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The Kenwood TH-F6A handheld transceiver can achieve an extended transmit frequency range of 137-174 MHz, 216-235 MHz, and 410-470 MHz by removing a specific diode and chip resistor from the main PCB. This modification also expands the receive range on the A-band to 142-152 MHz, 216-235 MHz, and 420-450 MHz. For the TH-F7E, the transmit range extends to 137-174 MHz and 410-470 MHz, with a corresponding receive range on the A-band. Performing these hardware changes will reset and initialize the radio's memory contents, necessitating prior backup of important channel frequencies. Instructions are provided for constructing a homemade PC programming cable compatible with the Kenwood TH-G71A, TH-F6A, and TH-F7E. The interface utilizes an RS-232-to-logic (0-3.3V) level-shifter and a full-duplex serial connection, adapting the Kenwood PG-4S cable schematic for the TH-G71's 2.5mm and 3.5mm phono plugs. Specific schematic tweaks include changing R1 from 150 ohms to 1K ohm to optimize power from the serial port and adding a 150K ohm resistor between the Radio TXD and ground to manage the 3.3V I/O pin. Detailed plug pinouts for the 2.5mm and 3.5mm connectors are presented, with the interface's TXD connecting to the ring of the 2.5mm plug and RxD to the shield of the 3.5mm plug. Ground connects to the shield of the 2.5mm plug, while the tips of both plugs are no-connects. Debugging procedures cover verifying positive and negative power rails from the serial port, checking component polarities, and testing level-shifting and inversion functions of the interface. Software setup involves enabling "TC ON" (Menu 15 for TH-G71, Menu 9 for TH-F6) and using Kenwood's MCP programming software.

Antenna was designed for SO-50 satellite operation but can be used for any VHF/UHF activity. It's a mix of a Moxon Antenna and a Yagi antenna. It has gains 4 dBd on 2m and 6.5 dBd on 70cm bands and it is fed via single 50 Ohm cable.

Coax cables, pictures and specifications

Illustrates the specific wiring and configuration steps required to interface an SGC-230 Smartuner with an Icom IC-706 HF/VHF/UHF transceiver. The document details the necessary connections for power, control, and RF signal paths between the two devices, ensuring proper impedance matching and automatic antenna tuning functionality. It specifies the pin assignments for the IC-706's ACC socket and the SGC-230's control port, crucial for successful integration. Outlines the operational considerations for the combined system, including initial setup procedures and potential troubleshooting tips for common connectivity issues. The resource presents a clear, diagrammatic representation of the interconnections, which aids in visual comprehension of the required cable fabrication or modification. Covers the specific settings within the IC-706 menu that need adjustment to enable external tuner control, such as the 'TUNER' function and other relevant parameters. This ensures the transceiver correctly communicates with the SGC-230 for efficient antenna tuning across various amateur bands.

Online shopping, Programming Software, Icom, Yaesu, Kenwood, Istron, HyGain, MFJ, cat cables interfaces and other radio control cables.

Some antenna manufacturers place baluns at the incorrect location in LPDA arrays, or tell you to route the cable incorrectly. This can cause substantial RFI and all sorts of weird problems like RF into house wiring.

Tower and antenna rotation equipment, insulators, rotor control cables, ancillary products

A 20-meter Moxon antenna design provides a compact directional solution for the 14 MHz band, achieving approximately **5.5 dBi** of forward gain and a front-to-back ratio exceeding 20 dB. This rectangular wire array, consisting of a driven element and a reflector, offers a smaller footprint than a traditional 2-element Yagi, making it suitable for space-constrained installations. Construction details focus on specific dimensions for the wire elements, fed with 50-ohm coaxial cable. The _Moxon rectangle_ inherently delivers wide bandwidth and a clean radiation pattern, simplifying tuning with a relatively low SWR across the entire 20-meter band. Its robust performance makes it a practical choice for both fixed stations with limited tower space and portable _DXing_ operations. The design's characteristics are particularly beneficial for contesting and long-haul communications on 20 meters.

DAVIS RF Co. has been in the business of supplying the staples of wire antennas for over 30 years. DAVIS RF Co. supply all coax cables, all connectors, ladder line, rotar control cable, insulators, and we have the largest selection of wire for wire antennas. DAVIS RF Co. is the designer and trade mark holder, and primary source for Bury-Flex Tm low loss coax cable. PolyStealth Tm high strength PE insulated antenna wire, and Flex-Weave Tm wire

Coax is a very important part of a satellite station. It is almost as important as the antennas you choose. This article discusses choosing coaxial cables for satellite communication, emphasizing factors like line loss. It compares types such as RG-8, RG-58, Belden 9913/9913F, LMR-400, and hardline, highlighting their impact on signal preservation.

A 37.6-meter Morgain antenna design provides dual-band operation on 80 and 160 meters without traps. The antenna uses 1.5 mm² stranded copper wire with vinyl insulation, commonly found as domestic electrical wire. Tuning involves adjusting lateral jumper wires for the 80-meter band, with initial positions 30 cm from the arm ends, yielding 3635–3715 kHz resonance with SWR below 1.5:1. For 160 meters, a straight wire length of 18.80 meters per arm is critical, achieving 1840–1850 kHz resonance with SWR below 1.1:1. The Morgain antenna exhibits a 50-ohm feed-point impedance, allowing direct connection of 50-ohm coaxial cable like RG-8X, which handles approximately 500 watts. Spacers and the central plate are constructed from 1 mm thick green fiberglass laminate, with spacers measuring 11 cm and installed every 1.90 meters. The central plate is 11 × 11 cm, designed to secure the coaxial cable mechanically. End supports utilize 3–6 mm thick bakelite terminal spacers, tensioned with nylon ropes.

Over **10 million** antennas and flags have been sold worldwide by Firestik Antenna Company, a veteran-owned manufacturer specializing in both CB and amateur radio communication products. Their offerings include a range of antennas, mounting accessories, and coaxial cables, designed for various mobile and fixed applications. The company provides technical support and maintains a network of dealers for product availability. Firestik products are known for their fiberglass construction, which is evident in their _Firestik_ and _Firefly_ antenna lines. The company also produces unique items like the "342 mile per hour Firestik flag," highlighting their diverse manufacturing capabilities beyond just radio antennas. They emphasize their commitment to quality and customer service, including direct technical assistance. The company is located in Tempe, Arizona, and operates under the registered trademark of _Pal International Corporation_. They actively protect their brand, including variations like Firestick and Firestix, ensuring proper representation of their products in the market.

Operating a ZS6BKW antenna often involves understanding its lineage from the _G5RV_ design, with specific modifications by ZS6BKW to optimize performance on several bands. Through computational analysis and field measurements, the antenna's dimensions were refined to allow operation on 10, 12, 17, 20, and 40 meters without an antenna tuner. For 80, 30, and 15 meters, a tuner is necessary, though efficiency on 30 and 15 meters is noted as not particularly high. The physical configuration consists of two 13.755-meter radiating elements fed by a 12.20-meter section of 450-ohm ladder line. Tuning the antenna on the 20-meter band is critical, and any deviation in the ladder line's characteristic impedance necessitates recalculating the element lengths. The design is also referenced in the 12th edition of _Rothammel's Antennenbuch_, page 219. Proper common mode current suppression is crucial at the transition from ladder line to coaxial cable. This can be achieved with a common mode choke, such as several turns of coax wound into a coil or over a ferrite toroid like an Amidon T130. While a 1:1 balun is an option, it may introduce issues.

Yaesu FT-2000 FT-2000D Cable connections

HD Communications Corp specializes in **RF and microwave amplifiers** engineered for demanding communication, defense, and industrial applications. Their product line includes precision-built, high-power solutions, along with RF connectors, filters, HF cables, and various accessories. The company also supplies tower hardware, valves, and tubes, catering to a broad spectrum of radio frequency infrastructure needs. Beyond amplifiers, HD Communications offers a range of **RF filters**, including low-pass filters, antenna filters, and solutions for RFI/TVI mitigation. Their inventory encompasses essential components like coaxial cable and various connector types, supporting both amateur radio and professional installations. The company operates as a manufacturer and vendor, providing direct sales of its specialized RF products.

A _Topfkreis_ antenna, also known as a "bicycle pump" antenna, is presented as a simple vertical design for the 70 cm band. This variant of the J-pole antenna is notable for not requiring a ground plane, simplifying deployment. The construction details specify using aluminum tubing for the radiating element, with precise measurements for the quarter-wavelength outer tube (32 mm diameter) and the three-quarter wavelength inner sliding tubes (10 mm and 8 mm). Feeding is via a 50-ohm coaxial cable connected 90 mm from the base of the central tube. This design can achieve a gain of **4 to 6 dB** when properly tuned using the adjustable radiating element. The article details the fabrication of a critical aluminum washer, suggesting a method using a hole saw and a drill press as a lathe for precise adjustment. The illustrated example is specifically for the 70-centimeter band, and the author, Pop, clarifies construction points in the comments, including material choices and assembly techniques, ensuring a robust build for VHF/UHF operation.

Table representing loss of Coax Cables in db per 100ft.

The "REAL TIME ANTENNA GAIN COMPARATOR SYSTEM" by IK0BDO details a low-budget amateur radio tool designed for optimizing homebrew VHF/UHF antennas. It facilitates the simultaneous comparison of two antennas, one a known reference (e.g., a dipole) and the other under test, displaying their relative gain directly in decibels. The system addresses limitations of previous measurement benches by enabling on-field optimization, accounting for balun performance, impedance mismatching, and cable losses. The core of the device is an electronic solid-state switch utilizing PIN diodes, which alternates signal sampling from the two antennas 100 times per second. This rapid switching prevents the receiver's Automatic Gain Control (AGC) from compensating for signal differences, allowing for precise comparative measurements. The document includes detailed schematic diagrams for both the RF switching unit and the associated measure unit, which employs two VU-meters to display cyclic signal levels. It also provides guidance on setting up the PIN diode switching with an oscilloscope and adjusting trimmer potentiometers P1, P2, and P3 for optimal operation. Further sections cover the construction of VHF (144.150 KHz) and UHF (432.360 MHz) beacons for testing, along with critical considerations for selecting an appropriate test range or site. Recommendations include maintaining a minimum distance of 50 wavelengths between transmitting and receiving positions, avoiding ground reflections, and using reference antennas with gains similar to the antenna under examination. The author notes satisfactory results from measurements on dipoles and other antennas, highlighting the system's ability to appreciate fractional decibel differences.

Useful data-sheet on RG coax cables compiled by NA5N

Schematic for Data, power, CAT, Key and Mic connection interface cable

Calculate Cable Loss from SWR and reverse. Text file with only two simply formulas

Power supplies, electrical testers, battery analyzers, cable tester, rf generators, spectrum analyzers, Digital/Analog Oscilloscopes, Multimeters , attenuators, frequency counter

DG6RBP homebrew project for a USB cable progtamming interface for the Yaesu VX-2 radio

Coaxial cables attenuation chart

easily design your cable, pick connectors and cable, print drawing, get immediate quote and place order, all online.

Amidon Associates, Inc. provides a comprehensive selection of inductive components, including ferrite toroids like the FT-50-61 and FT-50-43, alongside iron powder toroids such as the T50-2. These cores are frequently employed by radio amateurs for constructing baluns, ununs, and RF chokes, essential for impedance matching and common-mode current suppression in the shack. The company also supplies ferrite beads, split cores, and cable clamp-ons, which are critical for mitigating EMI and RFI in various electronic systems. Beyond core materials, Amidon offers mounts, bobbins, tunable inductors, and specialized wiring components like PTFE tubing, catering to diverse project requirements. They also provide custom winding services, allowing for tailored solutions in both amateur and commercial designs. Top-selling items include the BN-61-202, a common choice for broadband transformers, and the FB-43-801 ferrite bead, often used for decoupling and parasitic suppression in RF circuits. Amidon further expands its inventory by distributing products from other manufacturers, including Gowanda Electronics and Leader Tech, Inc., broadening the range of components available for hams and engineers.

SSB-electronic gmbh based in Germany produces coax cables and connectors, rf parts and components, SDR receivers and transceivers, transvertes, attenuators, coax relays, precision directional couplers.

Manufactures and distributes tower and wireless site components including antenna and sector mounts, site hardware, ice bridge and cable tray. Specializing in custom fabrication of work and equipment platforms; all hot-dipped galvanized.

G0KYA's Amateur Radio Blog, make a 2m Slim Jim antenna out of 300 Ohm ribbon cable.

A 10 meters band Slim Jim antenna project, made with a 450 Ohm slotted ribbon cable and secured on a 8 m fishing pole, by Steve G0KYA

Presents a construction project for a linear-loaded 40-meter rotatable dipole, detailing the design evolution from mid-element coils to 300-ohm twinlead loading. It covers material selection, including repurposed fishing poles and EMT conduit, and outlines the assembly process for the antenna elements and mounting plate. The resource provides specific measurements for element lengths and linear loading sections, along with SWR plots demonstrating the antenna's resonance at 7.035 MHz with a 1.1:1 SWR, and bandwidth up to 7.120 MHz below 2:1 SWR. The article documents the antenna's performance during various RTTY and CW contests, including the SARTG RTTY and SCC RTTY contests in August 2006, and the ARRL DX CW and CQWW WPX RTTY contests in February 2007. It reports successful operation at 500-1000W, noting improved performance after replacing a faulty coax cable. Specific DX contacts from British Columbia, including stations in Europe and South Africa, are listed, illustrating the antenna's capability despite its shortened length and relatively low height of 55 feet. The content highlights practical considerations such as weatherproofing the connections and supporting the fiberglass elements to prevent sagging. It also includes a brief comparison to an inverted-V at similar height and a ground-mounted vertical, noting the rotatable dipole's quieter reception. The author shares insights into the iterative design process and tuning adjustments made to achieve optimal resonance.

The Coaxman by Clear Signal Products, Inc. features a complete Wireman line of coaxial cable and antenna wire. Antenna wire, baluns, coax connectors, insulators, ladder line, magnet wire, rope.

Schematic diagram for the Kenwood KPG 46 programming cable interface for Kenwood TM 271E TK 71 TK 81 TK 7302 NX 700 NX 800 series

The ZS6BKW antenna, a popular multiband wire antenna, offers improved band matching compared to the traditional G5RV. This construction guide details the process, beginning with specific dimensions: 13.11 meters (43 feet) for the 450-ohm ladder line and initial dipole arm lengths of approximately 14.8 meters each. It emphasizes the critical role of an _antenna analyzer_ for accurate tuning, particularly for determining the velocity factor of the ladder line and achieving a 1:1 impedance match. The article outlines the materials required, including a 1:1 current balun, 450-ohm window line, wire for the dipole arms, and a 50-ohm non-inductive resistor for testing. It provides a step-by-step procedure for cutting the ladder line to its electrical half-wavelength, explaining how to calculate the velocity factor using measured and free-space frequencies. For instance, a measured 50-ohm impedance at 12.54 MHz with a calculated free-space half-wavelength frequency of 11.44 MHz yields a velocity factor of 0.91. Final adjustments involve hoisting the antenna to its operational height and fine-tuning the dipole arm lengths to achieve optimal SWR, specifically targeting 14.200 MHz. The _ZS6BKW_ design is noted for its performance on 80m, 40m, 20m, 10m, and 6m, though it is not optimized for 15m operation. The author, _VK4MDX_, shares practical tips for durable construction using stainless steel wire and cable clamps.

Based on original G2BCX design this J-Pole antenna for the six meter band is made with a homemade ribbon cable. The antenna shown in this article includes a coaxial cable choke feed to remove RF currents from flowing on the outer of the cable.

Connecting centre fed antennas, dipoles, yagis, rhombics, loops to coaxial cable, unless care is taken, it is not difficult to end up with feeder radiation resulting in power loss and the radiation characteristics changes

The **2M Moxon antenna** design presented operates at 144 MHz, providing a compact, directional solution for VHF communications. Construction involves aluminum tubing for the elements, with specific dimensions for the driven element and reflector to achieve optimal performance. The design aims for a good front-to-back ratio and a relatively low SWR across the 2-meter band, making it suitable for portable or fixed station use where directivity is beneficial. Element lengths are critical for proper resonance and pattern. The driven element measures approximately 38.5 inches, while the reflector is slightly longer at 40.5 inches. Spacing between the elements is 12 inches, forming the characteristic Moxon rectangle. This configuration yields a gain of about 5.5 dBi and a front-to-back ratio exceeding 20 dB, which is advantageous for reducing interference from unwanted directions. Feedpoint impedance is close to 50 ohms, allowing direct connection to coaxial cable without complex matching networks. The antenna's lightweight structure, typically under 2 pounds, facilitates easy deployment and rotation, making it a practical choice for field operations or as a compact home station antenna.

Communications products, communication systems products, fiber optic cables, global messaging service, gyroscope and navigation systems

A balun is a MUST for dipoles or similar antennas when they are feed with coaxial cables. Many hams connect the center conductor of the coaxial cable to one side of the dipole, and the shield to the other. Wrong!

This article presents a method of controlling preamps, antenna switching and polarization switching remotely without the use of control cables.

This simple modification is applicable to pretty much any 12 volt operated, positive earth equipment. by Chris Cox, N0UK, G4JEC

A homemade VHF/UHF vertical antenna made essentially with RG58 coax cable, with a 9 turns choke balun to prevent the shield acting as a RF Radiator.

The document provides a comprehensive overview of baluns, which are devices used to connect balanced loads, like dipole antennas, to unbalanced inputs, such as coaxial cables. It covers various types of baluns, including voltage and current baluns, and their design, construction, and testing. The text discusses the importance of baluns in preventing RF currents on coax shields and their applications in Ham radio setups. It also includes practical advice on selecting and using baluns based on antenna impedance and power ratings, along with detailed performance evaluations and construction tips for different balun configurations.

This program is for downloading, uploading the memory channels and various settings on the TS-2000(X)/B2000. To write data to or read the data from the TS-2000(X)/B2000 memory, an RS-232C straight cable is required. Runs on Windows 98.

How to easy connect two Pc together with a laplink cable

The Collins TRC-75 autotune linear amplifier, owned by JF2SVU, is presented with a focus on its internal modifications. This QRO amplifier utilizes three 4CX250 tubes in parallel for its final stage, delivering 1 KW output power. Notably, the amplifier achieves full power with only 100 mW of RF input, a characteristic often associated with Collins designs. The original 400 Hz power supply has been converted for easier shack integration, and the entire RF and power supply sections have been rehoused into a compact, clean enclosure. The control unit, positioned above the amplifier, features three meters for individual vacuum tube IP monitoring and a multi-meter on the right. A dedicated 7 MHz receiver, recently completed, is also part of this integrated system. The autotune functionality means the main amplifier unit only requires connections for power, control, and coaxial cables, simplifying its operation. Key components like the 4CX250 tubes and NF capacitors are visible, along with the gearing mechanism for the final tank circuit. A timer and relay system manages high-voltage delay and cooling fan off-delay, although the cooling fan's airflow is noted as somewhat insufficient. A central volume control, which experienced a contact issue, is also highlighted.

A Contestpedition Cable for TR-Log and the IC-706 by K6XX

Improper grounding or earthing system can cause several unwanted RF interferences (RFI) to television sets, broadcast receivers, hi-fi sets and telephone sets. In this Article the author explain how to setup a proper radio shack grounding using coaxial cable and ceramic disc capacitor

a methodology for connecting multiple LF/MF/HF receivers to a single antenna via readily available and inexpensive 75-ohm TV cable.

How to make a half l or quarter l coax cable for a specific frequency