UPDATES  &  INFORM OTHERS While you were away.... Subscribe/Unsubscribe   AUDIO-VISUAL Economical PA Speaker Cables Focused Sound Projection Piezo Direct Input Unit Economical Hearing Aid Loop Loops from Headphone Sockets Planning a Hearing Aid Loop SCART Pinouts Testing Hearing Aid Loops   RADIO 2 Band Dipole Antenna gain explained Cheating with Antenna Gain Choosing the correct antenna Converting µV & dBm Emergency antenna Lightning Protection: Why use it? MW Reception Antennas Simulcasting Techniques Tuning Traps Without GDO Wide Band HF Antenna   PROCESS CONTROL  &  I.T. A Real LAN twist cable Access LAN devices via GSM Good LANs in Noisy Sites Splicing CAT-5 Cable Ensuring Signal GND on RS232 Handy RS232 Sniffer Probe Protecting Notebook RS232 Ports RS232 Break-Out Box Understanding RS232 Using PC RS232 ports Using RS232 over long distances Using RS232 and Modems Using RS232 to Power Devices Upgrading NetGear DG8x4 Routers Careful of Common Mode Voltages   POWER  &  HV Generating 3-Phases from 2 Powering AC Adapters on DC Mains Spikes worse on Live or Neutral ? Suppressing Appliance Clicks Why a TV Chassis "Bites" Why a diode in line with this coil?   TEST  &  MEASUREMENT Analogue Multimeters and dB Deaf Aid Loop Tester Economical Impulse Generator Extending the HV input range "Lamp-Fuse" for safe 230V repair Locating Cable Shorts Measuring beyond 230VAC Measuring in Excess of 1kV RS232 and Instrumentation Simple Logger Input Amp "Soft Earthing" Instruments Summing CT Values Telephone Line Monitor When is a lead-acid dead!   OTHER Extending BT Telephone Sockets Low Energy Pet Repeller Mains LED Pool Algae Eliminator Resistor Attenuator tables The Ultimate Travel Adapter LINKS Some Interesting Sites Email the Author Using these Framed Pages   Independent Fault Investigation and Analysis Consultancy