RS232 INTERFACE

ehayes at VNET.IBM.COM ehayes at VNET.IBM.COM
Tue Apr 18 15:28:48 EDT 1995


First, thanks to all that responded to my query on the various
interfaces.  I am waiting on some of those I contacted for
info on their specific products.  In the meantime, I built the
one described in the Feb. '93 QST.  Works like a champ!!  But...
I don't care for having the additional power supply to run it.
Does anyone know where one might find a schematic for an
interface that gets its power from the computer.  I understand
that by inserting 3 diodes between selected lines on the
computer and the voltage regulator input on the interface circuit
that sufficient voltage is available.  I do not know which pins or
if additional modifications are necessary.  Can anyone help me
with this?

Thanks in advance,


73  KC5DVT   Wayne     email...ehayes at vnet.ibm.com
Austin, Texas

>From n6ig at netcom.com (Jim Pratt)  Tue Apr 18 20:52:39 1995
From: n6ig at netcom.com (Jim Pratt) (Jim Pratt)
Date: Tue, 18 Apr 1995 12:52:39 -0700 (PDT)
Subject: SS Results/logs
Message-ID: <199504181952.MAA21718 at netcom17.netcom.com>

Hello all...

1) I got many direct replies regarding my comment about getting a "return 
receipt" for electronically submitted contest logs to the League.  In my 
note, I mentioned their BBS;  I have not sent a log via internet, as I 
only recently got an account with direct access.  But, the overwhelming 
response what that logs submitted via internet DO get a return receipt 
soon after they are sent.  Good show!  I will try that next time...

2) I got my May QST yesterday...and my Sacramento Valley CW HP SO 
certificate.  Either the QST was really late (this is the normal time we 
on the "left coast" get our magazines), or the certificates were really 
early.  I suspect the latter.  Great job...

3) Sorry, no Poission D'Avril score to post, I accidentally sent it in with 
my tax forms.  Gee, I hope that doesn't lead to an audit!  Perhaps just a 
bigger refund.  But, judging from some of the political policies being 
discussed in the various forums these days, my score summary will fit 
right in...

73, Jim  N6IG

>From fish at crl.com (Bill Fisher, KM9P  Concentric Systems, Inc.)  Tue Apr 18 21:09:34 1995
From: fish at crl.com (Bill Fisher, KM9P  Concentric Systems, Inc.) (Bill Fisher, KM9P  Concentric Systems, Inc.)
Date: Tue, 18 Apr 1995 13:09:34 -0700
Subject: CATV Hardline Question Summary
Message-ID: <199504182009.AA11345 at mail.crl.com>

Responses have stopped coming in...  

Several people asked about good ways for making connectors for CATV
hardline.  Can someone that has some good ideas post something? 


> I have a ton of 75 ohm CATV hardline I am using at the new place.  Some of
> the 1/2" stuff doesn't have the jacket on it and in the process of bending
> it through the tower and other things - dimples have developed in places.
> Should I be concerned?
---
from the desk of N6TR:

Naw.  The impedance discontinuity is so small in wavelengths that it 
won't affect things.  It gives you a little extra capacitance so the 
impedance is lower at that point.  Imagine a 45 Ohm matching section that
is 1/1500th of a wavelength long (1 CM at 15 meters).  
---
from the desk of KH6BZF

 Bill: 
        Watch some of the dimples as you will obtain "perturbations in 
     impedance" if the center conductor and the outer shield are disturbed.
     The use of a TDR (Time-Domain Reflectometer) will confirm if you have 
     a problem with that in use, or TDR the remaining "ton" of hardline to 
     check which is the best.
     
        Generally, the manufacture will specify the minimum bending radius.
     Anything less presents problems. That's from 42-years of experiences
     in Radio Transmission Engineering....but I'm still learning! You too?
     
        I use a 1/2 wave coax from the antenna to a "barrel" to insert
     the SWR bridge to check the mono-bander. The SWR bridge belongs, in my 
     mind, at the antenna for checking and tuning. However, this is a 
     practical approach. The 1/2-wave coax length depends on the velocity
     factor(Vf). The Higher the Vf, the longer the antenna-to-barrel 
     breakout point, the longer the length. I believe my math is correst!
---


> Should I worry about water in it?

>From N6TR:

I have not seen much problem with water migration.  I think the foam is
pretty good in this respect.  I always cut a foot off (of course, you 
already thought of that).  I haven't ever seen anything looking like
water damage there.
---
>From K8LX:

One of the prime design requirements of CATV coax is that it not
accept water under any circumstance.

1) The foam (or in some cases, fused disc polyethelene) will not itself soak
up water.

2)  The dielectric is glued to the smooth shield; no chance for ingress
between the two.

3)  And lo and behold, the center conductor is smooth and glued to the
dielectric also.

What you have here is the perfect coax, in my opinion.  I use the 3/4" stuff
almost exclusively.

Of course, it must be handled carefully when you install it.  Kinks would
bother me; but if the kink does not overheat at full power, you are probably OK.
---
from K4XU/9 /blackhole /QRP /T92 /ect..

      Not to worry.  CATV hardline has closed cell foam and thus cannot wick
     water like the braid in flexible coax. As long as you do not kink the
     hardline so badly that the inner shorts to the jacket, you should be
     OK even on 10M at the power you are running.
---






---
Bill Fisher, KM9P   -    Concentric Systems, Inc.  




>From norf at euronet.nl (Rob_Snieder_PA3ERC)  Tue Apr 18 21:35:02 1995
From: norf at euronet.nl (Rob_Snieder_PA3ERC) (Rob_Snieder_PA3ERC)
Date: Tue, 18 Apr 1995 22:35:02 +0200
Subject: RTTY Controllers
Message-ID: <199504182035.WAA03075 at mail.euronet.nl>

Hi guys, I currently use a PK232 with WF1B RTTY Contest software. I'm not so 
happy with this controller because of the poor filters, when it is realy 
busy it only writes crap. I have also worked with a PTC Pactor controller 
which supports also RTTY and I must say that this worked 100% better, but
this controller does not support packet radio, so I'm thinking about a PK900 
from EAE. I like to know what your experience is with RTTY controllers, what 
is the best you can buy which is also supported by WF1B? I hope to hear soon 
from you, 73 de Rob PA3ERC
Rob Snieder
HAM Radio callsign PA3ERC


>From H. L. Serra" <hlserra at teetot.acusd.edu  Tue Apr 18 21:33:33 1995
From: H. L. Serra" <hlserra at teetot.acusd.edu (H. L. Serra)
Date: Tue, 18 Apr 1995 13:33:33 -0700 (PDT)
Subject: DX Proficiency Filter
Message-ID: <Pine.3.89.9504181139.A9582-0100000 at teetot.acusd.edu>

Re K0OD's question about the ethics of DXpedition stations sending a
cryptic "87" to direct the proficient to the right listening frequency
(Bouvet Split Technique), I don't think there is any question of ethics. 
Just as DX stations handling pile-ups use a "signal-strength filter"
(i.e., peel off the strongest signals first, so you can work the weaker
sigs without interference), what's wrong with using a "proficiency filter"
of higher code speed to indicate where you will listen, especially when
the pile-up is uncontrollable and all over the band? I hope it's not
"unethical"  for us to call CQ in the foreign portion of the 40M phone
band and say only "Two Three Zero" rather than "Listening Two Three Zero."
73, Larry N6AZE (6E2T team member)



>From H. L. Serra" <hlserra at teetot.acusd.edu  Tue Apr 18 21:33:33 1995
From: H. L. Serra" <hlserra at teetot.acusd.edu (H. L. Serra)
Date: Tue, 18 Apr 1995 13:33:33 -0700 (PDT)
Subject: DX Proficiency Filter
Message-ID: <Pine.3.89.9504181139.A9582-0100000 at teetot.acusd.edu>

Re K0OD's question about the ethics of DXpedition stations sending a
cryptic "87" to direct the proficient to the right listening frequency
(Bouvet Split Technique), I don't think there is any question of ethics. 
Just as DX stations handling pile-ups use a "signal-strength filter"
(i.e., peel off the strongest signals first, so you can work the weaker
sigs without interference), what's wrong with using a "proficiency filter"
of higher code speed to indicate where you will listen, especially when
the pile-up is uncontrollable and all over the band? I hope it's not
"unethical"  for us to call CQ in the foreign portion of the 40M phone
band and say only "Two Three Zero" rather than "Listening Two Three Zero."
73, Larry N6AZE (6E2T team member)



>From jreid at aloha.net (Jim Reid)  Tue Apr 18 22:00:48 1995
From: jreid at aloha.net (Jim Reid) (Jim Reid)
Date: Tue, 18 Apr 1995 11:00:48 -1000
Subject: Vanity Call Confusion
Message-ID: <m0s1KNi-000uaKC at hookomo>

>Return-Path: <jhennessee at arrl.org>
>From: "Hennessee, John,  KJ4KB" <jhennessee at arrl.org>
>To: Jim Reid <jreid at aloha.net>
>Cc: "Wyatt, Brad (Pacific Dir)" <5016932 at mcimail.com>
>Subject: RE: Vanity Call Confusion
>Date: Tue, 18 Apr 95 12:03:00 EDT
>Encoding: 97 TEXT
>
>
>Hi Jim,
>
>It is because of amateurs like you who live off the mainland that ARRL asked 
>the FCC to restrict amateurs seeking vanity calls to their call sign region 
>of residency.  Brad Wyatt, your ARRL Director, was instrumental in 
>convincing the ARRL Board of Directors that reconsideration was necessary on 
>that one small point and that any amateur shouldn't be eligible for any 
>call.  In the Report and Order, the FCC essentially said that if a person 
>really wanted a particular call, a PO Box could be obtained in the desired 
>region.  ARRL maintains that amateurs should be restricted to their home 
>call sign region and that the traditional call sign system should be 
>preserved.  It has been my own personal observation that the majority of 
>amateurs agree with the ARRL Petition for Partial Reconsideration in this 
>matter.  73.
>
>                                        
>John C. Hennessee, KJ4KB
>Regulatory Information Specialist
>ARRL HQ
>Internet: jhennessee at arrl.org
>
>
> ----------
>From: Jim Reid
>To: jhennessee
>Subject: Vanity Call Confusion
>Date: Thursday, April 13, 1995 9:25PM
>
>Hi John,
>
>I am sure I saw a posting here on the internet a few weeks ago which 
>described
>some new call assignments which were going to become available for  both
>Alaska and Hawaii.  I believe Alaska was to pick up calls such as KL8,  KL9,
>and so forth,  and Hawaii was to be assigned KH7,  since all the KH6 calls 
>had
>long been gone.  My  basic question is,  Are these new designators exclusive
>to
>Hawaii and Alaska,  or under the new Vanity Call system,  will  hams
>stateside,  who
>becomes aware of this change,  be able to receive these prefix's?
>
>I have spent a lot of time searching the Call Book to locate long abandoned
>KH6 calls,  KH6 by 1  or by 2,  that I might pick up to replace the AH6 call 
>I
>was assignes a few years ago  when I retired and upgraded to Extra.
>Now it seems,  I may have competition for these calls from mainland 
>amateurs!
>
>Would obviously be interested in the new KH7 prefix for Hawaii hams,  as if
>I were
>to act quickly when Gate 2 opens,  I  ought to be able to obtain one of the 
>26
>new KH7 by 1 calls!  Am particularly interested  in  KH7K,  because of my
>QTH  here
>on Kauai,  and it is both a good SSB and CW call for DX operation.   But,
>am sure
>I read in the  same posting back awhile ago,  that  KH7 was to be reserved 
>for
>Kure Island hams,  of whom there are now none!   Of course that is moot,  if
>the
>FCC really means anyone who is licensed by the FCC,  which includes quite a
>spread of folks and calls across the Western Hemisphere,  ie from Guam,
>Saipan,(both
>around 145E),   American Samoa,  and extending all the way to Puerto Rico
>(about  64W)!
>
>If that is the FCC's intent,  no one  neither in the US nor DX will have any 
>
>idea in a few years
>where over half the world a W, K, or N prefix may be!   I had better check
>and see if the
>American Samon call KH8K is going to be available;  of course,  one of  the
>new  Alaskan
>KL8K,  KL9K etc.  would probably be available.  Can just list them all on
>the new
>610-V and send it in when Gate 2 opens,  and see what happens.
>
>I have seen of the ARRL's petition to the FCC to restrict new Vanity Calls
>to the
>call district of the applicants address;  but assume the FCC will counter
>with the
>argument that anyone,  if he really wanted to,  could get a Hawaiian PO Box
>address  (at which most Hawaiians receive there mail)  and apply as a 
>resident
>of the Hawaiian Islands
>
>I certainly hope the FCC reconsiders this situation before throwing the
>flood gates
>wide open!
>
>Thanks for reading this!
>73 and Aloha,
>Jim Reid, AH6NB (Happily retired on the Island of Kauai)
>Hawaii,  USA     Email: jreid at aloha.net
>
>
73 and Aloha,
Jim Reid, AH6NB (Happily retired on the Island of Kauai)
Hawaii,  USA     Email: jreid at aloha.net


>From engberg at ctis.af.mil (Bob Engberg)  Tue Apr 18 16:22:46 1995
From: engberg at ctis.af.mil (Bob Engberg) (Bob Engberg)
Date: Tue, 18 Apr 95 15:22:46 AKD
Subject: Alaska - "L"
Message-ID: <9504182322.AA26553 at edfue0.ctis.af.mil>

So I can sign K0MVL/L instead of K0MVL/KL7
Or should I sign K0MVL/KL0?
Or KL0/K0MVL
Or L/K0MVL
Or K0MVL/KL
Or KL/K0MVL
Hmmmm.
The WPX is end of May.  This will be fun.


Bob Engberg
phone:  907-552-1895
e-mail: engberg at ctis.af.mil  or K0MVL at amsat.org
URL:	http://www.ctis.af.mil/~engberg/
packet: K0MVL at KL7AA.#NAK.AK.USA.NOAM
snail:  SAIC Attn: Bob Engberg
        911 W. 8th Ave., Suite 401
        Anchorage, AK 99501





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