HDTenEightyP/NetNews huggingface dataset:
From: smithw@physc1.byu.edu
Newsgroups: rec.models.railroad
Subject: Filtered DC (was: Pulse power)
Date: 8 Oct 92 16:34:57 GMT
Organization: Brigham Young University

With the pulse power discussion reflecting the thought that
pulse injection power packs are not healthy for good can
motors, are the antipulse folks recommending *filtered* DC, or
just full wave rectified DC?  

A related question I've been wondering about lately :
Is there commercial vendor who produces a pack with filtered 
DC output?

Finally, is there a commercial pack with full wave or filtered DC
that has the popular features of the pulsed wave form packs, like
"momentum" and "braking",  etc.?

Just wondering since I just spent about $200 motoring a set of custom
E7's and some scratch built turbines.

-Bill
Newsgroups: rec.models.railroad
From: fredm@progress.COM (Fred Mikkelsen)
Subject: Re: Pulse Power Supplies
Keywords: PULSE POWER FREQUENCY MOTORS OCCUPANCY DETECTION
Organization: Progress Software Corp.
Date: Fri, 9 Oct 1992 13:36:19 GMT

jsm@phoenix.Princeton.EDU (John Scott McCauley Jr.) writes:

fpm:
>>To summarize, most pulse control systems I've heard of use 40Hz to 60Hz
>>pulses. I'm wondering what the effect of 600Hz to 6KHz pulses would be.

jsm:
>Motors look like inductors and have very high impedence at 6 kHz.
>So the higher the frequency, the lower the current flowing through the
>motor.

fpm:
If I can extrapolate a bit then, when I am powering motor, I do not want
to have a lot of transitions between powered and unpowered states. This
to me indicates that I could have an overall 60Hz pattern where every
15th waveform is replaced by 400 6kHz pulses to multiplex through occupancy
detection like I'd want to do. And, if you're saying what I think you're
saying, it won't even be necessary to reverse the polarity of the sense
pulses because locomotives don't move at 6kHz. (Sounds risky!)
From: ken@aiai.ed.ac.uk (Ken Johnson)
Newsgroups: rec.models.railroad
Subject: Re: Helix Calculation
Date: 8 Oct 92 13:48:55 GMT
Followup-To: rec.models.railroad
Organization: Bugs-R-Us


In article <26673@dog.ee.lbl.gov> wbrown@bevsun.bev.lbl.gov (Bill Brown) writes:

>Well - it shouldn't be too hard.  The circumference of a circle is
>	
>	2 * pi * radius
>
>So one turn is equal to a run of 2 * 2.14 * 22" = 138"

Not quite.  The circumference is 138 in.  but the track rises (say) 5in. 
on one turn of the helix.  So the distance of track per turn of the
helix is sqt(138^2 + 5^2), about 138.1

The gradient of the track is then 5/138.1 or 1 in 27, which is very
steep.  My back of an envelope calculation suggests you need about a
40-inch radius curve to bring the gradient down to 1 in 40, which is the
steepest incline you're likely to be able to climb. 

If space is tighter than that, how about doing what the Victorians did:
keep two sets of locomotives (one set on each level) and link the levels
with a rope worked incline?

-- Ken Johnson



-- 
//// Advice to dieters:         ////  Ken Johnson, A I Applications Institute
////   Never eat more than      ////       80 South Bridge, EDINBURGH EH1 1HN
////   you can carry.           ////                 E-mail ken@aiai.ed.ac.uk
////              -- Miss Piggy ////     phone 031-650 2756  fax 031-650 6513
Newsgroups: rec.windsurfing
From: nickn@mummy.agsm.unsw.OZ.AU (Nick_Nikov)
Subject: Re: Winter Sailing Destinations?
Organization: Australian Graduate School of Management
Date: Wed, 14 Oct 1992 00:24:09 GMT

In article <1992Oct12.175124.27899@PA.dec.com> mohanram@wsl.dec.com (Narayan Mohanram) writes:
>In article <1992Oct12.094655@wsl.dec.com>, gringort@wsl.dec.com (Joel Gringorten) writes:
>|> Now that my wife has decided she likes windsurfing better than skiing,
>|> we are looking for a good sailing destination this winter.
>
>I have heard (not been there) that the Swan River in Perth Australia has
>20+ knots of wind every single day in the souther hemisphere summer time.
>It is known as `the doctor' and comes up without fail. I beleive that
>the swan river is a tidal river that is a few kilometers wide (5Km i think).
>
>The problem for joel g. is that this is about the furthest point on earth
>from the usa.
>
>Any board-heads in australia, comment on this (add more accurate info)?
>-- 
You are right on both accounts....

If joel lives in USA why not try another Hawaiian island.

For a sense of adventure try South Africa...dont worry about the politics.
It has great water and excellent sailing, surfing etc..

But if Joel is from Europe then try Perth then get a four wheel drive and head
up the coast and see the trees grow horizontally due to natures wind.



-- 
-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
Nick Nikov  		    Internet (AARnet): N.Nikov@unsw.edu.au
Australian Graduate School of Management,	Tel: 61 2 931 9263
P.O. Box 1, Kensington. N.S.W. 2033.		Fax: 61 2 662 7621
Newsgroups: rec.windsurfing
From: root@valhalla.csuohio.edu (Scott Finet)
Subject: Re: Great Whites at Hatteras
Reply-To: root@valhalla.csuohio.edu
Organization: Cleveland State University
Date: Wed, 7 Oct 1992 16:48:00 GMT

In article <1992Oct5.211048.11506@ryn.mro4.dec.com> stu@otop23.oto.dec.com (Stuart  
MacKay) writes:
> 
> I heard one the other day that I thought was interesting (or bulls**t :)
> 
> Apparently, Australias great white population has been over fished (killed).
> 
> Because of this, Cape Hatteras is now the largest population of
> Great White sharks in the world.  So much so that people are now
> afraid to sail on the ocean side and stick to the sound.
> 
> Now, I am from in land canada and would not even bother driving
> 20 hours to sail on flat water.  However, it is the best place around
> for wind.
> 
> Has anyone out there heard this one?
> 

I was on the Outer Bank/Hatteras in late September.  A local fisherman/guide told  
me that no great whites had been seen all summer.  Same problem you describe...  
they are "over fished".

There were scores of dolphins, however.  They were out every morning, feeding as  
close as 10-20 feet from shore.

> Regards,
> Stu MacKay
> Ottawa, Canada

Scott Finet
root@valhalla.csuohio.edu
Newsgroups: rec.windsurfing
From: ccicpg!al!jmp@uunet.UU.NET (Jim Paugh)
Subject: Thresher fins from Fiberglass Fin Co.
Date: Wed, 14 Oct 92 09:45:46 PDT
X-Received: by usenet.pa.dec.com; id AA10434; Thu, 15 Oct 92 01:58:13 -0700
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X-To: rec.windsurfing.usenet
From: ktc@onan.jhuapl.edu
Newsgroups: rec.windsurfing
Subject: Twist, sail range
Date: 14 Oct 92 14:16:12 GMT
Article-I.D.: aplcen.1992Oct14.141612.15432
Organization: Johns Hopkins University

In article <12600393@hpfcso.FC.HP.COM> toma@hpfcso.FC.HP.COM (Tom Albertz)  
writes:
> > I do not understand this, when a gust hits me on my 6.0 Prizma I
> > can look up and see the sail twist off. The twist is very noticable
> > and therefore the WIND must be spilled. 
> 
> When a gust hits, the sails probably do spill a little air.  The main
> thing about twist, tho, is that the sail is taking a more efficient
> alignment with the apparent wind.  This translates to speed.  The air
> is moving faster 12 feet above the water than at 3 feet.
> 
> tom.

If anyone is interested, I did a sample calculation of the desirable (optimal)  
twist based upon Marcaj's analysis of true wind veer and induced drag veer. If  
memory serves, optimal twist for a generic 7.5 was about 15 degrees. BTW,  
dinghy sailors (generally) believe that overtwisting a sail will ensure that at  
least part (horizontal section) of the sail is working well... For example, in  
gusty conditions it is unlikely that you can keep the sail at the proper angle  
of attack all the time, and thus an overtwisted sail will have a portion that  
is not either stalled or at less than the proper angle of attack.

On another note, I got to take a close look at a '92 North 7.2 Prisma and  
compare it to my '90 7.5 North Prisma. I can see how the range of the '92  
probably exceeds the range of the '90. I can also see that the bottom end of  
the '90 is much better than the '92. Probably have to use the '92 in  
significantly more wind. This is born out by the comparitive performance of the  
two sails in that days racing.

Kim
From: srgxnbs@grace.cri.nz
Newsgroups: rec.windsurfing
Subject: Re: NewZealand windsurf guide downdated
Date: Wed, 14 Oct 92 21:42:44 GMT  
Organization: Industrial Research Ltd., New Zealand.

>From: william@castle.ed.ac.uk (William Warburton)
>Subj: Re: NewZealand windsurf guide updated
>Date: 13 Oct 92 09:57:51 GMT
>
>In article <1687E11587.EPLUS17@vmd.cso.uiuc.edu>, EPLUS17@vmd.cso.uiuc.edu (Rich
>ard Engelbrecht-Wiggans) writes:
>|> In article <1992Oct12.234304.12591@am.dsir.govt.nz>
>|> srgxnbs@grv (Bruce Spedding) writes:
>|>  
>|> >                        For those not familiar with New Zealand it is
>|> >just below and to the left of Australia ......
>|>                        ****
>|>  
>|> I remember being told that New Zealanders and Australians oriented
>|> their maps and globes with south to the top (so that they would be
>|> "on top" rather than "underneath,") but this is the first confirmation
>|> from a native!
>
> But surely that would put NZ *above* Oz instead of below as Bruce said
>
> I read it as to the left when looking from the northern hemisphere
>although I'm still not sure about the "below" (behind?).
>
>
> OK, come clean Bruce: Did you screw up?		:-)

I guess thats how it would look to you, but from our perspective I
screwed down :)

Bruce
From: jackg@bears.ucsb.edu (Jack Greenbaum)
Newsgroups: rec.windsurfing
Subject: Re: wxmap update
Date: 7 Oct 92 04:43:38 GMT
Reply-To: jackg@ece.ucsb.edu
Organization: /usr4/research/jackg/.organization
In-reply-to: ngs@bellcore.com's message of 6 Oct 92 12:08:25 GMT


The following is from the file WX/WX-TALK.DOC on vmd.cso.uiuc.edu:

    The surface weather maps and upper air maps are generated by the WXMAP
    program, written by Charley Kline of the University of Illinois. The
    WXMAP program runs under the X window system. It can produce weather
    maps for any part of the country, showing any subset of what you see in
    the GIF file. It can display many more reporting stations than what
    appears in the maps; most are suppressed in order to keep that
    relatively small image legible.

    Wxmap gets the information it needs to produce the map from "packages"
    which are downloaded over the network. The "packages" are the result of
    a data reduction run which happens twice hourly on an IBM S/6000. The
    data reduction runs read "raw" weather data off the Alden/Zephyr
    Domestic Data Plus (DD+) weather feed, a 4800bps teletype circuit which
    is a merging of the NWS public products circuit and the NMC's domestic
    coded data circuit.

    Locally written server software running on a Microvax III sucks in the
    DD+ feed and breaks it down into disk files for each product. The data
    reduction runs then access these products via NFS and produce the
    "packages" which wxmap then uses to draw the maps.

    Unfortunately, due to contractual obligations with Alden/Zephyr, the
    packages can't leave the University of Illinois campus, since they are
    deemed by Zephyr to be too close to the raw data on the feed itself.
    Unless a site has its own DD+ contract with Alden, all that can be
    released are "value-addeds", like the WXMAP GIFs available on vmd.

It must be that Bellcore has a similar comercial feed, or has some type
of access to the UIUC net.
--
-------------------------------------------------------------------------------
Jack Greenbaum     | UC Santa Barbara
jackg@ece.ucsb.edu | Department of Electrical and Computer Engineering, Box 253
(805) 893-4461     | Santa Barbara, Ca. 93106, USA
-------------------------------------------------------------------------------
From: jackg@bears.ucsb.edu (Jack Greenbaum)
Newsgroups: rec.windsurfing
Subject: Periodic Posting -- files available by FTP
Date: 12 Oct 92 20:16:48 GMT
Reply-To: jackg@ece.ucsb.edu
Distribution: rec
Organization: /usr4/research/jackg/.organization


A quick comment about distribution lists:

	Sometimes information of only local importance is worth posting, 
	like swap meet anouncements. Most news posting software allows you
	to specify a "distribution" for the post. However the software
	that propagates messages throughout the world usually ignores
	the distribution. If you do post something like a swap meet 
	announcement it is worth trying to put a distribution on it. However
	if you are in Norway and read a post about a swap meet in the 
	Gorge it's because the distribution was ignored by the software,
	as opposed to not provided by the person who posted.

An FTP archive for rec.windsurfing exists on bears.ece.ucsb.edu
(128.111.56.56) in the directory /pub/rec.windsurfing. The contents
include the following:

Gorge-info    Common questions about sailing the Columbia River Gorge.
              Compiled by Wilton Hart (wiltonh@windsurf.WR.tek.com)

Corpus-Christi-info 
              More useful info from Wilton about sailing and vacationing 
              in the Corpus Christi TX area. 

SF-info       Windsurfing shops and launch sites in the San Francisco
              Bay area. Compiled by  Kirk Lindstrom (kirk@hpcc01.corp.hp.com)

wind-numbers  Phone numbers for various wind reporting services
              throughout the nation compiled from net postings. Please
              contribute additions or deletions.

net-weather   A FAQ on obtaining weather data over the Internet.
              Compiled by yours truly, Jack Greenbaum (jackg@ece.ucsb.edu)

pictures      Subdirectory containing several windsurfing bitmaps in gif
              and jpeg formats (crissy.gif is still my favorite).

threads	      Subdirectory containing interesting threads of
    	      discussion. If you ask a question and get many replies
    	      then most likely it was a good question that others will
    	      want an answer to in the future. Send your digest to
    	      windsurf@bears.ece.ucsb.edu.

	      Current threads avaiable :
		contacts	Contact lens experiences
		hatteras	Cape Hatteras sailing info
		upwind		Upwind techniques for shortboards

Please send *anything* you feel should be added to this archive to
either windsurf@bears.ece.ucsb.edu or jackg@ece.ucsb.edu. 

I will try to handle e-mail requests from those without ftp access, as
long as the volume is not too high.

Think Wind!

--
-------------------------------------------------------------------------------
Jack Greenbaum     | UC Santa Barbara
jackg@ece.ucsb.edu | Department of Electrical and Computer Engineering, Box 253
(805) 893-4461     | Santa Barbara, Ca. 93106, USA
-------------------------------------------------------------------------------
From: swisher@cs.utexas.edu (Janet M. Swisher)
Newsgroups: rec.windsurfing
Subject: Re: Regripping booms
Date: 7 Oct 1992 22:30:31 -0500
Organization: CS Dept, University of Texas at Austin
NNTP-Posting-Host: boogie.cs.utexas.edu

In article <1992Oct5.191157.8475@ryn.mro4.dec.com>
stu@otop23.enet.dec.com writes:

>Hi,

>With the seasons end comming near and a fairly abusive summer passed,
>I have decided to regrip my booms.

>Does anyone have any comments or recommendations onto 
>1) how to strip the ripped/trashed progrip off of my chinook booms.

The time I regripped a boom, it was because a big section of the grip
had come unglued anyway.  I just grabbed that section and yanked, and
the rest of the grip came off relatively easily.  For the little bits
and clumps that were left, I used steel wool, which did the trick and
didn't seem to damage the boom any (maybe some tiny scratches, but
that just gives the contact cement more to grab onto).

A guy in our local windsurfing club recommends the following
procedure, which I haven't had the opportunity to try:
1) go to your local windsurfing shop and get one or two of the plastic
sheaths that booms are shipped in.
2) wrap the boom in paper towels and put it in the plastic sheath,
tying off one end securely.
3) pour enough paint thinner into the bag to saturate the paper
towels; tie off the other end; leave overnight.
4) (take the boom out of the bag;) strip the grip; it should come off
easily.
5) *while the boom is still wet* with paint thinner, rub the boom with
your hand in a plastic glove; this should take care of leftover bits
and clumps.

>2) tips on putting on new grip

>In the old days, the process was to use contact cement, start in the
>inside of the booms in the center of the grip, overlap one edge and
>file the outside edge down to the inside one.  This would result in an ugly 
>seam on the outside of the boom but it worked well.

I think both the instructions that came with the grip I bought, and
the local guy cited above recommended starting at the curved end of
the boom.  But I could be misremembering.

If you bevel the under-lapped edge, you may be able to get a smoother
seam.

I'm not an expert, but I play one on the net.




Newsgroups: rec.windsurfing
From: price@helios.unl.edu (Chad  Price)
Subject: Re: Optimal Sail Quivers
Organization: University of Nebraska - Lincoln
Date:  7 Oct 92 13:08:46 GMT

rogerc@ssd.intel.com (Roger Christal) writes:

>>(Dan Driscoll) writes:
>>"Race sails handle a wider range than rec sails"?

>This is a pretty technical issue that is really hard to explain
>properly, especially since I am not a sail designer.  If you are
>interested, go to your local shop and pick up Issue 3, 1992 of
>Performance Windsurf Report.  It contains an interview with Sailworks
>designer Bruce Peterson who discusses in some detail how these sails
>work.  It's good reading.

>If you can't locate a copy of the interview, I'll contact the magazine
>and see about reprinting portions of the intervierw here.  Let me
>know.
>-- 

PLease reprint. The nearest dealer with a store and magazines from here is
either Kansas City (3.5 hrs drive) or Denver (8 hrs.)

thanks


--
chad
price@helios.unl.edu
cprice@molecular.unmc.edu
From: colas@trinidad.inria.fr (Colas Nahaboo)
Newsgroups: rec.windsurfing
Subject: Private to Jean-Yves Poublan
Date: 9 Oct 92 12:29:12 GMT
Organization: Koala Project, Bull Research France

(I cannot reply to you, your mail system seem starnge)

Telephones moi cet aprem, ca vaut mieux (ou maile moi ton telephone)

-- 
Colas Nahaboo, colas@sa.inria.fr, Bull Research Koala proj. Wool&Gwm Architect
Pho:(33) 93.65.77.70(.66 Fax), INRIA, B.P.93 - 06902 Sophia Antipolis, FRANCE.
Newsgroups: rec.windsurfing
From: moc@bnl.gov (Mike O'Connor)
Subject: Re: Board weight and planing
Reply-To: moc@bnl.gov
Organization: Brookhaven National Laboratory
Date: Fri, 9 Oct 1992 13:28:20 GMT

|> him but don't really understand the physics of the situation.  Does someone out
|> there know how to explain this?  Thanks.
|>

	Displacement of water is the difference between two boards of
equal volume and different weights.  The lighter board displaces less
water than the heavier board, so the light board sits higher in the
water.  The higher in the water a board sits the less drag it will have
in sub-planing conditions.  So a board with an EPS core can provide the 
same floatation as a larger board with a urethane core.  The larger the
volume the more difference this makes.

	Personally I like my urethane core 8'6" in heavy wind and chop,
the deeper waterline helps my control, and when on a plane the
extra two or three pounds is negligible.  I've tried my buddies 8'6"
EPS of the same model, it doesn't have a better top end and feels 
skidish in big chop.  I own an EPS 9'4" for lighter winds, 
I'd probably have to have a 9'6" to get the same amount of floatation 
from a urethane core, and then there is that extra couple of pounds 
that would make more of a difference in light air.

-------------------------------------------------------------------------------
Mike O'Connor			            |
Computing and Communications Division	    |  It's the time of the season
Brookhaven National Laboratory	Bldg. 515   |   
Upton NY 11973				    |    To spend them V days!       
INTERNET: 	moc@bnl.gov                 |
PHONE:  	(516) 282-7410              |    
-------------------------------------------------------------------------------
From: toma@hpfcso.FC.HP.COM (Tom Albertz)
Newsgroups: rec.windsurfing
Subject: Re: BOARDS ON SALE
Date: 12 Oct 92 14:46:04 GMT
Organization: Hewlett-Packard, Fort Collins, CO, USA

In rec.windsurfing, jmunro@wyse.wyse.com (Jim Munro x2497) writes:
> In article <3782@bcstec.ca.boeing.com> sjm2458@bcstec.ca.boeing.com (Steve McCarthy) writes:
> >In article <12600388@hpfcso.FC.HP.COM>, toma@hpfcso.FC.HP.COM (Tom Albertz) writes:
> >> In rec.windsurfing, <RAIMONDI@SLACVM.SLAC.STANFORD.EDU> writes:
> >> > 8.6 BIC RAP '91 in excellent conditions:       $370
> >> > 9.2 PURE FUN board in fiberglass in excellent conditions: $130
> >> > e-mail to RAIMONDI@SLACVM           OR PHONE ME AT:   415-926-2813
> >> 
> >> 	I've got 4 copies of this post.  Is anybody else getting pissed
> >> 	off about this?
> 
> Well, speaking purely for myself:
> 
> 7. I am not pissed of at all.

	My original point was that this post was going up almost every 
	day for over a week.  I don't mind seeing stuff for sale.  I
	do it, and have sold quite a bit of stuff.  Just post it.
	Don't post it over and over and over and over...
From: poulton@hpl-opus.hpl.hp.com (Ken Poulton)
Date: Wed, 7 Oct 1992 23:50:10 GMT
Subject: Re: Optimal Sail Quivers
Organization: HP Labs, High Speed Electronics Dept., Palo Alto, CA
Newsgroups: rec.windsurfing

> Maybe what you actually mean is
> "Race sailors can handle a wider rage than rec sailors"
> because race sailors are used to the rigors of controlling rigid-foil race
> sails?

Not at all.  I'm only intermediate, but I immediately found that
race sails are *easier* to control in gusty/overpowered conditions.

Race sails have lots of cambers and a rigid design generally to hold the
shape of the draft and keep the center of effort from moving back in the
sail in a gust.  I don't think they really spill wind because once the
sail is powered and the mast bends sideways (downwind), the floppy
leach is no longer floppy.  The result is that instead of a gust
deforming the sail, moving the draft back and pulling the boom away from
your back hand, it mostly just gives you more power.  At least, it does
better at this than the lower-end sails. 


Ken Poulton
poulton@hpl-opus.hpl.hp.com
Newsgroups: rec.windsurfing
From: bill@turing.toronto.edu (Bill Monhemius)
Subject: About mast sales
Organization: CSRI, University of Toronto
Distribution: usa
Date: 15 Oct 92 21:54:49 GMT

A small point about mast sales: Please specify the DIN or MCS rating.  This
is crucial.

-Bill

-- 
+-------------------------------------------------+
|* * * * * *|%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%|
| * * * * * |            Bill Monhemius           |
|* * * * * *|%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%|
| * * * * * |            bill@turing.toronto.edu  |
+-----------+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%|
|                        University of Toronto    |
|%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%|
|                        Turing Language Group    |
|%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%|
+-------------------------------------------------+
From: kirk@hpcc01.corp.hp.com (Kirk Lindstrom)
Date: Wed, 7 Oct 1992 14:57:25 GMT
Subject: Re: Optimal Sail Quivers
Organization: Shredding the water of SF Bay, HP-OCD