INSULATORS
LBA Technology offers a wide range of styles of high power radio frequency (RF) feedthrough, standoff, and tower insulators.
Tower Base Insulators and Guy Wire Insulators
LBA is your dependable source for radio frequency insulators such as tower base insulators and guy wire insulators for use in medium wave AM broadcast antennas. Our systems utilize high quality ceramic and fiberglass insulators. Our selection of insulators includes products of LBA and the most noted manufacturers.
Insulators and their installation are major cost components of medium wave (AM) and low frequency transmitting tower systems. These insulators also are a major cost for those constructing towers near such transmission systems, who need to isolate those towers from impacting the adjacent system. As transmission power and tower height increase, these costs escalate rapidly.
In addition to insulators, we offer many related products, including lightning protection systems, guy wire discharge systems, static lightning chokes, and many more RF accessories & parts.
High power base and guy insulators are custom to the project design requirements. For a quote, please contact LBA and a tecnhnical team member will discuss your requirements with you. Contact LBA.
Standard Strain and Suspension Insulators
Guy wires for small AM transmitting towers at power under 50,000 watts typically use inulators commonly referred to as "egg" or "johnny-ball" type. Wire antennas, such as many shortwave types typically use steatite rod or bar strain and suspension insulators. LBA offers a selection of all of these insulators.
| Typical johnny-ball insulator |
| Catolog No. | ANSI class | Tensile Strength Pounds | Length (inches) | Diameter (inches) | Hole (inches) |
| 500-D | 2 1/4 | 1 11/16 | 3/6 | ||
| 502 | 54-1 | 10.000 | 3 1/2 | 2 1/2 | 5/6 |
| 504 | 54-2 | 12.000 | 4 1/4 | 2 7/8 | 7/8 |
| 506 | 54-3 | 20.000 | 5 1/2 | 3 3/8 | 1 |
| 708 | 54-4 | 20.000 | 6 3/4 | 3 1/2 | 1 |
ANSI standard johnny ball egg insulators are intended for general purpose guy wire breakup for modest electrical and mechanical loads. They are designed for direct guy wire coupling, without shackles or other coupling devices. Multiple insulators may be strung together for greater voltage breakdown.
Insulators are manufactured of high quality electrical grade porcelain with vitreous glaze finish . They are designed to be rugged, resistant to mechnical breakage, and have zero moisture absorbtion.
| Typical suspension insulators |
Heavy duty steatite ceramic suspension insulators are used for applications in which large mechanical loads are encountered in high voltage antenna assemblies. They provide a long insulating path between the metal fittings to protect against electrical leakage and flashover. A wide range of sizes and strengths are available. Great strengths and leakage lengths are attainable by combining insulators into assemblies. Get the full specifications here (PDF).
| Typical strain insulators |
Steatite ceramic strain insulators are available in many sizes and lengths for light and moderate duty applications. Their simplicity makes them an economical choice over end-capped assembles. End configurations can be supplied for direct cable attachments with a variety for hole shapes. Bronze shackles may also be specified on one or both ends. Round light duty strain and spreader insulators are also available in many diameters and lengths. Get the full specifications here (PDF).
SmartGuy™ Guy Wire Insulator Design Service
You can save money on guyed towers!
Guy wires on AM towers, or towers near them, must be broken up with multiple insulators to prevent reradiation of AM energy and other bad impacts on AM operation. This can hit construction budgets hard. Our new SmartGuy™ guy wire insulator design service controls these costs and can save big money!
Problem:
Many of the insulators installed in guyed tower systems are simply unnecessary in the real world! But, every year, many thousands of dollars are spent needlessly on guy wire insulators for lack of adequate analysis alternatives.
Conventional designs specify guy wire insulators adjacent to the tower, at the guy anchor, and at intervals of 1/8 wavelength or less. This does not present a problem on electrically small towers or very lightweight towers with few insulators and small diameter guy wires. However, it is a significant problem on larger towers from both an expense and a mechanical standpoint.
Guy wire diameters for typical 300 to 400-foot cellular towers can range between 1/2 and 7/8 inch. On tall towers, as for FM and TV, guy diameters can range upward to 3 inches or so. Conventionally, from 20 to 100 guy wire insulators may be required. The installed cost of high quality insulators can range from $100 to thousands of dollars each. Thus, typical costs to insulate a tower may range from under $10,000 to over several hundred thousand dollars!
Solution:
The requirement for insulators is a function primarily of tower height, frequency and operating environment. By properly identifying these factors and applying modern numerical analysis techniques to them, LBA can identify the actual types and spacings of insulators needed, providing the required performance. We call this analysis, and the customer service, “SmartGuy ™”.
SmartGuy ™ results in a recommendation of the type and location of guy wire insulators for the approval of the customer’s structural engineer. Our convenient service can also furnish all insulators and hardware that will be needed to install the designed guy wire insulator system.
Two recent analyses demonstrate the savings potential. Two 300-foot cell towers were analysized to achieve protection of nearby AM stations operating on 640 kHz and 1490 kHz, respectively. Including analysis costs, the net savings at 640 kHz was about $1,000. For the 1490 kHz case, the saving was about $5,000. Another study of a 1200-foot tower indicated savings of nearly $300,000!
Feedthrough and Standoff Insulators
Feedthrough insulators are designed for either cabinet or building wall mounting, and are fabricated of melamine and Lexan polycarbonate resin. Both materials are very rugged and have exceptional RF properties. Melamine feedthrough insulators are flat plates that can be supplied to large sizes. Lexan units are fabricated as a machined insulator with deep grooves to increase arc path length. For high RF voltage applications, the two insulators are frequently combined for maximum power handling capability. Traditional steatite ceramic feedthrough insulators are also available.
Standoff insulators are manufactured in several standard lengths and diameters, and are supplied in a choice of Lexan, ceramic, or by special order Lexan/ceramic composite.
Composite Lexan/ceramic insulators are a proprietary LBA development which combines the best features of both insulation systems into a superior high voltage insulator. In these components, a ceramic insulator is fixed with epoxy into a Lexan base. Full advantage is made of the anti-tracking properties of the ceramic, while the slight flexibility of the Lexan prevents fracture of the ceramic insulator. This insulator may be used in the most critical applications.
Lexan insulators are recommended for general-purpose use. These heavy-duty insulators are furnished with brass thread inserts to sustain repeated connection stresses and to reduce voltage gradients at the screw.
Lexan insulators are very durable, and have the advantage over traditional ceramic insulators of not cracking under stress.
Custom standoff insulators are available to six feet long and two inches diameter. Corona rings, termination assemblies, and other accessories are available.
Standard Standoff insulators
The following lengths are available for 3/4" (19mm),
1" (25.4mm), and 1 1/4"(32mm) diameters:
| CERAMIC | LEXAN |
| 1 1/4" (25mm) | 1 1/2" (25mm) |
| 2" (50mm) | 2" (50mm) |
| 3" (75mm) | 3" (75mm) |
| 4" (100mm) | 4" (100mm) |
| 5" (125mm) | 5" (125mm) |
| 6" (150mm) | 6" (150mm) |
| 10" (250mm) | 10" (250mm) |
| 14" (350mm) | 14" (350mm) |
| 20" (500mm) | 20" (500mm) |
*Specifications subject to change without notice.
|
WARNING!
Failure to install guy wire insulators can be very expensive!
A number of cell towers have been installed near AM stations without proper analysis of AM protection requirements. When caught by the AM stations, complete replacement of uninsulated guy systems was required – a costly and time-consuming remedy.
Every tower should be evaluated for AM protection regulatory compliance at the design stage. LBA offers complete AM protection services, including free site screening tools. |
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About LBA
LBA Group companies serve technical infrastructure needs related to the broadcast, wireless, electromagnetic compatibility and safety sectors worldwide. We provide consulting, training and other telecommunications industry services. We also produce and market hardware for radio transmission, RF shielding, safety and testing.
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