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eHam Forums / Antennas and Towers and more / RE: Hex Beams?
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on: Today at 09:39:40 AM
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It seems you've looked into zoning requirements enough to find a height restriction. It might be a good idea to look a little closer at the regulations. Some zoning requirements will not allow a tower that high to be that close to the property line (or another structure for that matter). Others may but might require a variance or a special permit. It's certainly worth checking on before you get the tower up and discover there's a problem.
73,
Don, K2DC
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eHam Forums / DXing / RE: Tromelin 2014
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on: June 16, 2013, 06:33:46 AM
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Excellent News! Tromelin and Amsterdam & St. Paul are two of the five I have left to go and both coming up next year. And I thought I was going to have to wait an extra year for Heard for an ATNO (assuming I git 'em, of course).
73,
Don, K2DC
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eHam Forums / Elmers / RE: TS-940 Microprocessor Reset Question
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on: June 16, 2013, 06:20:32 AM
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REsetting the microprocessor will not help. The TS-940S Service Manual is available for download here: http://qrzcq.com/pub/RADIO_MANUALS/KENWOOD/KENWOOD--TS-940-Serv-Manual.pdfOn p. 69 there is a procedure for adjusting the Standard Oscillator which requires a lab quality 50 MHz signal generator and a 50 MHz scope. If you don't have those available, you basically have two options: 1. Send the rig to someone reliable for a full alignment. Check the reviews section under Amateur Radio Equipment Repair . 2. Learn to live with it. It's off by 50 Hz, and for a rig that's between 21 and 29 years old, that ain't half bad (as long as it's stable). 73, Don, K2DC
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eHam Forums / Elmers / RE: Stuck up a tree!
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on: June 14, 2013, 04:53:19 PM
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As far as getting it down - without a climber about all you can do is yank it and pray. I've always done something similar to what N4HRA suggested, but a simple snap-ring works just about as well as a pulley and it's a lot cheaper.
73,
Don, K2DC
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eHam Forums / Antennas and Towers and more / RE: Balun/Isolator on a Half-Sloper
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on: June 14, 2013, 04:28:20 PM
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Just to clarify - The shield of the coax is bonded to the downlead from the lightning rod which in turn is bonded to a ground rod at the base of the tower. The type of isolator I had in mind is ferrite beads over coax, which should not impact the connection from the shield to its ground return. My concern was the proximity of the coax bundled with that ground return, and any coupling that would result. Which brings the question - How effective is a choke balun at the feed point of any tower mounted half sloper if the coax is taped to the tower all the way down. I understand the comment about the effectiveness of a choke that happens to be placed at a common-mode current null.
73,
Don, K2DC
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eHam Forums / Antennas and Towers and more / Balun/Isolator on a Half-Sloper
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on: June 14, 2013, 01:54:04 PM
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Okay guys, looking for opinions. I'm getting a little RF in the shack from my low band antenna. It's an Alpha Delta DX-A. It's a half sloper for 80M in parallel with a trapped/loaded half sloper for 40/160M. Because it's hanging from my Hazer I can't bond the coax shield to the tower at/near the feed point. It's bonded to the downlead from the lightning rod above the beam.
So I'm considering putting a current balun/isolator in line to knock down some of the common mode RF. I don't know that it will help much to put it at the feed point, because the coax is bundled with the downlead which is essentially the other half of the antenna. It seems to me that the RF is just going to couple back on the shield after the isolator. I'm considering putting it at the bottom of the tower after the coax and downlead come out of the bundle and head in different directions. Whatever's coupled on between the feed point and the isolator should have little or no impact on the pattern because it's already bundle with half the antenna.
Any thoughts?
73 All,
Don, K2DC
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eHam Forums / Elmers / RE: Kenwood TS-120S Freq Display problem
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on: June 11, 2013, 02:01:27 PM
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I believe that's an indication that the PLL is coming unlocked. I once had a TS-440 with a somewhat similar problem. If that is th case, it will likely need component-level troubleshooting and repair.
73,
Don, K2DC
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eHam Forums / Elmers / RE: Kevlar or Dacron for guy-rope?
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on: June 07, 2013, 01:46:38 PM
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Agree that it depends on what you want to do. Dacron will stretch while Kevlar is resistant to that. Dacron is more UV resistant than Kevlar, but Dacron over Kevlar is out there as well. My choice would be Dacron for wire antennas, Dacron covered Kevlar for guys.
73,
Don, K2DC
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eHam Forums / Amplifiers / RE: SB200 amp.
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on: June 05, 2013, 02:22:37 AM
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Mike,
No you can absolutely NOT use 811A's in an SB-200, you will destroy them. The nominal plate voltage (no load) of an SB-200 is around 2300V. The maximum rated (ICAS) plate voltage for an 811A is 1500V. You can always use a 572B in place of an 811, but never the other way around. Unfortunately I no longer have an SB-200 (I'm in Lafayette) to test the tubes, but there must be several around because I bought both the one's I've had locally. You should check around some more, and maybe ask around at the RAGS Hamfest on 7/14.
73,
Don, K2DC
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eHam Forums / Elmers / RE: Yaesu microphone
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on: June 04, 2013, 05:17:50 AM
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Agree that a D-104 should work just fine, and you probably want an unamplified one. Tons on eBay for less than $50 and several listed here and on QTH.com.
73,
Don, K2DC
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