Search results
Query: article
Links: 289 | Categories: 6
This query is too generic. Please try adding an additional term to focus your research.
-
An article at NFARL web site about differences in setting up a half-square antenna versus a Loop Skywire by W4QO -
VHF UHF half wave flower pot antenna project by VK2ZOI -
-
A pdf file with drawings and instruction to properly assembly and solder most popular coax cable connectors -
QST Article on what you should know about matching networks for class C RF power amplifiers -
-
A eham article on a square copper dipole antenna for 50 MHz by K0FF -
These photos illustrate the basic steps in making a perfect solder joint on a p.c.b -
A collection of technical articles on antennas, radios and other stuff. -
Installing the optional TCXO, named SO-3 in the Kenwood TS-590S by TK5EP -
Taking the venerable SMK-1 design to 20m and adding an RF amp, audio filter, and a TiCK Keyer ... by Wayne McFee, NB6M -
Antenna tuners are crucial for matching the impedance of antennas to the 50 ohm output impedance of transmitters. The _LDG Z-11 Pro_ is an automatic antenna tuner designed to handle up to 125 watts, making it suitable for a wide range of amateur radio applications. Its compact form factor allows it to pair well with transceivers like the _FT-857D_, providing a portable solution for operators who frequently change locations or setups. The tuner covers the 80 through 6 meter bands, offering a broad impedance match capability. Although it struggles with some loads, it performs well with typical ham antennas, even managing to load an 80 meter dipole on 6 meters. One of the standout features of the _Z-11 Pro_ is its 8000 memory slots, which enable it to remember successful matches and quickly retune when revisiting frequencies. This memory function significantly reduces tuning time, often to less than half a second. The unit is well-constructed, with improved pushbuttons and a sturdy metal case that offers good shielding. However, users should be aware of potential RFI issues and the lack of a power switch, which requires disconnecting the power cord to turn off the unit completely. Overall, the _LDG Z-11 Pro_ is a user-friendly and cost-effective tuner, offering advanced features that enhance its utility in various amateur radio setups. -
Here is a simple, self-contained beacon which can run a few milliwatts or as much as a watt depending on choice of amplifier and supply voltage. -
-
Article on ham radio mobile operation from Andy D. Crouch N5NDD -
Accurate calibration of your receiver and sound card is necessary for good results with the weak signal modes in use at LF. Modern receivers with master oscillators that are synthesized to provide all conversion frequencies greatly simplify the process. This article describes a method of making the necessary measurements and adjustments to an ICOM R75 receiver and a sound card, using the ARGO software -
A personal review about the Yaesu FT-817 -
Discussion at eham about wire size used in wire antennas, and how it affects the gain of the antenna -
A complete EmComm portable station article on eham.net by K9RFZ -
Interesting article on how and when sleep during a contest -
-
75m Mobile Texas Bugcatcher Loading Coil Measurements -
-
Sensitivity of multi turn receiving loops William E. Payne, N4YWK -
-
Technical Correspondence, QST, July 1990 - Why even "perfect" phased array element currents don't produce perfect patterns. -
Getting the most out of LowFER transmitting antennas, designing an efficient antenna for the 1750-meter band by K0LR -
Understanding Solid State Linear Amplifiers -
The function of the XPhase is based on the fact that the interfering signal, received by an auxiliary antenna, is added phase-shifted to the signal received from the main antenna. When the phase-shift is more or less 180°, the interfering signal is canceled out. -
Key facts about how to solder, how to solder wire, how to solder pcb's, and including general soldering techniques and the best ways of making good solder joints for electronic circuits and construction. Includes video -
-
An article on RFD antennas, resonant feed-line antennas -
The Four Metres website offer a global overview graph of the four meter band plans world wide -
-
80 metre ceramix VXO with schematic and assembly instructions -
KD5FX, 20 through 6 meters, QRP to full legal power, lightweight, easy to carry -
Field strength meter for the 137 kHz band by PA0SE -
-
A Simple Delta Loop Antenna for Smaller Vessels -
A copper J Antenna for 144 and 430 article with design, feeding methods and pictures -
-
This unit uses four capacitors, only two of which are variables, and a single tapped coil. It is built in a die-cast box, and has been tested up to 80W input power on 70MHz by G4CJZ -
An home made CW beacon transmitter project running 1.5 W on the 80 meters band -
Exploring these mysterious transmissions and how their strong following has created a niche in the community. Free article in PDF Format from QST November 2019 -
Article about an end-fed anntenna for the 17 and 12 WARC Bands. 30 meters is not included in this project. This antenna includes a 14 windings unun impedance transformer using a FT-140-43 ferrite toroid, that should be enought for a 100W PEP. -
Antennas, Transmission Lines, Tuners - Myths, Mysteries and Qualifiers By Don Wilhelm W3FPR -
The intent of this article is to help the semi-non-technical person understand what is inside the Drake TR-7(A) Transceiver, how it works, and discusses simple adjustment and modifications the end-user can perform -
Hand made RF sweeper made to adjust the pass band of crystal filter -
This page is a short description of the four phased verticals system for 160m 80m and 40m -
Mobile RFI, often manifesting as persistent noise in the receiver even with the antenna disconnected, frequently originates from the vehicle's power supply system. This guide details systematic troubleshooting steps, beginning with isolating the radio from the car's 12-volt supply to confirm the power system as the noise source. It emphasizes the critical importance of drawing power directly from the battery using **heavy gauge wire**, bypassing the fuse block to leverage the battery's natural capacitance for RFI suppression and ensuring a solid RF ground. Proper routing of power lines through the firewall is also covered, advocating for dedicated grommeted holes to prevent inductive coupling from other wiring harnesses. The article stresses the necessity of fusing both positive and negative leads from the battery, a crucial safety measure to prevent damage to the rig and mitigate high-current risks should the battery's engine block ground become compromised during service. Addressing **alternator whine**, a common high-pitched noise that varies with engine speed, the resource suggests checking battery connections and the alternator-to-battery harness for looseness or corrosion. It also mentions the utility of adding an external RF noise suppression capacitor in parallel with the alternator's internal capacitor for enhanced filtering, and the effectiveness of commercially available in-line power supply filters.