Presentation on theme: "CTU Presents Station Notebook & Your 2013 Antenna Projects Tim Duffy K3LR."— Presentation transcript:
CTU Presents Station Notebook & Your 2013 Antenna Projects Tim Duffy K3LR
Contest University Update 7 th year for Dayton CTU 5 years for CTU Italy CTU Finland July 2012 CTU Australia Feb 2013 CTU Brazil April 2013 Over 3000 students have now attended CTU CTU Live Stream Look for more exciting CTU developments
Getting the most out of CTU 2013 Ask lots of questions this weekend and keep notes – if you are not asking questions you are falling behind! Meet someone totally new and ask them why they came to CTU Share some of your “secrets” with others here at CTU Commit to giving a CTU related talk or write a contesting article - in the next 12 months.
K3LR 2013 Notebook Ahha #1 RX Preamps can be good and can be bad. Be very careful with preamps around TX RF antennas Even the best preamps will cause bad IMD and harmonics when close TX overloads Using protection circuits that turn off (bypass) preamps when TXing - is a good option. Use BandPass filters when you can. The KD9SV Front End Saver is a good idea.
K3LR 2013 Notebook Ahha #2 Trying to RX in the same band you are TX (Field Day for example) is VERY hard to do. Proper placement of vertical and horizontal antennas (even close spaced) can provide amazing results. The placement is not super critical – once you know where the null is – and why it is there. Compromised configurations will reduce the isolation. This is not a fix all “tool” and your station “system” still needs to be very “tight” for best results.
100 watts is +50 dBm All horizontal antennas at 35 feet. One TX and One RX antenna on 20 meters Case #1 - 2 dipoles, spread 300 feet broadside to each other (worst case) = +17 dBm Case #2 – 2 dipoles, spread 300 feet side to side (both the same direction) so tip to tip = -10 dBm Case #3 – 2 three element Yagi’s spread 300 feet both at 0 degrees (max side isolation) = -20 dBm Case #4 – a dipole and the ¼ wave vertical spaced 75 feet = -160 dBm (the K3LR ahha) Case #5 - The vertical and dipole – 75 feet apart – but off the “tip” of the dipole (worst case) = +13.5 dBm
Your 2013 Antenna Projects I hope you add to, change or improve your own antenna system this year! Share your CTU passion with others – help THEM put up or fix an antenna. Have an open heart to all who are willing to learn – encourage and send congratulations emails. BE AN ELMER! Be active in your local club – not just Field Day. Join, pay dues and contribute your time experience! Help at least TWO operators with their antenna systems and be active in your local club = a CTU 2014 discount!
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