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CX2SA > SATDIG 20.05.08 00:02l 790 Lines 27252 Bytes #999 (0) @ WW
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To : SATDIG@WW
Today's Topics:
1. Re: 145 MHz IF on V/s? (Gary "Joe" Mayfield)
2. DELFI-C3 South America ?? (Raul Romero CA3SOC)
3. Re: 145 MHz IF on V/s? (i8cvs)
4. Re: AAUSAT-11 (Mike Rupprecht)
5. Re: DELFI-C3 South America ?? (Fabio Teixeira Magalhaes)
6. Re: AOP-1 Circular Polarization? (Sebastian)
7. Re: 145 MHz IF on V/s? (Edward Cole)
8. Re: GHz receivers and Mars (WB2LLP)
9. New rig ... SSB birds (Garie Halstead K8KFJ)
10. Re: 145 MHz IF on V/s? (i8cvs)
----------------------------------------------------------------------
Message: 1
Date: Mon, 19 May 2008 06:26:58 -0500
From: "Gary \"Joe\" Mayfield" <gary_mayfield(AT)hotmail.com>
Subject: [amsat-bb] Re: 145 MHz IF on V/s?
To: "'K & R Yoksh'" <yokshs(AT)sbcglobal.net>, "'Amsat BB'"
<amsat-bb(AT)amsat.org>
Message-ID: <BLU137-DAV161C50A6CCB1CF3FC283A8AC50(AT)phx.gbl>
Content-Type: text/plain; charset="us-ascii"
I have never tried using 145 MHz as an IF for S band. I have always used
123 MHz and never had a problem.
73,
Joe kk0sd
-----Original Message-----
From: amsat-bb-bounces(AT)amsat.org [mailto:amsat-bb-bounces(AT)amsat.org] On
Behalf Of K & R Yoksh
Sent: Sunday, May 18, 2008 5:57 PM
To: Amsat BB
Subject: [amsat-bb] 145 MHz IF on V/s?
Hi all,
Thanks for the replies, however, I've still not had my question answered, so
I'll ask again.
I'd like to hear from anyone using a 145 MHz IF when working mode V/s. Do
you experience
desense when operating V/s, but not other uplink modes?
I'm planning to use my AIDC 3731 with 145 MHz IF when I install my dish this
summer. I really want to use it for HEO operation, but it'd be a bonus if I
could also work the LEOs.
I could go with a 123 MHz IF unit if that'd work better.
Thanks and 73,
Kyle Yoksh
K0KN
Olathe, Kansas
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------------------------------
Message: 2
Date: Mon, 19 May 2008 08:00:59 -0400
From: "Raul Romero CA3SOC" <ce3soc(AT)gmail.com>
Subject: [amsat-bb] DELFI-C3 South America ??
To: "Delfi-C3 Mission Control" <missioncontrol(AT)delfic3.nl>
Cc: AMSAT-BB(AT)amsat.org
Message-ID: <EF881AC04DF64C1E91E5B34A93E7DB31(AT)p42800>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
hi one cuestion delfi-c3 shut down over pass CHILE South America ??
Only On in EEUU and Europe
Tnx Raul
CA3SOC
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Message: 3
Date: Mon, 19 May 2008 13:37:58 +0200
From: "i8cvs" <domenico.i8cvs(AT)tin.it>
Subject: [amsat-bb] Re: 145 MHz IF on V/s?
To: "K & R Yoksh" <yokshs(AT)sbcglobal.net>, "Amsat BB"
<amsat-bb(AT)amsat.org>
Message-ID: <001801c8b9a4$caca74a0$0201a8c0(AT)tin.it>
Content-Type: text/plain; charset="iso-8859-1"
----- Original Message -----
From: "K & R Yoksh" <yokshs(AT)sbcglobal.net>
To: "Amsat BB" <amsat-bb(AT)amsat.org>
Sent: Monday, May 19, 2008 12:56 AM
Subject: [amsat-bb] 145 MHz IF on V/s?
>
> Hi all,
>
> Thanks for the replies, however, I've still not had my question answered,
> so I'll ask again.
>
> I'd like to hear from anyone using a 145 MHz IF when working mode V/s. Do
> you experience desense when operating V/s, but not other uplink modes?
>
> I'm planning to use my AIDC 3731 with 145 MHz IF when I install my dish
> this summer. I really want to use it for HEO operation, but it'd be a
> bonus if I could also work the LEOs.
>
> I could go with a 123 MHz IF unit if that'd work better.
>
> Thanks and 73,
>
> Kyle Yoksh
> K0KN
> Olathe, Kansas
>
Hi Kyle, K0KN
Don't warry about to use 145 MHz IF for HEO operation because P3-E
will use the V band only for downlink.
The builders of P3-E are aware of the problem and they don't want to
complicate the life to the users.
For the LEOs S band using downconverters 2400-2402 MHz with an IF
144-146 MHz :
Receiving AO-51 at 2401.200 MHz the IF fall into 145.200 MHz and
transmitting at 145.920 MHz FM the difference between the IF and TX
frequency is 720 kHz
In this condition there are three possible outcomes:
The 145.200 MHz uplink signal is picked up directly by the cable after
the mixer of the S band converter and sent down to the shak into your IF
receiver flowing in general through the outside surface of the braid of
the coax cable. (common currents)
The 145.200 MHz uplink signal can pass directly through the converter
first stage up to the IF receiver in the shak.
The 145.200 MHz uplink signal is picked up directly by your IF receiver
because your power is very high and TX/RX are very close.
Since there are many variables involved mostly depending on your TX power
it is very difficult to say yes or not and so a test to see if you will
suffer or not a desensing is mandatory.
If you have a desensing there are many possible cures for it but if you
don't have the time to work on this problem it is best to use your 123 MHz
IF unit.
I remember that receiving AO40 I got interference over the 2401.323 MHz
bpsk beacon when an amateur friend living few miles away of me was locally
transmitting FM using high power at 145.325 MHz
145.325 MHz was at the same time his own frequency and my IF frequency.
My investigation demonstrated that the interfering signal was piched up
directly by the coax cable running from the S band downconverter to the
IF receiver in the shak.
Unfortunately i don't had on hand a S band downconverter with a 123 MHz IF
Best 73" de
i8CVS Domenico
------------------------------
Message: 4
Date: Mon, 19 May 2008 14:09:38 +0200
From: "Mike Rupprecht" <mail(AT)mike-rupprecht.de>
Subject: [amsat-bb] Re: AAUSAT-11
To: "'Robert Turlington'" <rob_g8ate(AT)hotmail.com>, "'Amsat Buleitin
Board'" <amsat-bb(AT)amsat.org>
Message-ID: <002601c8b9a9$36799b50$a36cd1f0$(AT)de>
Content-Type: text/plain; charset="iso-8859-1"
I Robert,
use TLE NORAD 32788:
AAUSAT
1 32788U 08021F 08138.85653900 .00000150 00000-0 25990-4 0 441
2 32788 097.9914 198.8372 0014372 231.3827 128.6096 14.81510869 2917
Signals are weak but in high elevation passes I can decode up to 8 beacons.
See here www.dk3wn.info/sat/afu/sat_aau.shtml
(it is in german...)
73, Mike
DK3WN
-----Urspr?ngliche Nachricht-----
Von: amsat-bb-bounces(AT)amsat.org [mailto:amsat-bb-bounces(AT)amsat.org] Im
Auftrag von Robert Turlington
Gesendet: Montag, 19. Mai 2008 10:15
An: Amsat Buleitin Board
Betreff: [amsat-bb] AAUSAT-11
Hi All
Has anyone heard AAUSAT-11 recently and if so what keps were used?I have
listened a few times but nothing heard!Regards Robert G8ATE
_________________________________________________________________
All new Live Search at Live.com
http://clk.atdmt.com/UKM/go/msnnkmgl0010000006ukm/direct/01/
_______________________________________________
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: 5
Date: Mon, 19 May 2008 09:38:43 -0300
From: Fabio Teixeira Magalhaes <ftmagalhaes(AT)terra.com.br>
Subject: [amsat-bb] Re: DELFI-C3 South America ??
To: Raul Romero CA3SOC <ce3soc(AT)gmail.com>
Cc: AMSAT-BB <amsat-bb(AT)amsat.org>
Message-ID: <483174D3.9020109(AT)terra.com.br>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Hi Raul - CA3SOC
I observed, in orbit 315, that when the satellite passed fron north to
south hemisphere (lat zero - 12:19 UTC) the signals had been
interrupted.............
73 es DX
Fabio - PY4AJ - Loc: GH70un
Amsat nr 19748
Raul Romero CA3SOC escreveu:
> hi one cuestion delfi-c3 shut down over pass CHILE South America ??
>
> Only On in EEUU and Europe
>
> Tnx Raul
> CA3SOC
>
>
>
------------------------------
Message: 6
Date: Mon, 19 May 2008 10:15:14 -0400
From: Sebastian <w4as(AT)bellsouth.net>
Subject: [amsat-bb] Re: AOP-1 Circular Polarization?
To: AMSAT-BB <amsat-bb(AT)amsat.org>
Message-ID: <DFB379A0-F55E-4A51-B312-312F51E86370(AT)bellsouth.net>
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
Thanks for everyone's replies. It looks like the consensus is to
mount the beams in the terrestrial + pattern (vertical/horizontal).
I'll be mounting the antennas on a fiberglass pole that served me well
years ago (it's been keep safe inside the attic). This is good,
because that way I should be able to use those antennas for local
repeater work with minimal loss if any, due to using both polarities
at the same time.
On May 19, 2008, at 4:44 AM, i8cvs wrote:
> ----- Original Message -----
> From: "Greg D." <ko6th_greg(AT)hotmail.com>
> To: "Ronald G. Parsons" <w5rkn(AT)amsat.org>; <amsat-bb(AT)amsat.org>
> Sent: Monday, May 19, 2008 9:17 AM
> Subject: [amsat-bb] Re: AOP-1 Circular Polarization?
>>
>> Actually, I was thinking about this today... There was an earlier
>> thread
>> which discussed the off-angle performance of a crossed Yagi, and if I
>> recall, the pattern becomes elliptical as you move off the
>> antenna's bore
>> sight. If this is true, then I conclude that it would be better
>> to mount
>> a crossed Yagi in the + orientation, vs X, as that way one of the two
>> antennas will be properly aligned for an off-angle linear station.
>> For
>> satellite work, with accurate keps, this is probably not a
>> significant
>> issue, but for terrestrial work and other situations where the
>> target's
>> position may not be known or tracked, + should be more forgiving
>> than X.
>> At least, that's my theory.
>>
>> I kind of hope I'm wrong on this... I just got a new 70cm antenna
>> from a
>> swap meet today, and it's already mounted in the X position.
>>
>> Greg KO6TH
>>
>>
> Hi Greg, KO6TH
>
> The interferometer-like effect that you mentioned is referred only
> to a dual
> boom antenna mounted configuration no matter if the antennas are
> mounted
> in a X or + configuration.
>
> The distance between the two antennas make the phase of the received /
> transmitted signals to be different when the antennas are moved bore
> sight
> from the satellite.
>
> Depending on the squint angle between the off-boom antennas and the
> satellite the above phase difference can make a RHCP signal to
> appear LHCP
> or elliptical or linear.
>
> If both antennas are mounted instead over a single concentric boom
> this
> interferometer-like effect cancel out no matter if the antennas are
> in a X
> or + configuration.
>
> This effect has been described into "The Satellite Experimenter's
> Handbook"
> by Martin Davidoff , K2UBC 2nd Edition pages 7-12 and 7-13
>
> By the way the X configuration is the best if you use a metal-boom
> while
> the X or + configuration can be used indifferently if you use an
> insulated
> boom like fiberglass or wooden boom as demonstrated with experiments
> by WA5VJB
>
> http://www.g6lvb.com/fibermetalboom.htm
>
> In addition the X configuration is nice if you want to add V and H
> linear
> polarizations using a relay switcher for V-H-RHCP-LHCP as described
> into the AMSAT Journal March/April 2007 and May/June 2007
>
> 73" de
>
> i8CVS Domenico
>
>> ----------------------------------------
>>> From: w5rkn(AT)amsat.org
>>> To: amsat-bb(AT)amsat.org
>>> Date: Sun, 18 May 2008 16:42:02 -0500
>>> Subject: [amsat-bb] Re: AOP-1 Circular Polarization?
>>>
>>> Assuming the antennas you reference do produce circular
>>> polarization,
>>> radiation wise, it doesn't matter whether you mount them in an X
>>> or +
>>> orientation. The only difference would be the phase of the
>>> radiation,
> and
>>> you are not concerned with that. There could also be a difference
> between
>>> right- or left-circular polarization, but whether that matters
>>> depends
> on
>>> the polarization the the satellite's antenna. But X or + does not
>>> change
>>> that.
>>>
>>> There might be some mechanical reason for an X or +, such as weather
>>> proofing, but not signal wise.
>>>
>>> Ron W5RKN
>>>
>>>> Date: Sun, 18 May 2008 14:28:34 -0400
>>>> From: Sebastian
>>>> Subject: [amsat-bb] AOP-1 Circular Polarization?
>>>> To: Amsat - BBs
>>>> Message-ID:
>>>> Content-Type: text/plain; charset=US-ASCII; format=flowed;
>>>> delsp=yes
>>>>
>>>> Hello all, I'm getting ready to put back up my old AOP-1 antennas
>>>> (the
>>>> old Cushcraft antennas that were popular in the days of AO-10 &
>>>> 13).
>>>> I'm wondering whether I should follow the same procedure of cross
>>>> polarization for the 440 beam? It was recommended at the time to
>>>> place the antenna in an X pattern instead of the cross pattern.
>>>> Also,
>>>> at the time, the 2 meter antenna was suggested to be placed in the
>>>> standard vertical/horizontal polarization.
>>>>
>>>> Please let me know which would be the best method to use for most
>>>> of
>>>> today's birds.
>>>>
>>>> 73s de W4AS
>>>>
>>>>
>
>
>
>
>
> _______________________________________________
> 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: 7
Date: Mon, 19 May 2008 06:29:07 -0800
From: Edward Cole <kl7uw(AT)acsalaska.net>
Subject: [amsat-bb] Re: 145 MHz IF on V/s?
To: "i8cvs" <domenico.i8cvs(AT)tin.it>, "K & R Yoksh"
<yokshs(AT)sbcglobal.net>, "Amsat BB" <amsat-bb(AT)amsat.org>
Message-ID: <200805191429.m4JET79Y053704(AT)iris.acsalaska.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed
I agree with Dom's analysis. What you are facing is almost the
classic problem of running in-band duplex (that is the problem every
repeater faces). One solution would be to use a repeater duplexer
tuned for your 720-KHz split. However there is a catch: duplexers
normally operate at a single channel frequency and do not allow
tuning a subband. If you are running low power you might be OK with
bandpass filters tuned for a wider band acceptance on the receive frequency.
So if you can receive on 123-MHz this is infinitely
easier/cheaper. I run 123-MHz on one of my Drake converters with no
problems from 145 MHz transmissions. MY other Drake is modified for
IF of 435 MHz which makes mode-LS simple as I nver have to face your dilemma.
73 Ed - KL7UW
At 03:37 AM 5/19/2008, i8cvs wrote:
>----- Original Message -----
>From: "K & R Yoksh" <yokshs(AT)sbcglobal.net>
>To: "Amsat BB" <amsat-bb(AT)amsat.org>
>Sent: Monday, May 19, 2008 12:56 AM
>Subject: [amsat-bb] 145 MHz IF on V/s?
> >
> > Hi all,
> >
> > Thanks for the replies, however, I've still not had my question answered,
> > so I'll ask again.
> >
> > I'd like to hear from anyone using a 145 MHz IF when working mode V/s. Do
> > you experience desense when operating V/s, but not other uplink modes?
> >
> > I'm planning to use my AIDC 3731 with 145 MHz IF when I install my dish
> > this summer. I really want to use it for HEO operation, but it'd be a
> > bonus if I could also work the LEOs.
> >
> > I could go with a 123 MHz IF unit if that'd work better.
> >
> > Thanks and 73,
> >
> > Kyle Yoksh
> > K0KN
> > Olathe, Kansas
> >
>Hi Kyle, K0KN
>
>Don't warry about to use 145 MHz IF for HEO operation because P3-E
>will use the V band only for downlink.
>The builders of P3-E are aware of the problem and they don't want to
>complicate the life to the users.
>
>For the LEOs S band using downconverters 2400-2402 MHz with an IF
>144-146 MHz :
>Receiving AO-51 at 2401.200 MHz the IF fall into 145.200 MHz and
>transmitting at 145.920 MHz FM the difference between the IF and TX
>frequency is 720 kHz
>In this condition there are three possible outcomes:
>The 145.200 MHz uplink signal is picked up directly by the cable after
>the mixer of the S band converter and sent down to the shak into your IF
>receiver flowing in general through the outside surface of the braid of
>the coax cable. (common currents)
>The 145.200 MHz uplink signal can pass directly through the converter
>first stage up to the IF receiver in the shak.
>The 145.200 MHz uplink signal is picked up directly by your IF receiver
>because your power is very high and TX/RX are very close.
>Since there are many variables involved mostly depending on your TX power
>it is very difficult to say yes or not and so a test to see if you will
>suffer or not a desensing is mandatory.
>If you have a desensing there are many possible cures for it but if you
>don't have the time to work on this problem it is best to use your 123 MHz
>IF unit.
>I remember that receiving AO40 I got interference over the 2401.323 MHz
>bpsk beacon when an amateur friend living few miles away of me was locally
>transmitting FM using high power at 145.325 MHz
>145.325 MHz was at the same time his own frequency and my IF frequency.
>My investigation demonstrated that the interfering signal was piched up
>directly by the coax cable running from the S band downconverter to the
>IF receiver in the shak.
>Unfortunately i don't had on hand a S band downconverter with a 123 MHz IF
>
>Best 73" de
>
>i8CVS Domenico
>
>
>
>
>_______________________________________________
>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: 8
Date: Mon, 19 May 2008 12:01:52 -0400
From: WB2LLP <wb2llp(AT)optonline.net>
Subject: [amsat-bb] Re: GHz receivers and Mars
To: "D. Mynatt" <dave(AT)mynatt.biz>, AMSAT-BB(AT)amsat.org
Message-ID: <005501c8b9c9$a7537a10$6401a8c0(AT)gene>
Content-Type: text/plain; format=flowed; charset=iso-8859-1;
reply-type=original
Dave,
Receiving the MARS Lander signal sounds like a real hoot, but without
knowing anything about frequency. mode, signal strength, I do not even know
if I can come close with the equipment I have. I suspect that we are
dealing with really weak signals.
Then there is the telemetry. For those of us who are not "into" digital
yet, what will that require?
Please supply more details.
73 de WB2LLP Gene
----- Original Message -----
From: "D. Mynatt" <dave(AT)mynatt.biz>
To: <AMSAT-BB(AT)amsat.org>
Sent: Sunday, May 18, 2008 9:24 PM
Subject: [amsat-bb] GHz receivers and Mars
> Any one in the group been dreaming or scheming to be able to directly
> receive Mars Lander telemetry?
>
> Dave/KA0SWT
> _______________________________________________
> 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, 19 May 2008 11:00:28 -0700 (PDT)
From: Garie Halstead K8KFJ <khyberpass65(AT)yahoo.com>
Subject: [amsat-bb] New rig ... SSB birds
To: amsat-bb(AT)amsat.org
Message-ID: <499544.38008.qm(AT)web65701.mail.ac4.yahoo.com>
Content-Type: text/plain; charset=iso-8859-1
I just purchased a new FT-817ND and plan to use it in conjunction with my
existing IC706MK2G. The plan being to perhaps work some SSB. I wondered how
much operation there is right now on VO-52 for instance. So, I picked a
midday pass with some excellent elevation for my activity test today. At TCA,
I still had not heard anything on the new 817. That was my fear ...
inactivity. I was beginning to give up when suddenly Chip (W4PBG) in FM19
calls CQ and hooks up with Don (K5BTK) IN EM42. The mode was CW.
I guess that answered any question I may have had regarding activity. I
hope to be on the bird soon with the new setup. Sounds as if an op could be
fairly busy just dealing with the Doppler aspect while sending, copying, etc.
Can someone guide me to a tutorial perhaps. Many thanks.
73, Gary -K8KFJ-
West Virginia (EM98)
AMSAT #32574
Sat VUCC #125
------------------------------
Message: 10
Date: Mon, 19 May 2008 19:51:57 +0200
From: "i8cvs" <domenico.i8cvs(AT)tin.it>
Subject: [amsat-bb] Re: 145 MHz IF on V/s?
To: "K & R Yoksh" <yokshs(AT)sbcglobal.net>, "Amsat BB"
<amsat-bb(AT)amsat.org>, "Edward Cole" <kl7uw(AT)acsalaska.net>
Message-ID: <006601c8b9d9$09bbbf00$0201a8c0(AT)tin.it>
Content-Type: text/plain; charset="iso-8859-1"
----- Original Message -----
From: "Edward Cole" <kl7uw(AT)acsalaska.net>
To: "i8cvs" <domenico.i8cvs(AT)tin.it>; "K & R Yoksh"
<yokshs(AT)sbcglobal.net>;
"Amsat BB" <amsat-bb(AT)amsat.org>
Sent: Monday, May 19, 2008 4:29 PM
Subject: Re: [amsat-bb] Re: 145 MHz IF on V/s?
> I agree with Dom's analysis. What you are facing is almost the
> classic problem of running in-band duplex (that is the problem every
> repeater faces).
Hi Ed, KL7UW
Receiving the satellite subband from 145.800 to 146.000 MHz here in the
gulf of Naples is like the classic problem you mentioned of running in-band
duplex because I am receiving the satellite band while my ham-radio fellows
are transmitting locally FM with high power from 145.450 to 145.475 MHz
desensing my receiving system and this problem started with OSCAR-13 early
1994 when high power 2 meters amplifiers where readily available in the
market.
> One solution would be to use a repeater duplexer
> tuned for your 720-KHz split. However there is a catch: duplexers
> normally operate at a single channel frequency and do not allow
> tuning a subband. If you are running low power you might be OK with
> bandpass filters tuned for a wider band acceptance on the receive
> frequency.
You are reading in my brain Ed because to overcome the problem of desensity
I had to build a Norton type preamplifier with an IP3 of +14 dBm relative to
the input and associate NF= 1.3 dB and G= 18.5 dB
This preamplifier have a 1 dB compression point at -1 dBm and is antenna
mounted but it was not in condition to complitely solve the problem of gain
reduction and gain compression of my receiving system while my near by
friends were locally transmitting FM about 500 KHz belove the satellite
band.
For the above reason I added in the shak a band-pass cavity filter centered
to 145.950 MHz tuned with a flatness of +/- 1 dB in to the satellite band
and rejecting the unwanted 145.450 MHz signals by only -12 dB
After the above BPF I added in series a notch cavity filter of the type used
for the 2 meters FM repeaters producing a hole -38 dB deep at 145.450 MHz
and only an attenuation of -1dB into the satellite band.
The output of the above notch is connected to the input of a homebrewed
144/28 MHz high dinamic range downconverter that make use of two Norton
input stages and a very high IP3 intercept point mixer type VAY-1 requiring
a power of +30 dBm for the LO
With this setup that was published in Radio Rivista's 3-94, 4-94, 5-94 and
6-94 I am actually safe of any station using high power in the gulf.
I remember that I was accustomed to locally show how OSCAR-13 was nice
receiving the bird at 145.950 MHz and translating it on 145.450 MHz only
500 kHz belove using 10 watt over another antenna.
Obviously I cannot move this receiver from the 2 meters satellite band for
wich it is completely tuned and dedicated but no way do do different because
the 2 meters life is very hard here in the gulf.
>
> So if you can receive on 123-MHz this is infinitely
> easier/cheaper. I run 123-MHz on one of my Drake converters with no
> problems from 145 MHz transmissions. MY other Drake is modified for
> IF of 435 MHz which makes mode-LS simple as I nver have to face your
> dilemma.
>
I agree
> 73 Ed - KL7UW
Best 73" de
i8CVS Domenico
>
> At 03:37 AM 5/19/2008, i8cvs wrote:
> >----- Original Message -----
> >From: "K & R Yoksh" <yokshs(AT)sbcglobal.net>
> >To: "Amsat BB" <amsat-bb(AT)amsat.org>
> >Sent: Monday, May 19, 2008 12:56 AM
> >Subject: [amsat-bb] 145 MHz IF on V/s?
> > >
> > > Hi all,
> > >
> > > Thanks for the replies, however, I've still not had my question
answered,
> > > so I'll ask again.
> > >
> > > I'd like to hear from anyone using a 145 MHz IF when working mode V/s.
Do
> > > you experience desense when operating V/s, but not other uplink modes?
> > >
> > > I'm planning to use my AIDC 3731 with 145 MHz IF when I install my
dish
> > > this summer. I really want to use it for HEO operation, but it'd be a
> > > bonus if I could also work the LEOs.
> > >
> > > I could go with a 123 MHz IF unit if that'd work better.
> > >
> > > Thanks and 73,
> > >
> > > Kyle Yoksh
> > > K0KN
> > > Olathe, Kansas
> > >
> >Hi Kyle, K0KN
> >
> >Don't warry about to use 145 MHz IF for HEO operation because P3-E
> >will use the V band only for downlink.
> >The builders of P3-E are aware of the problem and they don't want to
> >complicate the life to the users.
> >
> >For the LEOs S band using downconverters 2400-2402 MHz with an IF
> >144-146 MHz :
> >Receiving AO-51 at 2401.200 MHz the IF fall into 145.200 MHz and
> >transmitting at 145.920 MHz FM the difference between the IF and TX
> >frequency is 720 kHz
> >In this condition there are three possible outcomes:
> >The 145.200 MHz uplink signal is picked up directly by the cable after
> >the mixer of the S band converter and sent down to the shak into your IF
> >receiver flowing in general through the outside surface of the braid of
> >the coax cable. (common currents)
> >The 145.200 MHz uplink signal can pass directly through the converter
> >first stage up to the IF receiver in the shak.
> >The 145.200 MHz uplink signal is picked up directly by your IF receiver
> >because your power is very high and TX/RX are very close.
> >Since there are many variables involved mostly depending on your TX power
> >it is very difficult to say yes or not and so a test to see if you will
> >suffer or not a desensing is mandatory.
> >If you have a desensing there are many possible cures for it but if you
> >don't have the time to work on this problem it is best to use your 123
MHz
> >IF unit.
> >I remember that receiving AO40 I got interference over the 2401.323 MHz
> >bpsk beacon when an amateur friend living few miles away of me was
locally
> >transmitting FM using high power at 145.325 MHz
> >145.325 MHz was at the same time his own frequency and my IF frequency.
> >My investigation demonstrated that the interfering signal was piched up
> >directly by the coax cable running from the S band downconverter to the
> >IF receiver in the shak.
> >Unfortunately i don't had on hand a S band downconverter with a 123 MHz
IF
> >
> >Best 73" de
> >
> >i8CVS Domenico
> >
------------------------------
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End of AMSAT-BB Digest, Vol 3, Issue 253
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