Date: Wed, 26 Jan 94 10:08:41 PST
From: Ham-Space Mailing List and Newsgroup <ham-space@ucsd.edu>
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Subject: Ham-Space Digest V94 #10
To: Ham-Space
Ham-Space Digest Wed, 26 Jan 94 Volume 94 : Issue 10
Today's Topics:
Arsene
Daily IPS Report - 25 Jan 94
Low Pass filter vs Band Pass - Mode JD
Status of polar-orbiting weather satellites
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----------------------------------------------------------------------
Date: Mon, 24 Jan 1994 11:45:07 GMT
From: ucsnews!sol.ctr.columbia.edu!howland.reston.ans.net!torn!csd.unb.ca!upei.ca!UPEI.CA!seeler@network.ucsd.edu
Subject: Arsene
To: ham-space@ucsd.edu
Hi - Its been a long time since I've seen anything about Arsene and was
wondering if it has any funtions going at all at this time.
Tnx - Dave, VY2DCS
Internet : Seeler@upei.ca
------------------------------
Date: 24 Jan 94 23:29:06 GMT
From: swrinde!sdd.hp.com!think.com!cass.ma02.bull.com!syd.bull.oz.au!brahman!tmx!basser.cs.su.oz.au!metro!news.ci.com.au!eram!dave@network.ucsd.edu
Subject: Daily IPS Report - 25 Jan 94
To: ham-space@ucsd.edu
IPS RADIO AND SPACE SERVICES AUSTRALIA
Daily Solar And Geophysical Report
Issued at 2330 UT 24 January 1994
Summary for 24 January and Forecast up to 27 January
IPS Warning 02 was issued at 24/2200UT January and is current
for period January 27 - 29.
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity: low
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number : 129/082
1B. SOLAR FORECAST
25 January 26 January 27 January
Activity Low Low Low
Fadeouts None expected None expected None expected
Forecast 10.7 cm flux/Equivalent Sunspot Number : 130/084
1C. SOLAR COMMENT
None.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field at Learmonth : quiet
Estimated Indices : A K Observed A Index 23 January
Learmonth 02 2111 0001
Fredericksburg 02 07
Planetary 04 05
2B. MAGNETIC FORECAST
DATE Ap CONDITIONS
25 Jan 08 Quiet to unsettled.
26 Jan 08 Quiet to unsettled.
27 Jan 20 Unsettled to active.
2C. MAGNETIC COMMENT
Active periods expected during interval 27-29 Jan due to coronal
hole.
3A. GLOBAL HF PROPAGATION SUMMARY
LATITUDE BAND
DATE LOW MIDDLE HIGH
24 Jan normal normal normal
PCA Event : None.
3B. GLOBAL HF PROPAGATION FORECAST
LATITUDE BAND
DATE LOW MIDDLE HIGH
25 Jan normal normal fair
26 Jan normal normal fair
27 Jan normal fair poor
3C. GLOBAL HF PROPAGATION COMMENT
Degraded comms expected at mid/high lats during interval
27-29 January.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
MUFs at Sydney were about 15% above predicted monthly values
T index: 73
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
DATE T-index MUFs
25 Jan 75 About 15% above predicted monthly values.
26 Jan 75 About 15% above predicted monthly values.
27 Jan 75 About 15% above predicted monthly values.
Predicted Monthly T Index for January is 30.
4C. AUSTRALIAN REGION COMMENT
Degraded HF comms expected during Jan 27-29.
--
Dave Horsfall (VK2KFU) VK2KFU @ VK2OP.NSW.AUS.OC PGP 2.3
dave@esi.COM.AU ...munnari!esi.COM.AU!dave available
------------------------------
Date: Mon, 24 Jan 1994 11:53:17 GMT
From: ucsnews!sol.ctr.columbia.edu!howland.reston.ans.net!torn!csd.unb.ca!upei.ca!UPEI.CA!seeler@network.ucsd.edu
Subject: Low Pass filter vs Band Pass - Mode JD
To: ham-space@ucsd.edu
I have some desensing of my 440 rig on receive when the 2 meter rig fires
up on Mode JD. This is not a MAJOR problem but I would like to resolve it.
I suspect that it involves the 3rd harmonic of the 2 meter Transmitter.
The books suggest using a low pass or band pass filter - but they differ as
to which would be best ( opinion or operation differences?). I use the all
IC275 for Dx and local operations as well and suspect that the low pass
filter would be a good start. The filter in the VHF/UHF Dx book appears
to fit my needs - 35? db attenuation of the 2nd harmonic and 60 db
attenuation of the 3rd - with minimal (?) insertion loss.
My questio is this - is the low pass filter the best way to solve this
particular issue - and if so - does anyone have any suggestions as to
any particular filter design / schematics - and comments as to how they/it
works?
Thanks for considering this post.
Dave, VY2DCS
Internet: Seeler@upei.ca
------------------------------
Date: Tue, 25 Jan 94 17:46:00 +0200
From: swrinde!cs.utexas.edu!howland.reston.ans.net!pipex!uknet!EU.net!news.eunet.fi!gate.compart.fi!compart!leo.wikholm@network.ucsd.edu
Subject: Status of polar-orbiting weather satellites
To: ham-space@ucsd.edu
STATUS OF POLAR-ORBITING WEATHER SATELLITES
===========================================
No. 2, January 25, 1994
Station: Helsinki, +60.2N +25.1E
------------------------------------------------------
NOAA 9 137,62 MHz normal
NOAA 10 137,50 MHz VHF conflict with NOAA 12?
NOAA 11 137,62 MHz normal
NOAA 12 137,50 MHz normal
Meteor 3-5 137,30 MHz not actice in North
Meteor 2-21 137,30 MHz not active in North
------------------------------------------------------
Leo Wikholm
internet: leo.wikholm@compart.fi
fidonet : 2:220/861
------------------------------
Date: 24 Jan 94 09:24:44 -0700
From: ucsnews!newshub.sdsu.edu!usc!howland.reston.ans.net!europa.eng.gtefsd.com!news.umbc.edu!eff!news.kei.com!sol.ctr.columbia.edu!hamblin.math.byu.edu!yvax.byu.edu!physc1.byu.edu!peterson@
To: ham-space@ucsd.edu
References <2hd6ji$q5e@hpavla.lf.hp.com>, <1994Jan17.145311.25166@ke4zv.atl.ga.us>, <CK0E5n.LG9@world.std.com>tr.colu
Subject : Re: Vacuum tubes in spacecraft?
In article <CK0E5n.LG9@world.std.com>, dts@world.std.com (Daniel T Senie) writes:
> In article <1994Jan17.145311.25166@ke4zv.atl.ga.us> gary@ke4zv.atl.ga.us (Gary Coffman) writes:
>>Note also that program bloat can be traced almost completely to having
>>excess RAM available. Programs naturally expand to fill the space available,
>>witness Wordstar. It was a great fast program on a 48 kb Z-80 system, but
>
> common misconception. Wordstar NEVER fit in 48K. Sure it would run in a
> machine that had 48K, but every time you hit ^Y to delete a line, it
> had to swap in an overlay from disk to do the function, then swap back
> to the main code. When more memory is available, it is possible to
> improve performance.
>
>>now it's a multi-megabyte dog on a Windows PC with 8+ megs of RAM. And
>>that's 166 times more RAM to develop a bit error that can crash the system.
>>To a large degree, reliability is a function of parts count. The fewer
>>parts, the less to go wrong.
>>
>
> Actually in software the less is better philosopy does not always hold. To
> get program size smaller, one could always skip the bounds checking and input
> parameter checking. Fewer parts, but less reliability...
>
>>Gary
>>--
>>Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary
>
> --
> ---------------------------------------------------------------
> Daniel Senie Internet: dts@world.std.com
> Daniel Senie Consulting n1jeb@world.std.com
> 508-365-5352 Compuserve: 74176,1347
Actually there are two other driving forces in the software bloat that are only
allowed to operate because of the cheap RAM: 1) The demand for software that
requires no thought or training. Some of this is good and some of it is
useless "creeping featurism" (I have yet to understand why a top quality word
processing package would require you to remove your hands from the keyboard to
perform basic formatting functions). And 2) the trend toward using high-level
languages for all software development. Most of those "lean and mean" packages
of the past were written in optimized assembly code because RAM was tight. Now
they don't have to put any effort into optimizing the code and are able to
write using high-level languages and compilers that generate absolutely
horrendous code (from an efficiency standpoint). Yes, that allows them to meet
the demands of (1) above more quickly but at a tremondous cost in storage space
(just for grins look at the bloat in the distribution disks for ANY package
over the last few years - things that used to be delivered on 2 360K floppies
now require 4 to 6 1.44M floppies and add data compression to boot). Whether
this whole trend is good or bad is a totally religious argument (hardware is
cheap and features are nice versus why do I need so much hardware just to run
a simple application).
However, any way you look at it my hat goes off to the programmers who are able
to fit the entire control program for the Shuttle into the memory on those
computers. I can guarantee they are not using the bloated high-level languages
that you normally see in the PC world to do that.
Bryan Peterson, ki7td
peterson@physc1.byu.edu
------------------------------
End of Ham-Space Digest V94 #10
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