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CX2SA > SATDIG 01.07.08 08:05l 821 Lines 25417 Bytes #999 (0) @ WW
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From: CX2SA@CX2SA.LAV.URY.SA
To : SATDIG@WW
Today's Topics:
1. mirage preamp gasfets (James Cizek)
2. Re: Eliminating Desensing (Reicher, James)
3. Re: Estimating Distance (Clint Bradford)
4. UPDATE: Presat and Nanosail Satellite Launch (Michael L Miller)
5. Delfi-C3 RASCAL OS X trouble (John Zaruba Jr)
6. Fw: THIS SHOULD PISS YOU OFF...................IT DID ME!!!!
(Joe Krepps)
7. FO-29 schedule July (Mineo Wakita)
8. Re: FW: THIS SHOULD PISS YOU OFF...................IT DID
ME!!!! (John B. Stephensen)
9. Re: UPDATE: Presat and Nanosail Satellite Launch (G0MRF(AT)aol.com)
10. Re: FW: THIS SHOULD PISS YOU OFF...................ITDID
ME!!!! (Alan P. Biddle)
11. Re: FW: THIS SHOULD PISS YOU OFF...................ITDID
ME!!!! (Dave Guimont)
12. Best type of coax to use between preamps and antennas
(Ronald Nutter)
13. Re: RS-15 heard again (Auke de Jong)
14. Fwd: Carl Eilers, SK (Arthur Feller)
15. APRS FD (Stu)
16. Re: Eliminating Desensing (kc6uqh)
17. Re: Eliminating Desensing (David Donaldson)
----------------------------------------------------------------------
Message: 1
Date: Mon, 30 Jun 2008 13:05:45 -0600 (MDT)
From: James Cizek <jcizek(AT)yuma.acns.colostate.edu>
Subject: [amsat-bb] mirage preamp gasfets
To: amsat-bb(AT)amsat.org
Message-ID: <200806301905.m5UJ5jn223716(AT)yuma.acns.colostate.edu>
Content-Type: text/plain; charset=us-ascii
Hi all,
I have a pair of Mirage mast mount preamps, (1) KP-2/2M for 144mhz
and a KP-2/440 for 70cm both that have blown GasFets. My old house
for some reason ate a lot of those FET's and i used to replace them
once in a while when it blew. But, I have moved, had the preamps in
a box for last several years and no longer have any idea what device
each of them took. They were bought in the late 90's. Mirage is
trying to find someone to help me but haven't been able to yet so I
thought I'd try here and see if anyone had a schematic, or knew what
FET's might be in each of those preamps! Thanks for any help. -James
KI0KN
------------------------------
Message: 2
Date: Mon, 30 Jun 2008 15:10:51 -0500
From: "Reicher, James" <JReicher(AT)hrblock.com>
Subject: [amsat-bb] Re: Eliminating Desensing
To: <amsat-bb(AT)amsat.org>
Message-ID:
<95ADAAE74104344D9B6F961E4DAD659803725694(AT)WHQMSG05.hrbinc.hrblock.net
>
Content-Type: text/plain; charset="us-ascii"
My station is an FT-847, into 11 elements on both 2M and 70cm. The two
yagis are on the same polarization plane, perpendicular to the
cross-boom. Coax runs are about 50 feet. The cross-boom is about 4
feet separation but will be closer to 10 feet on my home station. I had
no external pre-amps in place during FD but will have at least a 70cm
mast-mounted pre-amp at home.
When uplinking on Mode B, I hear some static on the downlink at
approximately S-4 to S-6. This effect is less pronounced on SSB than on
CW but is still noticeable.
I did not notice this when uplinking on 2 meters with 70cm down, but
it's probably because I didn't have to swish the dits to find my
downlink when working the Mode J FM birds.
73 de W0HV, Jim in Raymore, MO
Light travels faster than sound... This is why some people appear
bright until you hear them speak.
Date: Mon, 30 Jun 2008 14:45:08 -0400 (EDT)
From: Clint Bradford <clintbrad4d(AT)earthlink.net>
Subject: [amsat-bb] De-sense
To: amsat-bb(AT)amsat.org, amsat-bb(AT)amsat.org
Message-ID:
<18909860.1214851508223.JavaMail.root(AT)elwamui-milano.atl.sa.earthlink.ne
t>
Content-Type: text/plain; charset=UTF-8
>>...significant de-sensing of my 2 meter downlink from my 70cm
uplink...
Just so we're all on the same page, could you please be a little more
specific with your symptoms? And briefly describe your station?
Clint Bradford, K6LCS
--------------------------------------
Clint Bradford, K6LCS / KAF3359
------------------------------
Message: 3
Date: Mon, 30 Jun 2008 13:30:12 -0700
From: Clint Bradford <clintbrad4d(AT)earthlink.net>
Subject: [amsat-bb] Re: Estimating Distance
To: amsat-bb(AT)amsat.org
Message-ID: <A717D1C0-2244-4252-A9A3-E26A1B0929E8(AT)earthlink.net>
Content-Type: text/plain; charset=US-ASCII; format=flowed
>>...SatPC32...Instant Track...
THANKS, gentlemen. And for the record, MacDopplerPRO does, too!
Clint Bradford, K6LCS / KAF3359
909-241-7666
------------------------------
Message: 4
Date: Mon, 30 Jun 2008 14:47:14 -0600 (MDT)
From: "Michael L Miller" <mlmiller(AT)intellus.us>
Subject: [amsat-bb] UPDATE: Presat and Nanosail Satellite Launch
To: amsat-bb(AT)amsat.org, nb2f(AT)amsat.org
Message-ID:
<3004.216.14.249.143.1214858834.squirrel(AT)webmail.intellus.us>
Content-Type: text/plain;charset=iso-8859-1
This launch has been postponed. I will provide a new launch date when it
has been determined.
Please let me know any questions.
Thanks,
Mike Miller
KE7EGC
> Please put the following on the bb and on the ANS.
>
> PreSat and NanoSail-D Beacon Alerts
>
> Santa Clara University students invite amateur radio operators worldwide
to participate with them by receiving beacon signals from PreSat and
NanoSail-D, two pioneering cubesat missions that will launch from the
Reagan Test Site (Omelek Island, Kwajalein Atoll, Republic of Marshall
Islands) on June 23, 2008 at about 7:00 pm PDT. Both spacecraft will go
into Low Earth Orbit as secondary payloads aboard a SpaceX Falcon-1
launch
> vehicle. The vehicles will be launched into a 685x330 km, 9 degree
orbit,
> with line of site communications only possible at low latitudes. PreSat
is a 10 x 10 x 30 cm. spacecraft, that will evaluate the performance of
a
> generic biofluidic sample management and handling system for future
advanced in situ spaceborne biology experiments. NanoSail-D is a 10 x
10
> x 30 cm. spacecraft, which will deploy a solar sail that also will be
used
> as a drag sail to demonstrate orbital debris mitigation technology.
These
> missions follow the earlier efforts of Santa Clara U. students in
launching Genesat 1, in 2006.
>
> Of particular interest to the amateur radio satellite community are the
PreSat and NanoSail-D beacons. The PreSat beacon will operate at
437.318
> MHz FM, sending an AX.25 packet every 5 seconds; the packet contains
data
> about the spacecraft systems operation. The NanoSail-D beacon will
operate at 437.269 MHz FM, sending an AX.25 packet every 10 seconds; the
packet contains data about the spacecraft systems operation. The
beacons
> will initiate transmission as soon as each spacecraft is deployed from
their separate carriers, which are attached to a Ride Share Adapter.
Amateur radio operators are encouraged to submit received beacon packets
through the mission websites in order to receive a web-based QSL card.
>
> The PreSat mission website at www.presat.org; the NanoSail-D mission
website is at www.nanosaild.org. These sites provide general mission and
spacecraft information, instructions on how to contact the Santa Clara
University PreSat and NanoSail-D Mission Operations teams, and the
latest
> orbit datam beacon packet format, and other information needed to work
the
> beacons.
>
> 73,
>
> Mike Miller
> KE7EGC
>
------------------------------
Message: 5
Date: Mon, 30 Jun 2008 17:11:33 -0400
From: John Zaruba Jr <aa2bn(AT)comcast.net>
Subject: [amsat-bb] Delfi-C3 RASCAL OS X trouble
To: amsat-bb(AT)amsat.org
Message-ID: <2CABDBEF-6022-41C7-99BA-81D6E448FCA6(AT)comcast.net>
Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
Hi All,
I've been trying to get RASCAL to run on my Intel Mac mini (10.4.11).
I've installed soylatte16 to get the JRE 1.6 compatibility, but when
I launch the .jar I get the following error:
Unknown error javax/swing/GroupLayout$Group
The is not found on your computer.
please check: javax/swing/GroupLayout$Group or reinstall Rascal
I'm trying to run the .jar from my home directory, I kept the folder
structure the same (i.e. the lib folder is inside the RASCAL folder).
Any suggestions on resolving this error?
73,
John AA2BN
------------------------------
Message: 6
Date: Mon, 30 Jun 2008 17:47:38 -0400
From: Joe Krepps <occupant(AT)ytpress.com>
Subject: [amsat-bb] Fw: THIS SHOULD PISS YOU OFF...................IT
DID ME!!!!
To: amsat-bb(AT)amsat.org
Message-ID: <4869547A.2090107(AT)ytpress.com>
Content-Type: text/plain; charset=us-ascii; format=flowed
> Liscensed since 1952, politics and women were NEVER DISCUSSED in/on
> HAM RADIO!!
>
> What in the hell has changed????......
People got lazier and lazier! "They say..." has become gospel.
Worse yet, apparently some people aren't bright enough to run this kind
of BS through a reputable source _BEFORE_ they post it!
http://www.snopes.com/politics/immigration/refugees.asp
almost as condemning as the snopes.com page:
http://www.truthorfiction.com/rumors/p/petition-illegals.htm
...as if it REALLY had any business on this list to begin with!
Joe WB3CFN <-licensed in '76
------------------------------
Message: 7
Date: Tue, 01 Jul 2008 06:48:14 +0900
From: Mineo Wakita <ei7m-wkt(AT)asahi-net.or.jp>
Subject: [amsat-bb] FO-29 schedule July
To: amsat-bb(AT)amsat.org
Message-ID: <9AC8DAFAFFBF88ei7m-wkt(AT)asahi-net.or.jp>
Content-Type: text/plain; charset=us-ascii
July UTC
1 2:25 -
2 1:30 -
3 2:20 -
4 1:26 -
5 2:16 -
6 1:23 -
7 none
8 1:18 -
9 2:08 -
10 none
11 15:03 -
12 1:10 -, 14:07 -
13 2:00 -
14 none
15 none
16 2:45 -
17 1:50 -
18 2:40 -
19 1:45 -
20 0:57 -, 2:35 -
21 1:40 -
22 none
23 1:35 -
24 2:25 -
25 1:33 -
26 2:23 -
27 1:26 -
28 none
29 1:23 -
30 2:13 -
31 1:18 -
Aug.
1 2:08 -
2 1:15 -
3 0:20 -, 2:05 -
4 none
------------------------------
Message: 8
Date: Mon, 30 Jun 2008 22:01:29 -0000
From: "John B. Stephensen" <kd6ozh(AT)comcast.net>
Subject: [amsat-bb] Re: FW: THIS SHOULD PISS YOU
OFF...................IT DID ME!!!!
To: "Nick Laub" <minn_nick(AT)hotmail.com>, "Dave Guimont"
<dguimon1(AT)san.rr.com>
Cc: amsat-bb(AT)amsat.org
Message-ID: <005d01c8dafc$da6bc9d0$0201a8c0(AT)your6bvpxyztoq>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
This has nothing to do with immigration. Eveyone born before 1924 gets lower
benefits as congress figured that they paid in for a smaller amount of time.
What's realy unfortunate is that the "Notch Victims Register" solicits
donations from these people with no hope of ever increasing benefits.
73,
John
KD6OZH
----- Original Message -----
From: "Dave Guimont" <dguimon1(AT)san.rr.com>
To: "Nick Laub" <minn_nick(AT)hotmail.com>
Cc: <amsat-bb(AT)AMSAT.Org>
Sent: Sunday, June 29, 2008 03:30 UTC
Subject: [amsat-bb] Re: FW: THIS SHOULD PISS YOU OFF...................IT
DID ME!!!!
>
>>
>>Subject: Fw: THIS SHOULD PISS YOU OFF...................IT DID ME!!!!
>>Date: Mon, 30 Jun 2008 01:40:29 +0000
>>
>>
>>----------
>>From: JAGTRIG9(AT)aol.com
>>Sent: Thursday, June 12, 2008 7:44 PM
>>To: JAGTRIG9(AT)aol.com
>>Subject: THIS SHOULD PISS YOU OFF...................IT DID ME!!!!
>>
>>
>>This is an insult and a kick in the butt to all of us...
>>
>>Get mad and pass it on - I don't know how, but maybe some good
>>Will come of this travesty.
>>
>>
>>If the immigrant is over 65 they can apply for SSI and Medicaid and get
>>More than a woman on Social Security, who worked from 1944
>>till 2004, only getting $791 per month because she was born in 1924 and
>>There is a 'catch 22.
>
> Liscensed since 1952, politics and women were NEVER DISCUSSED in/on
> HAM RADIO!!
>
> What in the hell has changed????......
>
> Women ok, but had no idea the Republicans are that desperate!!
>
> Good for the dems!!
>
> END OF MY POLITICS...
>
>
>
>
>
>
> 73, Dave, WB6LLO
> dguimon1(AT)san.rr.com
>
> Disagree: I learn....
>
> Pulling for P3E...
>
> _______________________________________________
> 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
------------------------------
Message: 9
Date: Mon, 30 Jun 2008 18:09:35 EDT
From: G0MRF(AT)aol.com
Subject: [amsat-bb] Re: UPDATE: Presat and Nanosail Satellite Launch
To: mlmiller(AT)intellus.us, amsat-bb(AT)amsat.org
Message-ID: <bc8.31d4c6c0.359ab39f(AT)aol.com>
Content-Type: text/plain; charset="UTF-8"
The SpaceX website has the following launch windows:
"The next launch window opens 29 July and runs through 6 August, followed by
one from 29 August to 5 September.
The Falcon 1 will carry the Trailblazer satellite for the Jumpstart Program
of the Department of Defense?s Operationally Responsive Space Office (ORS).
Additional secondary payloads include an adapter system developed by the
government of Malaysia that holds two small NASA satellites.
SpaceX will provide complete launch day coverage and a live webcast of the
launch and ascent into orbit.
Details will be announced as the launch date approaches via the _SpaceX.com_
(http://www.spacex.com/) website."
Thanks
David G0MRF
In a message dated 30/06/2008 21:08:35 GMT Standard Time,
mlmiller(AT)intellus.us writes:
This launch has been postponed. I will provide a new launch date when it
has been determined.
Please let me know any questions.
Thanks,
Mike Miller
KE7EGC
------------------------------
Message: 10
Date: Mon, 30 Jun 2008 17:27:59 -0500
From: "Alan P. Biddle" <APBIDDLE(AT)UNITED.NET>
Subject: [amsat-bb] Re: FW: THIS SHOULD PISS YOU
OFF...................ITDID ME!!!!
To: "'John B. Stephensen'" <kd6ozh(AT)comcast.net>, "'Nick Laub'"
<minn_nick(AT)hotmail.com>, "'Dave Guimont'" <dguimon1(AT)san.rr.com>
Cc: amsat-bb(AT)amsat.org
Message-ID: <274B8FEA3905465283C91975C79A58F5(AT)WA4SCA>
Content-Type: text/plain; charset="us-ascii"
Guys,
I am all for freewheeling discussion, but does this truly belong on
AMSAT-BB? Just wondering?
Alan
WA4SCA
------------------------------
Message: 11
Date: Sun, 29 Jun 2008 16:27:35 -0700
From: Dave Guimont <dguimon1(AT)san.rr.com>
Subject: [amsat-bb] Re: FW: THIS SHOULD PISS YOU
OFF...................ITDID ME!!!!
To: <APBIDDLE(AT)MAILAPS.ORG>
Cc: amsat-bb(AT)amsat.org
Message-ID:
<20080630232745.CDEO4229.cdptpa-omta06.mail.rr.com(AT)Dave.san.rr.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed
>Guys,
>
>I am all for freewheeling discussion, but does this truly belong on
>AMSAT-BB? Just wondering?
>
>Alan
>WA4SCA
Alan, you are absolutely right!!
Nick and I kissed an made up, privately!! We are both from
Minnesota, and probably made our first contact maybe forty years ago,
and dozens on hamsats..
As I just said to Nick, I could have cut my finger off after pressing
the "send", and he basically voiced the same sentiments...
My apologies to all...
73, Dave, WB6LLO
dguimon1(AT)san.rr.com
Disagree: I learn....
Pulling for P3E...
------------------------------
Message: 12
Date: Mon, 30 Jun 2008 19:49:00 -0500
From: Ronald Nutter <rnutter(AT)networkref.com>
Subject: [amsat-bb] Best type of coax to use between preamps and
antennas
To: amsat-bb(AT)amsat.org
Message-ID: <48697EFC.5010100(AT)networkref.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
After problems I had on Field Day in trying to operate the satellites, I
am looking to upgrade the coax I use between the preamps and the
antennas. I am using 9913FX from the IC-910H and the preamps. I had
been using RG Mini 8/U for the connection between the preamps and
antennas. Should I also use 9913FX between the preamps and the
antennas? The run between the radio and the preamp is 50 ft. The run
from the preamp to the antennas is about 10 - 15 ft depending on where I
set the antennas up. I am concerned about how flexible the 9913FX would
be in terms of the antennas rotating back and forth. I was planning on
ordering the cables pre-made from CableXperts since working with N
connectors isnt my strong point and dont want to worry about my
soldering and having a good connection on both ends of the cable.
Any suggestions appreciated.
Thanks,
Ron
KA4KYI
------------------------------
Message: 13
Date: Mon, 30 Jun 2008 19:36:36 -0600
From: Auke de Jong <sparkycivic(AT)shaw.ca>
Subject: [amsat-bb] Re: RS-15 heard again
To: AMSAT-BB <amsat-bb(AT)amsat.org>, w7lrd(AT)comcast.net
Message-ID: <00ea01c8db1a$e686b680$6400a8c0(AT)sparkys>
Content-Type: text/plain; charset="iso-8859-1"
I have thought of another possible cause, which is still purely speculation,
yet it's fun to talk about! ...
Perhaps, some of the battery cells have failed and shunted-keeping the voltage
very low accross the power system. Then as the voltage builds from charging
via the solar panels, the remaining battery cells become charged, lowering
their resistance, and thus the total resistance of the battery system. A
threshold is reached where the voltage gets just high enough so the
transmitter is keyed. Then the transmitter further draws the voltage down
from the system, and out of the remaining battery capacity, untill another
low-voltage threshold is reached, de-activating the transmitter, and starting
another cycle.
This could explain why the timing periods vary from one moment to the next, as
the sun-angle changes along the orbit, and maybe some solar panels are better
than others on the different faces of the craft with spacecraft rotation,
creating different combinations of charging currents, and transmitter keying.
Higher charging currents would cause a shorter off-period, and longer
transmitting period. unfavorable sun-angles, such as facing the antenna-side
of the craft, would cause very long off-periods, and very short transmissions.
If only we could know what the actual electronics inside the spacecraft
entailed, a lot of good analysis and education could come from this gradual
failure. At this point, I dont' even know what the design capacity of the
solar array was, much less be able to determine if they could power the
transponder system or beacon encoder successfully without a battery!
I really hope that someday, satellite builders will be more forthcoming with
technical data about the flight electronics, just as they were with AO-7 and a
few others. The benefit of this data to the larger community of Amateurs, and
to spacefraft science itself, can't be overstated! Heck! I might as well say
the obvious logical extension of this line-of-thought: It might help us to
understand our past mistakes as well as the eventual failure-modes for
satellites, so that we might prevent the mistakes from being repeated, and
create even longer-lasting satellites!
I would think that the ultimate goal should be that they CAN create satellites
that operate forever, should they want to. Not all of them need to, but for
Communications birds in particular, the design lifespans advertised in the
literature, always strike me as very short...
enough typing, time for more operating:
73
----- Original Message -----
From: w7lrd(AT)comcast.net
To: Auke de Jong, VE6PWN ; AMSAT-BB
Sent: Sunday, June 29, 2008 7:23 PM
Subject: Re: [amsat-bb] RS-15 heard again
I have tried at times to give it a shot of RF uplink, "just in case". I
mean after all AO-7 came back to us! Maybe it just needs enough up RF to jump
start it. Does anyone know what it's final demise was from?
73 Bob W7LRD
------------------------------
Message: 14
Date: Mon, 30 Jun 2008 22:03:18 -0400
From: Arthur Feller <afeller(AT)ieee.org>
Subject: [amsat-bb] Fwd: Carl Eilers, SK
To: AMSAT-BB <amsat-bb(AT)amsat.org>
Message-ID: <3B8F27C9-AFF2-42EC-AAFE-D6832A47F364(AT)ieee.org>
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
Begin forwarded message:
> THIS WEEK'S HONORARY UNSUBSCRIBE goes to Carl G. Eilers. When he
> went to
> work for Zenith Electronics in 1948, Eilers' assignment was to
> work on
> "Phonevision", or pay television. "Even then he developed the core
> concepts that are used today, such as scrambling a signal and you
> only
> get an unscrambled signal if you pay for it," a Zenith spokesman
> said.
> But Eilers is better known for a couple of other Zenith
> innovations: he
> led the team that created the standard for FM stereo, which was
> adopted
> by the FCC in 1961 and is still in use today, and Eilers later
> expanded
> that work for another medium: TV. Zenith's multichannel television
> sound, or stereo TV with a "separate audio program" that for
> instance
> could carry the soundtrack in other languages, was adopted
> industry-
> wide in 1984. Eilers stayed at the company for 50 years before
> retiring. He died June 20 from an apparent heart attack at 83.
Life is short. Be swift to love! Make haste to be kind!
- Henri Frederic Amiel, philosopher and writer (1821-1881)
------------------------------
Message: 15
Date: Mon, 30 Jun 2008 20:17:43 -0400
From: Stu <stu(AT)stu2.net>
Subject: [amsat-bb] APRS FD
To: amsat-bb(AT)AMSAT.Org
Message-ID: <486977A7.50807(AT)stu2.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Are there any success stories for APRS and FD? If so, can you share them?
We (W4IY) worked a couple stations through VO-52 and I was surprised how
many SSB ops were on. I used a couple of omnis, TS-2K and Ham Radio
Deluxe for doppler correction.
Nice to see all the activity!
Stu
W7IY
------------------------------
Message: 16
Date: Mon, 30 Jun 2008 21:40:34 -0700
From: "kc6uqh" <kc6uqh(AT)cox.net>
Subject: [amsat-bb] Re: Eliminating Desensing
To: "Simon Brown \(HB9DRV\)" <simon(AT)hb9drv.ch>, <amsat-bb(AT)amsat.org>
Message-ID: <00a801c8db34$9a264200$0200a8c0(AT)kc6uqh>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
I had problems on AO-40 several years ago. The problem was traced to the
connection of a silver plated brass connector bolted to an aluminum surface
where crossion had set in. Cleaning the connection stopped the 70 cm uplink
from crashing my 13 cm receive.
Art,
KC6UQH
----- Original Message -----
From: "Simon Brown (HB9DRV)" <simon(AT)hb9drv.ch>
To: <amsat-bb(AT)amsat.org>
Sent: Monday, June 30, 2008 10:18 AM
Subject: [amsat-bb] Re: Eliminating Desensing
> Same here with TS-2000, 6ft *aluminium* boom and SSB Electronics masthead
> pre-amps.
>
> I'm thinking about a 6ft to 9ft fibreglass boom anyway, I would be
> interested also in user comments.
>
> Simon Brown, HB9DRV
>
> --------------------------------------------------
> From: "Reicher, James" <JReicher(AT)hrblock.com>
>
>> I got significant de-sensing of my 2 meter downlink from my 70cm uplink
>> at
>> Field Day. I know a good part of it was due to the short cross-boom
>> (about 4 feet) I was using. I would like to decrease the de-sense on
>> this
>> set-up before I permanently install it at my home station. Any and all
>> suggestions are welcome.
>
>
> _______________________________________________
> Sent via AMSAT-BB(AT)amsat.org. Opinions expressed are those of the author.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 17
Date: Tue, 01 Jul 2008 00:57:31 -0500 (CDT)
From: "David Donaldson" <wb7dru(AT)usfamily.net>
Subject: [amsat-bb] Re: Eliminating Desensing
To: "'Andrew Glasbrenner'" <glasbrenner(AT)mindspring.com>,
"'Reicher,James'" <JReicher(AT)hrblock.com>, <amsat-bb(AT)amsat.org>
Message-ID: <016f01c8db3f$b6edf5d0$01fea8c0(AT)DAVEBEDROOM>
Content-Type: text/plain; charset="iso-8859-1"
The quality of the devices and the design of the amp is significant. In
the cellular world at 850 I have seen cheap poorly designed (talking
thousands for these units) TTA's generate more crud from minimial
colocated signals then the well designed cheap ones. All the units I
now use have a high IP3 point with integrated filters or duplexers. The
unit ADC Telecom used to make had the filter integrated in the housing
(machined out of a solid aluminum block). I was able to use these in
downtown settings without fear of intermod. Newer units work as well
but now have a seperate filter from the housing.
Moral of the story: It's design not price that is the key. Cheaper not
always badder. Compare specs.
Other suggestion would be to establish the power level where the
interference begins. Though it is not linear it will give u a sense of
the degree of interaction between the UL and DL antennas. Intermod and
desense always has a bit of magic to it thanks to its none linear
behaivor
Hope this helps someone
Dave D
WB7DRU
Sent with Wireless Sync from Verizon Wireless
Another option is to use a preamp with good filtering on the input. I
had issues with Mode J desense with my Icom AG-35 preamp, but have none
now that I have switched to SSB Electronics preamps.
As always, Your Mileage May Vary (YMMV).
73, Drew KO4MA
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End of AMSAT-BB Digest, Vol 3, Issue 326
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