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CX2SA > SATDIG 06.12.13 22:04l 432 Lines 12145 Bytes #999 (0) @ WW
BID : AMSATBB8444
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Subj: AMSAT-BB-digest V8 444
Path: IZ3LSV<IK2XDE<DB0RES<DB0ANF<CX2SA
Sent: 131206/2003Z @:CX2SA.SAL.URY.SA #:1205 [Salto] FBB7.00e $:AMSATBB8444
From: CX2SA@CX2SA.SAL.URY.SA
To : SATDIG@WW
Today's Topics:
1. EZnec experts? (cubesat Circ Antenna) (Robert Bruninga)
2. Re: EZnec experts? (cubesat Circ Antenna)(oops) (Robert Bruninga)
3. Re: AO-73 (FunCube) Transponder Schedule (Paul Stoetzer)
4. PCSat32 question (Tom Worthington)
5. Re: Freq program (Rich/wa4bue)
6. Re: EZnec experts? (cubesat Circ Antenna) (corrected)
(Robert Bruninga)
7. AMSAT-NA 2013 Symposium Proceedings? (Mike McCann)
----------------------------------------------------------------------
Message: 1
Date: Fri, 6 Dec 2013 11:58:20 -0500
From: Robert Bruninga <bruninga@xxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] EZnec experts? (cubesat Circ Antenna)
Message-ID: <28346b174a902f4182bd3d864f9cce16@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=windows-1252
EZnec kibitzers welcome:
See this model image: http://aprs.org/psat/VHF-circ-tuned-ask.gif
We are placing two ? wave VHF whip antennas on a single feed at the corner
of a 1.5U cubesat.
We want them +/-45 degrees out of phase so that we get cross polarization
when paralleled to a single feed point for simplicity.
Modeling each one individually, we got the desired short one to -45 degrees
with a coordinate of 23.04? and the long one to +45 degrees with a
coordinate of 25.7?. Great?
But when we connect them both to the same feed point, we get a combined
real R term about half of the others as expected, but do not get the
desired J0 term but get something near -45 degrees and a resonance several
MHz higher.
To fix that, we lengthened each exactly the same amount to get the
resonance down to 145.8 MHz and J=0 term. Good antenna?.
The QUESTION IS: Are they still 90 degrees out of phase and will they work
as a cross polarized antenna? And how can we verify that?
The feed point is the center of a 0.1? wire between the cubesat wire frame
and the combined end point of the antennas which are also 0.1? above the
top of the cubesat.
Maybe I should have included both wires in the original model, but only
connected one at a time to a source and grounded the other one while
trying to find their individual +/-45 degree lengths. This way, their
passive action as a possible counterpoinse to the whole frame may be
accounted for.
Also, to get within the 500 data points for EZnec, we had to make all of
the wire model 1? segments be a single segment per wire. Is fidelity
maintained with only 1 segment per 1? wire?
Bob, WB4APR
------------------------------
Message: 2
Date: Fri, 6 Dec 2013 12:12:50 -0500
From: Robert Bruninga <bruninga@xxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: EZnec experts? (cubesat Circ Antenna)(oops)
Message-ID: <f106386d77104520835f24229f81bf8c@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=windows-1252
OOPS, One error I made is confusing R+j45 ohms as ?45 degrees?, when +45
degrees is really R+jR? Right? So I am now starting over. Ignore my post
until I fix it and repost the results.
Bob
-----------------------------------------------------------
EZnec kibitzers welcome:
See this model image: http://aprs.org/psat/VHF-circ-tuned-ask.gif
We are placing two ? wave VHF whip antennas on a single feed at the corner
of a 1.5U cubesat.
We want them +/-45 degrees out of phase so that we get cross polarization
when paralleled to a single feed point for simplicity.
Modeling each one individually, we got the desired short one to -45 degrees
with a coordinate of 23.04? and the long one to +45 degrees with a
coordinate of 25.7?. Great?
But when we connect them both to the same feed point, we get a combined
real R term about half of the others as expected, but do not get the
desired J0 term but get something near -45 degrees and a resonance several
MHz higher.
To fix that, we lengthened each exactly the same amount to get the
resonance down to 145.8 MHz and J=0 term. Good antenna?.
The QUESTION IS: Are they still 90 degrees out of phase and will they work
as a cross polarized antenna? And how can we verify that?
The feed point is the center of a 0.1? wire between the cubesat wire frame
and the combined end point of the antennas which are also 0.1? above the
top of the cubesat.
Maybe I should have included both wires in the original model, but only
connected one at a time to a source and grounded the other one while
trying to find their individual +/-45 degree lengths. This way, their
passive action as a possible counterpoinse to the whole frame may be
accounted for.
Also, to get within the 500 data points for EZnec, we had to make all of
the wire model 1? segments be a single segment per wire. Is fidelity
maintained with only 1 segment per 1? wire?
Bob, WB4APR
------------------------------
Message: 3
Date: Fri, 6 Dec 2013 13:34:37 -0500
From: Paul Stoetzer <n8hm@xxxx.xxx>
To: Les Rayburn <les@xxxxxxxxxxxx.xxx>
Cc: AMSAT Mailing List <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: AO-73 (FunCube) Transponder Schedule
Message-ID:
<CABzOSOpMh=xnxqgeg-X=nmqfbD7wF3Go6MXKbjo59WnZkYiOBA@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
It's on for all nighttime passes at the moment. Check funcube.org.uk for
updates to the schedule.
73,
Paul, N8HM
On Fri, Dec 6, 2013 at 10:54 AM, Les Rayburn <les@xxxxxxxxxxxx.xxx> wrote:
> Is there a reliable way to predict what status the transponder on AO-73
> will be on a given pass over the US? Perhaps a web page that I missed? Any
> help appreciated.
>
>
> --
> --
> 73,
>
> Les Rayburn, N1LF
> 121 Mayfair Park
> Maylene, AL 35114
> EM63nf
>
> 6M VUCC #1712
> AMSAT #38965
> Grid Bandits #222
> Southeastern VHF Society
> Central States VHF Society Life Member
> Six Club #2484
>
> Active on 6 Meters thru 1296, 10GHz & Light
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. 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: 4
Date: Fri, 6 Dec 2013 08:30:57 -1000
From: "Tom Worthington" <worth@xxxx.xxx>
To: <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] PCSat32 question
Message-ID: <009801cef2b1$4e844eb0$eb8cec10$@xxxx.xxx>
Content-Type: text/plain; charset="us-ascii"
I use PCSat32 with two radios, an Icom IC7000 for 2m and a Yaesu FT-857 for
70 cm. (I use this particular setup because the FT-857 doesn't respond to
the tone settings when in FM mode on SO-50)
This seems to work, it correctly assigns selects the proper radio for uplink
or downlink and band.
The problem arises when I try to run AO-7 in mode A. PCSat assigns the
FT-857 to 2m and the IC-7000 to 10m which means I need to move the 2m
antenna coax to the other radio. (both radios have a separate coax connector
for the 10m antenna.)
Is there a way to fix this 'feature'? If I change the order of the
frequencies in the Doppler file the radios get assigned properly but the
Doppler corrections are of the wrong sign.
Thanks, Tom, NH6Y
------------------------------
Message: 5
Date: Fri, 06 Dec 2013 14:04:26 -0500
From: "Rich/wa4bue" <richard.siff@xxxxxxx.xxx>
To: "Clayton Coleman" <kayakfishtx@xxxxx.xxx>
Cc: AMSAT-BB <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Freq program
Message-ID: <1AA62922A86E43D9AAF16D1F3D18A1F4@xxxxxxxxx>
Content-Type: text/plain; format=flowed; charset=iso-8859-1;
reply-type=original
Thanks
God Bless
Rich
W4BUE
----- Original Message -----
From: "Clayton Coleman" <kayakfishtx@xxxxx.xxx>
To: "Rich/wa4bue" <richard.siff@xxxxxxx.xxx>
Cc: "AMSAT-BB" <amsat-bb@xxxxx.xxx>
Sent: Friday, December 06, 2013 10:38 AM
Subject: Re: [amsat-bb] Freq program
> To use the two Baofeng radios on SO-50:
>
> 1. Program one memory channel for 145.85 MHz with a 67 Hz tone.
>
> 2. Program another memory channel for 145.85 MHz with a 74.4 Hz tone.
> This channel will serve to turn on the 10-minute timer when required.
>
> 3. Next, program a set of memory channels sequentially: 436.805,
> 436.800, 436.795, 436.785, and 436.780 MHz
>
> 4. Use one of the radios as your uplink radio, transmitting on either
> of the 145.85 MHz memory channels as necessary.
>
> 5. Use the other radio as your downlink radio, listening on
> 436.805-780. Based on my experience with Baofengs I consider them to
> be slow in changing memories, so I would stick to the VFO-mode for the
> downlink receiver. Manually set the VFO to 436.805 and adjust down as
> necessary for Doppler.
>
> You may program the Baofengs to operate "split" mode but then you're
> limiting yourself to semi-duplex operation.
>
> 73
> Clayton
> W5PFG
>
> On Fri, Dec 6, 2013 at 7:56 AM, Rich/wa4bue <richard.siff@xxxxxxx.xxx>
> wrote:
>> I have two BOAFANG (SP?) that the club want to program for SO 50. and
>> possibly in advance for FOX 1. (I know that SO 50 has a tone.)
>>
>> The questions:
>> * What freq should be programed for S0 50 to comp for Doppler?
>> * Same for FOX 1
>>
>> Thanks everyone for their help.
>>
>> Rich
>> W4BUE
>>
>> _______________________________________________
>> Sent via AMSAT-BB@xxxxx.xxx. 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: 6
Date: Fri, 6 Dec 2013 14:01:34 -0500
From: Robert Bruninga <bruninga@xxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: EZnec experts? (cubesat Circ Antenna)
(corrected)
Message-ID: <bf8b67f1963d190c999d9c20d86f39c2@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=windows-1252
EZnec kibitzers welcome: (corrected version)
See this model image: http://aprs.org/psat/VHF-circ-tuned-ask.gif
We are placing two ? wave VHF whip antennas on a single feed at the corner
of a 1.5U cubesat.
We want them +/-45 degrees out of phase so that we get cross polarization
when paralleled to a single feed point for simplicity.
Modeling each one individually, we got the desired short one to -45 degrees
with a coordinate of 23.4? and the long one to +45 degrees with a
coordinate of 25.68?. Great?
But when we connect them both to the same feed point, we get a
combined29-j68 ohms and a significantly higher resonant frequency.
The R Real part
seems reasonable, but do not get the desired J0 term. To fix that, we
lengthened each exactly the same amount to get the resonance down to 145.8
MHz and J=0 term. Good antenna?.
The QUESTION IS: Are they still 90 degrees out of phase and will they work
as a cross polarized antenna? And how can we verify that?
The feed point is the center of a 0.1? wire between the cubesat wire frame
and the combined end point of the antennas which are also 0.1? above the
top of the cubesat.
Maybe I should have included both wires in the original model, but only
connected one at a time to a source and grounded the other one while
trying to find their individual +/-45 degree lengths. This way, their
passive action as a possible counterpoinse to the whole frame may be
accounted for.
Also, to get within the 500 data points for EZnec, we had to make all of
the wire model 1? segments be a single segment per wire. Is fidelity
maintained with only 1 segment per 1? wire?
Bob, WB4APR
------------------------------
Message: 7
Date: Fri, 6 Dec 2013 11:12:57 -0800 (PST)
From: Mike McCann <kb2fmg@xxxxx.xxx>
To: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] AMSAT-NA 2013 Symposium Proceedings?
Message-ID:
<1386357177.1236.YahooMailNeo@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
Is the 2013 Symposium Proceedings book going to be available for purchase ?
------------------------------
_______________________________________________
Sent via amsat-bb@xxxxx.xxx. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
http://amsat.org/mailman/listinfo/amsat-bb
End of AMSAT-BB Digest, Vol 8, Issue 444
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