danazlin
| Joined: | Sat, Apr 4th 1998, 00:00 | Roles: | N/A | Moderates: | N/A |
Latest Topics
| Topic | Created | Posts | Views | Last Activity |
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| Battery Recommendations | Sep 21st, 01:22 | 1 | 316 | on 21/9/24 |
Latest Posts
| Topic | Author | Posted On |
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| Battery Recommendations | danazlin | on 21/9/24 |
| I have a G90 that I want to set up for portable use. I estimate that a 10-20AHr battery will be a practical choice. LiFePO4 technology seems the most practical as long as it doesn't die after a few charge cycles. My question is your opinion on the brand and size of battery that I should be considering? KE6PO |
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| Which Wire for 40 meters | rsaun58043 | on 21/9/24 |
| Use whatever you have as you will probably go through several iterations of your antenna design before you settle on one for long term use. My first was made from 18AWG insulated stranded hookup wire. Great antenna. For longer term planning, W4IQ is right: you don't want wire that will stretch or break. Breakage is obviously bad. But stretching is more common, especially when using soft copper wire. This will change the resonant point & SWR of your antenna. Long term wire antennas usually are made from wire that will not stretch or break when the wind blows. (Although there are also mechanical methods to mitigate this.) Typically, these are hard drawn copper, copper clad steel, kevlar reinforced copper wire, or something similar. Lots of people get good results from 16 or 14 AWG THHN copper house wire as the jacket helps support the wire and it is big enough to resist stretching excessively. Though YMMV. There is also specialty stealth antenna wire at 22 or 24 AWG whose wire strands are interwoven with strands of Kevlar to add strength. The jacket is UV resistant and the kevlar mitigates the stretch and low strength of the wire. Great wire for stealth antennas. Good luck. KE6PO |
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| Curious how good of an antenna I had? | KF6HHH | on 21/9/24 |
| Repeat after me: "Any antenna is better than no antenna" "All antennas are a compromise" That said, are you able to get a match on your 100' dipole? A decent SWR? What kind of balun are you using (1:1, 4:1, 9:1 or something else)? Are you using a choke? What bands can you tune it to? Are you using a tuner? 100' is close to the 3rd multiple of 14.2Mhz (99' actually). You are longer than a half wave on 40M, so you might get something there. For a resonant dipole you won't get good results on 10.1Mhz or 18Mhz, as those are even multiples. It might work on 10M as it is twice the 3rd multiple. On the other hand, 84' or 107' is a reasonable length for an end fed non-resonant long wire antenna for HF and might be a better option. If you can get it a few inches away from the roof that would help, but isn't critical. KE6PO |
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| OCF in Inverted V support point | K7IOC | on 21/9/24 |
| Can't address the pattern off hand (as that is usually a function of the OCF ant design... where your mileage may vary), but two concerns about the mechanics are worth mentioning. First, the center point is good for support when the weight distribution is equal on both legs of the antenna. But the OCF feedpoint will weight down one leg and potentially cause problems. You might mitigate that with a secondary support under the feedpoint to support its additional weight. Secondly, the feedline is usually positioned to exit the feedpoint at 90 degrees from the plane of the antenna when configured as a horizontal dipole. Moving too far from 90 degrees can alter the Z match to the antenna depending on how the matching system is configured. Running the feedline 90 degrees from the plane of the feed leg down to the center support and then down to the ground will likely give the best performance. |
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| Antenna under Roof | d.lowrey@cox.net | on 21/9/24 |
| Keeping in mind that wire is your friend, you have two options: 1. OCF dipole set up as a horizontal V config along your 20' and 30' path. 2. End Fed wire about 48' long along the same path. That one is non-resonant and (with a tuner) will probably give you good HF coverage. Also, in my experience, HOAs have very little basis to complain about wire antennas that are "stealthy" due to PRB1's admonition that local laws and ordinances be "reasonable." In my own case the city specifically states that there are no restrictions on wire antennas. And, unless the HOA has specific language prohibiting a wire antenna (satellite TV antennas are a bigger eye-sore), they are unlikely to object. And, if they make an issue of it, you can point out the public safety role of HR during disasters and your potential services at such a time with your "modest" Federally licensed station. |
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