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Total 1348 documents matching your query.

341. Topband: Loop-family antenna notes (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Fri, 1 Dec 2000 09:19:54 -0500
Hi Art, It sounds like your system is working as it should. Maybe I'm wrong, but I get the impression a large part of our fraternity thinks noise is "electric" and signals are "magnetic". Wellintenti
/archives//html/Topband/2000-12/msg00000.html (9,503 bytes)

342. Topband: Loop-family antenna notes (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Sun, 3 Dec 2000 20:34:07 -0500
Hi Larry, As it should! You have removed a local dominant noise source, which is all the small loop is good for except..... Yes indeed. Small loops (and even Flags and the family of terminated loops)
/archives//html/Topband/2000-12/msg00013.html (9,271 bytes)

343. Topband: Conditions (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Sun, 3 Dec 2000 21:03:36 -0500
Well, it just goes to show you the A and K index doesn't mean much for predicting propagation on 160! Some of the best days have high A and K numbers, and some real bummers have low A and K numbers!
/archives//html/Topband/2000-12/msg00014.html (6,598 bytes)

344. Topband: The A and K indicators (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Mon, 4 Dec 2000 07:39:50 -0500
Hi Ford, I've heard that also, but some of the very best days I've seen have had an A or K index that was high, some of the worse days when they are low. I've given up totally on watching the A and K
/archives//html/Topband/2000-12/msg00032.html (7,179 bytes)

345. Topband: 2 Element Hybrid with Broadside Capability (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Wed, 6 Dec 2000 19:26:42 -0500
One thing to remember is the dump resistor neither guarantees correct phase, nor does it guarantee correct current distribution. While the Comtek system is a good system, I wouldn't use a hybrid sys
/archives//html/Topband/2000-12/msg00050.html (7,534 bytes)

346. Topband: Phasing Inv.L question (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Thu, 7 Dec 2000 10:29:49 -0500
You must match at the common point, not at the inverted L's....unless you really know what you are doing with transmission lines and phasing systems. You are also headed for trouble if the inverted
/archives//html/Topband/2000-12/msg00055.html (9,761 bytes)

347. Topband: Strange signal on Top Band. (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Thu, 7 Dec 2000 12:30:36 -0500
Hi Giulio, I hear the same or a similar thing on some days when the band is open into deep Asia. From here it is generally north in direction, anything from NE to NW. I was told it is something runn
/archives//html/Topband/2000-12/msg00057.html (7,506 bytes)

348. Topband: Flag Antenna Feedline Decoupling (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Sun, 10 Dec 2000 20:41:51 -0500
Use a bead that is mostly resistive at 1.8MHz, but remember the bead will only help if you put it between your receiver and a ground rod on the feedline near the antenna. Having modeled the common m
/archives//html/Topband/2000-12/msg00069.html (8,162 bytes)

349. Topband: Surge suppression for Beverage? (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Sun, 17 Dec 2000 01:54:43 -0500
You might bypass the relay coil with a .1 uF 50 volt capacitor in parallel with a low voltage MOV. Choke each of the leads leaving the coil with a single layer choke of about 100 uH. Be sure you tie
/archives//html/Topband/2000-12/msg00098.html (7,959 bytes)

350. Topband: Lightning in December (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Sun, 17 Dec 2000 11:03:40 -0500
If you wonder why 160 sounded like mid-July last night in the eastern USA, have a glance at this page. http://www.weather.com/golf/maps/national_lightning_720x486.html 73, Tom W8JI w8ji@contesting.co
/archives//html/Topband/2000-12/msg00100.html (6,747 bytes)

351. Topband: Dual Band Inv L - 2 Points to clarify (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Tue, 19 Dec 2000 00:00:46 -0500
Hi Brian, Feeding an almost perfectly unbalanced antenna, like an inverted L with a good ground system, with a balanced line is not a good idea. While you can tune the antenna on a couple bands, the
/archives//html/Topband/2000-12/msg00108.html (9,418 bytes)

352. Topband: DUAL BAND INVERTED L (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Wed, 20 Dec 2000 14:59:06 -0500
Be careful what you use for traps in a Marconi antenna, especially a bent antenna. The voltage is at least double that of a dipole, as is the current, through the trap. A 1 kW trap in a dipole only
/archives//html/Topband/2000-12/msg00118.html (8,086 bytes)

353. Topband: Dual Band INV L (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Wed, 20 Dec 2000 18:31:30 -0500
I suppose you're talking about daytime noise. Unless something changed in the area around your QTH (making more noise) it probably is because you now have a vertical that is receiving and transmitti
/archives//html/Topband/2000-12/msg00122.html (6,927 bytes)

354. Topband: 160 antennas (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Thu, 21 Dec 2000 15:10:17 -0500
Hi Bill, Grounding the far end only works when the antenna is 1/2 wl from end-to-end, unless you "tune it" at the feedpoint or the far end, or both. If it is shorter than 1/2 wl, you'd have to add in
/archives//html/Topband/2000-12/msg00125.html (8,427 bytes)

355. Topband: inverted U antenna (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Sat, 23 Dec 2000 21:13:43 -0500
Hi Curt, Even if we (incorrectly) assume all losses are "connection" losses that show up at the feedpoint and the U reduces feedpoint current by a factor of two, the system losses only drop in half.
/archives//html/Topband/2000-12/msg00135.html (9,644 bytes)

356. Topband: Wideband Noise on 160 (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Tue, 26 Dec 2000 21:19:41 -0500
Hi Ford, Anything switching or arcing can cause a problem like that. Most likely it is something arcing, or switching very hard at a very low frequency (like a light dimmer, battery charger, or gas v
/archives//html/Topband/2000-12/msg00147.html (9,819 bytes)

357. Topband: Phased "Flags" (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Thu, 28 Dec 2000 19:37:07 -0500
Remember it's a three dimensional problem. Wider spacing moves the nulls up off the ground and makes them more useful for distant noise. 1/2 wl spacing is will actually give you less of a null direc
/archives//html/Topband/2000-12/msg00178.html (8,230 bytes)

358. Topband: Finding break in Beverage wire (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Sun, 31 Dec 2000 21:05:43 -0500
The suggestion of using a radio is a good one. Here's another way. An MFJ-259 will locate the break if you connect the 259 at the matching transformer to the beverage and use the "distance to fault"
/archives//html/Topband/2000-12/msg00204.html (7,679 bytes)

359. Topband: Ph.Verticals (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Thu, 2 Nov 2000 11:33:02 -0500
Hi Martin, I'm assuming the system correctly had the same impedances to each element, but the different was different in the two cases. The impedance's at the feedpoint will always vary because the p
/archives//html/Topband/2000-11/msg00010.html (8,942 bytes)

360. Topband: Pennant working? (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Fri, 3 Nov 2000 11:01:37 -0500
You should hear a definite increase in noise level on the narrowest selectivity you plan on using at the quietest time of the day you expect to operate when the antenna is connected.... as opposed t
/archives//html/Topband/2000-11/msg00017.html (7,498 bytes)


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