Date: Mon, 7 Mar 94 19:13:10 PST
From: Info-Hams Mailing List and Newsgroup <info-hams@ucsd.edu>
Errors-To: Info-Hams-Errors@UCSD.Edu
Reply-To: Info-Hams@UCSD.Edu
Precedence: Bulk
Subject: Info-Hams Digest V94 #260
To: Info-Hams
Info-Hams Digest Mon, 7 Mar 94 Volume 94 : Issue 260
Today's Topics:
4-1000A Chimney
400 Hz xtal ladder filter, help. (2 msgs)
ANARTS RTTY NEWS BULLETIN 799 06/03/94
copying cw on typewriters
IPS Daily Report 06 03 94
Send Replies or notes for publication to: <Info-Hams@UCSD.Edu>
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We trust that readers are intelligent enough to realize that all text
herein consists of personal comments and does not represent the official
policies or positions of any party. Your mileage may vary. So there.
----------------------------------------------------------------------
Date: Mon, 7 Mar 1994 20:22:32 GMT
From: ihnp4.ucsd.edu!sdd.hp.com!col.hp.com!srgenprp!alanb@network.ucsd.edu
Subject: 4-1000A Chimney
To: info-hams@ucsd.edu
Don Turner (don.turner@eabbs.com) wrote:
: Hi Guys: I need a chimney for my 4-1000A tube. The Eimac part number
: is SK-506. If any of you are will to let go of one of these, leave a
: message. .....Don Turner WA6WRX
I know that a Coleman lantern globes work perfectly for 3-1000's. Not sure
if they work with 4-1000's. They are much cheaper than Eimac chimneys.
AL N1AL
------------------------------
Date: Mon, 7 Mar 1994 20:33:56 GMT
From: ihnp4.ucsd.edu!sdd.hp.com!col.hp.com!srgenprp!alanb@network.ucsd.edu
Subject: 400 Hz xtal ladder filter, help.
To: info-hams@ucsd.edu
asirene@ntuvax.ntu.ac.sg (asirene@ntuvax.ntu.ac.sg) wrote:
: Hi,
: My homemade QRP xcvr has a 600 Hz BW xtal ladder filter
: consisting of 4 12.0000 MHz xtals. However I still find it hard to
: work pile-ups due to insufficient selectivity. I am planning to
: change it to 400 Hz. Does anyone know how much improvement I can
: expect to see? Also, how can this be done in the easiest way? Do
: I need to add xtal stages or just change to capacitor values?
: 72 es 73,
: Daniel
------------------------------
Date: Mon, 7 Mar 1994 20:56:18 GMT
From: ihnp4.ucsd.edu!sdd.hp.com!col.hp.com!srgenprp!alanb@network.ucsd.edu
Subject: 400 Hz xtal ladder filter, help.
To: info-hams@ucsd.edu
: asirene@ntuvax.ntu.ac.sg wrote:
: : My homemade QRP xcvr has a 600 Hz BW xtal ladder filter
: : consisting of 4 12.0000 MHz xtals. However I still find it hard to
: : work pile-ups due to insufficient selectivity. I am planning to
: : change it to 400 Hz. Does anyone know how much improvement I can
: : expect to see? Also, how can this be done in the easiest way? Do
: : I need to add xtal stages or just change to capacitor values?
Going from 600 Hz to 400 Hz may not be enough of a change to make
a significant difference. You might want to shoot for a bit narrower.
I'm assuming the circuit has the capacitors in series between input
and output with shunt capacitors at input/output and the junctions
of each pair of crystals. Increasing the capacitance should narrow
the bandwidth. It will also lower the resonant frequency a bit
and increase the insertion loss slightly.
Zack Lau (KH6CP) (zlau@arrl.org) wrote:
: ... Increasing the capacitor values will
: decrease the bandwidth, but will also decrease the impedance.
: Impedance matching is important to maintain the proper filter
: shape. ...
To clarify, the load impedance is not really matched to the crystals,
it is matched to the source. Consider a single-section series crystal
with no matching capacitors. So long as the crystal series resistance
is small compared to the load resistance, the crystal has no effect
on source/load match at resonance.
When you add the shunt capacitors on input/output, you basically have
added L-networks at both ends, with the crystal providing the required
series inductance to effect the proper match. (The crystal looks
inductive above resonance.) The "L-network" transforms the 50 ohm
source/load impedance down to a lower value, which increases the
loaded Q of the crystal, narrowing the bandwidth. That also increases
the insertion loss, which is proportional to (loaded Q) / (unloaded Q).
The bigger the capacitor, the greater the impedance transformation and
the narrower the bandwidth.
In the following "schematic", L is the net inductance of the off-resonant
crystal, and R is the crystal's effective series resistance:
L-network L-network
|<---------->| |<---------->|
_______________________
| |
Input ------+--|-- L/2 --- R --- L/2 --|--+------ Output
| |_______________________| |
| Crystal |
Input Cap Output Cap
| |
Gnd Gnd
AL N1AL
------------------------------
Date: 7 Mar 94 12:12:44 GMT
From: nprdc!ihnp4.ucsd.edu!munnari.oz.au!newshost.anu.edu.au!sserve!usage!metro!news.ci.com.au!eram!dave@network.ucsd.edu
Subject: ANARTS RTTY NEWS BULLETIN 799 06/03/94
To: info-hams@ucsd.edu
[ ANARTS - Australian National Amateur Radio Teletype Society ]
ANARTS NEWS BULLETIN 799 06/03/94
SUNDAY TRANSMISSION DETAILS.
3.545 MHz 0930 UTC This relay is in
recess until 3rd April.
7.045 MHz -3 0030 UTC VK2CTD (Col)
14.070 MHz (amtor/fec) 0030 UTC VK2DPM (Alan)
14.091 MHz 0030 UTC VK2BQS (JIM)
146.675 MHz 0030/0930 UTC VK2JPA (PAT)
144.850 MHz (ax25 bbs) VK2JPA AT VK2RWI
146.675 MHz (rtty mmbbs/repeater) VK2RTY
Views expressed in this news bulletin are not necessarily
those of the Broadcast Officer, the Relay Officers, or of the
Society.
Well, did you see us at the Central Coast Field Day? We were
on the top floor of the stand if you could not find us. I
believe this happened to other clubs whose displays were on a
lower floor last year. Shall suggest to the host club that a
location board be displayed outside the stand main entrance so
that all club stands can be found more easily next year. It is
a great location, spacious outlook, but I suppose it is a bit
hard to get past the refreshment floor, hi hi.
The winner of the Morse Contest held on the ANARTS Stand at
Wyong last Sunday was VK2IC (he sounds more like a computer
specialist than a practitioner of the Ancient Art of Morse
Code). He had two errors in sending and one in receiving. He
was the proud and pleased recipient of the prizes : the
President's Bottle(s).
All in all, the day appeared to be a great success -- did you
meet the IPS team ? There were four on deck during the day. I
am looking forward to seeing the attendance figures for the
day. With this new venue, the attendance seems to be spread
out more, or is it just because there are more places to look
for people and stands.
We look forward to next year and seeing you all again.
----------------------------------------
BARTG Contest
-------------
Date: March 19-21 1994, sponsored by the British Amateur Radio
Teledata Group.
Exchange: Send: RST + QSO number + time in UTC.
Multipliers: Each DXCC country, including first QSO with W, VE
and VK, counts as a multiplier on each band. Each call
district in W, VE and VK will count as an additional on each
band. Also, each continent (6) will count once, not once per
band.
QSO Points: Count 1 (one) point per QSO.
Final score: Total QSOs x total multipliers x number of
continents (max 6).
Logs: Use separate logsheets for each band. Logs must show:
BAND, DATE and TIME (UTC), CALLSIGN, MESSAGE Sent and
Received, COUNTRIES and POINTS claimed.
Summary sheet must show full scoring, times of operation, and
address for correspondence.
Logsheets, summary sheets and multiplier and dupesheets are
all available for copying from the RTTY Contester's Guide,
published by RTTY Journal.
Deadline: Logs must be received by May 25 to qualify.
Mail logs to:
BARTG c/o John Barber, G4SKA
32 Wellbrook Street
Tiverton, Devon
EX165JW, England
Have fun!
----------------------------------------
IPS weekly report
-----------------
24 FEBRUARY - 3 MARCH 1994
Issue No 09
Date of issue: 4 March, 1994
INDICES:
Date 25 26 27 28 01 02 03
10cm 097 094 095 093 094 098 101
A 12 06 06 09 10 17 ( 17 estimated)
T 71 27 55 57 47 73 64
SUMMARY OF ACTIVITY
Solar activity was very low 25th-26th and 28th February-1st
March, moderate on 27th, and low on 2nd-3rd March. There was
an M2 flare on 27th february.
The geomagnetic field at Learmonth (WA) was quiet on 27th,
quiet to unsettled 26th, 28th-3rd March, apart for a period of
minor storm activity on 3rd.
Ionospheric F2 critical frequencies at Sydney were uo to 20
per cent above predicted monthly values on 25th, near
predicted levels on 26th, near predicted with enhancement
periods of up to 30 per cent on 27th-1st, and enhanced 10 t0
15 per cent on 2nd-3rd March. Sporadic E may have degraded F
layer communications at times on 1st March.
FORECAST FOR THE NEXT WEEK (4 -10 MARCH)
SOLAR: low
GEOMAGNETIC: active-minor storm periods expected March 4-9, due
to a solar coronal hole.
IONOSPHERIC: degraded HF comms expected March 4-9. Depressions
of up to 20% may be experienced at times during
this interval.
Updated IPS Monthly Predicted Smoothed T-indices
Prepared on Mon Feb 28 12:58:20 1994
YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
==============================================================
1993 42
1994 39 37 36 35 34 31 29 27 24 22 21 19
1995 19 18 17 16 15 14 14 13 12 11 11 10
1996 10 9 9 8 8 7 8 8 9 10 11 12
1997 13 14 16 18 20 22 25 28 32 35 40 46
Courtesy of IPS Radio and Space Services
----------------------------------------
VK2SG RTTY DX NOTES 25 FEB 94
VK2SG RTTY DXNOTES WEEKENDING 25 FEBRUARY 1994 (BID RTDX0225)
OUR INFORMATION THIS WEEK CAME FROM: 9X5LJ, DJ3IW AND THE
CENTRAL-EUROPE DX CLUSTER NODE DB0SPC, I5FLN, IK5AAX AND THE
IK5PWJ PACKET CLUSTER, W2JGR AND THE NJ0M NODE THE TWIN-CITIES
DX PACKET CLUSTER, W5KSI AND ZS5S. THANK YOU ALL FOR YOUR
ASSISTANCE.
BANDPASS
FRIDAY 18
DX NOT SLEEPIN, JUST RESTIN
SATURDAY 19
0114-14088 S92ZM 0707-14082 UN7LR
1110-21073 5Z4FO FEC 1516-14085 ZS9A
1520-21083 8ZD7DP 1527-14088 ER3ED
1529-21088 V50CM 1537-14085 5R8DG
1542-14087 EX2U 1706-14087 5B4VX
SUNDAY 20
0843-21086 9N1AA 0843-21089 9M1AA
1045-21086 FR5ZU 1052-21083 TZ6FIC
1129-21085 ZD8M 1253-21083 ZD7DP
1355-21086 9H1ET 1358-21091 HJ4SAN
1401-14086 UT5DX 1407-14084 5B4VX
1421-14084 XU7VK 1448-14088 UN7LR
1450-14089 YL3FW 1455-21086 5R8DS
1627-14084 S59F 1633-14090 5B4ABU
1835-14087 ZS1CU 2230-14064 TY1PS CLOVER
MONDAY 21
1317-14086 EA8/ON8RI 1720-14083 V31WW
2044-14085 V31DV 2044-14090 J88BS
2052-14083 ZD7DP 2135-14086 V31EN
2209-14085 S92ZM 2156-14085 CO2JJ
2330-14085 V31DV
TUESDAY 22
0113-14086 V31II 1634-14086 V31WW
1814-14087 V31EO QSL KF8NN 1954-14083 J88BS
2012-14085 V32GM 2017-14086 CO2KG
2019-14082 V31GM 2139-14085 V31MV
2339-14083 V31JU
WEDNESDAY 23
1620-14088 HK1LAQ
THURSDAY 24
0021-14086 CX7BF 2006-14084 ZS0X QSL DJ6JC
NOTES OF INTEREST.
PENGUIN ISLANDS, ZS0 AND WALVIS BAY, ZS9. THE GOVERNMENT OF
SOUTH AFRICA, AGREED TO HAND OVER THE THIRTEEN PENGUIN ISLANDS
AND WALVIS BAY, TO THE REPUBLIC OF NAMIBIA ON 28 FEBRUARY.
DJ6JC, DJ6SI AND V51BI, USING THE CALL ZS0X, SHOULD HAVE BEEN
ACTIVE ON 23-28 FEBRUARY FROM PENGUIN ISLANDS AND ZS6EZ AND
G3XTT WITH THE CALL, ZS9Z, FROM WALVIS BAY. THEY BOTH BECAME
PART OF NAMIBIA BEGINNING 1 MARCH AND MORE THAN LIKELY WILL BE
DELETED AS DXCC COUNTRIES.
DESECHEO, KP5. THE PLANNED DXPEDITION BY A GROUP OF OPERATORS
FOR 1-7 MARCH, HAS BEEN CANCELLED. PERMISSION TO LAND HAS BEEN
DENIED BECAUSE A GROUP OF HAITIAN SQUATTERS. UNTIL THIS CAN BE
RESOLVED, NO LANDING PERMISSION CAN BE GIVEN.
REVILLA GIGEDO, XF4. THIS OPERATION WAS ON UNTIL 4 MARCH.
QSL HECTOR, XE1BEF.
MAYOTTE, FH. HERMANN, DJ2BW SHOULD BE SIGNING FH/DJ2BW FOR A
MUCH NEEDED ONE IN RTTY FROM 1-9 MARCH. KYFC
FOR NEXT WEEK'S BULLETIN, SEND YOUR BANDPASS AND NOTES OF
INTEREST TO JULES, W2JGR AT W2TKU.#SRQ.FL.USA.NA
REMEMBER, DX DON'T SLEEP.
GL DE BOB, WB2CJL AT W5KSI.NOLA.LA.USA.NA
---------------------------------------
Coming events
-------------
1994
March 19th-20th BARTG WW RTTY Contest
April 16th-17th SARTG WW AMTOR Contest
------------------------------------
Society information
The Society may be contacted at : PO Box 860, Crows Nest 2065
Australia, for such matters as membership and general
enquiries. Enquiries can also be made by packet to the
President (Col) VK2CTD, or the Secretary (Pat) VK2JPA @ VK2OP.
News items may be sent to Broadcast Officer PO Box 60
Blacktown 2148 Australia, or by packet to VK2JPA @ VK2OP.
Email addresses for the Broadcast Officer are :
patl@extro.ucc.su.oz.au or VK2JPA@VK2OP nsw.aus.oc
The Society welcomes news items on any digital subjects from
anywhere in the broadcast footprint. We know we reach ZL and many
South Pacific islands. We are looking forward to news from your
areas to let other amateurs know what you are doing in the hobby.
Hope to hear from you.
73s de Pat VK2JPA Broadcast Officer
That concludes ANARTS NEWS BULLETIN 799 06/03/94.
INSERTED BY VK2BQS (Jim) Vice-President ANARTS.
--
Dave Horsfall (VK2KFU) VK2KFU @ VK2OP.NSW.AUS.OC PGP 2.3
dave@esi.COM.AU ...munnari!esi.COM.AU!dave available
------------------------------
Date: 7 Mar 94 21:47:00 GMT
From: nprdc!ihnp4.ucsd.edu!usc!howland.reston.ans.net!gatech!swrinde!cs.utexas.edu!geraldo.cc.utexas.edu!astro.as.utexas.edu!oo7@network.ucsd.edu
Subject: copying cw on typewriters
To: info-hams@ucsd.edu
MAHJMAC@DELPHI.COM asks:
>>If the only goal [of CW testing sessions] is to make
>>certain people are proficient in code, no matter what the means, then why
>>couldn't a decoding device that takes audible morse and converts it into
>>text be allowed. In under a week I could develop a program for the Sound
>>Blaster or other audio cards that could do exactly that.
Because when you are shipwrecked and have built your CW radio transmitter
out of coconuts and paper clips, you won't be able to decode any messages
received in response to your distress call. You have to know whether
someone is saying "Ship will be there in 2 days", "pse QSY have been on
this freq for last 10 hrs", or "599 TX qsl via buro, QRZ?"
Derek "May Day" Wills (AA5BT, G3NMX)
Department of Astronomy, University of Texas,
Austin TX 78712. (512-471-1392)
oo7@astro.as.utexas.edu
------------------------------
Date: 6 Mar 94 23:08:35 GMT
From: nprdc!ihnp4.ucsd.edu!munnari.oz.au!newshost.anu.edu.au!sserve!usage!metro!ipso!rwc@network.ucsd.edu
Subject: IPS Daily Report 06 03 94
To: info-hams@ucsd.edu
IPS RADIO AND SPACE SERVICES AUSTRALIA
Daily Solar And Geophysical Report
Issued at 2330 UT 6 March 1994
Summary for 6 March and Forecast up to 9 March
IPS Warning 7 was issued on 02 March and is still current.
-----------------------------------------------------------
1A. SOLAR SUMMARY
Activity: low
Flares: none.
Observed 10.7 cm flux/Equivalent Sunspot Number : 096/043
1B. SOLAR FORECAST
07 March 08 March 09 March
Activity Low Low Low
Fadeouts None expected None expected None expected
Forecast 10.7 cm flux/Equivalent Sunspot Number : 098/045
1C. SOLAR COMMENT
None.
-----------------------------------------------------------
2A. MAGNETIC SUMMARY
Geomagnetic field at Learmonth : quiet to unsettled
Estimated Indices : A K Observed A Index 5 March
Learmonth 08 2222 1233
Fredericksburg 12 06
Planetary 10 05
2B. MAGNETIC FORECAST
DATE Ap CONDITIONS
07 Mar 20 Unsettled to active.
08 Mar 20 Unsettled to active.
09 Mar 20 Unsettled to active.
2C. MAGNETIC COMMENT
It appears that the expected coronal hole disturbance is
not going to eventuate, or if it does it will be significantly
milder than originally expected.
3A. GLOBAL HF PROPAGATION SUMMARY
LATITUDE BAND
DATE LOW MIDDLE HIGH
06 Mar normal normal normal
PCA Event : None.
3B. GLOBAL HF PROPAGATION FORECAST
LATITUDE BAND
DATE LOW MIDDLE HIGH
07 Mar normal fair poor
08 Mar normal fair poor
09 Mar normal fair poor
3C. GLOBAL HF PROPAGATION COMMENT
Degraded HF comms did not eventuate.
-----------------------------------------------------------
4A. AUSTRALIAN REGION IONOSPHERIC SUMMARY
MUFs at Sydney were 10 to 20% above predicted monthly values
T index: 89
4B. AUSTRALIAN REGION IONOSPHERIC FORECAST
DATE T-index MUFs
07 Mar 70 10 to 20% above predicted monthly values.
08 Mar 60 About 15% above predicted monthly values.
09 Mar 60 About 15% above predicted monthly values.
Predicted Monthly T Index for March is 40.
4C. AUSTRALIAN REGION COMMENT
It appears that the expected HF degradations are not going to
eventuate.
--
IPS Regional Warning Centre, Sydney |IPS Radio and Space Services
email: rwc@ips.oz.au |PO Box 5606
tel: +61 2 4148329 |West Chatswood NSW 2057
fax: +61 2 4148331 |AUSTRALIA
------------------------------
Date: 7 Mar 1994 12:47:35 -0800
From: usc!math.ohio-state.edu!howland.reston.ans.net!europa.eng.gtefsd.com!news.umbc.edu!eff!news.kei.com!yeshua.marcam.com!insosf1.infonet.net!usenet.ee.pdx.edu!news.reed.edu@ihnp4.ucsd.edu
To: info-hams@ucsd.edu
References <1994Mar2.175938.12119@alw.nih.gov>, <1994Mar3.144159.3607@ke4zv.atl.ga.us>, <1994Mar3.185052.18759@oracle.us.oracle.com>com
Subject : Re: Further criminalization of scanning
Douglas Marsh (dmarsh@erpyr.us.oracle.com) wrote:
: In article <1994Mar3.144159.3607@ke4zv.atl.ga.us> gary@ke4zv.atl.ga.us (Gary Coffman) writes:
: -- Other Quote Deleted --
: >
: >I agree, both with the idea that government is too quick to say "there
: >ought to be a law" and that scanner hobbiests are at heart voyeurs. That's
: >where the basic difficulty arises. Laws against Peeping Toms have existed
: >for centuries. Congress is trying to extend that principle into the wireless
: >age, but they're making the same mistake here as they are with the problem
: >of violence in society. Banning scanners will be no more effective than
: >banning guns, and has the undesirable side effect of causing unnecessary
: >harm to legitimate users of these tools. The real problem in both cases
: >is sick and twisted individuals with no sense of morals or ethics, not
: >the hardware that enables them to pursue their voyeurism or violence.
: >
: >Gary
: >--
: >Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary
: >Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary
: >534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary
: >Lawrenceville, GA 30244 | |
: How many people were killed by scanner last year?
: Doug :~}
Private citizens stopped appoximately 1,000,000 crimes last year with
handguns. (Prof. Gary Kleck)
If only ONE life is saved, mustn't we maintain the right to own handguns?
^^^
How many crimes were stopped/lives were saved with a scanner radio?
(Better sharpen up the antennas on those "Assault Radios")
73's
Gene
KB7WIP
------------------------------
Date: Mon, 7 Mar 1994 18:46:44 GMT
From: ihnp4.ucsd.edu!swrinde!gatech!wa4mei!ke4zv!gary@network.ucsd.edu
To: info-hams@ucsd.edu
References <1994Mar3.153014.6322@arrl.org>, <1994Mar4.132650.9466@ke4zv.atl.ga.us>, <1994Mar6.173414.5886@arrl.org>
Reply-To : gary@ke4zv.UUCP (Gary Coffman)
Subject : Re: Medium range point-to-point digital links
In article <1994Mar6.173414.5886@arrl.org> zlau@arrl.org (Zack Lau (KH6CP)) writes:
>Gary Coffman (gary@ke4zv.atl.ga.us) wrote:
>: In article <1994Mar3.153014.6322@arrl.org> zlau@arrl.org (Zack Lau (KH6CP)) writes:
>: >BTW--how else does one improve a point to point link,
>: >besides using bigger antennas and more power?
>
>: Ah, the DXer mentality at work. That's what those guys
>: thought too. The only problem was, that wasn't why the
>: link was flakey. The real problem was that they had
>: established the world's worst exposed terminal in their
>: single frequency network, and the link was being killed
>: by all the DXer's with 160 watt amps and beams trying to
>: make it to their hubs and capturing the link node's receiver.
>: It would be held off for minutes at a time by the continous
>: collisions.
>
>Actually, if you are forced to do it all on a single
>frequency, bigger antennas and more power *is*
>just about the only solution (to improve the link).
>The more directive antennas would reduce chance of
>collisions, while more power would reduce the effect
>of a collision. Admittedly, an *ugly* situation. But,
>politics makes it difficult to find other frequencies
>that are those compatible with radios already in use.
No, the better solution is to convince people to use
*lower* power, and *lower* sites to reduce the exposed
terminal problem. 40 db over S9 signals are not required,
S2 is fine. The best solution is to use a separate non-
contending link frequency, of course.
>Yes, I know you could modify all the TNCs for some sort
>of optimized slotted Aloha protocol, but I doubt this
>is really practical.
Right, it isn't practical, and all it takes is one joker
who doesn't want to play to screw it up for everybody.
>Getting links on clear frequencies is where microwaves
>show their superiority. Not only is it more difficult
>to fill the wider bands with wall to wall signals, but
>highly directive antennas make frequency reuse more of a
>possibility. All that money spent on VHF bricks
>might be put to better use on microwave transverters.
The price of a VHF brick might make a down payment on
a stable microwave transverter, but you still are faced
with the LOS problems. Cheap, narrow, stable, pick one.
As far as I know, the cheapest suitable microwave
*appliance* is the SSB Electronics system. It costs
about what a VHF kilowatt does. Gunnplexers are neither
narrow nor stable. (not to say they won't *work* for
some unimpeded paths, but you can't co-locate a lot of
them in one of our bands).
>I'm pretty sure an analysis of the phone calls I've
>recorded would show that its not just DXers who run
>beams and amplifiers into their local BBS. I usually
>end up spending an extra few minutes explaining that
>while a beam results in stronger signals, this advantage
>is often eliminated by the extra collisions that result.
Yeah, there are others besides DXers who think power is
the answer to every problem. And it's true that too little
power, or too low an antenna can create hidden terminal
problems as well. The overall MAN system has to *balance*
to work well.
>I've found that an open wire fed *HF* dipole, even
>though it is cross polarized, works a lot better than
>an indoor yagi for packet work, because it hears more
>stations than the yagi.
A nice outdoor vertical that hears nearly as well as
your BBS or node is even better. Especially when coupled
with the minimum necessary transmit power. (Phil Karn's
pseudo-cellular approach would be best *if* the average
ham density was high enough. Unfortunately, it's not.)
Gary
--
Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary
534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244 | |
------------------------------
Date: 7 Mar 94 04:16:42 GMT
From: nprdc!ihnp4.ucsd.edu!munnari.oz.au!newshost.anu.edu.au!sserve!usage!metro!news.ci.com.au!eram!dave@network.ucsd.edu
To: info-hams@ucsd.edu
References <gradyCLxxqM.IID@netcom.com>, <5220@eram.esi.com.au>, <alh-050394143621@twilight1h160.its.utas.edu.au>
Subject : Re: personal communication Australia <-> USA
In article <alh-050394143621@twilight1h160.its.utas.edu.au>,
alh@postoffice.utas.edu.au (Alan Hughes) writes:
| But you dont *have* to leave the header there, it can be deleted and then
| added back again later.
True. I guess you could always leave the file un-armoured, and 7PLUS it
fot transport; all of which makes the anti-encryption laws silly, since
they're so easily circumvented. Not that I've ever done it, of course :-)
--
Dave Horsfall (VK2KFU) VK2KFU @ VK2OP.NSW.AUS.OC PGP 2.3
dave@esi.COM.AU ...munnari!esi.COM.AU!dave available
------------------------------
Date: 7 Mar 1994 16:23:04 -0500
From: yale.edu!noc.near.net!news.delphi.com!news.delphi.com!not-for-mail@yale.arpa
To: info-hams@ucsd.edu
References <1994Feb17.144029.3459@ke4zv.atl.ga.us>, <rohvm1.mah48d-280294100619@136.141.220.39>, <2MAR199408091550@nssdca.gsfc.nasa.gov>
Subject : Re: Keyboards at testing sessions
>Just couldn't resist adding to his thread. Copying by typewriter has been
>around for as long as their have been typewriters. Even the FCC when it
>gave the test would let you bring a typewriter. The computer is just the
>late 20th century typewriter. The object really is to demonstrate the
>ability to receive code at the required level. The mechanism by which you
>(as distinct from some computer program) write down the code is immaterial
>and not germane to the testing of code proficiency. Not even the FCC is
>requiring a handwriting proficiency test at a particular speed.
>Erich
>N3OXM
As I was learning the code, I developed an application that would sound random
letters, numbers, or pro-signs, and I would then press the proper key on the
keyboard. As a high speed touch typist (> 120 wpm) I found that after a
while, my fingers were conditioned to pressing a certain key in response to
a certain audible pattern. When I then began attempting to write down
what I heard, instead of hitting a key, I discovered that I was not nearly
as proficient as I was on the keyboard.
But, you bring up an even different point. If the only goal is to make
certain people are proficient in code, no matter what the means, then why
couldn't a decoding device that takes audible morse and converts it into
text be allowed. In under a week I could develop a program for the Sound
Blaster or other audio cards that could do exactly that.
It would be no different than a person who can only decode morse if they have
a typewriter or other keyboard device available. It seems to me that in this
day and age, it is so easy to develop inexpensive devices that could decode
morse, that the only reason to keep the test is to be certain people are
proficient in reading and writing without devices to assist them.
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End of Info-Hams Digest V94 #260
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