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1. Topband: How Would You Load This Tower? (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sat, 03 Apr 2004 22:04:55 -0600
Here's a brain teaser that I would appreciate some help thinking about. The tower in the photo (the big one with the dishes on it) is about 150 ft tall. 32 ft square at the base, roughly 24 ft square
/archives//html/Topband/2004-04/msg00023.html (8,262 bytes)

2. [TowerTalk] Re: W4AN Silent Key (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 05 Apr 2004 11:53:02 -0600
Because I was inactive on HF for most of the last 18 years, I didn't get to know Bill, and worked him only a few times since my return in a contests. But because Bill was such an active supporter of
/archives//html/Topband/2004-04/msg00032.html (8,305 bytes)

3. Topband: AEA VIA or CIA? (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 12 Apr 2004 08:25:13 -0500
I've used a CIA-HF for while that I borrowed from another ham, but it's time for me to buy my own. I also have a GR-1606 in the closet, but the CIA and VIA fit in my briefcase. I like the CIA, but am
/archives//html/Topband/2004-04/msg00060.html (7,635 bytes)

4. Re: Topband: TRANSCEIVER WITH SEPERATE RECEIVER? (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 13 Apr 2004 09:13:13 -0500
VERY important distinction -- what do you mean by "in phase" and "out of phase?" Phase is a continuous function having an infinite number of values, and is proportional to frequency. Any network that
/archives//html/Topband/2004-04/msg00066.html (9,016 bytes)

5. Re: Topband: AEA VIA or CIA? (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 13 Apr 2004 11:50:42 -0500
What I'm trying to get at are the differences between the VIA and the VIA Bravo in technical terms. And what are the differences between the VIA and the CIA besides speed? Price is an obvious differe
/archives//html/Topband/2004-04/msg00068.html (7,772 bytes)

6. Topband: Polarity and Phase (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 14 Apr 2004 09:13:32 -0500
You are absolutely incorrect! First, you don't understand (or are unwilling to admit) that phase and polarity are different. When you reverse the wires that connect elements of a system (e.g., a rec
/archives//html/Topband/2004-04/msg00083.html (12,352 bytes)

7. Topband: Re: phase (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 14 Apr 2004 09:43:13 -0500
Only if you use a sine wave as a source, and look only at a single frequency. Use a broadband signal (or try to get broadband performance from an antenna system) and you will see significant differen
/archives//html/Topband/2004-04/msg00084.html (10,278 bytes)

8. Re: Topband: Polarity and Phase (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 14 Apr 2004 16:42:50 -0500
If the receivers are tuned to different frequencies, the resulting audio signals are of different frequencies, and phase has no meaning! Phase is only defined for sine waves of the same frequency! Yo
/archives//html/Topband/2004-04/msg00087.html (9,322 bytes)

9. Re: Topband: Polarity and Phase (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 14 Apr 2004 20:52:26 -0500
No problem. When you have time to think about it, I'll try to help you get your head around it. This is stuff that we in the pro audio world have had to spend a lot of effort understanding thoroughly
/archives//html/Topband/2004-04/msg00091.html (11,718 bytes)

10. Re: Topband: Polarity and Phase (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 14 Apr 2004 21:27:58 -0500
I understand your examples and it is, indeed, excellent work. Thanks for sharing it. 73, Jim _______________________________________________ Topband mailing list Topband@contesting.com http://lists.c
/archives//html/Topband/2004-04/msg00093.html (7,702 bytes)

11. Re: Topband: Polarity and Phase (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 15 Apr 2004 08:26:07 -0500
No, it does not. But it IS one way that it is done. And my point is that the phase shift achieved in that line is DIFFERENT from changing the polarity. I could also have used the example of a passive
/archives//html/Topband/2004-04/msg00100.html (16,964 bytes)

12. Re: Topband: Polarity and Phase (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 15 Apr 2004 10:51:03 -0500
No, I'm not. We're trying to separate a signal from noise. Our signal may be narrowband (CW), but the noise is not. We can, of course, help ourselves by reducing the bandwidth with narrow filters, bu
/archives//html/Topband/2004-04/msg00103.html (9,018 bytes)

13. Re: Topband: Polarity and Phase (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Fri, 16 Apr 2004 07:19:19 -0500
Yes. I think your example (an excellent one) helps illustrate how time, frequency, and phase are so tightly related that it is hard for us to get our brains around the relationships between them. W0
/archives//html/Topband/2004-04/msg00113.html (12,001 bytes)

14. Topband: Field Day (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 19 Apr 2004 06:57:02 -0500
With the swing of sunspot cylce, I'm wondering if it would be productive to spend time on 160 during Field Day. I've been off the air most of the last 25 years, but am now active again. Our club is p
/archives//html/Topband/2004-04/msg00154.html (6,750 bytes)

15. Re: Topband: Field Day (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 19 Apr 2004 09:27:01 -0500
I think you're confusing the Sweepstakes rules with Field Day rules. On Field Day, CW and phone are considered separate bands, and another station can we worked once per band. So hitting 160 for a co
/archives//html/Topband/2004-04/msg00158.html (7,851 bytes)

16. RE: Topband:mode separation...small stn dx oppty (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 22 Apr 2004 19:30:26 -0500
Mine is 100 watts to a 100 ft long dipole fed as a long wire on a Chicago city lot. I can't even HEAR DX on 160, let alone work it. Jim K9YC _______________________________________________ Topband ma
/archives//html/Topband/2004-04/msg00207.html (7,128 bytes)

17. RE:Topband:mode separation...small stndx oppty (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Fri, 23 Apr 2004 09:45:06 -0500
Perhaps a definition of DX is needed. With my limited station, a couple of contests, and some pre-sunrise prowling, I've managed to work 45 US states, 5 Canadian provinces, a Carribean DX superstatio
/archives//html/Topband/2004-04/msg00212.html (7,904 bytes)

18. RE: Topband:mode separation...small stndx oppty (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Fri, 23 Apr 2004 11:19:45 -0500
Yes, I did exactly that, and the noise level dropped a bit (perhaps an S-unit) in parts of the band. But the frequency-variable noise is clearly coming from some un-intentional radiators. At least on
/archives//html/Topband/2004-04/msg00213.html (8,211 bytes)

19. Topband: PSK-31 (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 26 Apr 2004 07:29:59 -0500
In the recent discussion of allocations and band segmentation, someone seemed to be suggesting that PSK31 was a broadband mode. When I look at signals on my PSK31 software, they seem rather narrow ba
/archives//html/Topband/2004-04/msg00227.html (6,709 bytes)

20. Re: Topband: PSK-31 (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 26 Apr 2004 21:06:37 -0500
Thanks, Tom. That makes sense. So it really isn't any different from the massive distortion we hear during SSB contests when lousy operators (and lousy technicians) shove way too much audio from thei
/archives//html/Topband/2004-04/msg00233.html (8,040 bytes)


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