practical wireless số 2010 04

NOW IN NOW IN ITS 78th ITS 78th YEAR!YEAR! April 2010 £3.50 ISSN 0141-0857 Hm-r Tr rsHm-r Tr rs Pracc Way Wt Grg Ds G3RJVWt Grg Ds G3RJV Vv Nn Vv Nn SytsSyts Stf Niwiad cu s rcl  v frnc  ts Buyng S n-hnBuyng S n-hn Wt Crs Lr G4HCL Wt Crs Lr G4HCL Mng r rs 1950s Mng r rs 1950s tl t tl t B Jvs GM8APXB Jvs GM8APX Brwi  ng Day O   ArBrwi  ng Day O   Ar Wt GG100ACD n t Nrt Wl Rai Sci yWt GG100ACD n t Nrt Wl Rai Sci y D' t th pty ! D' t th pty ! Atn Wrho Mk rf  c  m tn!Mk rf  c  m tn! [...]... pleasantly surprised at how broadcast signals just ‘back off ‘the much you can hear with it regeneration control until it’s just below Cheerio for now the point of oscillation Practical Wireless, April 2010 Please mention Practical Wireless when replying to advertisements KITS, MODULES & AERIALS NEW PRODUCT POUNDBURY 20/80m SSB RECEIVER Classic superhet receiver for 20 and 80m using a 9MHz IF and a 5.05.5MHz... WM3610 33p T2 MPF102 or 2N3819 22ł 4k7 +9V 7V5 Zener 100ł 22 10ł 10ł 1 T1 2N3 904 0ł1 330p L1 7 LM386 3 100k 6 4 5 Phones 100ł VC1 10 330p 1-10k 0ł1 8 2 0ł1 Antenna 100ł 10n 47k 3k3 10n 27k 0ł1 0V L1 = 32t 28swg on T50-2 Input winding 5t on ground end of L1 VC1 = 60p section of Polyvaricon Cap 30 Practical Wireless, April 2010 Rev George Dobbs G3RJV PW Publishing Ltd., Arrowsmith Court, Station Approach,... traders) and admission will be £2.00 There will be talk-in on S22, trade stands, lectures, a Bring & Buy, catering and facilities for the disabled Laurence M0LCM Tel: 01223 654880 Practical Wireless, April 2010 E-mail: rally2010@cambridgerepeaters.net www.cambridgerepeaters.net April 11th The Lough Erne Rally The Lough Erne Amateur Radio Club Annual Rally will be held at The Share Holiday Village, Lisnaskea,... by: PW Publishing Ltd., Arrowsmith Court, Station Approach, Broadstone, Dorset BH18 8PW Tel: 0845 803 1979 Trading Post Second-hand bargains 34 Practical Wireless, April 2010 Taking the toil out of coils! Feature Done to a Turn Part 2 A gentle introduction to practical coil making! W elcome to Part 2, where I really am planning to take the toil out of coil winding by using a coil wind machine! However,... 40/20/15/10/6/2/70cm, Length just 200cm, 200W (2/70) 120W (40-6M) PL259 fitting, (Brilliant antenna HF to UHF with changeable coils) £79.95 If we advertise it – we stock it! Practical Wireless, April 2010 Commercial quality trapped wire dipoles that resonate, so require no ATU! MDT-6 FREQ:40 & 160m LENGTH: 28m POWER: 1000 Watts £79.95 MTD-1 (3 BAND) FREQ:10-15-20 Mtrs LENGTH:7.40... Approx 30ft erect 8ft collapsed £179.95 TMF-2 Fibreglass mast 5 sections 240cm each 60mm to 30mm Approx 40ft erect 9ft collapsed £199.95 PICTURES ARE FOR REFERENCE ONLY New lower prices! Practical Wireless, April 2010 Tex Swann’s antenna workshop Taking time off from making or drinking coffee, Tex Swann G1TEX makes use of the tin Tex Swann G1TEX Fig 1: When on coffee-duty at the Poole Radio PW Publishing... the idea that this was a circumference of almost 500mm, which is just quarterwave on 144MHz So, would it work as a DDRR antenna? If you’ve not heard of a discontinuous direct ring radiator Practical Wireless, April 2010 B is matched to a feedpoint impedance of 50P, suiting ‘normal’ coaxial feeder+ ⁄/4 ⁄/4 C is a low-profile ‘Blade’ antenna, but still with a feedpoint impedance of 50P+ To make the antenna... attached about 12mm from the knee bend of the antenna element When I build another version I’ll mount the BNC feed-point element version, socket from the underside of the p.c.b material 18 Practical Wireless, April 2010 omni-directional radiation pattern Look at the photographs of Fig 3 and Fig 4 and you should be able to see the layout of the antenna I’ve created To form the coffee tin top into the... 146MHz, with the best match occuring at 145.26MHz, almost in the middle of the f.m band section, thus suiting the original idea of a simple and cheap antenna to improve a hand-held radio Practical Wireless, April 2010 19 Feature Finding and choosing that tiny hand-held radio at a bargain price! Buying Second-hand There are plenty of radio goodies about and Chris will guide you to the best buys W elcome... instead there are keypad membrane Up/Down buttons for the operating frequency, plus Chris Lorek G4HCL gives a few ideas and hints on finding and buying a tiny dual-band hand-held transceiver 20 Practical Wireless, April 2010 receive volume in eight pre-set steps after a press of the Vol/Sql button, a further press of this switching to squelch level adjustment in five pre-set up-down steps The often-used buttons . y0 w1 h1" alt="" Practical Wireless April 2010 contents Volume 86. Number 4. Issue 1235. On sale 11 March 2010 Practical Wireless, April 2010 5 Copyright © PW PUBLISHING LTD. 2010. Copyright. some Practical Wireless readers’ letters The Star Letter will receive a voucher worth £20 to spend on items from our Book Store or other services offered by Practical Wireless. Practical Wireless, . ‘Visitor’ status can be clearly identified. More news when it’s available. Practical Wireless, April 2010 10 Practical Wireless Newsdesk news & products A comprehensive round-up of what’s