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This is a simple 2.4 GHz SWR meter which is based around surplus microwave hardware which can be easily found. The main component is a MECA -20/-20 dB Directional Coupler which has a frequency range of approximately 700 MHz to 2.5 GHz.

Torbay Amateur Television and Microwave Group GB3TB 23cms Repeater at IO8ØFL

The DK7ZB-Dualband-Moxon-Beam provides a compact, high-performance antenna solution for 28 MHz and 50 MHz operations, utilizing a single 50-ohm feedpoint. This design functions as a mini-beam on 10 meters, achieving a gain of **4.0 dBd** with a front-to-back ratio of _30 dB_, while operating as a 2-element Yagi on 6 meters, yielding a gain of **4.3 dBd** and an 11 dB F/B ratio. The antenna's dimensions are approximately two-thirds that of a full-size 10-meter beam, making it suitable for smaller spaces. Construction details include a parts list specifying aluminum tubes of various diameters and lengths for the reflector and radiator elements. Builders like Aleks (S54S) and Marcio (PY2OK) have successfully replicated the design, with Aleks noting the utility of bending corners during assembly. Fine-tuning is accomplished by adjusting the length of specific elements that slide into larger tubes. The feeding system incorporates a balun, with options for either 300 watts using RG188 on an FT140-43 core or 1 kilowatt using _Aircell-5_ on an FT240-43 core, ensuring versatility for different power levels.

Review of the excellent ICOM IC-R8600 Wide Band SDR communications receiver. Featuring Direct Sampling SDR below 30 MHz Hybrid Superhet / SDR above 30 MHz.

The Icom IC-7700 spectrum scope feature a minimum resolution bandwidth of just 100 Hz and provide also an accurate vertical amplitude tracking permitting to use the 7700 as a bench spectrum analyser.

Risca and District Amateur Radio Society Tredegar Terrace Risca Nr Newport

This stacking offers a well known simple phasing technique. All elements can be fed in parallel by open wires provided that they are fed in phase. This can be achieved by twisting the open wire phasing-lines at 180 degrees.

The author has build the Hermes-Lite SDR v1 and v2 versions describing with a very accurated text and picture the process. Additionally has documented measurements for each component

This is some general information about the lowell amateur radio club!

Mounting on roof at the right ground level can greately impact on antenna performances because will affect the radiated angle of energy.

G0TRG - Trafford England

Operating within the low-frequency spectrum, transformers serve critical roles in antenna systems, particularly for 160m applications. The resource details the construction and performance of 1:1 transformers built on BN-73-202 cores, emphasizing their use as hybrid combiners or phase inverters for RX antenna arrays. Measurements reveal that these transformers exhibit minimal losses, around 0.12 dB at 1.8 MHz, with variations based on wire type and number of turns. The analysis includes comparative data on transformer performance, highlighting the impact of different winding techniques on frequency response. Notably, the use of coaxial cable for winding improves bandwidth while maintaining low-frequency efficiency. The resource also discusses braid breaker transformers, which minimize inter-winding capacitance, achieving low losses around 0.21 dB at 1.8 MHz. These insights are crucial for optimizing low-band antenna systems, allowing operators to make informed decisions regarding transformer design and implementation.

This web page is part of a self-help program for licensed amateur radio operators and radio pirates.

DXFile is a Windows shareware application designed for amateur radio operators, providing comprehensive log management capabilities. The software, developed in Pascal, facilitates real-time and deferred QSO entry, automatically populating fields like frequency, mode, and DXCC country based on user input and system time. It includes features for searching, modifying, and deleting QSO records, with options to sort logs by date, callsign, or entry order. The program offers various printing functions, including QSL card labels in multiple formats, and can generate standard logbook printouts. Beyond basic logging, DXFile integrates modules for tracking progress towards major operating awards such as DXCC, _IOTA_, WAZ, WAS, DDFM, and DIFM. It provides detailed summaries of contacts by band and mode, including graphical representations of HF traffic. A dedicated QSL Manager module assists in processing received QSLs, allowing users to mark confirmations and print multi-line QSL labels. The application also incorporates a DXCC list viewer, which can be updated to ensure accurate country and zone data for logging and award tracking. A distinctive feature is its HF propagation prediction module, which calculates optimal frequencies and signal levels for paths between **250 km** and **6000 km**, considering both E and F layer ionospheric conditions. This module helps operators determine the best times for long-distance contacts. Additionally, DXFile includes a _Web-Cluster_ interface, enabling connection to various DX cluster servers like DXLITE, DXSCAPE, and NC7J for real-time spot information.

Presents two distinct hardware modifications for the Icom IC-7300 transceiver, detailing the necessary steps for each. The first modification, a _MARS_ transmit expansion, involves the physical removal of specific surface-mount diodes (D422) from the main board, enabling transmit capabilities across a broader frequency range, including out-of-band frequencies. It specifies the diode location on US versions of the IC-7300 and suggests using small diagonal cutters if a soldering iron is not preferred or available. The second modification focuses on the internal antenna tuner, aiming to provide wider impedance matching capabilities. This involves adding a **100k ohm** resistor to a designated point within the tuner circuit. The resource also briefly mentions a microphone modification for the _HM219_ and a general power increase, though without specific instructions for the latter two. It emphasizes safety precautions, such as disconnecting power and inspecting the work area.

The Bishop Auckland Radio Amateur Club

A list of links on Crystal Radio projects and related reources

The club is based in the Newhey area of Rochdale in North West England at the Ellenroad Steam Museum.

Modification to an old cellular phone base station modules, with a fairly reduced output power (10 watts or so), the stock power amplifier modules will cover the 2.3 GHz and 2.4 GHz amateur radio bands.

A SSTV interfsace (soundcard) to minimize RF feed back and a soundcard limiter to prevent over driving the soundcard

Common-mode chokes are useful solutions for RFI reduction. Winding a few turns of coaxial cable on the FT 240-31 toroid can reduced the noise below the received noise floor. In this article author measure different chokes

Home made 40 meter transceiver project. The receiver is a Progressive Receiver with a few modifications. The Transmitter is a modified MFJ Cub circuit. Includes schematic and circuit diagrams for Receive Input Filter, 3-Pole 500 Hz Cohn Filter and 7 MHz Double Tuned Bandpass Filter

Sint Maarten by K1GI (PJ7I) 7L4DXT (PJ7XK) - 18 to 24 Nov 2012

A home mande spectrum analyzer project with several pictures and disposition of components boards based on a project by S57C

This page describes a printed circuit board that you may use to build a QRP keyer.

Elkhorn Valley Amateur Radio Club Norfolk

Icom IC-R9500 Professional Receiver with 5 roofing filters, 48 kHz DSP

The "Beginner’s Guide to Small-station EME" by Paul Bock, K4MSG, offers an insightful look into Earth-Moon-Earth communication, a fascinating aspect of VHF and above amateur radio. This presentation demystifies moonbounce, explaining how two-way radio contacts are made by reflecting signals off the Moon. K4MSG highlights the historical context of EME, noting the substantial investment and technical challenges that once characterized these operations, often requiring setups like the W5UN "Mighty Big Array" (MBA). Historically, path loss exceeding 250 dB, spatial polarization offset, Faraday rotation, and galactic noise made EME a formidable pursuit, with CW being the mode of choice for signals that had to be audibly detectable. Equipment limitations in noise figure and coax performance further compounded the difficulty for early moonbouncers. However, the landscape of amateur EME dramatically shifted around 2003 with the introduction of the JT65 software. This innovation, specifically designed for EME, allowed for signal decoding well below the noise floor, making small-station EME a practical reality for more hams using common transceivers and less complex antenna systems.

This page includes an interesting and comprehensive review of the ICOM IC-7300 SDR HF / 50 MHz transceiver. The author focuses on many aspects of this transceiver with impressions based on his experience

A collection of QSL cards from and old operator, Art J. Cook, VE4KZ, who lived in Calgary Alberta, that contained some from the far north of Canada.

DL7AFS, Babs and DJ7ZG 5-19 November 2012

QSLinfo.de is a QSL manager and address database for radio amateurs, maintained by Lothar, DL1SBF for more than 25 years already.

Review of the ICOM IC-R9500 Wide Band DSP Receiver

Departamento de Radio Escutismo do Nucleo Moinhos de Vento Portugal

What is a QSL Card and what should be the content of each QSL card, collecting cards, electronic QSL LoTW eQSL, QSL Bureau, and QSL managers.

Free PDF book to start learning morse code and to improve your proficiency, freely available in four languages english, german french and italian.

A guest review of the FLEX-6400M DSP HF Trasnceiver considering just the receiver part of this radio.

Official download page of TQSL software provided by ARRL as LoTW signing tool to upload QSO confirmations valid for ARRL Awards. TQSL download page provide links for Windows MacOS and Linux platforms.

International Police Association Radio Club, OO6P

Transmission lines have many uses other than simply transferring RF power from one point to another. Impedance matching, baluns and filters are probable the most common of these.

A single coil Z-Match. This QRP version by G3WQW, using a T130-2 toroidal inductor and polyvaricon variable capacitors was published in Sprat 84.

A QSL Cards collection divided into North American Shortwave Pirate Radio QSLs abd European Shortwave Pirate Radio QSLs

Here are some hints and tips for construction of a good preamp for satellite work.

Documents the design and construction of a **four-band Moxon beam** antenna, covering 20, 15, 10, and 6 meters. Author W7JMP shares his journey from initial research and computer modeling using 4NEC2 to the final on-air testing and optimization. The project aimed for gain over a dipole on 20 meters, with a budget under $500, including the antenna rotor. The design incorporates fiberglass spreaders and a single feedpoint, avoiding complex relay switching. The article details the selection of materials, assembly techniques, and the critical tuning process. W7JMP describes fabricating the hub, mounting spreaders, and attaching elements made from stripped THTN wire. A notable innovation is the use of a half-wave tuning stub with a loading coil for in-situ adjustment of the 20-meter reflector, optimized via remote S-meter readings using a webcam and smartphone. This method allowed for fine-tuning the **front-to-back ratio** without lowering the antenna. Initial testing revealed a dipole-like pattern, which was significantly improved after tuning, resulting in reported 2 to 4 S-unit front-to-back ratios and enhanced signal strength for DX contacts on multiple bands, including sporadic E on 10 and 6 meters.

Personal web site by N9SKN about portable QRP operations with pictures of several portable setups and antenna solutions.

The high-frequency inductance of single-turn loops of various shapes made of round wire can be estimated accurately with a simplified formula

Review of the 150 kHz to 30 MHz Ten-Tec receiver

For low voltage applications, like cathode bypass capacitors, most vintage types have an axial configuration, which is less common today but still available. Electrolytic power supply caps likely constitute the single worst liability in old audio, radio and test equipment. Rap about Electrolytics, Reforming, Chassis-Mount Replacements, Under-Chassis Installation, Rebuilding Capacitors

Collection of modifications for the Retevis RT3, a monoband handheld transceiver for DMR (digital voice) and analog FM. It is almost identical to the Tytera MD-380.