notch filters

G3SEK's Amateur Radio Technical Notebook - A lot of good informations concerning antennas, filters, moonbounce, and circuitry data.

Workman Electronics - Amateur radio accessories, power supplies, tvi filters, speakers, microphones, swr meters, preamplifiers, switches, cable and connectors,

K-Com - comprehensive line of products for rejection of Radio Frequency Interference (RFI) to telephone equipment.

Eurofrequence Dierking NF HF Technik - UFB Hamradio audio filters and more accessories

Array Solutions - WX0B - Stacking and phasing HF and 6m arrays antenna switches and contesting devices. Custom low band antenna arrays, bandpass filters,commercial/Mil STd filters,microwave components, commercial broadcast filters.

Hi-Q Antennas - HF Ham Radio mobile operation antennas manufacturer, W6HIQ, HA5CMG, VE7BOC, HF mobile antennas, screwdriver antenna, coils and filters.

WIMO - All kinds of antennas, RF connectors, radio transceivers and accessories like power supplies, morse keys, lowpass filters and so on.

Dunestar Systems - Manufacturer of single band and multiband transceiver bandpass filters for HF. High pass filters, two radoi headphones mix and switch, 6 meter portable antenna, antenna remote switching and steering.

Davis RF - provide electronic and electrical wire, cable, RF connectors, DSP audio filters, rope, non-conductive guy cables for aerial or tower support; plus sundry aerial related parts

Palstar - Receivers, Antenna Tuners and accessories, antenna analyzers, dummy loads, wattmeters, shortwave radio receivers, baluns, filters

Timeware tech. - Amateur Radio Products, Noise Reduction Filters, Data Controllers, deviation meter, Software, DSP-RTTY

INRAD International Radio - Supplier of custom designed, high performance quartz crystal filters for communications receivers and transceivers, for Yaesu Icom Kenwood and Collins radios

Heros Technology Ltd - HF Radio Preselectors,BCB filters,Low Pass filters,Band Pass filter

HD Communications - Rf Connectors,RF Amplifiers,RF Filters,HF cable and accesories. Tower hardware valves and tubes

Kiwa - Filters and performance upgrades for many receivers

Industrial Communication Engineers - RF parts, filters, rf switching products.

Bencher Inc. - Paddles, Keys, Filters, Antennas

RMS international - RMS International, italian distributor of Alcava batteries and power supply, since 1975 manufacture power amplifiers, watt meters, antenna tuners, TVI filters and other accessories for hams and cb radio

AEA - AEA Technology Inc. is a pioneer and leading manufacturer of RF and cable test equipment for the wireless, Telco, CATV, NMR & MRI, RFID, telemetry, aviation, commercial, military, and two-way radio industries. Produces SWR Meters, Pre Amplifiers, filters, power meters and antenna testing products

Vectronics - Antennas, Filters, accessories, wattmeters, tuners and amplifiers.

WINRLC - Simple freeware tool to calculate several kinds of HF filters. Use to calculate L-C and R-C band filters and bandpasses, L-C, L-R and R-C highpasses and lowpasses, coils and capacitors.

MultiPSK  ^pop - Windows freeware miltimode program by F6CTE that supports BPSK31 QPSK31 PSK63 PSK63F PSK10 PSKFEC31 PSKAM CW CCW THROB 4 bauds THROBX RTTY SITOR-AMTOR-NAVTEX FELD HELL PSK JT65 HELL HF FAX SSTV FILTERS

DXCluster for iPhone  ^updated - DXCluster let you know in real time who is on the frequencies and where it was listened the last time. It let you create filters to only see which frequency/CQ Zone/ITU Zone and/or Country and after that you can have an alarm corresponding to a specific Zone or a specific country that raise a popup

TVI and BCI Filters - TVI and BCI bandpass and bandstop filters in SMD technique. Schematics and images.

K1TTT Technical Reference Priority listing - Technical reference about Accessories, Amplifiers, Antennas, Cable and Connectors, Filters, Geography, Grounding, Gunk, Matching Networks, Projects, Propagation Info Radios, RFI/EMI, Rotors, Station Setup, Towers.