other vehicles may be provided on request.

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NOTE !!!!!!!!

WE STRONGLY RECOMMEND SUPPORTING THE "Texas BugCatcher" AS HIGH UP THE MAST AS POSSIBLE BECAUSE OF ITS WEIGHT AND WIND LOADING.


Check back again soon for an illustrated listing of all available parts and accessories, complete with pictures.



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