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Tallguide Layout
Design Rules of the Run

The purpose of this article is to present design rule tips on Tallguide layout design. Like rigid waveguide, Tallguide runs need to be laid-out between the transmitter starting point and the antenna. Often the Tallguide end location is an antenna feed assembly or azimuth or elevation rotary joint. Since the transmitter control room angular orientation and elevation may differ from the antenna and may have several hundred feet separation, computer aided drafting programs are one method of keeping track of the layout features. Of course, back-of-the envelope sketch drawings serve the same function. DBS DirecTV broadcast site using RSI 9m and 11m antennas and Tallguide TG87.
DBS DirecTV broadcast site, California, using 9m and 11m antennas. Tallguide TG87 is used on each antenna uplink.

Tallguide Design Rules

Line Item

Component or Feature

Design Tip


Tallguide Transition

Every Tallguide run begins with and ends with a Tallguide transition from standard WR waveguide into or out of Tallguide. Transitions come in two models: -1 or 2. When 1 is added to the Tallguide transition model number, the designation refers to a WR waveguide input flange that is a flat cover flange. In contrast, the 2 designation refers to a WR waveguide pressure gasket grooved flange. For example, part number 181-1078-1 refers to a TG115 transition with a mating WR75 flat cover flange.


Mode Suppressor
Tallguide Mode Suppressor

Every Tallguide run contains one mode suppressor located between the input and output transitions. Mode suppressors are reciprocal devices. Either end may be used as input or output.


High Power Runs
Mode Suppressor Location

For high power Tallguide runs, the mode suppressor is located on the output (antenna) side of the run just before the output transition. Low power is defined as 1/10 the maximum Tallguide power rating. High power is everything else.


H-Plane Bend
Tallguide H-plane Bend

A Tallguide H-plane bend is a bend in the broad wall. There is no change in polarization direction. AFC fabricates special H-plane bend angles for customers all the time. Contact AFC's sales department to inquire about your unique bend angle.


Tallguide Twist

A twist changes polarization direction. For example a 90-degree twist changes vertical polarization into horizontal polarization.


E-Plane Bend
Tallguide E-plane Bend

There are no direct methods of fabricating a Tallguide E-plane bend (a bend in the narrow wall) and keeping transmission loss low. To create a Tallguide E-plane bend substitute, a Tallguide E-plane bend is composed of an H-plane bend and a twist. For example, a 90-degree E-plane bend uses a 90-degree H-plane bend and a 90-degree twist.


Straight Section
Tallguide Straight Section

Tallguide straight sections may be fabricated in any length up to 144-inch (3.7-m). When ordering straight sections, the length in inch units are added to the model number as 3 digits. For example, part number 181-0911-076 refers to a TG115 straight section of length 76-inch (1.93-m).


Tallguide Straight Section TBD Lengths and Layout Uncertainty

Due to inadequate site knowledge, to customer modifications and to system engineering design changes, Tallguide layouts are often not known with any great precision. To accommodate design uncertainty and still meet scheduled deployment, some straight sections may be ordered with a "to be determined" (TBD) length. AFC will prepare the TBD straight section for immediate fabrication for any length up to 144-inch (3.7-m). A TBD straight section is ordered by attaching the letters TBD to the part number. For example, part number 181-0911-TBD refers to a TG115 straight section of length "to be determined."


Tallguide Flange
and Pressurization

Tallguide flanges are high precision gasket grooved flanges. Tallguide components are shipped with Tallguide pressure gaskets and hardware.


Layout Notes

Keep track of Tallguide component lengths for the transition, mode suppressor, H-plane bend and twists. Because of these components physical length, straight section lengths must be modified to accommodate such components.


Tallguide Cross-section

Like waveguide, the flange height and width determine the Tallguide cross-section. Cross-section is important when placing Tallguide into a plastic pipe or carrier.


Tallguide Hangers

AFC supplies both rigid and sliding hanger for many Tallguide bands. Hangers are usually spaced every 5-ft (1524-mm).


Tallguide Installation

Tallguide installs like ordinary waveguide. No special tools or alignments are necessary.


Waveguide and
Tallguide and Waveguide Size Comparison


The electric field of waveguide is straight and parallel to the narrow waveguide wall. In contrast, the electric field of Tallguide is parallel to the broad Tallguide wall. The name, Tallguide, is derived from the "tall" appearance of the Tallguide rectangular shape in comparison to waveguide. Note that the Tallguide cross-section is larger than waveguide.

For other Tallguide frequency bands and component information, visit the Tallguide data sheets below.
5.8 - 8.2 GHz 7 - 10 GHz 8.2 - 12.4 GHz 10 - 15 GHz 12 - 20 GHz 15 - 22 GHz 17 - 27 GHz 22 - 33 GHz 26 - 40 GHz 33 - 55 GHz 50 - 75 GHz 60 - 90 GHz 75 - 110 GHz
WR137 WR112 WR90 WR75 WR62 WR51 WR42 WR34 WR28 WR22 WR15 WR12 WR10
TG215 TG170 TG134 TG115 TG87 TG80 TG62 TG50 TG40 TG31 TG23 TG17 TG16
Tallguide Data SheetHow to Combat Uplink Power Loss

AFC manufactures, markets and sells worldwide satellite dish antennas, radomes, antenna feeds, microwave and waveguide components and ultra low loss waveguide transmission line Tallguide. Our customers serve the broadcast, communications, radar, weather and cable industry, defense, government, and government agencies worldwide. AFC's quality control manufacturing standards are certified under ISO 9001 : 2015.

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