Simple interference fix for the Chinese Pixie. The Chinese Pixie transceiver operating at 7023 kHz has become very popular.
It often costs less than 5 USD on Ebay. Like most Pixies it is susceptible to broadcast breakthrough and intermodulation. Much of this is caused by the keying circuit of the audio amplifier, the LM386. The cure is to move the muting diode from the power supply pin (no. 6) to the bypass pin (no. 7). I have described this in another blog post with title: "Using pin 7 of the LM386 to reduce BCI and add side tone to Pixie 2". Here are two pictures that show how this can be done for the Chinese Pixie. PE4BAS Amateur Radio Weblog: GPS timing for JT modes. After my last post about the Denmark holiday experimental radio activity I got a lot of e-mail if the GPS timing I wanted to make is already working.
Strange not many amateurs use GPS timing instead of a NTP internet timing. It is very common with for example the WSPR kits from Hans Summers G0UPL. If you are in the field without a internet connection GPS might do the trick and you get some extras as well. Small Transmitting Loop Antenna Calculator. Small transmitting loop antennas, commonly called "magnetic loops" or "mag loops," can give surprisingly good performance when they are carefully designed and constructed.
Although this online calculator is intended to assist with designing and building homemade, ham radio loop antennas for use in the HF bands, magnetic antennas have been constructed that function in the VHF or even the UHF frequencies. The most common material for home building small ham radio loop antennas is common copper plumbing pipe.This calculator enables you to test the design of an octagonal loop antenna and to answer "what if" questions until you arrive at a design that meets your needs without a lot of experience in electronics. Length of Conductor (antenna "circumference") feet Please enter the length of the conductor. Diameter of Conductor (For efficiency, should be > 3/8" or 1 cm) inches Please enter the diameter of the conductor.
Frequency megahertz Please enter the frequency. Units of Measurement. Loftur E. Jónasson - TF3LJ / VE2LJX. Here is my own version of a disclaimer: This is an Amateur Radio Techno Blog site.
Everything on these webpages has been put here for my own benefit and enjoyment. If I happen to have included an inappropriate link, please notify me, lofturj (-at-) gmail (-dot-) com, and it will be promptly deleted. No responsibility whatsoever is taken for any material published on these webpages. Some projects described here may include an element of original thought, now this is unlikely but statistically possible, remember the monkeys and the typewriters. This site is not set up to be esthetically beautiful. 2+3 element 2m (145 MHz) and 70cm (435MHz) duoband ultra portable yagi’ by ok1cdj. Tape measurement yagi.
The longest part is 530 mm, easy fit to your backpack. Very easy and fast deploy. Great for SOTA and portable operation. Can be used in horizontal or vertical polarization. Apollo-NG - Active Wideband Receiver Antenna for your SDR. Dressler ARA-2000 Software Defined Radio (SDR) has finally reached a much broader mass of people, who wanted to play with RF technology, but didn't find the time or resources to learn all necessary skills, to build a hardware based radio.
Thanks to the work of the GNU-Radio and OsmoCom developer crowd, this barrier is finally gone and everyone can, more or less, directly access, what the antenna receives. The last Mission-Log about a GNU-Radio based NFM SDR receiver pulled in a lot of people, looking for examples, to better understand GRC and to improve their own SDR projects. The real beauty about it is this: Unlike hardware receivers, which can't simply be replicated and shared, we only have to come up with good software receivers/transceivers once and then may just share them amongst each other, without any limitation.
However, the antenna itself, is still hardware and will most likely never be replaceable by software. Moon Tracking. Inputs to the DLL are: Date as Year, Month, Day Time as Hour, Minute, Second Station information as Height ASL (metres) , Latitude (decimal degrees with negative for southern hemisphere), Longitude (decimal degrees with negative for West of Greenwich) Switches for Refraction effect of light, Sun/Moon choice Band information for Doppler calculations Outputs from the DLL are: Azimuth and elevation of the body from the observer's perspective Doppler shift of body at the band entered above Distance of the remote body from the observer.
Frequency synthesiser si5351a. Experiments with a si5351a frequency synthesiser The si5351a can be programmed to produce a frequency from 8kHz to 200MHz.
The datasheet describes it as: Yagi Calculator. There have been minor fixes to improve reliability in different machines and better program flow.
No changes were made to the essential algorithms apart from the additions needed to cater for alternate boom and element material shapes. If you run Vista I recommend you run it as Administrator. NEW in 2013: YC now produces .maa files for MMANA-GAL optimiser. Features of the free but copyrighted program include: calculation of the element length and element spacings of a yagi for a particular frequency, different size materials for boom and elements are catered for as are different methods of mounting, dimensions of baluns are calculated, there is provision for entering the dimensions of an existing DL6WU antenna for optimisation through an external program or to gather information on its gain, beamwidth etc.
A handy SWR calculator and feedline loss calculator are included as part of the package. The program on this site was developed in the early 90s as a DOS program. 12 v Battery Box with Charger & Battery Booster – KJ6VU. I wanted to build a fully integrated, portable, 12 V battery box for portable operations like Field Day.
When I found these Ridgid cases at Home Depot, I thought they were a convenient size, well built, looked great and were a reasonable price. I also noticed there are clips on the sides that allows you to stack the boxes and lock them in place. It occurred to me that I could build up a set of modular radio cases and easily stack them up and snap them together. J Pole Antenna Handbook Home Page. The "Windom Antenna" was described by Loren G. Windom in QST magazine, September 1929. Pages 19 through 22. Loren Windom, W8GZ, was first to reveal the antenna to the radio amateur community by describing the antenna in the September 1929 issue of QST.
It was by Windom's name that the antenna became known. VK4ADC's web - Squid Pole Use for HF Antennas - A Topic Revisited. Squid Pole Use for HF Antennas - A Topic Revisited 10 April 2015 My original squid pole use article is here and it shows a lot of detail of the mounting of the bottom of the squid pole. Security Check Required. Remoterig. A 70cm Big Wheel Antenna.
07.08.1998 creation21.12.1998 article from UKW-Berichte added D: Für den 70cm-Teil der Bake DB0FAI benötigen wir dieses 70cm-Big-Wheel. Das Gehäuse ist eine Transportdose für Obstkuchen. Yet another Arduino Nano and si5351 DDS VFO/BFO. The second weekend in January 2017 afforded time to build something I’ve been wanting to build for several years, my first DDS VFO. I’ve built a kit DDS VFO with pre-soldered surface mount parts and burned-in firmware, but this was to be a scratch build with Arduino Nano, Arduino/C code with modifications, and a Silicon Labs si5351 on a breakout board. I used the wiring map and script from Tom AK2B. It is modified from one by SQ9NJE and uses Jason NT7S si5351 library. The script is elegantly simple, supporting a single push-button to cycle frequency increments, and dealing with encoder interrupts, contact debouncing, refreshing the LCD display, IF offset and VFO/BFO outputs. At the code level Jason’s si5351 library hides the gutsy device interfacing, giving you just a handful of common-sense functions to call… for example, set_frequency() takes as its argument the frequency in centi-hertz (1/100th of a hertz) and the ‘clock 0/1/2’ flag.
M0JCQ's Ham Blog ← Adventures in Ham Radio. Setting up an APRS RX only iGate using a Raspberry Pi, RTL-SDR dongle and a pre-built image. After my previous post, it was suggested that an easier way to set up a receive only APRS iGate would be to provide a pre-built image which only needs slight tweaking to go live. That seemed like a good idea to me so I’ve prepared an image that just requires a handful of configuration changes which I will go through in detail below. The entire process detailed here should take less than half an hour to complete. You will only need to edit two or perhaps three files in total. First, download my custom built Raspberry Pi image from here or preferably as a torrent from here. LNA for all: DIY 137 MHz WX SAT V-dipole antenna. This is a short version, the final of the ARTICLE describing how to build the Weather satellite 137 MHz V-dipole antenna. Complete text article will be published soon in the PDF format that will include background and a bit of theory how I came to idea to design this simple to build antenna.
The BIG List of RTL-SDR Supported Software. ALE Antennas for HF Automatic Link Establishment - HFLINK. Sub 9kHz Amateur Radio. How to Build Several Easy Antennas for Amateur Radio. <img alt="Image titled Build Several Easy Antennas for Amateur Radio Step 1" src=" width="728" height="546" class="whcdn" onload="WH.performance.clearMarks('image1_rendered'); WH.performance.mark('image1_rendered');">1Emphasis on the Antenna! The heart of the system of Amateur Radio is the antenna. Jopohl/urh: Universal Radio Hacker: investigate wireless protocols like a boss. RADIO NEWS MAGAZINE - Radio and Electronics magazine started in 1919 by Hugo Gernsback58.
Highly mobile packet radio. Highly mobile packet radio. The Mobilinkd TNC1 started its life, as with many things these days, as an Arduino project. It quickly took on a life of its own, first gaining Bluetooth capabilities when I discovered the latent abilities of APRSdroid. Signal Direction Finding with an RTL-SDR, Raspberry Pi and REDHAWK. The Alternative Multi-band Solution – Cobra UltraLite Antennas. Covers More Bands than a G5RV (Shorty).Goes up Fast, Easy on Trees.All Stainless HardwareBlack Marine ABS Insulator BlocksHandles a Full kW on All Bands.Tough–Pull-tested for Ice and Snow Loads.Professionally Engineered and Built.Center or End Supported.Fully Assembled with 81-Feet of Ladder Line (40-Feet with UltraLite Kid).NEW UltraLite Kid: 40-6m, Lightweight and Small, Great for Small Lots, Camping, Backpacking.USA-built by Granite State Antenna of Northwood, NH by people who answer the phone. WSPRlite & End Fed Antenna Testing – Surprise DX on WSPR!
Telepost Inc. Home Page. Technical Section - Miklor. Stealth Telecom - Leading Supplier of Radio Communications Equipment, System Integrated Products and RF-engineering services. Manufacturer of Mobile Loop HF Antennas. Distributor of Motorola, Kirisun, Sinclair, Andrew, Maxrad, Hustler, Diamond. We offer C. Coil-loaded 40/80 Meter Inverted V Dipole Antenna. Chm0117. Remote ham radio operation through a Raspberry Pi – Standard Thoughts. Build a Ten Gallon Loading Coil Variometer for MF/LF. A Homebrew 11.7 uHy Variometer. SNR. A Software-Defined Radio Remote Station Design. DDS VFO Kits. Mike Fedler's Radio Page - N6TWW. Mike Fedler N6TWW - 2 Meter Halo Antenna. Resonant Frequency Calculator. Radio Tower. PROJECTS. Amateur Radio Station W6PQL. Rotator Control for HyGain HAM-IV by dxzone.com. Repairing Rotators by dxzone.com.
Simulating JT modes: how low can they get? – Daniel Estévez. Use a Surplus Primestar Dish as an IEEE 802.11 Wireless Networking Antenna. How to build a tin can waveguide antenna. Mini Iambic Magnetic Morse Paddle by ok1cdj. Antenna controller. Audio - MRP40 Morse Code Decoder. Antennas – LY3H. RBN activity of K0MD. Portable UHF 4 elements Yagi Antenna. Home Page. AT-1000. Wireless antenna switch. Antenna-article-small-ant-efficiency.
Sounds & spectra. KGD mini dipoles. The KA7OEI FT-817 page. BOG antennas. N1EU's Beverage Transformer Notes. N1EU's Beverage Antenna Tips. Selectable-direction 2-wire Beverage Receiving Antenna information and construction by WØBTU. WDØM - Pagosa Springs, CO. Analyzing Three Antenna Analyzers. Utilizing GNU Radio in the Design of a Geosynchronous Experimental Radio Hosted Payload.pptx. WNDW - Wireless Network in Developing World. NVIS Army FM 24-18. Coax Loss Calculator.
PG1N's HAM Radio Site - 6m Projects - Transceivers. Radio Mobile WEB Site. Force 12 / InnovAntennas Superstore. HB9MTN "REMOTE" HB9MTN CPACITIVE ANTENNAS. BUDDIPOLE VERTICAL DIPOLE FOR 40 METERS. VERTICAL DIPOLE FOR 40M (AND HIGHER) HB9MTN INDOOR MULTIBAND DIPOLE FOR 40M - 10M. HB9MTN MAGNETIC LOOP WITH CAPACITIVE LOAD FOR 30-10M. HB9MTN MAGNETIC LOOP FOR 80M - 40M. GUI for rtl_power download. Measuring filter characteristics and antenna VSWR with an RTL-SDR and noise source.
CHA CHA RT-RR. Ncqrpp. VOACAP Quick Guide: HF Propagation Prediction and Ionospheric Communications Analysis.