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eHam Forums / Antennas and Towers and more / RE: Sharing one antenna with two radios in different rooms at same QTH - ? switch
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on: April 30, 2013, 07:47:23 PM
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Another source for good ideas comes from the ham contesting world. Search the web for SO2R (Single Operator Two Radio) station designs and you'll see what I mean. Basically you can partially or fully automate the switching process to make it much safer for your radios to coexist. The goal is to eliminate human error as much as possible. Otherwise sooner or later you just might accidentally feed the output of one radio into the input of the other.
If you're going to use those radios for separate bands (like using one radio only on 40 meters and the other only on 20, 15, and 10) then I'd seriously investigate putting bandpass filters on their inputs. The filters add cost but rebuilding the front end of a modern transceiver is much more expensive.
Good luck and 73, Jim W.
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eHam Forums / Antennas and Towers and more / RE: Help with S9 31 Vertical
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on: December 18, 2012, 07:36:24 PM
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Keith, something is wrong with your antenna setup, the feedline, or the antenna analyzer. I have an old R7 vertical that I've been using for years, and it gets a reasonable SWR (under 1.5:1), both as measured on my MFJ 259 and with an external SWR meter sitting next to the transmitter. If you measure that balun with an ohmmeter you'll read something very close to zero ohms. That's normal and nothing to worry about.
Are you near a high-power RF source of any sort, like a broadcast band transmitter? If so that can overload the input of the antenna analyzer and give you bad readings. If not then let's assume your antenna analyzer is OK, and move to the installation itself.
My next questions would be: do you have the number and length of the recommended radials connected to the base of the antenna? If you measure where each radial is attached to the base plate, ring, or whatever you're using for the connection, does each radial connection measure zero ohms across it? Do the two connections between the balun's output wires and the antenna also measure zero ohms?
When you measure continuity of the coax, do you see very low resistance connections between the two center pins and between the two shields, like a fraction of an ohm? Is there any reading of any sort between the center pin and the shield? There should be no continuity whatever between the coax shield and the center conductor.
These are the sorts of things I'd check first. Forgive me if I've mentioned something obvious that you already know about. It's just that those are the problems I've encountered over the years when I've set up HF verticals. The 50-ohm analyzer reading tells me that you're probably close to having this antenna set up right. But assuming your analyzer is working OK and the antenna isn't mounted within a few feet of some big metal object, the high SWR would seem to indicate a high-resistance connection somewhere, or something wrong with the coax, coax connectors, or the radials.
Let us know how you're progressing. When you find the problem it should turn out to be something simple.
73, Jim W9FI
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eHam Forums / Computers And Software / What's easiest to use in adding QSOs from a paper log?
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on: August 15, 2012, 07:55:04 PM
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I'm looking to going back to my old paper logs, entering QSOs into some logging software, and then exporting them to LOTW and eQSL. Once I get these Q's into an electronic record form I next want to export them to other logging programs, so I can choose the best one that meets my operating style going forward.
I'm looking in two specific areas.
1. Which logging programs have the quickest and easiest data entry requirements for non-contest DX QSOs where I'll be changing dates, times, calls, bands, and modes frequently?
2. Of this group, which programs allow me to easily export the QSO file in a standard HR electronic record format, like ADIF or Cabrillo?
Thanks in advance for your advice.
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