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1. [TowerTalk] Pull rope twisted in conduit (score: 1)
Author: (Jim Lux)
Date: Fri Aug 1 12:03:57 2003
My vote would be to pull all the cables and ropes out, and suck a brand new rope through, then use that one to pull several new ones. A shopvac on one end will nicely pull mason's twine or equivalent
/archives//html/Towertalk/2003-08/msg00007.html (9,947 bytes)

2. [TowerTalk] Relay Contact rating for RF useage? (score: 1)
Author: (Jim Lux)
Date: Mon Aug 11 14:41:17 2003
It's not, really... RF properties are sufficiently different that you basically have to measure it. The big difference you see in voltage ratings for AC and DC more reflect typical usage (i.e. 110-22
/archives//html/Towertalk/2003-08/msg00360.html (9,593 bytes)

3. [TowerTalk] Single point ground system connection to tower(??????) (score: 1)
Author: (Jim Lux)
Date: Mon Aug 11 15:20:58 2003
Don't forget that there is a big difference between: 1) electrical safety ground (the green wire) 2) Lightning protection ground 3) RF common Single point ground is fine "within a box", but you start
/archives//html/Towertalk/2003-08/msg00363.html (10,299 bytes)

4. [TowerTalk] Antenna element vibration damping - How (score: 1)
Author: (Jim Lux)
Date: Mon Aug 11 17:03:10 2003
Any round element will vibrate in the wind...simple mechanics and aerodynamics (shed vortices), and forms the basis of such things as aeolian harps. The vibration might not be noticable, or it might
/archives//html/Towertalk/2003-08/msg00372.html (12,393 bytes)

5. [TowerTalk] Re: [FCG] Relays in RF usage (score: 1)
Author: (Jim Lux)
Date: Tue Aug 12 17:29:15 2003
Even at 100 kHz, skin effect is very significant! and at HF it's a real big deal: this is why copperweld wire works as well as solid copper (electrically). Skin depth in copper at 100 MHz is 0.26 mil
/archives//html/Towertalk/2003-08/msg00400.html (9,215 bytes)

6. relays and capacitors Re: [TowerTalk] relays (score: 1)
Author: (Jim Lux)
Date: Wed Aug 13 12:21:59 2003
At what frequency? What sort of RF current capability and voltage rating do you need? How much loss are you willing to tolerate? How stable does the capacitance have to be? For instance, will standar
/archives//html/Towertalk/2003-08/msg00412.html (8,944 bytes)

7. [TowerTalk] Relays in RF usage UPDATE (score: 1)
Author: (Jim Lux)
Date: Wed Aug 13 20:13:01 2003
That would be the voltage along a transmission line with that kind of mismatch, and a resistive one to boot.. What number will you use for the impedance of the relay, and is there any reactive power
/archives//html/Towertalk/2003-08/msg00450.html (8,916 bytes)

8. [TowerTalk] Relays in RF usage UPDATE (score: 1)
Author: (Jim Lux)
Date: Thu Aug 14 01:20:30 2003
I'd also encourage anyone with interest in this sort of thing to take a look at the XLZIZL spreadsheet from Dan, AC6LA Very cool.. handles every kind of transmiss
/archives//html/Towertalk/2003-08/msg00472.html (10,495 bytes)

9. [TowerTalk] Relays in RF usage UPDATE (score: 1)
Author: (Jim Lux)
Date: Thu Aug 14 10:03:55 2003
look plotting Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.
/archives//html/Towertalk/2003-08/msg00492.html (8,922 bytes)

10. [TowerTalk] Tower legal battles [was Chicago Tribune:AntennaStirs Static Among Neighbors] (score: 1)
Author: (Jim Lux)
Date: Thu Aug 14 10:29:15 2003
Thousand Oaks, CA has a similar strategy.. More a question for the ham-law forum: Is $1000 a "reasonable accommodation" under PRB-1? In the OTARD rules, a $5 fee for a Ku-band dish was held to be unr
/archives//html/Towertalk/2003-08/msg00493.html (12,847 bytes)

11. [TowerTalk] Neighbors "rights" (score: 1)
Author: (Jim Lux)
Date: Thu Aug 14 12:46:28 2003
Actually, they can make new rules that affect existing operations, etc. However, they also have to compensate you for the loss (so they don't get into trouble with the "takings" clause of the 14th am
/archives//html/Towertalk/2003-08/msg00500.html (12,684 bytes)

12. [TowerTalk] Mobile antennas? (score: 1)
Author: (Jim Lux)
Date: Fri Aug 15 10:24:10 2003
You might want to take a look at Q-MAC (an Australian company) who has a very interesting take on a magnetic compact loop roof top antenna. The SGC HF manual also talks about using autotuners and loo
/archives//html/Towertalk/2003-08/msg00548.html (10,236 bytes)

13. [TowerTalk] My local tower restriction (score: 1)
Author: (Jim Lux)
Date: Fri Aug 15 11:13:26 2003
That is, you have a "fall radius within property lines" kind of restrictions. Short answer: it is unreasonable, because a totally laid out flat kind of failure isn't particularly credible (depending
/archives//html/Towertalk/2003-08/msg00553.html (9,551 bytes)

14. [TowerTalk] Neighbors "rights" (score: 1)
Author: (Jim Lux)
Date: Fri Aug 15 11:20:18 2003
-- Original Message -- From: "Bill Turner" <> To: <> Cc: "Jim Lux" <>; <>; <> Sent: Friday, August 15, 20
/archives//html/Towertalk/2003-08/msg00554.html (10,742 bytes)

15. [TowerTalk] Fancy Coax Switches? Coax Crossbar? (score: 1)
Author: (Jim Lux)
Date: Sat Aug 16 11:09:46 2003
you might want to consider a fairly straightforward "relay module" that is a simple PCB with the relays and a bit of drive electronics (kickback supression diode, transistor with/without optocoupler
/archives//html/Towertalk/2003-08/msg00586.html (10,505 bytes)

16. [TowerTalk] W0IYH Feed line Choke Performance (score: 1)
Author: (Jim Lux)
Date: Wed Aug 20 09:10:31 2003
<snip> Hmmm.. is a quarter wave actually how far apart you want them? I don't know that putting two chokes at 1/4 wave apart guarantees that one is at a high current place in the line (maybe they win
/archives//html/Towertalk/2003-08/msg00699.html (11,249 bytes)

17. [TowerTalk] W0IYH Feed line Choke Performance (score: 1)
Author: (Jim Lux)
Date: Wed Aug 20 14:21:59 2003
OK.. good point.. the choke acts like an open on the TL formed by the Coax shield /environment Excellent idea... What does your probe look like, and is it broadband or tuned? I agree... d and e are b
/archives//html/Towertalk/2003-08/msg00704.html (12,835 bytes)

18. [TowerTalk] Bending Rebar (score: 1)
Author: (Jim Lux)
Date: Wed Jul 2 12:59:10 2003
One uses a rebar bending tool (looks like a conduit bender) to get nice bends. Alternate approach is to get a piece of iron pipe of sufficient ID that the rebar will slide inside and use it as a tool
/archives//html/Towertalk/2003-07/msg00027.html (8,650 bytes)

19. [TowerTalk] Reminder - Deadline for Comments on Broadband Over Powerline NOI (score: 1)
Author: (Jim Lux)
Date: Thu Jul 3 12:37:09 2003
I'd also mention that all too many of those comments seem to be along the lines of "BPL will make HF unusable, don't do it" When the FCC has said that BPL is a done deal, and they're just looking for
/archives//html/Towertalk/2003-07/msg00048.html (13,241 bytes)

20. [TowerTalk] Insurance claim (score: 1)
Author: (Jim Lux)
Date: Thu Jul 3 13:00:49 2003
Read the policy... Is it "replacement cost as installed" or "parts and materials"? Say part of your roof had been blown off. Would the policy cover the shingles, or the shingles and the labor to repl
/archives//html/Towertalk/2003-07/msg00049.html (11,629 bytes)

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