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CX2SA > SATDIG 07.08.08 01:41l 911 Lines 31522 Bytes #999 (0) @ WW
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To : SATDIG@WW
Today's Topics:
1. Re: OSCAR - Acronym for...? (David Goncalves)
2. Re: OSCAR - Acronym for...? (James Whitfield)
3. Re: More than Sats Lost Last Week (Armando Mercado)
4. Re: OSCAR - Acronym for...? (Trevor)
5. love QRM (w7lrd(AT)comcast.net)
6. Re: brain picking time (i8cvs)
7. Re: OSCAR - Acronym for...? (George Henry)
8. Re: OSCAR - Acronym for...? (Greg D.)
9. For sale: Yaesu FT-736r (Dave hartzell)
10. Re: brain picking time (Edward Cole)
11. Re: brain picking time (w7lrd(AT)comcast.net)
12. Re: love QRM (Larry Gerhardstein)
13. Re: brain picking time (i8cvs)
14. Th-D7A(G) & HMC-3 (Jeff Yanko)
----------------------------------------------------------------------
Message: 1
Date: Tue, 5 Aug 2008 16:41:11 -0400
From: "David Goncalves" <davegoncalves(AT)gmail.com>
Subject: [amsat-bb] Re: OSCAR - Acronym for...?
To: amsat-bb(AT)amsat.org
Message-ID:
<efbd6ca10808051341l3beecc07ref848fc156d94cfe(AT)mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
>I think the maintainance of the true, historical record is important.
>And would respect those SKs who have passed on since their OSCAR
>ventures...May I browse through those 26 boxes next time I'm in the
>San Jose area???
Is it really that important?
David Goncalves
W1EUJ
------------------------------
Message: 2
Date: Tue, 5 Aug 2008 16:05:30 -0500
From: "James Whitfield" <n5gui(AT)cox.net>
Subject: [amsat-bb] Re: OSCAR - Acronym for...?
To: <amsat-bb(AT)amsat.org>
Message-ID: <000901c8f73e$fec44dd0$6401a8c0(AT)Sony2G4>
Content-Type: text/plain; charset="iso-8859-1"
Reading this thread has been entertaining, particularly the discussion about
its importance. I am pleased, if also surprised, that there are writers and
editors that actually care that much about the accuracy of what they write
and edit.
I have had a moderately long technical career, occasionally punctuated by
what I now view as futile attempts to get co-workers, most of whom were
supposedly well educated, to understand the meaning of the term "acronym".
The difficult, and most frustrating, part is in trying to communicate what
an acronym is not. COBOL is an acronym, but IBM and BLT are not. ( Since
most of the time I have tried to point out the distinction, the reaction
that I got was "serious don't care". )
With that as a back drop, I would speculate that since the term OSCAR was
coined during a rampant epidemic of the alphabet soup of both government and
industry, the term was created for its panache and the actual words for
which it would stand were finalized afterward. The strongest evidence that
I can bring forth is that it was a common practice at the time. If anyone
can tell the story as it happened, or even some of the unverifiable legends
of the time, I would enjoy hearing about it.
Sputnik certainly proved that amateurs could receive signal from a radio in
a man made satellite. The really great creative spark was suggesting that
one could be build, not by the military or a government agency...or even an
industrial corporation, but by amateurs, for amateur experimentation.
Eventually it had to lead to the need to name it. Amateur radio equipment
onboard a satellite. AREOS. Nothing to grab attention there. Satellite
with amateur radio - SWAR. Nope. Satellite carrying amateur radio --
SCAR. Better, but not a positive message.
However the name got to OSCAR, it was and still is a good name. Even so, I
am a bit troubled by the thought that the expanded name for the project
might not have been selected simply for the contraction to OSCAR. Suppose
that Orbital ( or perhaps Orbiting ) Satellite Carrying Amateur Radio was
really the name and OSCAR came later. What exactly would be the reason to
use the combined term "orbital satellite". A quick check of the dictionary
suggests to me that in the technical context, satellite is an object that is
in orbit. That being the case, why use the term "orbital satellite"? At
the time were there "non-orbital satellites" that needed to be distinguished
from the amateur radio variety? The dictionary doesn't help, what with all
of the different ways that the terms orbital, orbiting, and satellite are
used, one can concoct a lot of different concepts, none of which I can tie
into the basic concept, which in my mind needs not additional
discrimination.
It is only my opinion, but the term OSCAR has outgrown its roots as an
acronym. Consider the word "radar". It has been so ingrained into the
every day language of our society, even allowing for the dependence of
society on technology, that it is no longer recognized as an acronym.
Perhaps there are linguistic scholars that can trace its origins, but in the
language of today, the term radar has lost its distinction from other words.
So it is within the language of amateur radio. An OSCAR is a recognized
thing. The term OSCAR, though perhaps it is still capitalized, invokes
direct meaning rather than translation into the components that made up its
origin phrase. Perhaps it is a fitting tribute to those whose genius and
sweat built and operated OSCARs that the word has been accepted as a normal
part of the amateur radio lexicon.
My thanks to each of you, old timers and newcomers alike.
James
n5gui
------------------------------
Message: 3
Date: Tue, 5 Aug 2008 17:39:49 -0400
From: "Armando Mercado" <am25544(AT)triton.net>
Subject: [amsat-bb] Re: More than Sats Lost Last Week
To: <clintbrad4d(AT)earthlink.net>
Cc: amsat-bb(AT)AMSAT.Org
Message-ID: <002b01c8f743$e4801d50$b511acd1(AT)hppav>
Content-Type: text/plain; format=flowed; charset="Windows-1252";
reply-type=original
Hello,
Only a "symbolic portion of cremated remains" are sent into space.
See http://www.memorialspaceflights.com/process.asp
Looks like a few grams per "participant."
Fortunately, Celestic does offer a re-fly guarantee.
73, Armando N8IGJ
>Date: Mon, 4 Aug 2008 16:57:25 -0700
>From: Clint Bradford <clintbrad4d(AT)earthlink.net>
>Subject: [amsat-bb] More than Sats Lost Last Week
>To: amsat-bb(AT)amsat.org
>Message-ID: <2D2B4E7F-7ED0-485F-A789-34D9B96FE235(AT)earthlink.net>
>Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
>Not only were three satellites lost in the SpaceX problem last week,
>but so were ashes of 208 people...
>http://www.boingboing.net/2008/08/04/unfulfilled-space-fu.html
>Clint Bradford, K6LCS / KAF3359
http://www.memorialspaceflights.com/process.asp
------------------------------
Message: 4
Date: Tue, 5 Aug 2008 21:50:39 +0000 (GMT)
From: Trevor <m5aka(AT)yahoo.co.uk>
Subject: [amsat-bb] Re: OSCAR - Acronym for...?
To: AMSAT BB <amsat-bb(AT)amsat.org>
Message-ID: <988661.82032.qm(AT)web27201.mail.ukl.yahoo.com>
Content-Type: text/plain; charset=utf-8
I've missed some of the earlier posts on this but there is only one meaning
for OSCAR given on the AMSAT-NA website so at the risk of repeating what
someone may have already pointed out:
OSCAR stands for "Orbiting Satellite Carrying Amateur Radio"
Intro to sats: http://www.amsat.org/amsat-new/information/faqs/Intro_sats.pdf
OSCAR Numbers Policy: http://www.amsat.org/amsat/amsat-na/oscar.html
The Project Oscar website at http://www.projectoscar.net/
also gives the same definition.
73 Trevor M5AKA
----
__________________________________________________________
Not happy with your email address?.
Get the one you really want - millions of new email addresses available now at
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------------------------------
Message: 5
Date: Wed, 06 Aug 2008 02:22:22 +0000
From: w7lrd(AT)comcast.net
Subject: [amsat-bb] love QRM
To: AMSAT-BB(AT)amsat.org (AMSAT-BB)
Message-ID:
<080620080222.18617.48990ADE000AA149000048B922165662760B9D04C999(AT)comc
ast.net>
Content-Type: text/plain
Hello
What! has Bob lost it? Love QRM! In the context of satellite communications
yes QRM can be indicative of a good thing. It tells me this stuff up there is
getting used. I can't tell you how many passes of AO7 right up the middle of
the US my plaintive CQ calls went unanswered. Looking at the AO-7 Logbook
http://www.planetemily.com/ao7/main.php our European friends are using AO-7
like no tomorrow! AO-7 has the largest footprint of all our sats. I suppose
this subject makes as much sense as acronyms.
73 Bob W7LRD
--
"if this were easy, everyone would be doing it"
------------------------------
Message: 6
Date: Wed, 6 Aug 2008 03:54:23 +0200
From: "i8cvs" <domenico.i8cvs(AT)tin.it>
Subject: [amsat-bb] Re: brain picking time
To: <w7lrd(AT)comcast.net>, "AMSAT-BB" <AMSAT-BB(AT)AMSAT.Org>, "Edward
Cole" <kl7uw(AT)acsalaska.net>
Message-ID: <012501c8f767$59dff200$0201a8c0(AT)tin.it>
Content-Type: text/plain; charset="iso-8859-1"
----- Original Message -----
From: "Edward Cole" <kl7uw(AT)acsalaska.net>
To: <w7lrd(AT)comcast.net>; "AMSAT-BB" <AMSAT-BB(AT)AMSAT.Org>
Sent: Tuesday, August 05, 2008 8:24 AM
Subject: [amsat-bb] Re: brain picking time
At 04:35 PM 8/4/2008, w7lrd(AT)comcast.net wrote:
>Next question- which probably would be more aimed at a EME bb. I
>have a 12 foot TVRO I am building a patch feed for 1296, and feed it
>through 50 feet of LMR400 to my IC-1271A. I want to see if I am
>able to "hear" EME signals. Of course if I am able to, you can
>guess what my next effort will be. This will be a cheapie effort as
>I am only using stuff I already have. I do have a KJ6KO L band 70 watt
amp.
>73 Bob W7LRD
>Seattle
> Bob,
>
> Is your patch feed circular polar? EME on 1296 is RHCP in transmit
> and LHCP in receive.
Hi Ed, KL7UW
It is best to specify to Bob that on 1296 MHz the dish in transmit must
radiate RHCP in direction of the moon so that the patch or any other
feed must radiate LCHP in direction of the surface of the dish.
> The switch of polarity sense is due to the fact
> that reflection at the moon reverses the sense of polarization.
OK
So that on receiving the wave coming from the moon is received LHCP
over the surface of the dish but the dish reverse by reflection the signal
in direction of the feed that must be made RHCP polarized on receiving.
In addition a TVRO dish works well with a patch feed if the F/D ratio of
the dish is ranging from 0.35 to 0.45
> might be difficult to achieve with a patch feed.
W0LMD make a patch feed for RHCP and LHCP but never I tested it
Since the target of Bob is to see if he is able to only "hear" EME signals
at 1296 MHz without to complicate his life I suggest at the very beginning
to build only a patch feed RHCP polarized.
To receive a 1296 EME signal with a 12 foot TVRO and a IC-1271A
it is strictly necessary to connect directly to the patch connector a low
noise preamplifier with a NF in the order of 0.5 dB
Since the gain of a low noise EME preamplifier for 1296 MHz is
in the order of 30 dB or more then 50 feet of LMR400 connected from
the output of the preamplifier up to the input of the IC-1271A will not
deteriorate the overall NF of the system that will be only a little bit
higher than 0.5 dB
> 73 Ed - KL7UW
73" de
i8CVS Domenico
------------------------------
Message: 7
Date: Tue, 5 Aug 2008 22:35:02 -0500
From: "George Henry" <ka3hsw(AT)att.net>
Subject: [amsat-bb] Re: OSCAR - Acronym for...?
To: "amsat bb" <amsat-bb(AT)amsat.org>
Message-ID: <005101c8f775$698705f0$0601a8c0(AT)parents>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
----- Original Message -----
From: "James Whitfield" <n5gui(AT)cox.net>
To: <amsat-bb(AT)amsat.org>
Sent: Tuesday, August 05, 2008 4:05 PM
Subject: [amsat-bb] Re: OSCAR - Acronym for...?
[snip]
> I have had a moderately long technical career, occasionally punctuated by
> what I now view as futile attempts to get co-workers, most of whom were
> supposedly well educated, to understand the meaning of the term "acronym".
> The difficult, and most frustrating, part is in trying to communicate what
> an acronym is not. COBOL is an acronym, but IBM and BLT are not. ( Since
> most of the time I have tried to point out the distinction, the reaction
> that I got was "serious don't care". )
>
[snip]
IBM and BLT are actually "initialisms".... distinguished from an "acronym"
by virtue of not being pronounceable like COBOL, OSCAR, SNAFU, etc.
73,
George, KA3HSW
------------------------------
Message: 8
Date: Tue, 5 Aug 2008 21:00:38 -0700
From: "Greg D." <ko6th_greg(AT)hotmail.com>
Subject: [amsat-bb] Re: OSCAR - Acronym for...?
To: George Henry <ka3hsw(AT)att.net>, amsat bb <amsat-bb(AT)amsat.org>
Message-ID: <BLU133-W26D627F7C4EFA91CD4FBFEA97A0(AT)phx.gbl>
Content-Type: text/plain; charset="iso-8859-1"
Ah, thanks. I was wondering (seriously!)
Greg KO6TH
(IBM can also be a sentence, but we shouldn't talk about that here...)
----------------------------------------
> From: ka3hsw(AT)att.net
> To: amsat-bb(AT)amsat.org
> Date: Tue, 5 Aug 2008 22:35:02 -0500
> Subject: [amsat-bb] Re: OSCAR - Acronym for...?
>
>
> ----- Original Message -----
> From: "James Whitfield"
> To:
> Sent: Tuesday, August 05, 2008 4:05 PM
> Subject: [amsat-bb] Re: OSCAR - Acronym for...?
>
>
> [snip]
>> I have had a moderately long technical career, occasionally punctuated by
>> what I now view as futile attempts to get co-workers, most of whom were
>> supposedly well educated, to understand the meaning of the term "acronym".
>> The difficult, and most frustrating, part is in trying to communicate what
>> an acronym is not. COBOL is an acronym, but IBM and BLT are not. ( Since
>> most of the time I have tried to point out the distinction, the reaction
>> that I got was "serious don't care". )
>>
> [snip]
>
>
> IBM and BLT are actually "initialisms".... distinguished from an "acronym"
> by virtue of not being pronounceable like COBOL, OSCAR, SNAFU, etc.
>
>
> 73,
>
> George, KA3HSW
>
> _______________________________________________
> Sent via AMSAT-BB(AT)amsat.org. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
_________________________________________________________________
Reveal your inner athlete and share it with friends on Windows Live.
http://revealyourinnerathlete.windowslive.com?locale=en-
us&ocid=TXT_TAGLM_WLYIA_whichathlete_us
------------------------------
Message: 9
Date: Tue, 5 Aug 2008 21:41:28 -0700
From: "Dave hartzell" <hartzell(AT)gmail.com>
Subject: [amsat-bb] For sale: Yaesu FT-736r
To: "Amsat BB" <amsat-bb(AT)amsat.org>, vhf(AT)w6yx.stanford.edu
Message-ID:
<1c096fd70808052141i7e4ade22q3d8f5df7baf8107b(AT)mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Hello,
I'm selling my trusty Yaesu FT-736R rig. This has been a great
satellite rig. The unit works fine, and is in good shape (but NOT
mint). It has been used but NOT abused. No major scratches or
blemishes on the front panel.
The price is $550, plus shipping. I take PayPal only (or cash if the
deal is local).
The FT-736r has the following features:
* Factory Standard 2m and 70cm modules ONLY
* AM/FM/SSB/CW modes
* 25 Watts on both bands
* Built-in AC power supply
* MH-1 Microphone (standard, with box)
* FTS-8 Tone board
* 9600-baud tap (to a new 1/8" plug on back, very professional, so you
know I didn't do it)
* CAT to RS-232 adapter included (non-Yaesu)
* Manual with schematics (used a bit, written in, but complete)
* Stack of information about the rig (9600-baud mods, CAT info).
* AC Power cord
* Includes Original box and Styrofoam packing
* Non-smoking home
The unit works great, but there are some minor issues which will NOT
hamper operation:
* Keypad beeps were disabled (previous owner)
* Meter light-bulb is out
* 2" strip of Velcro on the side
* .75" rubber feet on the top
Pictures are available at: http://picasaweb.google.com/hartzell/FT736r
I would love to coordinate a hand-off in the San Francisco Bay Area
(south Bay). Or, shipping (via FedEx) will be around $45.
Contact me OFF LIST for more information: hartzell at gmail dot com
73,
Dave
AF6KD
------------------------------
Message: 10
Date: Tue, 05 Aug 2008 21:14:25 -0800
From: Edward Cole <kl7uw(AT)acsalaska.net>
Subject: [amsat-bb] Re: brain picking time
To: "i8cvs" <domenico.i8cvs(AT)tin.it>, <w7lrd(AT)comcast.net>, "AMSAT-BB"
<AMSAT-BB(AT)AMSAT.Org>
Message-ID: <200808060514.m765EP8S008790(AT)hermes.acsalaska.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed
Domenico,
You said it well. I forgot to mention that polarity sense will
reverse upon reflection at the dish surface, so the feed sense should
be Rx=RHCP; Tx=LHCP. In other discussions about using a patch for
eme, concern has been about sidelobe performance and high power
rating of the patch if full QRO eme is considered. Up to 200w it
probably is OK.
I assumed that Bob was savy enough about microwave weak-signals to
know that on eme a preamp is not a luxury but an absolute
necessity. LMR-400 would be fine for connection from the preamp to
the receiver in the shack, if at least 15-dB net gain is left after
the cable loss is subtracted. More gain is desirable if the receiver
NF is high. A preamp of 0.3 dBNF is standard at 1296 for eme.
I have a WD5AGO two-stage preamp with 0.30dBNF and 31-dBgain bought
from Radio Astronomy Supply.
73 Ed - KL7UW
At 05:54 PM 8/5/2008, i8cvs wrote:
>----- Original Message -----
>From: "Edward Cole" <kl7uw(AT)acsalaska.net>
>To: <w7lrd(AT)comcast.net>; "AMSAT-BB" <AMSAT-BB(AT)AMSAT.Org>
>Sent: Tuesday, August 05, 2008 8:24 AM
>Subject: [amsat-bb] Re: brain picking time
>
>At 04:35 PM 8/4/2008, w7lrd(AT)comcast.net wrote:
>
> >Next question- which probably would be more aimed at a EME bb. I
> >have a 12 foot TVRO I am building a patch feed for 1296, and feed it
> >through 50 feet of LMR400 to my IC-1271A. I want to see if I am
> >able to "hear" EME signals. Of course if I am able to, you can
> >guess what my next effort will be. This will be a cheapie effort as
> >I am only using stuff I already have. I do have a KJ6KO L band 70 watt
>amp.
> >73 Bob W7LRD
> >Seattle
>
> > Bob,
> >
> > Is your patch feed circular polar? EME on 1296 is RHCP in transmit
> > and LHCP in receive.
>
>Hi Ed, KL7UW
>
>It is best to specify to Bob that on 1296 MHz the dish in transmit must
>radiate RHCP in direction of the moon so that the patch or any other
>feed must radiate LCHP in direction of the surface of the dish.
>
> > The switch of polarity sense is due to the fact
> > that reflection at the moon reverses the sense of polarization.
>
>OK
>So that on receiving the wave coming from the moon is received LHCP
>over the surface of the dish but the dish reverse by reflection the signal
>in direction of the feed that must be made RHCP polarized on receiving.
>
>In addition a TVRO dish works well with a patch feed if the F/D ratio of
>the dish is ranging from 0.35 to 0.45
>
> > might be difficult to achieve with a patch feed.
>
>W0LMD make a patch feed for RHCP and LHCP but never I tested it
>
>Since the target of Bob is to see if he is able to only "hear" EME signals
>at 1296 MHz without to complicate his life I suggest at the very beginning
>to build only a patch feed RHCP polarized.
>
>To receive a 1296 EME signal with a 12 foot TVRO and a IC-1271A
>it is strictly necessary to connect directly to the patch connector a low
>noise preamplifier with a NF in the order of 0.5 dB
>
>Since the gain of a low noise EME preamplifier for 1296 MHz is
>in the order of 30 dB or more then 50 feet of LMR400 connected from
>the output of the preamplifier up to the input of the IC-1271A will not
>deteriorate the overall NF of the system that will be only a little bit
>higher than 0.5 dB
>
> > 73 Ed - KL7UW
>
>73" de
>
>i8CVS Domenico
------------------------------
Message: 11
Date: Wed, 06 Aug 2008 05:39:03 +0000
From: w7lrd(AT)comcast.net
Subject: [amsat-bb] Re: brain picking time
To: Edward Cole <kl7uw(AT)acsalaska.net>, "i8cvs"
<domenico.i8cvs(AT)tin.it>, "AMSAT-BB" <AMSAT-BB(AT)amsat.org>
Message-ID:
<080620080539.25176.489938F7000B29B20000625822165279660B9D04C999(AT)comc
ast.net>
Content-Type: text/plain
Ed and all
Many thanks for the information from many of you. I realize I will need a
preamp. For now I will be content to see what I can hear. As you can guess
once I can copy signals I will want to join in. That will require at very
least mounting the amp at the antenna and a sequencer. I have seen W0LMD' web
site as well as several others. I want to start out slow, before I "lose it".
73 Bob W7LRD
--
"if this were easy, everyone would be doing it"
-------------- Original message --------------
From: Edward Cole <kl7uw(AT)acsalaska.net>
> Domenico,
>
> You said it well. I forgot to mention that polarity sense will
> reverse upon reflection at the dish surface, so the feed sense should
> be Rx=RHCP; Tx=LHCP. In other discussions about using a patch for
> eme, concern has been about sidelobe performance and high power
> rating of the patch if full QRO eme is considered. Up to 200w it
> probably is OK.
>
> I assumed that Bob was savy enough about microwave weak-signals to
> know that on eme a preamp is not a luxury but an absolute
> necessity. LMR-400 would be fine for connection from the preamp to
> the receiver in the shack, if at least 15-dB net gain is left after
> the cable loss is subtracted. More gain is desirable if the receiver
> NF is high. A preamp of 0.3 dBNF is standard at 1296 for eme.
>
> I have a WD5AGO two-stage preamp with 0.30dBNF and 31-dBgain bought
> from Radio Astronomy Supply.
>
> 73 Ed - KL7UW
>
> At 05:54 PM 8/5/2008, i8cvs wrote:
> >----- Original Message -----
> >From: "Edward Cole"
> >To: ; "AMSAT-BB"
> >Sent: Tuesday, August 05, 2008 8:24 AM
> >Subject: [amsat-bb] Re: brain picking time
> >
> >At 04:35 PM 8/4/2008, w7lrd(AT)comcast.net wrote:
> >
> > >Next question- which probably would be more aimed at a EME bb. I
> > >have a 12 foot TVRO I am building a patch feed for 1296, and feed it
> > >through 50 feet of LMR400 to my IC-1271A. I want to see if I am
> > >able to "hear" EME signals. Of course if I am able to, you can
> > >guess what my next effort will be. This will be a cheapie effort as
> > >I am only using stuff I already have. I do have a KJ6KO L band 70 watt
> >amp.
> > >73 Bob W7LRD
> > >Seattle
> >
> > > Bob,
> > >
> > > Is your patch feed circular polar? EME on 1296 is RHCP in transmit
> > > and LHCP in receive.
> >
> >Hi Ed, KL7UW
> >
> >It is best to specify to Bob that on 1296 MHz the dish in transmit must
> >radiate RHCP in direction of the moon so that the patch or any other
> >feed must radiate LCHP in direction of the surface of the dish.
> >
> > > The switch of polarity sense is due to the fact
> > > that reflection at the moon reverses the sense of polarization.
> >
> >OK
> >So that on receiving the wave coming from the moon is received LHCP
> >over the surface of the dish but the dish reverse by reflection the signal
> >in direction of the feed that must be made RHCP polarized on receiving.
> >
> >In addition a TVRO dish works well with a patch feed if the F/D ratio of
> >the dish is ranging from 0.35 to 0.45
> >
> > > might be difficult to achieve with a patch feed.
> >
> >W0LMD make a patch feed for RHCP and LHCP but never I tested it
> >
> >Since the target of Bob is to see if he is able to only "hear" EME signals
> >at 1296 MHz without to complicate his life I suggest at the very beginning
> >to build only a patch feed RHCP polarized.
> >
> >To receive a 1296 EME signal with a 12 foot TVRO and a IC-1271A
> >it is strictly necessary to connect directly to the patch connector a low
> >noise preamplifier with a NF in the order of 0.5 dB
> >
> >Since the gain of a low noise EME preamplifier for 1296 MHz is
> >in the order of 30 dB or more then 50 feet of LMR400 connected from
> >the output of the preamplifier up to the input of the IC-1271A will not
> >deteriorate the overall NF of the system that will be only a little bit
> >higher than 0.5 dB
> >
> > > 73 Ed - KL7UW
> >
> >73" de
> >
> >i8CVS Domenico
>
------------------------------
Message: 12
Date: Tue, 5 Aug 2008 23:19:21 -0600
From: "Larry Gerhardstein" <larry(AT)3-cities.com>
Subject: [amsat-bb] Re: love QRM
To: <w7lrd(AT)comcast.net>, <amsat-bb(AT)amsat.org>
Message-ID: <002a01c8f783$fcb388e0$0300a8c0(AT)hop>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Bob, Don't stop listening! I will try AO-7 as soon as I get my sat
station built and working.
Larry W7IN - DN27
Plains, MT
------------------------------
Message: 13
Date: Wed, 6 Aug 2008 09:40:24 +0200
From: "i8cvs" <domenico.i8cvs(AT)tin.it>
Subject: [amsat-bb] Re: brain picking time
To: <w7lrd(AT)comcast.net>, "Edward Cole" <kl7uw(AT)acsalaska.net>,
"AMSAT-BB" <AMSAT-BB(AT)AMSAT.Org>
Message-ID: <002c01c8f797$b05f0a00$0201a8c0(AT)tin.it>
Content-Type: text/plain; charset="iso-8859-1"
Hi Bob, W7LRD
Before to start anyting you must to know the F/D ratio of your dish because
this parameter will tell you if a patch as
a feed is suitable or not for it.
If your TVRO dish is a prime focus dish to measure the F/D ratio is very easy
Put your dish horizontal on the ground looking up 90 degrees and strain a
rope passing just through the center of the mouth and measure the diameter D
Measure the depth of the dish just from the center of the mouth between the
rope and the bottom of the dish and call the deepth c
2
D
D
F/D = ----------------- and the focal point F = ------------
-- from the bottom of the dish
16 x c
16 x c
If the F/D ratio is less than 0.5 then a patch can be used but if F/D is
greater then 0.5 then a patch is not suitable.
By the way a patch as a feed is not used at all for EME because there are type
of specialized feed that are much and much better.
If the F/D ratio is less of 0.5 then a VE4MA feed can be used and if the F/D
ratio is greater of 0,5 then a dual mode dish W2IMU must be used.
Both VE4MA and W2IMU are dual port feeds one the LHCP is used to transmit and
the other one the RHCP is used to receive.
Waiting for P3E and depending of the F/D ratio of a 5 meter dish that I plan
to build for 1296 MHz EME I have already built both a VE4MA and a W2IMU feeds
in order to be prepared for EME in the future because unfortunately the future
seems to be not bright for the HEO satellites.
73" de
i8CVS Domenico
----- Original Message -----
From: w7lrd(AT)comcast.net
To: Edward Cole ; i8cvs ; AMSAT-BB
Sent: Wednesday, August 06, 2008 7:39 AM
Subject: Re: [amsat-bb] Re: brain picking time
Ed and all
Many thanks for the information from many of you. I realize I will need a
preamp. For now I will be content to see what I can hear. As you can guess
once I can copy signals I will want to join in. That will require at very
least mounting the amp at the antenna and a sequencer. I have seen W0LMD' web
site as well as several others. I want to start out slow, before I "lose it".
73 Bob W7LRD
--
"if this were easy, everyone would be doing it"
-------------- Original message --------------
From: Edward Cole <kl7uw(AT)acsalaska.net>
> Domenico,
>
> You said it well. I forgot to mention that polarity sense will
> reverse upon reflection at the dish surface, so the feed sense should
> be Rx=RHCP; Tx=LHCP. In other discussions about using a patch for
> eme, concern has been about sidelobe performance and high power
> rating of the patch if full QRO eme is considered. Up to 200w it
> probably is OK.
>
> I assumed that Bob was savy enough about microwave weak-signals to
> know that on eme a preamp is not a luxury but an absolute
> necessity. LMR-400 would be fine for connection from the preamp to
> the receiver in the shack, if at least 15-dB net gain is left after
> the cable loss is subtracted. More gain is desirable if the receive r
> NF is high. A preamp of 0.3 dBNF is standard at 1296 for eme.
>
> I have a WD5AGO two-stage preamp with 0.30dBNF and 31-dBgain bought
> from Radio Astronomy Supply.
>
> 73 Ed - KL7UW
>
> At 05:54 PM 8/5/2008, i8cvs wrote:
> >----- Original Message -----
> >From: "Edward Cole"
> >To: ; "AMSAT-BB"
> >Sent: Tuesday, August 05, 2008 8:24 AM
> >Subject: [amsat-bb] Re: brain picking time
> >
> >At 04:35 PM 8/4/2008, w7lrd(AT)comcast.net wrote:
> >
> > >Next question- which probably would be more aimed at a EME bb. I
> > >have a 12 foot TVRO I am building a patch feed for 1296, and feed it
> > >through 50 feet of LMR400 to my IC-1271A. I want to see if I am
> > >able to "hear" EME signals. Of course if I am able to, you can
> > >gu ess what my next effort will be. This will be a cheapie effort as
> > >I am only using stuff I already have. I do have a KJ6KO L band 70
watt
> >amp.
> > >73 Bob W7LRD
> > >Seattle
> >
> > > Bob,
> > >
> > > Is your patch feed circular polar? EME on 1296 is RHCP in transmit
> > > and LHCP in receive.
> >
> >Hi Ed, KL7UW
> >
> >It is best to specify to Bob that on 1296 MHz the dish in transmit must
> >radiate RHCP in direction of the moon so that the patch or any other
> >feed must radiate LCHP in direction of the surface of the dish.
> >
> > > The switch of polarity sense is due to the fact
> > > that reflection at the moon reverses the sense of polarization.
> >
> >OK
> >So that on receiving the wave coming from the moon is received LHCP
> & gt;over the surface of the dish but the dish reverse by reflection the
signal
> >in direction of the feed that must be made RHCP polarized on receiving.
> >
> >In addition a TVRO dish works well with a patch feed if the F/D ratio
of
> >the dish is ranging from 0.35 to 0.45
> >
> > > might be difficult to achieve with a patch feed.
> >
> >W0LMD make a patch feed for RHCP and LHCP but never I tested it
> >
> >Since the target of Bob is to see if he is able to only "hear" EME
signals
> >at 1296 MHz without to complicate his life I suggest at the very
beginning
> >to build only a patch feed RHCP polarized.
> >
> >To receive a 1296 EME signal with a 12 foot TVRO and a IC-1271A
> >it is strictly necessary to connect directly to the patch connector a
low
> >noise preamplifier with a NF in the order of 0.5 dB
> >
&g t; >Since the gain of a low noise EME preamplifier for 1296 MHz is
> >in the order of 30 dB or more then 50 feet of LMR400 connected from
> >the output of the preamplifier up to the input of the IC-1271A will not
> >deteriorate the overall NF of the system that will be only a little bit
> >higher than 0.5 dB
> >
> > > 73 Ed - KL7UW
> >
> >73" de
> >
> >i8CVS Domenico
>
------------------------------
Message: 14
Date: Wed, 6 Aug 2008 03:28:01 -0700
From: "Jeff Yanko" <wb3jfs(AT)cox.net>
Subject: [amsat-bb] Th-D7A(G) & HMC-3
To: <amsat-bb(AT)amsat.org>
Message-ID: <CD5548E1D1794F66AFFCA2E82ECB0080(AT)QUECREEK>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Hi all,
Just wondering if anybody on the BB is using the combination of the
TH-D7A(G) and the HMC-3 headset? I have a few questions to ask about this
setup.
73,
Jeff WB3JFS
------------------------------
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End of AMSAT-BB Digest, Vol 3, Issue 396
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