three phase emi filter

3 Elements on 40 Meters - The inverted "U" 3 elements on 40 meters by ik2egl

Hex Beam for 6 meters - This is a hex beam designed for six meters. It has three elements with a turning radius of 54 inches. This antenna can be built from low cost materials available from the local hardware store. By WB3BEL

2 elements U Beam for 80 meters - An U Beam antenna for 80 meters band by ik2egl

The Simple Collinear - Wherever there is a need for a vertically polarized omni-directional antenna with gain, a collinear is used. The vertically polarized collinear takes the form of two or more half waves in-line and in-phase, resulting in an omni-directional pattern with maximum radiation near the horizon.

Chokes Explained - A "choke" is the common name given to an inductor that is used as a power supply filter element. They are typically gapped iron core units, similar in appearance to a small transformer, but with only two leads exiting the housing

BiQuad Antenna for 144/440 - This is a vertically polarized Broadside and Collinear Array each Loop is a vertically polarized Broadside Array both the right and the left side of the Loop is a bent 1/2 wave dipole working 180 degrees out of phase with the other one and that gives you 4.15dbi of gain by KE4UYP

Vertical amtennas among the trees - Experiments on vertical antennas among the trees by ik2egl

Automatic SWR meter  ^updated - Automatic SWR meter and semi-automatic tuning unit by F1FRV

www.whiskyoscar.com - Dutch speaking international radio club. Established over 25 years ago. With many emigrated dutch members abroad

Ham Lookup by ZipCode - This Database Lookup will return the amateur radio call sign holders which currently hold an active license and will be limited to the zip code specified You must enter at least three digits of the desired zip code.

Shortest Vanity Callsigns  ^updated - This is a service for finding the shortest available vanity callsign in your amateur radio class. It filter through all possible callsigns and provide just the unused ones weighted by their length in morse code or their actual number of letters.

Amateur Radio Country Files - This web site represents the home of "Country Files", databases of entities (countries), prefixes and callsigns that are used by amateur radio logging software. There are three "flavors" of country files: CTY.DAT used by contest logging software such as CT, N1MM, NA, TR and Writelog DX4WIN.CTY used by the DX4WIN logging software WPXLOC.DAT used by packet cluster software such as AR-Cluster, CC Cluster and DX Spider maintained by Jim Reisert, AD1C

Chile Awards - More chielean awards including the Pablo Neruda Award

The Renfrew CountyAmateur Radio Club - The Renfrew County Amateur Radio Club is located in the County of Renfrew in the province of Ontario, Canada.

Yuma Hamfest & Electronics Expo - Yuma County Fairgrounds, Yuma AZ. On site RV/camping facilities. Seminars, Exams, Tailgating.

Accute Micro - China supplier of ceramic bandpass filters in standard resonator sizes of 2~6mm , 8mm , 10mm and 12mm with freqency from 400Mhz~4Ghz and sections 2~10

Duplexers for Ham Radio repeaters - We produce duplex filters and antennas for 2m,70 cm and 23 cm repeaters.

I6HWD Morse Key Collection - A collection of morse code keys including verticals, semi atumatic, automatic and other accessories

Phase Noise. - This is perhaps the most important parameter in many oscillators and it deserves an in-depth discussion on what it is, how it affects a system and how it can be minimised in an oscillator design.

Garth RF Filters - ATV Filters, RF filters dealer

Audio processor for SSB transceiver - This circuit consists of microphone amplifier and a high pass filter. Suitable to improve signal readability.

Second-Harmonic-Optimized Low-Pass Filters - Sometimes we need a little more output filtering than traditional designs offer. Look at a new filter that can give you that extra boost. QST article by W3NQN

500 KHz Low Pass Filter - This article describes a shielded low pass filter with a cut off frequency of about 500 KHz. It is built with components suitable for receiving, and was designed to use in front of a low frequency receiver for LOWFER work.

VHF signal generator - a simple VHF signal generator in order to measure the characteristic of low pass filter.

A single board no tuning 23 cm transverter - This transverter uses bandpass filtering with printed hair-pin filters. By KK7B