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Mailing list for people interested in building radio and electronics equipment from kits or from scratch. Frequent topics include shortwave radio receivers, construction techniques, and ham radio project.

The SDR-908 is a software defined radio designed specifically for portable use, without the bother of being tethered to a PC or soundcard for the modulation/demodulation processing performed in this kind of radio.

Hammarlund HQ-129X Receiver, Heathkit C-3 Condenser Checker, Heathkit QF-1 Q-multiplier and more

Yaesu FT-2000 Panadapter, using the Softrock 9 Lite, SDR receiver kit

Supplier of radio based kits to the electronics hobbist

QRP kits for Radio Amateurs

The Rock-Mite is a 40m CW kit offered by Small Wonder Labs . It features built-in keyer, direct conversion receiver with a crystal RF bandpass filter, 500 milliwatts of power, and switchable frequency offsets to work around QRM

A rebuild job on a Heathkit SB-200 amplifier by N4NAB

This article by Seabury Lyon, AA1MY describe how homebrew kits for amateur radio pourposes, in order to support wire antennas

Heathkit Amateur Radio Repair, parts, and manuals. Amateur radio equipment sales and service.

Digital Signal Processor Kits

IV3GFN modification and restore of an HeathkitSB220

1500 watts PEP output from a Kenwood TL-922 amplifier requires careful attention to parasitic suppression and component selection to ensure stability and longevity. This resource critically examines common modifications, often based on anecdotal evidence rather than sound engineering principles, that can degrade performance or introduce new issues. It highlights how replacing aged components often gets misattributed to the efficacy of unnecessary modifications, leading to widespread misinformation within the amateur radio community regarding amplifier stability. The article details specific, effective modifications for the TL-922, such as shortening anode-to-chassis and anode-to-grid paths to improve VHF stability and efficiency. It addresses issues like incorrect capacitor types in the tank circuit, inadequate grid grounding, and poor RF sheet metal design, providing practical solutions like adding direct ground connections for the plate tune variable capacitor. The author also discusses proper parasitic suppressor design, emphasizing the importance of lead length and component selection for optimal performance and harmonic suppression, contrasting these with less effective or detrimental 'magical suppression kits'.

Fabricates baseplate components, and provides hardware kits for DIY hex beam, spiderbeam and moxon antennas.

5000+ member discussion group for the low-cost series of SoftRock SDR receiver and transceiver kits.

Heathkit Icom Kenwood Power Transistors Ten Tec Yaesu spare Hamradio parts.

Heathkit Manuals

Repairt a Heathkit SB-220 Linear Amplifier with a bad Plate Voltage meter

Heathkit SB-220 Amplifier modification by KE5YA

Article about assembling of a Dick Smith Electronics (DSE) 100 Watt VHF Linear Amplifier kit.

Boom Microphone Headsets for use on amateur transceivers- assembled and kit form.

Heathkit SB 220 mods, replacing the Zener ZD1, replacing the plate-voltage voltage divider, adding a keying circuit for solid state transceivers

Third-order Cauer filters can boost performance of multi-transmitter, multi-operator contest stations to the next level. The filters are practical and you don’t need expensive test equipment to align them.

Pioneer supplier in the radio parts field, and electronic components, alternative power products, kits, test equipment and computer components.

EB5AGV / EC5AAU Boatanchor collection. Useful data on TV-testers, Collins, Drake, Hammarlund, Hallicrafters, National, Heathkit, EF Johnson.

W5UXH version of OZ1JHM Morse Code decoder project

A workbench instrument capable of testing transistors, diodes, FETs, usefull constructing QRP circuitry.

Over 45 years of dedicated work by Robert Sherwood, NC0B, culminated in a wealth of technical insights, particularly concerning **receiver performance** and the intricacies of transceiver design. The site provides access to numerous presentations from events like Dayton Contest University and W4DXCC, covering topics such as optimizing rig performance, the evolution of lab testing, and the impact of roofing filters on transmitted IMD and receiver characteristics. These resources offer detailed analyses and practical advice for serious operators and contesters. While product manufacturing, including the SE-3 MK IV synchronous detector and various Drake R-4C accessories like roofing filters and cooling kits, has ceased, the legacy of technical documentation remains. The site details specific products like the Icom IC-781 and R-9000, and offers insights into 455 kHz mechanical and crystal filters, along with DSP protection strategies. Crucially, the site features extensive receiver test data, allowing radio amateurs to compare the performance of various transceivers. This data, often presented in white papers and slide shows, includes detailed measurements and explanations of key performance metrics, serving as a valuable reference for understanding and selecting high-performance HF gear.

Eham user's review on the Heathkit SB-200 HF amp

Australia's largest range of Electronic Kits & Components In Stock for the Radio Experimenter, ATV, microwaves, HF Band pass filters

Building the MFJ Cub QRP transceiver kit for 20 meters band by G4ILO

A led electroluminescent radio receiver

Manufacturer of fiberglass parts for kites

Supplying Toroids, Electronic Parts and Kits to Engineers, Schools and Hobbyists. Capacitos, filters, inductors, qrp products

Portuguese Antenna dealer, offer also HF Converter Kit for the SDR Fun Cube Dongle and RTL SDR sticks

Ham Radio Antenna parts and kits manufacturer, based in Germany

Restoration of Viking Valiant, Hammarlund SP-600 and Heathkit HX-10 Marauder by KG9OM and KJ4W

Solar Panels, Grid Tie Systems, Solar Power Kits, Solar Cells and more. DMsolar carries solar energy products for your needs.

The following are the opinions expressed by various amateurs.

Accessories, Antennas and Battery chargers. Radiators, Repeaters, Yagi, Mag, Car, Tetra, Marine, Multiband, Brackets, Mounting accessories, cables and connectors, radiokits, special cables etc. Based in Finland

USA

A complete restoration of a Heathkit SB-200 HF power amplifier

Promoting Amateur Radio in Kitsap County Washington

Demonstrates the construction and tuning of a **20-17-15 meter fan dipole** using 12-gauge PVC insulated copper wire and an Alpha-Delta C kit feedpoint. The project details the use of 14-inch pine dowels with 6-inch spaced holes to maintain wire separation for the parallel elements. Initial tuning was performed at shoulder height, with final adjustments made after elevation to 38 feet, accounting for frequency shifts observed between ground-level and elevated antenna positions. SWR analysis graphs are presented, showing performance below 1:3 across the entire 20-meter band, below 1:2 for 17 meters, and below 1:3 for 15 meters. The author notes significant RX improvements of +3 to +9 dB, occasionally exceeding +20 dB, compared to a commercial Alpha Delta DX LB Plus. The total hardware cost for this DIY antenna project was approximately $90, with the author emphasizing the utility of an **antenna analyzer** like the RigExpert AA54 for precise tuning. The fan dipole also exhibits tunable resonance on 12, 10, and 6 meters, though with reduced efficiency. Performance comparisons on 20 meters showed the fan dipole outperforming the Alpha-Delta on long-path north-south DX contacts.

Clean Up Your Signals with Band-Pass Filters

Magnetic Loop antenna for 20 to 80 meters band using home made butterfly condensator kit

Cushcraft A3S performances with the A743 kit to add 30 and 40 meters

KN-Q10 Assembly Manual four band (3.5, 7, 14 & 21MHz) 5W SSB/CW transceiver kit Translated by BD6CR/4,

HobbyPCB.com provides quality products and boards for amateur radio including the popular HARDROCK 50 amplifier

Banana plugs, coaxial cable assemblies, patch cords, oscilloscope and DMM test lead and probe kits and accessories, IC test clips, boxes, RF connectors, XLR and 75-ohm cable assembly products.