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References: [ +subject:/^(?:^\s*(re|sv|fwd|fw)[\[\]\d]*[:>-]+\s*)*\[TowerTalk\]\s+Lossy\s+traps\?\s*$/: 19 ]

Total 19 documents matching your query.

1. [TowerTalk] Lossy traps? (score: 1)
Author: foxbw@comcast.net
Date: Tue, 28 Oct 2008 14:22:36 +0000 (UTC)
How lossy are traps on a trap tri-bander?   Some manufacturers of non-trapped tri-banders cite the lossy aspect of traps, but how real is that loss?   Can it be measured?   Would someone 500 or 5000
/archives//html/Towertalk/2008-10/msg00598.html (7,188 bytes)

2. Re: [TowerTalk] Lossy traps? (score: 1)
Author: Jerry K <w5kp@hughes.net>
Date: Wed, 29 Oct 2008 09:04:56 -0500
A fixed element non-trapped tribander with only three elements appears to be an oxymoron. In the only comparison I can offer, I ran a standard Moseley TA-33 trapped tribander for years with decent re
/archives//html/Towertalk/2008-10/msg00601.html (8,797 bytes)

3. Re: [TowerTalk] Lossy traps? (score: 1)
Author: Pat Barthelow <aa6eg@hotmail.com>
Date: Wed, 29 Oct 2008 07:29:16 -0700
And three related questions: 1. Is the loss in gain, due to the RF lost/dissapated as heat, or due to pattern degradation caused by "lumpy" current patterns along the elements? 2. Is it reasonable to
/archives//html/Towertalk/2008-10/msg00604.html (9,175 bytes)

4. Re: [TowerTalk] Lossy traps? (score: 1)
Author: "Dan Hearn" <n5ar@air-pipe.com>
Date: Wed, 29 Oct 2008 08:37:50 -0700
Did you ever stop to think that the usual tri band trapped beam uses a single coax feed for all bands and to get a 50 ohm feed point impedance it is necessary to detune the elements from their best l
/archives//html/Towertalk/2008-10/msg00608.html (10,046 bytes)

5. Re: [TowerTalk] Lossy traps? (score: 1)
Author: Jerry K <w5kp@hughes.net>
Date: Wed, 29 Oct 2008 11:33:08 -0500
Yes Sir, I did. That's why I bought the Force 12 C3XLD. 73, Jerry W5KP _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk
/archives//html/Towertalk/2008-10/msg00612.html (10,670 bytes)

6. [TowerTalk] Lossy traps? (score: 1)
Author: Tom-W3FRG <w3frg1@gmail.com>
Date: Wed, 29 Oct 2008 13:18:22 -0400
I've always wondered why that when a simple LC tuned circuit is used in our transceivers and other electronic gadgets its loss is not mentioned, but once one of these is placed in an antenna radiatin
/archives//html/Towertalk/2008-10/msg00614.html (7,153 bytes)

7. Re: [TowerTalk] Lossy traps? (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 29 Oct 2008 10:37:04 -0700
It is often important in antennas because the resistance of the traps can be a significant fraction of the radiation resistance. It is important in receivers to the extent that it determines the Q (b
/archives//html/Towertalk/2008-10/msg00615.html (9,068 bytes)

8. Re: [TowerTalk] Lossy traps? (score: 1)
Author: jimlux <jimlux@earthlink.net>
Date: Wed, 29 Oct 2008 15:55:40 -0700
But how much of a compromise? I think that's what the original question was getting at. Let's talk in terms of modern antenna design, so we're not necessarily talking about designs from the 1960s whi
/archives//html/Towertalk/2008-10/msg00620.html (11,409 bytes)

9. Re: [TowerTalk] Lossy traps? (score: 1)
Author: "Al Williams" <alwilliams@olywa.net>
Date: Wed, 29 Oct 2008 17:19:38 -0700
-- Original Message -- From: "jimlux" <jimlux@earthlink.net> To: "Dan Hearn" <n5ar@air-pipe.com> Cc: "Tower Talk" <towertalk@contesting.com>; "Jerry K" <w5kp@hughes.net> Sent: Wednesday, October 29,
/archives//html/Towertalk/2008-10/msg00622.html (8,282 bytes)

10. Re: [TowerTalk] Lossy traps? (score: 1)
Author: "Joe Subich, W4TV" <w4tv@subich.com>
Date: Thu, 30 Oct 2008 00:58:05 -0400
It's rather difficult to do an analysis for more than two bands due to the various interactions and changing loss with frequency due to circulating currents, etc. However, I believe L.B. Cebik, W4RN
/archives//html/Towertalk/2008-10/msg00628.html (15,621 bytes)

11. Re: [TowerTalk] Lossy traps? (score: 1)
Author: "Joe Subich, W4TV" <w4tv@subich.com>
Date: Thu, 30 Oct 2008 01:07:59 -0400
The current in the trapped, parasitic element creates an I^2R loss in the traps of that element. The decrease in current available for re-radiation represents an effective I^2R loss to the driven el
/archives//html/Towertalk/2008-10/msg00629.html (10,028 bytes)

12. Re: [TowerTalk] Lossy traps? (score: 1)
Author: "David J Windisch" <davidjw@cinci.rr.com>
Date: Thu, 30 Oct 2008 05:52:43 -0400
For one man's research, go here http://www.w8ji.com/traps.htm 73 Dave W8FGX _______________________________________________ _______________________________________________ TowerTalk mailing list Towe
/archives//html/Towertalk/2008-10/msg00632.html (8,201 bytes)

13. Re: [TowerTalk] Lossy traps? (score: 1)
Author: "Julio Peralta" <jperalta4@verizon.net>
Date: Wed, 29 Oct 2008 09:58:35 -0400
Good question I look forward to seeing what posts follow this. It's my feeling that the percentage is quite small maybe under 10%. Julio, W4HY How ?lossy? are traps on a trap tri-bander?   Some manuf
/archives//html/Towertalk/2008-10/msg00634.html (9,224 bytes)

14. Re: [TowerTalk] Lossy traps? (score: 1)
Author: jimlux <jimlux@earthlink.net>
Date: Thu, 30 Oct 2008 06:55:03 -0700
Why would it be difficult? You run the model with different FR cards, you look at the loss number. We run NEC models at work over a decades of bandwidth all the time, although some care is needed in
/archives//html/Towertalk/2008-10/msg00644.html (10,430 bytes)

15. Re: [TowerTalk] Lossy traps? (score: 1)
Author: jimlux <jimlux@earthlink.net>
Date: Thu, 30 Oct 2008 07:03:21 -0700
Same is true for the multi monoband on a beam untrapped design. Currents in the other elements will have loss. I think, overall, that loss source is probably a wash either way. I would guess that the
/archives//html/Towertalk/2008-10/msg00645.html (10,063 bytes)

16. Re: [TowerTalk] Lossy traps? (score: 1)
Author: "Joe Subich, W4TV" <w4tv@subich.com>
Date: Thu, 30 Oct 2008 10:26:45 -0400
Because the loss (trap Q) is not constant. If you are willing to rebuild your models from band to band it is possible to get close but optimization can be difficult. The change in Q effects both cur
/archives//html/Towertalk/2008-10/msg00648.html (12,513 bytes)

17. Re: [TowerTalk] Lossy traps? (score: 1)
Author: "Al Williams" <alwilliams@olywa.net>
Date: Thu, 30 Oct 2008 10:15:51 -0700
If I am reading this response correctly, then any metal anywhere decreases the radiated field from the driven element?! I am not discussing directivity loss or gain--I am just curious of whether the
/archives//html/Towertalk/2008-10/msg00658.html (12,174 bytes)

18. Re: [TowerTalk] Lossy traps? (score: 1)
Author: "Joe Subich, W4TV" <w4tv@subich.com>
Date: Thu, 30 Oct 2008 17:21:55 -0400
A changing electromagnetic field generates current in any conductive element in that field. The amount of current is proportional to the level of the field, the resistance in the conductive element
/archives//html/Towertalk/2008-10/msg00660.html (15,204 bytes)

19. Re: [TowerTalk] Lossy traps? (score: 1)
Author: jimlux <jimlux@earthlink.net>
Date: Thu, 30 Oct 2008 21:50:06 -0700
No.. not decrease, necessarily... "change" is the operative word. Any conductor (or dielectric) will change the current distribution (and if it's a conductor, it will have a induced current distribut
/archives//html/Towertalk/2008-10/msg00674.html (9,631 bytes)

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