Project Solutions (2011/08/23)
Index
Butterfly Dipole for DVB-T: Simple and economical DIY indoor antennas 3
Published:2011/8/23 22:12:00 Author:Amy
Rolf Badenhausen Construction The whole butterfly dipole antenna assembly, including transformer and coupling capacitor, is only the thickness of a ballpoint pen. It can be constructed on a single-sided piece of 1.5 mm thick epoxy resin printed circuit board. The mounting ... (View)
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Butterfly Dipole for DVB-T: Simple and economical DIY indoor antennas 2
Published:2011/8/23 21:59:00 Author:Amy
Rolf Badenhausen Butterfly dipole The real antenna impedance of a butterfly dipole is of the same order of magnitude as that of a hill-wave dipole. For such a full-wave dipole system a typical impedance would be between 240 Si and 300 Q, and in practice probably nearer 300 SI than 24012. In any case, matching is required to the nominal 75 Q input impedance of the antenn... (View)
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Butterfly Dipole for DVB-T: Simple and economical DIY indoor antennas 1
Published:2011/8/23 21:43:00 Author:Amy
Rolf Badenhausen Digital terrestrial television (DVB-T) is now available in many parts of the country. Of course, you need a DVB-T receiver and a (new) UHF TV antenna. If you don’t have a suitable antenna, the small indoor DIY alternative described here is a simple and economical solution. Terrestrial digi... (View)
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VHF FM Antenna Booster: New horizons in 3-metre band DXing 3
Published:2011/8/23 2:32:00 Author:Amy
N. S. Hori Sankar VU3NSH Setting up Give the PCB a final, thorough inspection for bad soldering, wrong components, etc., and resolve all problems before proceeding. Set all presets and trimmers to the centre of their travel. Apply power to the amplifier and check the various test voltages indicated in the circuit diagram. These voltages are typical and should not be taken to mean the ’law’ ’... (View)
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VHF FM Antenna Booster: New horizons in 3-metre band DXing 2
Published:2011/8/23 2:28:00 Author:Amy
N. S. Hori Sankar VU3NSH Construction The amplifier is built on the single-sided printed circuit board shown in Figure 2. The inductors in the design are all very simple to make, see the parts list for construction details. LI, 1.2 and L3, are wound on a 4.5-mm dia. drill or pencil. LI then needs to be stretched to a length of about 10 mm. You’ll find that a relatively large (View)
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VHF FM Antenna Booster: New horizons in 3-metre band DXing 1
Published:2011/8/23 2:17:00 Author:Amy
N. S. Hori Sankar VU3NSH Together with a good directional antenna this high performance two-stage antenna amplifier for the VHF FM broadcast band will enable you to capture far removed (DX) stations. Alternatively, it will drastically improve reception of FM signals you’ve come to accept as marginal and noisy in your area. FM broadcast(View)
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Part 1: PCB design basics （2）
Published:2011/8/23 1:58:00 Author:Li xiao na
By Karel Walraven Get cracking We’ll now gel lo work, keeping the above information in mind. A little bit of searching on the Internet will quickly produce a number of free demo versions of nice printed circuit board layout software. At the end of the article we have included a few links lo get you started. When designing a PCB layout you start with the fixed constra... (View)
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Part 1: PCB design basics （1）
Published:2011/8/23 1:26:00 Author:Li xiao na
By Karel Walraven What do most electronics engineers enjoy a lot? Designing printed circuit boards, of course! In an irregular series of articles we would like to familiarize you with this subject. We start as simple as possible and it will become more difficult as we progress. Feedback and requests to cover certain topics are encouraged and welcomed! When you’re just designing ... (View)
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