Search String: Display: Description: Sort:

Results:

References: [ +from:jim@luxfamily.com: 315 ]

Total 315 documents matching your query.

201. Re: [TowerTalk] solid THHN vs jacketed copperweld (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Tue, 27 Sep 2022 16:39:04 -0700
I know this is a scenario of diminishing returns...how many skin depths does one shoot for? That's an interesting question.  It has to do with the fraction of current in the "skin".  If you've got 5
/archives//html/Towertalk/2022-09/msg00142.html (14,812 bytes)

202. Re: [TowerTalk] solid THHN vs jacketed copperweld (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Tue, 27 Sep 2022 21:31:23 -0700
John KK9A Skin depth in copper at 4 MHz is 1.3 mils, 32 microns. skin depth calculator at microwaves101.com I used 1.62 as the resistivity of copper. https://www.microwaves101.com/calculators/869-ski
/archives//html/Towertalk/2022-09/msg00144.html (9,193 bytes)

203. Re: [TowerTalk] Portable soldering iron (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Thu, 29 Sep 2022 15:17:49 -0700
I've used the propane torch soldering tip attachment. They are quite large for small, "tight" spaces like on a 'Jones connector. Even worse is the flame/heat that shoots out from the side holes that
/archives//html/Towertalk/2022-09/msg00155.html (8,948 bytes)

204. Re: [TowerTalk] Tower base equipment enclosure (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Mon, 3 Oct 2022 07:10:50 -0700
I am familiar with Hoffman enclosures, however I might want to place a mini-PC/Raspberry Pi (for wireless antenna switching) or even a QRO remote antenna tuner along with several stack matches in the
/archives//html/Towertalk/2022-10/msg00010.html (9,102 bytes)

205. Re: [TowerTalk] Tower base equipment enclosure (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Mon, 3 Oct 2022 07:12:12 -0700
On 10/3/22 6:42 AM, Grant Saviers wrote: Not at the tower base, but I use a 42h x36w x18d office supplies cabinet, 2 doors for my entrance j-box.  I bought the welded up one. 3x 3" + 3x 2" bottom and
/archives//html/Towertalk/2022-10/msg00011.html (8,647 bytes)

206. Re: [TowerTalk] Peak Voltage at the tips of ants ? (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Tue, 4 Oct 2022 08:30:26 -0700
Same question, but ant is not full size, and may have various forms of loading schemes used. (Say 50-80%) of full size. Ok, what about a single, full size 1/4 wave vertical ? Or a loaded vertical ? I
/archives//html/Towertalk/2022-10/msg00019.html (9,953 bytes)

207. Re: [TowerTalk] Peak Voltage at the tips of ants ? (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Tue, 4 Oct 2022 08:45:10 -0700
On 10/4/22 8:30 AM, Lux, Jim wrote: On 10/4/22 8:07 AM, jim.thom jim.thom@telus.net wrote: Ok, simple question.  With 1.5 kw (measured at feedpoint)  applied to the 50 ohm input  of the (full sized)
/archives//html/Towertalk/2022-10/msg00020.html (11,224 bytes)

208. Re: [TowerTalk] Fwd: Peak Voltage at the tips of ants ? (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Tue, 4 Oct 2022 09:06:57 -0700
In theory (!) all the power would have been radiated by the time you get to the tip - so zero voltage. However the real case is very complex and depends on the environment and therefore the actual im
/archives//html/Towertalk/2022-10/msg00023.html (10,630 bytes)

209. Re: [TowerTalk] Fwd: Peak Voltage at the tips of ants ? (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Tue, 4 Oct 2022 10:50:08 -0700
yes.. The power radiated is related to the current, and since the current is highest at the feedpoint (for a half wave dipole) that's the part that radiates the most. That's why shortened antennas wi
/archives//html/Towertalk/2022-10/msg00033.html (15,352 bytes)

210. Re: [TowerTalk] Voltage at Wires End (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Tue, 4 Oct 2022 13:26:05 -0700
You might look at this approach. While a bit theoretical, the concept seems sound.  https://www.witpress.com/Secure/elibrary/papers/BE99/BE99016FU.pd <https://www.witpress.com/Secure/elibrary/papers/
/archives//html/Towertalk/2022-10/msg00035.html (11,872 bytes)

211. Re: [TowerTalk] Peak Voltage at the tips of ants ? (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Wed, 5 Oct 2022 06:52:14 -0700
Is this no longer a thing? Kurt The picture is probably an example as a teaching aid.  In real life, the meter (and the leads) would affect the currents and voltages in the antenna, since the antenna
/archives//html/Towertalk/2022-10/msg00047.html (9,120 bytes)

212. Re: [TowerTalk] Peak Voltage at the tips of ants ? (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Wed, 5 Oct 2022 06:57:28 -0700
On 10/4/22 11:28 PM, Jim Brown wrote: On 10/4/2022 10:30 PM, KD7JYK DM09 wrote: I may be crazy here, but, am I the only one that remembers using, and all the drawings in all the books of using, a met
/archives//html/Towertalk/2022-10/msg00048.html (12,847 bytes)

213. Re: [TowerTalk] How to calculate aluminium transmission line impedance? (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Sun, 9 Oct 2022 21:26:33 -0700
https://hamwaves.com/zc.square/en/ Running this gives a value of about 115 ohms. The fact that it is aluminum doesn't affect Zo it would affect the loss, but not Zo.  There might be some sort of weir
/archives//html/Towertalk/2022-10/msg00063.html (9,674 bytes)

214. Re: [TowerTalk] How to calculate aluminium transmission line impedance? (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Tue, 11 Oct 2022 14:03:09 -0700
Is there a similar calculator for "angle" conductors - e.g. the "half a square" conductors used in some commercial antennas? Viewed from one end, they might be an 1/2" or 3/4" "L" with the top/bottom
/archives//html/Towertalk/2022-10/msg00080.html (10,392 bytes)

215. Re: [TowerTalk] stretched EHS (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Wed, 12 Oct 2022 16:04:34 -0700
It's a fair ways from yield (fy) to failure  (fu) for steel. I don't know the alloy here, but looking over a table, it looks like fu is 10% higher than fy for most of the "high strength" steels. EHS
/archives//html/Towertalk/2022-10/msg00085.html (9,418 bytes)

216. Re: [TowerTalk] Peak Voltage at the Tip of Antennas (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Thu, 20 Oct 2022 13:50:34 -0700
73, Pete N4ZR Check out the new Reverse Beacon Network web server at<https://reversebeacon.net>. For spots, please use your favorite "retail" DX cluster. On 10/20/2022 1:43 PM, Edward McCann wrote: I
/archives//html/Towertalk/2022-10/msg00146.html (9,371 bytes)

217. Re: [TowerTalk] Peak Voltage at the Tip of Antennas (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Thu, 20 Oct 2022 13:53:30 -0700
73, Pete N4ZR Check out the new Reverse Beacon Network web server at<https://reversebeacon.net>. For spots, please use your favorite "retail" DX cluster. On 10/20/2022 1:43 PM, Edward McCann wrote: I
/archives//html/Towertalk/2022-10/msg00147.html (9,713 bytes)

218. Re: [TowerTalk] Sources for SS Hardware ?? (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Fri, 11 Nov 2022 06:36:36 -0800
https://www.energy.gov/sites/default/files/2022-05/Fastener-Headmark-List-2022.pdf https://www.standards.doe.gov/standards-documents/1200/1221-bhdbk-2016/@@images/file On Fri, Nov 11, 2022 at 5:12 AM
/archives//html/Towertalk/2022-11/msg00062.html (9,921 bytes)

219. Re: [TowerTalk] TIC-Ring Question (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Fri, 11 Nov 2022 13:16:48 -0800
On 11/11/22 12:24 PM, Mike Lyon wrote: If I was a coding geek, it would be cool to take 2x, highly accurate, GPS receivers, place one GPS antenna on the front and back booms of the beam and then diff
/archives//html/Towertalk/2022-11/msg00070.html (10,932 bytes)

220. Re: [TowerTalk] Fwd: Anchoring (score: 1)
Author: "Lux, Jim" <jim@luxfamily.com>
Date: Fri, 18 Nov 2022 06:51:47 -0800
On 11/17/22 9:51 PM, KD7JYK DM09 wrote: On 11/17/2022 18:33, Hans Hammarquist via TowerTalk wrote: I used the same type as the utility companies. They are a lot cheaper if you buy them from a utility
/archives//html/Towertalk/2022-11/msg00109.html (10,369 bytes)


This search system is powered by Namazu