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References: [ +from:k1ttt@verizon.net: 232 ]

Total 232 documents matching your query.

1. Re: [TowerTalk] Fwd: Adjusting a Gamma Match on a Yagi with an AntennaAnalyzer (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Wed, 10 Nov 2010 07:18:31 -0600 (CST)
changing the de length has a very, very, tiny effect on f/b and gain... its only the slight difference in coupling due to the usually small changes in length that would cause changes to f/b and gain
/archives//html/Towertalk/2010-11/msg00135.html (9,411 bytes)

2. Re: [TowerTalk] which type of coax? (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Wed, 17 Nov 2010 13:42:59 -0600 (CST)
I still prefer Belden. RG8 or RG213 for indoors stuff, only RG-213 for outdoors. Now??? What are your thoughts on brands? What about types? RG8? RG213? LMR400? BuryFlex? Something else? Thanks, de Do
/archives//html/Towertalk/2010-11/msg00256.html (7,704 bytes)

3. Re: [TowerTalk] Ground Rods (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Wed, 01 Dec 2010 06:56:19 -0600 (CST)
normally when measuring ground resistances a higher voltage source is used to overcome the drift problems that you are seeing. There are also special methods used that require either a large remote g
/archives//html/Towertalk/2010-12/msg00004.html (9,280 bytes)

4. Re: [TowerTalk] Noise puzzle (longish) (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Wed, 08 Dec 2010 09:33:30 -0600 (CST)
what is the noise? does it have a power line frequency component? does it have other peaks in the spectrum, if so at what spacing? if it is just white noise is the direction dependent on the time of
/archives//html/Towertalk/2010-12/msg00202.html (9,715 bytes)

5. Re: [TowerTalk] RF current in REF + DIR ..how much ? (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Wed, 22 Dec 2010 09:41:24 -0600 (CST)
some googling will show some experimental and modeled results for this... but a bit of thought will give you some idea of what is going on. consider for example a simple 2 element yagi that is tuned
/archives//html/Towertalk/2010-12/msg00340.html (9,673 bytes)

6. Re: [TowerTalk] Fwd: WHOLE HOUSE SURGE SUPRESSORS (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Mon, 03 Jan 2011 13:16:34 -0600 (CST)
DANGER WILL ROBINSON! those two examples are both BAD! first the SurgeX one appears to show that when the MOV arresters divert current to the ground/neutral they feed that to one component, but not t
/archives//html/Towertalk/2011-01/msg00047.html (12,518 bytes)

7. Re: [TowerTalk] Fwd: WHOLE HOUSE SURGE SUPRESSORS (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Tue, 04 Jan 2011 06:36:14 -0600 (CST)
in the grand scheme of lightning protection going from 120v to 200v is MUCH better than going from 120v to 200kv or more. We don't truly mean "equalize" and "same potential" here. When MOVs conduct,
/archives//html/Towertalk/2011-01/msg00079.html (9,160 bytes)

8. Re: [TowerTalk] WHOLE HOUSE SURGE/LIGHTNING PROTECTION -resp. DAVISRF Co. (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Wed, 05 Jan 2011 11:25:31 -0600 (CST)
that would be great if you didn't ever hook up an antenna, or anything with wires to pick up induced voltage from a nearby lightning strike, and didn't power anything that had a startup or shutdown s
/archives//html/Towertalk/2011-01/msg00126.html (13,339 bytes)

9. Re: [TowerTalk] Complex Guying Question (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Mon, 09 May 2011 14:45:05 -0500 (CDT)
His question is how do you determine the tension requirement for mixed guy materials. I would recommend using the lowest tension that you would get if each material were used for the whole guy... tha
/archives//html/Towertalk/2011-05/msg00112.html (9,692 bytes)

10. Re: [TowerTalk] Plastic Antenna (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Thu, 19 May 2011 08:37:59 -0500 (CDT)
Its out there... or at least the precursors for it: http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=364418&tag=1 http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=180351 http://teramobile.org
/archives//html/Towertalk/2011-05/msg00354.html (9,044 bytes)

11. Re: [TowerTalk] Fw: Why radials improve radiation! (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Mon, 23 May 2011 11:25:52 -0500 (CDT)
<but never a discussion on why or how radials actually effect the not really beyond the scope, but often leading to long heated discussions. it does get a bit more complex than that, but thats enoug
/archives//html/Towertalk/2011-05/msg00381.html (11,859 bytes)

12. Re: [TowerTalk] Slightly OT - antenna damage (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Thu, 09 Jun 2011 12:24:17 -0500 (CDT)
i have been through this a couple times now. the process usually goes like this: 1. get a pro like k7lxc or kc1xx to write up an estimate that includes EVERYTHING, travel time for crew, removal of br
/archives//html/Towertalk/2011-06/msg00056.html (10,202 bytes)

13. Re: [TowerTalk] Antenna Stubs (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Tue, 02 Aug 2011 06:20:23 -0500 (CDT)
as long as you use decent coax putting them in a can doesn't help shielding. you also may have to worry about heat buildup if you are running power. Hi all I want to upgrade and put more stubs on the
/archives//html/Towertalk/2011-08/msg00003.html (8,284 bytes)

14. Re: [TowerTalk] Maximum Guy Radius (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Wed, 21 Sep 2011 09:03:40 -0500 (CDT)
the answer is a definate maybe... with a caveat to 'do what the manufacturer says'. The problem is that as you move the guy point farther out you increase the length of the guys which also increases
/archives//html/Towertalk/2011-09/msg00257.html (8,555 bytes)

15. Re: [TowerTalk] Celwave 4bay dipole (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Wed, 09 Nov 2011 11:41:43 -0600 (CST)
no, its worse than that... he is going lower in frequency so needs an element and coax stretcher. fortunately it is only about 1% so shouldn't be too hard. Nothing is easy.... You might get away with
/archives//html/Towertalk/2011-11/msg00151.html (8,254 bytes)

16. Re: [TowerTalk] weird coax (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Mon, 12 Dec 2011 06:29:59 -0600 (CST)
I don't know if i can trust my meters with such a high loss, but i think it is around 150 ohm... but i'm sure that none of the methods i used take into account the high loss. for instance, the minivn
/archives//html/Towertalk/2011-12/msg00292.html (9,415 bytes)

17. Re: [TowerTalk] weird coax (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Mon, 12 Dec 2011 12:55:22 -0600 (CST)
Ok, we found the original engineer who bought the stuff... he has dim memories of using it as a long high voltage probe hooked to a plate capacitively coupled to a transmission line tower to measure
/archives//html/Towertalk/2011-12/msg00313.html (8,472 bytes)

18. Re: [TowerTalk] Mastrant Rope ? guy wire ? (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Tue, 03 Jan 2012 11:57:06 -0600 (CST)
thats just a polyester rope not a tower guy material unless you need it for a temporary field day type tower. Hi TT'ers HNY Planning my spring 10 meter tower antenna 5/5 35'-72' rebuild. The 3/16 guy
/archives//html/Towertalk/2012-01/msg00059.html (8,285 bytes)

19. Re: [TowerTalk] Using an iPhone App to line up your antenna (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Wed, 04 Jan 2012 13:51:27 -0600 (CST)
maybe just use a real compass, lots cheaper than dropping an i-thingy off a tower! personally i just line up antenna booms based on known directions of either guy wires or some convenient object in t
/archives//html/Towertalk/2012-01/msg00101.html (8,238 bytes)

20. Re: [TowerTalk] Chipmunks (score: 1)
Author: David Robbins <k1ttt@verizon.net>
Date: Mon, 16 Jan 2012 09:31:26 -0600 (CST)
yes, a nice thick blob of duct seal does seem to stop mice. i think they could eventually chew their way through the foam though so where i have used that to seal holes i have first packed in steel w
/archives//html/Towertalk/2012-01/msg00284.html (14,005 bytes)


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