Chameleon Antenna Tactical Delta Loop Operator's Manual

Introduction

Thank you for purchasing and using the Chameleon Antenna™ Tactical Delta Loop antenna. The Tactical Delta Loop antenna is a portable High Frequency (HF) antenna specially designed for transportability, quick setup, and a small footprint. This antenna is ideal for camping or temporary installation in a townhome or other houses with a small yard or antenna restrictions. It can operate on all amateur radio bands from 3.5 to 54.0 MHz (80-6m), but is most effective on the bands from 10.1 to 54.0 MHZ (30-6m). The Tactical Delta Loop will also provide acceptable shorter range Near-Vertical Incidence Skywave (NVIS) propagation on the 3.5 to 7.0 MHz bands (80-40m) making it a useful backup EMCOMM antenna or for amateur radio operators (hams) involved in disaster preparedness.

The Tactical Delta Loop can easily be configured as a horizontally polarized inverted Delta Loop or as a ground mounted vertical antenna. Some of the advantages of a Delta Loop antenna over a vertical are increased efficiency, reduced noise, and some broadside directionality. An antenna tuner or coupler is required for operation on the amateur radio bands from 3.5 to 7.0 MHz (80-40m). Setup can typically be accomplished by one operator in 5 minutes.

Please read this operator's manual so you may obtain the maximum utility from your Tactical Delta Loop antenna.

The Tactical Delta Loop antenna is comprised of two 17-foot telescoping whip antennas, a matching transformer, a 25-foot loop wire, a ground spike mount, a “V” coupling.

Antennas built by Chameleon Antenna™ are versatile, dependable, stealthy, and built to last.

Plate (1). Tactical Delta Loop Antenna.

HF Propagation

HF radio provides relatively inexpensive and reliable local, regional, national, and international voice and data communication capability. It is especially suitable for undeveloped areas where normal telecommunications are not available, too costly or scarce, or where the commercial telecommunications infrastructure has been damaged by a natural disaster or military conflict.

Although HF radio is a reasonably reliable method of communication, HF radio waves propagate through a complex and constantly changing environment and are affected by weather, terrain, latitude, time of day, season, and the 11-year solar cycle. A detailed explanation of the theory of HF radio wave propagation is beyond the scope of this operator's manual, but an understanding of the basic principles will help the operator decide what frequency and which of the EMCOMM III Portable's configurations will support their communication requirements.

HF radio waves propagate from the transmitting antenna to the receiving antenna using two methods: ground waves and sky waves.

Ground waves are composed of direct waves and surface waves. Direct waves travel directly from the transmitting antenna to the receiving antenna when they are within the radio line-of-sight. Typically, this distance is 8 to 14 miles for field stations. Surface waves follow the curvature of the Earth beyond the radio horizon. They are usable, during the day and under optimal conditions, up to around 90 miles, see table (1).

Low power, horizontal antenna polarization, rugged or urban terrain, dense foliage, or dry soil conditions can reduce the range very significantly. The U.S. Army found that in the dense jungles of Vietnam, the range for ground waves was sometimes less than one mile.

Sky waves are the primary method of HF radio wave propagation. HF radio waves on a frequency below the critical frequency (found by an ionosonde) are reflected off one of the layers of the ionosphere and back to Earth between 300 and 2,500 miles, depending upon the frequency and ionospheric conditions.

Table 1. Maximum Surface Wave Range by Frequency.

HF radio waves can then be reflected from the Earth to the ionosphere again during multi-hop propagation for longer range communication. The most important thing for the operator to understand about HF radio wave propagation is the concept of Maximum Usable Frequency (MUF), Lowest Usable Frequency (LUF), and Optimal Working Frequency (OWF). The MUF is the frequency for which successful communications between two points is predicted on 50% of the days of in a month. The LUF is the frequency below which successful communications are lost due to ionospheric loses. The OWF, which is somewhere between the LUF and around 80% of the MUF, is the range of frequencies which can be used for reliable communication. If the LUF is above the MUF, HF sky wave propagation is unlikely to occur.

The HF part of the Radio Frequency (RF) spectrum is usually filled with communications activity and an experienced operator can often determine where the MUF is, and with less certainty, the LUF by listening to where activity ends. The operator can then pick a frequency in the OWF and attempt to establish contact. Another method is using HF propagation prediction software, such as the Voice of America Coverage Analysis Program (VOACAP), which is available at no cost to download or use online at www.voacap.com. The operator enters the location of the two stations and the program show a wheel with the predicted percentage of success based on frequency and time. ALE, which is the standard for interoperable HF communications, is an automated method of finding a frequency in the OWF and establishing and maintaining a communications link.

Even under optimal conditions, there is a gap between where ground waves end (around 40 to 90 miles) and the sky wave returns to Earth on the first hop (around 300 miles). NVIS propagation can be used to fill this gap. The frequency selected must be below the critical frequency, so NVIS is can normally only be used on frequencies from around 2 to 10 MHz. Frequencies of 2 – 4 MHz are typical at night and 4 – 8 MHz during the day.

Parts of the Antenna

The Tactical Delta Loop antenna is comprised of the following components, see plate (2):

a. Matching Transformer

The Matching Transformer is a CHA HYBRID MICRO and provides impedance matching for the Tactical Delta Loop antenna.

b. Line Winder

The Line Winder is used to store the Loop Wire (g) and enables rapid deployment and recovery of the Tactical Delta Loop antenna.

Plate 2. Tactical Delta Loop Components.

c. Antenna Socket

The Antenna Sockets are the 3/8” x 24 threaded sockets used to attach the Telescoping Whips (h) and "V" Coupling (j).

d. Counterpoise Connection

The Counterpoise Connection is the red knurled knob, on the side of the Spike Mount (l), used to connect the Loop Wire as a counterpoise in the vertical antenna configuration.

e. UHF Socket

The UHF Socket, SO-239, is located on the side of the Matching Transformer (a).

f. Antenna Clip

The Antenna Clips (not pictured) connect the ends of the Loop Wire to the tips of the Telescoping Whips (h).

g. Loop Wire

The Loop Wire consist of a 25-foot 4-inch length of insulated wire, wrapped around the Line Winder (b). It is used as part of the antenna in the Inverted Delta Loop configuration and as the counterpoise in the Vertical configuration.

h. Telescoping Whip

The Telescoping Whip is a telescoping metal vertical radiator. It extends to 17 feet and collapses to 24 inches.

i. Base Stud

The Base Stud is a 3/8” x 24 threaded stud used to connect the Matching Transformer, “V” Coupling, and Telescoping Whips to the Antenna Sockets (c).

j. "V" Coupling

The "V" Coupling connects the vertical legs of the Delta Loop to the Spike Mount.

k. Coaxial Cable Assembly - NOT INCLUDED

l. Spike Mount

The Spike Mount provides the base for the antenna.

m. Mount Socket

The Mount Socket is a 3/8" x 24 threaded socket used to mount the “V” Coupling or Matching Transformer to the Spike Mount.

Antenna Configurations

Using the supplied components, the Chameleon Antenna™ Tactical Delta Loop antenna can be deployed into two useful configurations. They are described in this manual and each has unique operational performance characteristics. Table (2) can assist the operator to quickly select the most appropriate antenna configuration to meet their operational requirements.

Table 2. Antenna Configuration Selection.

To use the table, decide which distance column (Ground = 0 to 90 miles, Short = 0 - 300 miles, Medium = 300 – 1500 miles, Long > 1500 miles) best matches the distance to the station with whom you need to communicate. Then, determine if the OWF is in the lower (↓ = 1.8 – 10 MHz) or upper (↑ = 10 – 30 MHz) frequency range. Finally, select the Tactical Delta Loop configuration with the corresponding symbol in the appropriate distance column. Both Tactical Delta Loop configurations provide some capability in each distance category, so depending upon the complexity of your communications network, you may need to select the best overall configuration. The directionality column indicates the directionality characteristic of the antenna configuration. When using NVIS, all the configurations are omnidirectional.

Inverted Delta Loop Configuration

The Tactical Delta Loop, Inverted Delta Loop configuration, see figure (1), is a short to medium range HF antenna. It can provide acceptable NVIS propagation below 10 MHz and good medium range communications above 10 MHz. This configuration is bidirectional broadside to the “V” of the antenna above 10 MHz and omni-directional below 10 MHz. Elevating the base will greatly improve the performance of the antenna, although it will decrease the portability.

Figure 1. Inverted Delta Loop Configurations.

Ground Mounted Vertical Configuration

The Tactical Delta Loop, Ground Mounted Vertical configuration, see figure (2), is an omnidirectional medium range HF antenna. It will provide good overall performance using skywave and ground wave propagation. This configuration is quick and easy to setup. Improved performance can also be obtained using the optional Counterpoise Kit; which will create an efficient ground-plane for the Vertical configuration.

Assembly and Deployment

Inverted Delta Loop Configuration Assembly

1. Select a site to deploy the Tactical Delta Loop Inverted Delta Loop configuration. The best site would be a clear circular area, around 26 feet in diameter.
2. Drive the Spike Mount (l) half way (approximately eight inches) into the ground in the center of the cleared area. Use a plastic or rubber tent mallet to avoid damaging the face of the Spike Mount.
3. Thread the Base Stud (i) on the bottom of the “V” Coupling (j) into the Mount Socket (m) on top of the Spike Mount. Tighten by hand until snug.
4. Starting at the bottom, extend a Telescoping Whip (h), one section at a time, until it is fully extended.
5. Thread the Base Stud of the Telescoping Whip into the Antenna Socket (c) on top of the “V” Coupling. Tighten by hand until snug.
6. Thread the base Stud of the Matching Transformer (a) into the other Antenna Socket on top of the “V” Coupling.
7. Starting at the bottom, extend the other Telescoping Whip (h), one section at a time, until it is fully extended.
8. Thread the Base Stud of the Telescoping Whip into the Antenna Socket (c) on top of the Matching Transformer. Tighten by hand until snug.
9. Unwind the Loop Wire (g) from the Line Winder (b). Secure the Line Winder to prevent it becoming lost.
10. Clamp the Antenna Clip (f) from one end of the Loop Wire to the end of one of the Telescoping Whips just below the Corona Ball. Clamp the Antenna Clip from the other end of the Loop Wire to the other Telescoping Whip.
11. Connect your Coaxial Cable Assembly to the UHF Socket (e) on the Matching Transformer.
12. The assembled antenna should look like that depicted in figure (1) and plate (3).
13. Perform operational test.

Plate 3. Installed Inverted Delta Loop Configuration.

Ground Mounted Vertical Configuration Assembly

1. Select a site to deploy the Tactical Delta Loop Vertical configuration. The best site would be a clear circular area around 26 feet in diameter.
2. Drive the Spike Mount (l) half way (approximately eight inches) into the ground in the center of the cleared area. Use a plastic or rubber tent mallet to avoid damaging the face of the Spike Mount.
3. Thread the base Stud of the Matching Transformer (a) into the Mount Socket (m) on top of the Spike Mount.
4. Starting at the bottom, extend the Telescoping Whip (h), one section at a time, until it is fully extended.
5. Thread the Base Stud of the Telescoping Whip into the Antenna Socket (c) on top of the Matching Transformer. Tighten by hand until snug.
6. Unwind the Loop Wire (g) from the Line Winder (b). Secure the Line Winder to prevent it becoming lost.
7. Clamp the Antenna Clip (f) from one end of the Loop Wire to the threads of the Knurled Knob on the Spike Mount.
8. Extend the Loop Wire as the counterpoise in any convenient direction.
9. Connect your Coaxial Cable Assembly to the UHF Socket (e) on the Matching Transformer.
10. The assembled antenna should look like that depicted in figure (2) and plate (4).
11. Perform operational test.

Figure 2. Vertical Configuration.

Plate 4. Vertical Configuration.

Recovery Procedure

1. Disconnect the Coaxial Cable Assembly from the radio set.
2. Unscrew the Telescoping Whips.
3. Starting from the top, collapse one section at a time until the Telescoping Whips are completely collapsed.
4. Disconnect the Coaxial Cable Assembly from the Matching Transformer.
5. Unscrew the Matching Transformer and “V” Coupling (if used).
6. Pull the Spike Mont out of the ground.
7. If used, wind the Loop Wire onto the Line Winder and secure with attached shock cord.
8. Carefully roll (do not twist) the Coaxial Cable Assembly.
9. Remove dirt from antenna components and inspect them for signs of wear.
10. Store components together ready for next antenna deployment.

Troubleshooting

1. Inspect the Loop Wire for breakage or signs of strain.
2. Ensure UHF Plug from the Coaxial Cable Assembly is securely connected to the UHF Socket.
3. Inspect Coaxial Cable Assembly for cuts in insulation or exposed shielding.
4. If still not operational, replace Coaxial Cable Assembly. Most problems with antenna systems are caused by the coaxial cables and connectors.
5. If still not operational, contact Chameleon Antenna™ at support@chameleonantenna.com for technical support, be sure to include details on the antenna configuration, symptoms of the problem, and what steps you have taken.

Accessories

The following accessories are available for purchase from Chameleon Antenna™.

• Counterpoise Kit. The Counterpoise Kit is ideal for portable antenna deployment. The system will create an efficient ground-plane for the Tactical Delta Loop Vertical configuration. It contains four 25-foot wire radials secured around plastic wire winders and four steel Tent Stakes.

Please contact support@chameleonantenna.com for current prices and availability.

Specifications

• Frequency: Amateur Radio Service bands 3.5 MHz through 54.0 MHz (80 - 6m). Performance is limited on the 3.5 and 5.4MHz bands (80 and 60m) when using the inverted Delta Loop configuration.
• Power: 50 W continuous duty cycle (CW, AM, FM, RTTY), 100 W intermittent duty cycle (SSB and SSB-based digital modes)
• RF Connection: UHF Plug (PL-259)
• SWR: Subject to frequency and configuration, as measured see figure (3), but typically less than 2.5:1 above 10.1 MHz (30m). An antenna tuner or coupler will be required for operation on Amateur Bands from 3.5 to 7.0MHz (80 - 40m).
• Length: 25 ft 4 in.
• Weight: Approximately 5 lbs.
• Personnel Requirements and Setup Time: One operator, approximately 5 minutes.

Far Field plots for the Tactical Delta Loop antenna configurations are shown in figures (4) and (5).

Figure 3. Typical Tactical Delta Loop Measured SWR.

Description of SWR graph: The graph shows SWR (Standing Wave Ratio) on the Y-axis against Frequency (MHz) on the X-axis, ranging from 2.0 to 30.0 MHz. Three lines represent different configurations: 'Loop (ground)', 'Vertical', and 'Loop (elevated)'.

Figure 4. Inverted Delta Loop Far Field Plot.

Description of plot: A polar plot showing radiation pattern for the Inverted Delta Loop at 14 MHz, with Perfect Ground, Height 8 in. The plot displays signal strength in dB on radial lines and direction in degrees. An 'X' marks a specific direction.

Figure 5. Ground Mounted Vertical Far Field Plot.

Description of plot: A polar plot showing radiation pattern for the Ground Mounted Vertical antenna at 14 MHz, with Perfect Ground, Height 8 in. The plot displays signal strength in dB on radial lines and direction in degrees. An 'X' marks a specific direction.

Chameleon Antenna™ Products

The following products are available for purchase at Chameleon Antenna™.

Visit http://chameleonantenna.com for ordering and more information.

CHA P-LOOP 2.0

The CHA P-LOOP 2.0 was designed with portability, ease of use simplicity, ruggedness and high performance in mind. Unlike any other similar antennas on the market, the CHA P-LOOP 2.0 is made with premium materials that are precisely manufactured and assembled in the USA! This is an exciting new product from Chameleon Antenna. Easily deployable HF magnetic loop antennas, also called small transmitting loops, have been routinely used for many years in military, diplomatic, and shipboard HF communication links, where robust and reliable general coverage radio communication is a necessity. Covers 7.0-29.7 MHz.

CHA F-LOOP 2.0

The CHA F-LOOP 2.0 was designed with portability, ease of use simplicity, ruggedness and high performance in mind. Unlike any other similar antennas on the market, the CHA F-LOOP 2.0 is made with premium materials that are precisely manufactured and assembled in the USA! Easily deployable HF magnetic loop antennas, also called small transmitting loops, have been routinely used for many years in military, diplomatic, and shipboard HF communication links, where robust and reliable general coverage radio communication is a necessity. Covers 3.5-29.7 MHz.

CHA EMCOMM III

The EMCOMM III Portable antenna is a portable High Frequency (HF) antenna specially designed for short to long range portable and man-pack HF communications. The EMCOMM III Portable antenna is ideal for hiking, backpacking, and both tent and Recreational Vehicle (RV) camping. It would also be ideal as a backup emergency HF antenna.

CHA MPAS 2.0

The Modular Portable Antenna System (MPAS 2.0) is a concept allowing the radio operator to configure and deploy the antenna system in a variety of configurations. It covers 1.8 to 54.0 MHz and comes in a military-style backpack.

CHA TD Tactical Dipole

The CHA TD (Tactical Dipole) Antenna is a HF broadband antenna specially designed for portable HF communication where rapid deployment and simplicity of operation is essential. The antenna will operate at all frequencies from 1.8-30.0 MHz without any adjustment with most modern internal antenna tuners. It is ideal for use in conjunction with modern, digitally configured, HF communication transceivers where features such as ALE and frequency hopping require true broadband capability. The antenna will work successfully supported by trees, masts, the tops of vehicles or any convenient object or structure. The CHA TD comes in a military-style backpack.

CHA FT-817 BRACKETS 2.0

CHA FT-817 Brackets are built exclusively by the skilled machinists of Chameleon Antenna™. It is a military-style pair of precision fabricated brackets and high-quality carrying strap for the popular Yaesu FT-817 series portable QRP transceiver. The CHA FT-817 Brackets will ruggedize and help protect your FT-817 from the many hazards of field operations.

References

1. Silver, H. Ward (editor), 2013, 2014 ARRL Handbook for Radio Communications, 91st Edition, American Radio Relay League, Newington, CT.
2. 1987, Tactical Single-Channel Radio Communications Techniques (FM 24-18), Department of the Army, Washington, DC.
3. Turkes, Gurkan, 1990, Tactical HF Field Expedient Antenna Performance Volume I Thesis, U.S. Naval Post Graduate School, Monterey, CA.

Warnings

⚠️ WARNING! Never mount this, or any other antenna near power lines or utility wires! Any materials: ladders, ropes, or feedlines that contact power lines can conduct voltages that kill. Never trust insulation to protect you. Stay away from all power lines.

⚠️ WARNING! Never operate this antenna where people could be subjected to high levels of RF exposure, especially above 10 watts or above 14 MHz. Never use this antenna near RF sensitive medical devices, such as pacemakers.

Proprietary Information

All information on this product and the product itself is the property of and is proprietary to Chameleon Antenna™. Specifications are subject to change without prior notice.