RFI Mitigation
Radio Noise from Internal/External Sources at Radio Receiving Sites
This document was prepared because of the widespread lack of valid technical
information about site performance at all levels of receiving-site operation. For example,
the information about grounds and grounding available to site personnel was especially
confusing and often downright incorrect.
Complex analytical procedures have been avoided to make the text as readable as
possible, but it is assumed the serious reader will have a good knowledge of the physical
laws related to basic electricity. This includes an understanding of the flow of electricity
in complex circuits, some understanding of the impact of reactive impedance on the flow
of electricity, a basic knowledge of the properties of electric and magnetic fields
surrounding conductors carrying electric current at both low and high frequencies, and
the inductive and capacitive coupling of current and voltage from one conductor to
another.
The basic principles of noise and interference mitigation techniques are also included.
The integrated use of electromagnetic barriers, filters and grounds to confine
electromagnetic noise to its source device is described. This is an effective technique to
mitigate identified sources. Practical mitigation examples are described as well as
ineffective solutions. Continue reading
Review of W8WWV’s S-Meter Lite
S-Meter Lite will graph S-Meter readings in real time, save spreadsheet ready files over very long time frames of your S meter values, assist in generating a pattern for your beam antenna, show RF levels in S units or in dB, and show signal level differences in dB between one signal and another on the same graph. Continue reading
Review of the MFJ-856 Directional Noise Finder W/ 3 El. Beam
Overall it was useful to me in locating a few sources of RFI, you point it in the general direction of a noise source, and wave it around until you get a peak in the meter. Once you have that, you walk towards the source, waving the antenna around, following the peaks.
The device is reasonably well constructed, MFJ quality control seems to be good, as the unit I got has no defects in it. It came boxed nicely, and was simple to construct. There were a few items to note… Continue reading
The Mitigation of Radio Noise from External Sources at Radio Receiving Sites
Radio noise from sources associated with hardware on distribution power lines was the
primary kind of radio noise affecting the signal-reception capability of radio receiving sites for many years. Only a very few remote sites that did not obtain power from overhead distribution lines and did not have distribution lines within line of sight of the uppermost part of antennas were free from the noise problems described in this document. Continue reading
Review of ARRL Log Book of the World
The ARRL is currently sponsoring a program for exchanging QSL information in a secure way for use in obtaining various awards from the ARRL. This program is called “Logbook of the World”. The ARRL was late to the blocks in implementation, eQSL.cc was first, however the ARRL decided to implement a tighter security model than eQSL. Hence eQSL ended up being on line earlier than LOTW. Continue reading
