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Antenna Restrictions, Power Restrictions, RFI Problems, or Limited Space keeping you off the air?

Examines the current geopolitical landscape of Armenia, offering detailed reports on regional developments and internal political discourse. The station, _Radio Azatutyun_, covers critical discussions such as the potential for conflict in September, with one source suggesting a "war is coming, it won't be delayed," alongside ongoing debates about Armenia-EU visa liberalization, which is projected to require "another 2-3 years" for completion. It also highlights the contentious rhetoric surrounding the Prime Minister's interactions with displaced persons from Artsakh. The resource delves into significant international relations, including discussions between Bayramov and Araghchi on regional situations, and Iran's denial of recent negotiations with the US. It also features updates on former President Trump's demands for an additional **$200 billion** for defense and his assertion that "regime change" in Iran is effectively underway. Further content includes analyses of drone attacks in Baku, the proposed new Constitution, and local issues such as the delayed reconstruction of Gyumri's central market and the persistent problem of Vanadzor's temporary kindergartens. The platform also hosts podcasts like "The Choice is Yours," exploring the reliability of pre-election polls.

Excellent guide to using ferrite cores for interference suppression. Understanding and Solving RF Interference and Noise Problems by Jim Brown K9YC Audio Systems Group, Inc. PDF File

Source of common model manuals and amateur help on amplifier problems for the amateur bands, Discussion of vacuum tube amplifiers. Technical information and discussion of obselete tube replacement.

Information regarding CB radio and the problems you may encounter during installation and use of your system.

WA6CDE write about a major problem, a design flaw on two Icom 706 caps that have corrosive liquid that can seriously damage this icom transceiver.

These yagis and groups were designed with YO7.23 from K6STI and checked with EZNEC from W7EL. With a gain of 14/17/20dBd they have a good relation between gain and mechanical problems.

Bill Orr W6SAI ham radio techniques. Improving ground connection, computer analysis of the antenna, modelling sample antennas pdf file

The purpose of this web page is to try to investigate the ICOM IC-746PRO Dead TX problem reported by many radio amateurs through out the world; and unfortunately not properly taken care of by ICOM. If you are the owner of either the ICOM IC-746PRO or the IC-7400 you may already have experienced the Dead TX Issue. If not you may sooner or later.

An analysis of the cebik dipole and other small limited space dipoles fed with open wire ladder line.

If you want to use an RTL SDR USB dongle with Windows 10 and you experience problems, you may find this free utility very useful

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.

This note describes a relatively small, but efficient, loop antenna initially created for portable operation. With suitable modifications, it can be adapted for fixed station use. In this age of CC&Rs, an antenna similar to this may very well be the answer to your problems. Have a look, be inspired, get out the torch / soldering iron and create your own version!

Are you experiencing very high SWR with the 10M Modification to Ameritron AL-811 amplifier ? This is a good forum topic to fix this problem.

Loop antennae have been used from ELF to UHF since the beginning of radiocommunications. At low frequencies, the main problem for loop antennae is to have enough sensitivity; the antenna being very small respect to the wavelength the collected energy is also small. To increase the output level the loop may be made resonant, so loosing it%u2019s intrinsic aperiodic characteristics.

Solves antenna matching problem with two phased antennas. Stacked rotary beams are popular. However, connecting two 50 Ohm antennas together presents some problems.

The IC-746PRO is a great rig. But it has a few reliability issues, especially with the earlier-production units. This article addresses four problem areas:. IC151 on the RF Unit. Driver circuit on the PA Unit. HRX-muting circuit on the CTRL Unit. Predriver on the PA Unit.

Yaesu FT-101 Users Group purpose and scope is to serve as a sort of benevolent, protective, mutual aid and social club, essentially for the purpose of interchanging information, ideas, experiences and problems. By and for owners of Yaesu amateur radio equipment. Founded in 1972 by Amateur Radio operator Milton Lowens N4ML

The problem with making your own trapped HF antennas is usually getting the coaxial traps tuned to frequency.

This article presents a technical investigation into spurious emissions from the Yaesu FT-847 transceiver when operating on the 70MHz (4-meter) band. The author discovered significant problems with both factory "UK spec" and modified units. Spectrum analysis revealed that when transmitting at 70.2MHz, the radio produces numerous spurious signals, with the most prominent emission at 45.6MHz measuring only 3dB below the fundamental frequency. The study also documents poor power efficiency on 4m (10.3% at 30W output) compared to 6m operation (23.5% at 30W). Tests verified that jumper configurations had no effect on filter selection. The author warns that using these radios on 4m may violate license conditions due to excessive spurious emissions.

Engineering Solutions for Unique Problems. Manufacturer of high Voltage, high Current, high Power Power Supply

A Working analysis of the gamma match problem that gives useful practical results in a article dated April 1969.

Are you having RF problems in the shack since you put up your HF vertical antenna? This is a common problem with an easy solution.

Causes and advices on malfunctioning display in the control head of the FT-857, where several scan lines in the dot-matrix display cease to function, so the display seems streaked at places

Problems using the tuner interface in the ICOM IC7000

At the moment the most used program is UA1AAF. It is an excellent program written by Boris, UA1AAF, to handle ARI International DX Contest. It can simulate K1EA or N6TR workings; it will be possible to connect the RTX to the computer using a standard interface in such a way as to transmit directly in CW from the keyboard; most of the controls are like K1EA's CT and N6TR's TR ; on line help provides almost all the information necessary for using the program. Is possible to insert QSO after the contest. An appropriate utility in included for conversion in ADIF format. The program is very small and therefore works without any problems on any IBM compatible computer with DOS 3.3 and over or Windows 95/98.

Battery problem with TS-570

Part 2 You're now much closer to saying goodbye to your unwanted signal problems!

Understanding and solving RF interference problems using ferrite

How resolve low power problems on Icom IC-7000

Have you problem with your RG cables ? This page describes a smart antenna box using an RG-cathode for 3 antennas. The remote control needs just a simple wire and the GND for remote-control

This article explores the claim an amplifier might arc from a parasitic oscillation, damaging capacitors, bandswitches, or other components.

Sometimes many VHF-UHF modern transceivers have problems with BROADCAST Interference and CROSS-modulation from FM commercial broadcast stations this article shows a simple Batteworth HI-Pass VHF Filter to reduce this problem

Common problems and improper operations of Yaesu FL 2100 RF power amplifier

Sherwood Engineering Inc. (SEI) offers a repository of technical presentations and white papers focused on optimizing amateur radio transceiver and receiver performance. Content includes detailed analyses of _roofing filters_, transmitted IMD, and receiver characteristics, with specific discussions on products like the Drake R-4C and Icom IC-781. Presentations from events such as Dayton Contest University (2008-2014) cover topics like "How To Optimize Rig Performance," "Transceiver Performance: 10 Years of Change," and "Choosing a Transceiver: Far from Simple." Additional white papers address HF mobile antenna efficiency, ground screen alternatives to buried radial systems, and common receiver problems with solutions. The site also provides historical product information for items like the SE-3 MK IV synchronous AM detector and various 455 kHz mechanical and crystal filters, though many products are no longer in production. Receiver test data and alignment tips for the R-4C are also available, offering insights into rig modifications and performance enhancements.

This type of filter can be used in a Mode J satellite station (uplink on 2m, downlink on 70cm) to reduce the problem of the uplink signal desensing the receiver

As the sunspots return and DX propagation conditions to improve, the age old problem with QRM begins to show up on the amateur bands. Thif filter help you on improving reception

The intrepid newcomer encounters common mode problems in a mobile environment. Implementing some common mode chokes will be possible to reduce interferences

This resource details the four primary functions of a ground system: lightning energy dispersion, equipment safety, RF return path provision for end-fed antennas, and management of induced RF currents. It clarifies that a ground system's effectiveness varies depending on its specific function, noting that a good lightning ground might not be an effective RF ground. The content emphasizes that proper antenna system design, including baluns and appropriate feedline lengths, often negates the need for an RF station ground to mitigate common mode currents or RFI in the shack. The article quantifies lightning energy, stating its peak is in the dozens or hundreds of kilohertz, with damaging energy extending to hundreds of megahertz, and currents reaching thousands of amperes. It recommends solid, wide, smooth copper surfaces for ground leads to achieve low impedance across a wide frequency range. The author, W8JI, shares practical insights from his station, which includes two 300-ft towers and four 130-ft wire verticals, detailing his use of common point grounds and _DX Engineering RR-8 HD_ antenna switches for lightning protection without coaxial surge protectors. Specific examples of antenna systems prone to common mode current problems are listed, such as random wire antennas without proper feedline lengths and off-center fed dipoles. The text also explains how a ground screen or radial system can reduce local noise sensitivity for vertically polarized antennas by covering the lossy earth.

Examines the Icom IC-2100H 2-meter mobile transceiver, detailing its operational characteristics and user experience. The review highlights the clear, easy-to-read display with internal labels, the button-filled microphone's functionality, and the rig's physical construction, including its weighty heat-sink and lack of a cooling fan. It also discusses memory programming, the unique amber-to-green backlight color options, and the radio's performance against _intermodulation_ in urban environments, noting it performs "pretty darn good" compared to other rigs. The analysis delves into a significant low-voltage cutoff problem, where the microphone ceases to function below approximately **12.6 VDC**, rendering the radio receive-only or causing it to stick in transmit. The author describes testing the voltage cutoff, observing it fluctuate from _12.38 VDC_ to 12.69 VDC. An update from Icom involved a "factory update" to the CPU's control code, which is strongly recommended for early-serial number units to prevent operational failure in low-power emergency scenarios.

The lithium battery problem in the Kenwood TS-570

Problem width the memories, TS-570 Batteries, MARS/CAP Modification

Cannot record CW message, AFSK not working, tracking not working, meter peak hold, on Yaesu FT-920.

The purpose of this web page is to try to investigate some of the issues around ICOM IC-746PRO reported by many radio amateurs through out the world; and unfortunately not properly taken care of by ICOM.

Telephone EMI, questions and answers on how to solve interference problems to phone lines

Why all the mystery surrounding baluns ? To use or not to use baluns

Article on tubes and their usage in power amplifiers design. Explain failures of tube in RF power amplifiers, a common problem in the SB-220 SB-221, TL-922 and other amplifiers.

Program which will allow you easy migration from logPlus to another logging software. Tested with Logger by K4CY so let me know it you have problem ADIF import to other software.

With all the wire you have out, you may run into a problem with static buildup on the antennas. This static may try to make its way into your receiver, causing you major problems and damage that can run into a lot of money.

This article is about the characteristics and use of various filters and ferrites for solving amateur radio electromagnetic compatibility problems involving breakthrough of amateur signals into domestic equipment such as television sets, video recorders stereo sytems etc.