The following first appeared on the UK packet BBSs: INSULATING VARNISH Insulating varnish for coils is made by dissolving shellac in methylated spirits. Proportions: one ounce of shellac to quarter pint of spirit. CHATTERTON'S COMPOUNDS Chattertons compound is a plastic insulating material often used by electricians in joints, etc. It is made from 3 parts of gutta percha, 1 part of resin and 1 part of stockholm tar. from ELECTRIC HINTS AND GADGETS Pete, G4MRU NEED A PP3 TYPE CONNECTOR? IF you are stuck for a 9v battery connection , for your construction then get an old PP3 type battery , and using a pair of cutters grip the top side on , pull downwards and peel the metal case away from the plastic connector ... then ones opened , just cut the 2 wires , or in some cases a metal band and wire .... simply solder to these two contacts and insulate the back .... Please be careful , of the sharp edges that can cut you once the battery has been opened , i suggest you wrap it up in plenty of news paper and dispose of it in the bin Wash your hand properley , and if you feel it necessary to wear gloves, or eye protection then i suggest you do you .... just in case of any acid droplets hope you find the info useful Paul G7IZX CARBON LAMPS GIVE UV RAYS It is claimed that therapeutically active ULTRA VIOLET RAYS compararable to mountain sun treatment are emited by carbon filament lamps when screened by a sheet of horticultural or vita glass. The glass is mounted in front of an ordinary bowl reflector (as used for bowl fires) with a 32 c.p. or 50 c.p. carbon lamp giving a pleasant sensation when bathing in the warm rays... from :- ELECTRIC HINTS AND GADGETS. Pete, G4MRU FROSTING OR COLOURING LIGHTING GLASS A pleasing frosted effect can be given to the glass of lighting fittings by dipping in or painting with a solution made up as follows. To 5 parts of Epsom salts and 2 parts of white Dextrine (obtainable from most chemists) add 20 parts of water. Mix by first disolving the Epson salts in hot water and then adding the dextine. If a coloured finish is required, add any ordinary water dye. Pete, G4MRU TRACE THAT INTERFERENCE! Are you having difficulty in finding interference in your shack or noises , burps , or other such strange things ? Well a small telephone pick up coil , plugged into a small walk about amplifier , like a baby alarm , or intercom master . will help you locate some of them noises , hopefully walk round your shack holding the pick up coil in one hand and the Amp within a 12 inches of your ear , making sure the volume is not to loud Now follow your audio , rf leads by moving the coil around and down the leads and see if they start to make any noises in the amp that you would not expect .. like wise holding it near clock-radios ,frequency displays , computers , tnc , receivers or anything else in the shack .and especially anything with micro processor in will give off different noise , power supplies are really good to listen to , likewise tv screens Anyway this might be the one of the noises you are getting on your transceiver , thus you will be able to put your finger on the culprit . which one is causing the noise I myself had a noise on 24-mhz to about 40mhz and using the method above found that my RF LEAD FROM MY COMPUTERS MODULATOR , had a nick in the outer sheath by moving the pickup coil down the coax I discovered a faint noise , until i came across the cut , then it became loud! once this was found i replaced the lead and hey presto my noise disappeared >>>> THIS PICKUP COIL ALSO WORKS THROUGH PLASTER BOARD WALLS <<<<< >>>> WHEN LOOKING FOR LIVE WIRES , WHEN PUTTING UP SHELVES <<<<<< PLEASE NOTE: THIS IS NOT A 100 PERCENT INDICATION THAT THERE ARE NO OTHER LIVE WIRES , OR WIRES THAT ARE NOT BEING USED AT THE PRESENT TIME , PLEASE PLEASE , DONT USE THIS METHOD AND TAKE ANY NOTICE TO YOUR FINDINGS , USE ONLY AS A GUIDE , AND I SUGGEST YOU USE A PROPER PIECE OF EQUIPMENT MADE FOR THE JOB , OF FINDING LIVE WIRES , AND PIPE-WORK STUDS , SOLDERING OUTSIDE When soldering aerial wires outside clean and make the joint in your usual way. Wrap multi-cored solder around the joint then wrap kitchen foil over the joint.(one thickness is enough or it slows the heat transfer).Apply heat and you get a perfect soldered joint. If the wires are thin and it is a calm day you may find a cigarette lighter will provide enough heat but for thicker wires or a cold windy day you will need a small blow torch. You can tell when the solders runs because the flux burns with an orange flame as the gases come out of the tinfoil. GM3UHT IS YOUR MICROWAVE MODULES LINEAR GETTING TOO HOT ??? Then get a 12v brushless fan the type used in power supplies and the like they have a case that surrounds them ,Next screw 4 small wooden dowels to the base using the holes that normally bolt it to a case. then stand the dowels in the deep groves on the heat sink so that the air blows down onto the heat sink .. it will look something like this when finished If you are a gardener you might find, as I did, that the reels of soft string used to tie up plants become tangled. Take an empty squeezy bottle and remove the little "jet" from the spout. Cut the bottle in two and feed the string though the hole in the top half. Force the bottom of the bottle over the top, Usually it is a tight fit, but you might need to use sticky tape to secure the halves together. You can then use the string without it tangling. Tom, G4UGR NEED A HEAT SHUNT? If you dont own a heat shunt , then a heat shunt can be made out of a 4mm split pin , this is just slid over the leg of the component when soldering the rear .. in theory the heat will travel up the split-pin rather than heating the component up ..thus preventing it from burning out . a proper shunt is made of aluminum ,but the steel split pin heat shunt is better than none at all .... G7IZX QUALITY VALUE RESISTORS Ever had an occasional job requiring a particular value of Resistor ?. For example, a 10M for checking the Resistance range on your meter? If you do, get four of the best quality you can afford, and put them in series/parallel. It will tend to reduce the errors of the tollerance and gives better confidence in the result. G8UYZHave you any 'top tips' to add to these? Just let me know!