Search String: Display: Description: Sort:

Results:

References: [ +from:W4EF@dellroy.com: 691 ]

Total 691 documents matching your query.

281. Re: [TowerTalk] CobWebb antennas - success stories? (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Wed, 22 Sep 2004 19:55:19 -0700
Hey Jim, It would be interesting to look at near field plot from the Cobb vs. a regular dipole. On his website, the inventor claims that it doesn't couple very strongly to nearby objects and is there
/archives//html/Towertalk/2004-09/msg00508.html (12,797 bytes)

282. Re: [TowerTalk] CobWebb antennas - success stories? (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Wed, 22 Sep 2004 21:14:25 -0700
Hi Jim, I just plugged a quick model into MultiNec and got results similar to yours in terms of feedpoint impedance and pattern. The 2:1 VSWR bandwidth (12.5 ohm reference) is about 175 KHz with ante
/archives//html/Towertalk/2004-09/msg00510.html (10,290 bytes)

283. Re: [TowerTalk] CobWebb antennas - success stories? (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Thu, 23 Sep 2004 04:09:26 -0700
I don't know. He seems to shift at random between measurement references. First he compares his antenna measured over ground to an isotropic reference, then he compares a straight dipole over ground
/archives//html/Towertalk/2004-09/msg00513.html (10,541 bytes)

284. Re: [TowerTalk] CobWebb antennas - success stories? (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Thu, 23 Sep 2004 04:18:52 -0700
Well, it goes to his overall credibility. He claims that the E-field off the ends of his antenna is lower than for a straight dipole. As to whether that matters or not to anything performance wise, I
/archives//html/Towertalk/2004-09/msg00517.html (10,385 bytes)

285. Re: [TowerTalk] Re: gain specifications (was CobWebb antennas) (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Thu, 23 Sep 2004 05:27:15 -0700
Fortunately, we have very good computer modeling tools these days, Con, so it is much harder to fool the consumer if he is doing his homework (at least when it comes to antennas that lend themselves
/archives//html/Towertalk/2004-09/msg00518.html (11,503 bytes)

286. Re: [TowerTalk] Misinformation Highway (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Thu, 23 Sep 2004 05:30:21 -0700
I was particulary impressed by the 18dB Front-to-Back ratio :):) That is almost as bad as those "Jo-Gunn" CB Antennas that have "Audio Gain" :) Mike, W4EF............................... _____________
/archives//html/Towertalk/2004-09/msg00519.html (9,837 bytes)

287. Re: [TowerTalk] Re: Importance of Amateur Radio Emergency Comms (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Fri, 24 Sep 2004 11:25:15 -0700
Good points, Rick. That is probably why the ARRL came up with contests and the DXCC program. Both programs motivate vast numbers of hams to maintain top notch HF communications capability. DXers and
/archives//html/Towertalk/2004-09/msg00577.html (13,007 bytes)

288. Re: [TowerTalk] Chicago Tribune news: Ham radio tower has the OKsignal (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Fri, 24 Sep 2004 19:33:00 -0700
If your hobbies don't include outdoor things like ham radio, living in an HOA controlled community is probably not a big encumberence. If your passions are listening to music (well not loud anyway),
/archives//html/Towertalk/2004-09/msg00598.html (18,246 bytes)

289. Re: [TowerTalk] Restrictions v. rural life and towers (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Sat, 25 Sep 2004 11:57:52 -0700
It's interesting where I live here in Tujunga, Ca - Rob. We are right in the foothills of the San Gabriel mountains just a stones throw from the Angeles National Forest, but only 15 minutes from down
/archives//html/Towertalk/2004-09/msg00620.html (9,932 bytes)

290. [TowerTalk] Screwdriver Antennas? (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Tue, 28 Sep 2004 22:29:15 -0700
I was thinking of getting a screwdriver antenna for my pickup truck and was wondering if anyone out there has any experience with the various models of the N9JMX Predator or the Tarheel line of screw
/archives//html/Towertalk/2004-09/msg00674.html (7,245 bytes)

291. Re: [TowerTalk] 2 element 40m steppir yagi (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Thu, 7 Oct 2004 10:39:31 -0700
What I was thinking about for my small suburban lot was a big IR driven element attached to a mast pipe in concert with a single regular IR parasitic element cantilevered on a short boom off the mast
/archives//html/Towertalk/2004-10/msg00111.html (11,120 bytes)

292. Re: [TowerTalk] 2 element 40m steppir yagi (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Thu, 7 Oct 2004 11:59:38 -0700
Yes, for an 80/75 meter design you are probably correct that a set of variable lumped elements would be just a flexible in terms of adjusting the center frequency and pattern of the antenna. It would
/archives//html/Towertalk/2004-10/msg00116.html (10,350 bytes)

293. Re: [TowerTalk] Wilson 5 element 20 meter monobander (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Sat, 9 Oct 2004 14:03:15 -0700
I think what everybody is trying to say is that for a fixed 40 ft boom length, you don't gain much by increasing the number of elements beyond 4. That doesn't mean that 5 can't or won't work as well
/archives//html/Towertalk/2004-10/msg00158.html (12,835 bytes)

294. Re: [TowerTalk] (no subject) (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Sun, 10 Oct 2004 18:06:50 -0700
Joe, Here is a commercial solution made by K5RC http://www.consultpr.com/SNMain.htm Looks like it would work, but I haven't tried one myself. 73 de Mike, W4EF.........................................
/archives//html/Towertalk/2004-10/msg00197.html (8,148 bytes)

295. Re: [TowerTalk] Double shield (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Wed, 13 Oct 2004 02:56:17 -0700
Another way to look at it is to think about what length of run would represent 3dB difference between the good feedline and the cheap feedline: LMR-400 vs RG-8X 1.8 MHz 1300 ft Delta $ 390 3.5 MHz 87
/archives//html/Towertalk/2004-10/msg00282.html (9,186 bytes)

296. Re: [TowerTalk] BPL (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Thu, 14 Oct 2004 17:25:29 -0700
If you guys are talking about Michael Copps, he has been the lone dissenting voice on BPL since the beginning. While I think his main concern has been that electric rate payers might end up cross-sub
/archives//html/Towertalk/2004-10/msg00371.html (12,831 bytes)

297. Re: [TowerTalk] BPL -- my ONLY comment (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Thu, 14 Oct 2004 19:41:59 -0700
I have heard people who seem to know about this stuff saying that BPL is just a political tool that the commissioners are using to light a fire under the DSL and CATV people to extend coverage to und
/archives//html/Towertalk/2004-10/msg00376.html (15,596 bytes)

298. Re: [TowerTalk] Tower height increments (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Sat, 16 Oct 2004 12:00:08 -0700
During his talk at Visalia, I asked Dean, N6BV why his TOA statistics showed that takeoff angles would be higher on 10 meters than 15 (he was showing a case study comparing TOAs at W6NL and N6RO). Th
/archives//html/Towertalk/2004-10/msg00483.html (13,132 bytes)

299. Re: [TowerTalk] BPL interference (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Sat, 30 Oct 2004 20:44:13 -0700
Maybe we should ask this guy what his position is: http://www.vote-smart.org/bio.php?can_id=BZZ91748 :):) Mike, W4EF....................... _______________________________________________ See: http:/
/archives//html/Towertalk/2004-10/msg00810.html (8,167 bytes)

300. Re: [TowerTalk] A3 problem (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Wed, 3 Nov 2004 07:58:15 -0800
Tony, is the A3's Front-to-Back on 10 meters about the same as it was before the change in 20 meter VSWR (it is probably worth checking front-to-back on 15 and 20 as well)? If the F/B is unchanged, t
/archives//html/Towertalk/2004-11/msg00063.html (9,859 bytes)


This search system is powered by Namazu