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As far as pre-amp and booster amps, make your decision on noise figure. ATSC is very sensitive to noise, so get the lowest noise amp no matter the company. And with that you can get a good gain amp too... I have a pre-amp, and a distribution amp. and ground everything, it keeps the noise down too..
dtvmcdonald; where can I find good antenna design stuff so I can make myself a better yagi for those trouble stations....? Thanks.
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Yes you can call me "Squirrel boy" Last edited by Username1; 06-15-2013 at 03:30 PM. |
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#2
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Quote:
old special ones the made for antennas and transmission lines. Let me search eBay ... search for ARRL ANTENNA. They are there, cheap. For the plain Antenna book, 60s or 70s or early 80s should have what you need. There is also a current "classic" one that might. In any case ... what I used was a very basic multielement Yagi for 432 Mhz simply scaled to the frequency I wanted. The only problem is the coax attachment. I STRONGLY suggest a driven element that works like the old twin-lead antennas, a 4:1 step UP in impedance ... the natural impedance is about 25 ohms. For balun use the kind that attaches the coax directly to the two elements, and has a 1/4 wave piece of 1/2" copper tubing attached to the shield of the coax 1/4 wave plus 1/2 inch down. I can email you a design scanned from an ancient book. These things are NOT CRITICAL ... they just work, and put commercial ones in their rear view mirror. For indoor use or reachable outdoor, you can make the boom out of 3/8 in copper, steel, or brass rod or tube and the elements out of 1/8 inch copper rod or tuning, soldered on. Equally important is the preamp. I suggest the best, the difference really does matter: http://www.advancedreceiver.com/page12.html near the bottom, the 0.6 dB one for TV, its GaAsFET and not cheap. Made for specific channel, but rather wide, see the Amateur or Commercial pages for price, its same as nearby standard ones. Really ... the difference between this and a wideband one is just what the specs say. For digital 1 dB is a really huge difference if its on the edge. Really. Last edited by dtvmcdonald; 06-17-2013 at 03:43 PM. |
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