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CX2SA > SATDIG 02.01.09 23:45l 837 Lines 25895 Bytes #999 (0) @ WW
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From: CX2SA@CX2SA.LAV.URY.SA
To : SATDIG@WW
Today's Topics:
1. Costs of getting cargo to ISS (Trevor)
2. Re: ISS: L band repeater 04:40utc pass Europe (Henk, PA3GUO)
3. Re: Costs of getting cargo to ISS (Jeff Yanko)
4. Re: Costs of getting cargo to ISS (Eric Fort)
5. Delfi-C3 / DO-64 status update January 2nd 2009 14:00 UTC
(Wouter Jan Ubbels)
6. ISS: L band repeater 1354 UTC pass over SE US (Alan P. Biddle)
7. Question adding RHCP to Cheap Yagi (Curt Nixon)
8. Re: Delfi-C3 / DO-64 status update January 2nd 2009 14:00 UTC
(Alan P. Biddle)
9. Re: Question adding RHCP to Cheap Yagi (Howard Long)
10. FT 736 Question (Dimitrios Pallis)
11. Re: G-5500 stuck problem (wa6fwf)
12. Re: Question adding RHCP to Cheap Yagi (Curt Nixon)
13. Re: Question adding RHCP to Cheap Yagi (Curt Nixon)
14. Re: FT 736 Question (Mark Spencer)
15. Re: Question adding RHCP to Cheap Yagi (Howard Long)
----------------------------------------------------------------------
Message: 1
Date: Fri, 2 Jan 2009 10:02:33 +0000 (GMT)
From: Trevor <m5aka@xxxxx.xx.xx>
Subject: [amsat-bb] Costs of getting cargo to ISS
To: AMSAT BB <amsat-bb@xxxxx.xxx>
Message-ID: <221681.59792.qm@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
Article at
http://www.theregister.co.uk/2008/12/24/nasa_iss_cargo_deals/
"Overall, each kilo of cargo delivered to the station by commercial resupply
will cost NASA $87,500. The Shuttle was said to carry stuff to orbit for
$44,000 per kg, but that didn't include development costs."
73 Trevor M5AKA
----
------------------------------
Message: 2
Date: Fri, 2 Jan 2009 11:34:25 +0100 (CET)
From: "Henk, PA3GUO" <hamoen@xxx.xx>
Subject: [amsat-bb] Re: ISS: L band repeater 04:40utc pass Europe
To: <dave@xxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Message-ID: <1120.212.61.85.20.1230892465.squirrel@xxxxxxx.xxx.xx>
Content-Type: text/plain; charset=iso-8859-1
To bad I gave up too early !
Seems the lower elevation passes later gave much better
results for some reason. Also I understand the kepler
sets got updated inbetween ?
Enough reason to try again tomorrow :-)
(but then I skip the 4am pass and focus on the later ones)
Till tomorrow morning,
Henk, PA3GUO
> That was three of trying this morning then Henk.
>
> David and I heard a couple of carriers and that
> was it. Don't know whether it was his carrier or
> mine that lifted the squelch or not.
>
> If I am still awake, I will try the next pass too.
>
> 73, Dave. G1OCN
> Portland. Dorset.
> IO80SM
> AMSAT UK 5766
------------------------------
Message: 3
Date: Fri, 2 Jan 2009 04:02:07 -0800
From: "Jeff Yanko" <wb3jfs@xxx.xxx>
Subject: [amsat-bb] Re: Costs of getting cargo to ISS
To: "Trevor" <m5aka@xxxxx.xx.xx>, "AMSAT BB" <amsat-bb@xxxxx.xxx>
Message-ID: <B2ADD1185959471F83ED95AF831F2647@xxxxxxxx>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
About the typical cost over run in U.S. :)
Jeff WB3JFS
----- Original Message -----
From: "Trevor" <m5aka@xxxxx.xx.xx>
To: "AMSAT BB" <amsat-bb@xxxxx.xxx>
Sent: Friday, January 02, 2009 2:02 AM
Subject: [amsat-bb] Costs of getting cargo to ISS
> Article at
> http://www.theregister.co.uk/2008/12/24/nasa_iss_cargo_deals/
>
> "Overall, each kilo of cargo delivered to the station by commercial
> resupply will cost NASA $87,500. The Shuttle was said to carry stuff to
> orbit for $44,000 per kg, but that didn't include development costs."
>
> 73 Trevor M5AKA
> ----
>
>
>
>
> _______________________________________________
> 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, 2 Jan 2009 04:57:56 -0800
From: "Eric Fort" <eric.fort@xxxxx.xxx>
Subject: [amsat-bb] Re: Costs of getting cargo to ISS
To: Trevor <m5aka@xxxxx.xx.xx>
Cc: AMSAT BB <amsat-bb@xxxxx.xxx>
Message-ID:
<2ad2af430901020457l1d9054dfof71c76aa819ce8a9@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
How much for the eva to have it installed?.....Could think of all
sorts of things to have sent at that price point if only one could
arrange for installation.
AF6EP
On Fri, Jan 2, 2009 at 2:02 AM, Trevor <m5aka@xxxxx.xx.xx> wrote:
> Article at
> http://www.theregister.co.uk/2008/12/24/nasa_iss_cargo_deals/
>
> "Overall, each kilo of cargo delivered to the station by commercial resupply
will cost NASA $87,500. The Shuttle was said to carry stuff to orbit for
$44,000 per kg, but that didn't include development costs."
>
> 73 Trevor M5AKA
> ----
>
>
>
>
> _______________________________________________
> 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: 5
Date: Fri, 2 Jan 2009 15:07:12 +0100
From: "Wouter Jan Ubbels" <wjubbels@xxxxx.xxx>
Subject: [amsat-bb] Delfi-C3 / DO-64 status update January 2nd 2009
14:00 UTC
To: "Amsat-Bb@xxxxx. Org" <amsat-bb@xxxxx.xxx>
Message-ID:
<af4c9b1b0901020607r14532969w603fdcef1f492ca3@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Hi all,
please find a status update of the Delfi-C3 / DO-64 satellite below.
1. On behalf of the Delfi-C3 / DO-64 team we would like to wish you
all a very happy 2009!
2. Delfi-C3 is currently operational in basic mode, transmitting housekeeping
telemetry at 1200Bd BPSK AX.25 on 145.870MHz. Basic mode is the "safest"
mode the spacecraft can be in, since it transmits continuously and
furthermore commanding is easiest when in this mode. The craft has
been in this mode for a while so that we can analyze a possible issue
with the linear transponder :(. As some of you may have noticed, the
transponder has been hard to access during its last weeks of
operation, contrary to the first weeks where it performed fine. We
have performed a number of tests in order to assess this issue, up
till now it seems like the issue is in the receiver frontend. Over the
coming weeks, we will continue to investigate this issue, so whenever
the satellite is over Europe and in range of our groundstation, it may
be switched to transponder mode. In this mode, a CW beacon is
transmitted at 145.870MHz. When you hear the satellite in this mode,
please DO NOT transmit to the satellite until further notice. This
will allow us to further characterize the issue and work out a
solution, if possible.
3. All other subsystems continue to perform fine on orbit.
4. In the meantime, telemetry can still be received using the RASCAL
software package, and forwarded to our server. We have again received
a lot of frames already from various hams worldwide, thank you all for
your efforts! Note that the primary server at 83.138.144.157 is not
operational, but the backup server is and will continue to be
operational.
5. During our free time at Christmas, we have implemented a number of
improvements / bug fixes in RASCAL, the most noticeable one being an
improved tuning range of the demodulator, allowing the input audio
carrier to be between 900 and 2300Hz, instead of 1400-1800Hz. This
makes tuning much easier.
These fixes have been implemented in RASCAL version 1.1.0, which is
available for download as of now from the website at:
http://www.delfic3.nl/rascal
on this page, in the "upgrading RASCAL" paragraph, you can also find
instructions on how to upgrade to this newer version without losing your
original settings and telemetry repository.
73 on behalf of the Delfi-C3 / DO-64 team,
Wouter Jan Ubbels PE4WJ
------------------------------
Message: 6
Date: Fri, 2 Jan 2009 08:54:31 -0600
From: "Alan P. Biddle" <APBIDDLE@xxxxxx.xxx>
Subject: [amsat-bb] ISS: L band repeater 1354 UTC pass over SE US
To: "AMSAT-BB" <amsat-bb@xxxxx.xxx>
Message-ID: <F2248B47506E4508A15F21AFF6A80601@xxxxxx>
Content-Type: text/plain; charset="us-ascii"
Morning,
>From a technical standpoint, had the best pass ever here. AOS at 295
degrees, 12 degrees elevation, slant range 1000 miles (1600 km). LOS at 150
degrees, 6 degrees elevation, 1570 miles (2500 km). Both are at or near my
local horizon. This pass was qualitatively different in that I did not
notice a single dropout, and it required modest power even at extreme range.
100-200 watts ERP compared with the 2500 needed on some passes.
One thing I did was recheck the deviation of my transmitter yesterday. I
had noticed in previous passes that when I spoke, I would _sometimes_ lose
the downlink, and it came back when I stopped. That is indicative of over
deviation, and/or a really marginal signal at the ISS. I had set the
deviation years ago at 3.2 KHz, and have gotten nothing but good reports on
terrestrial and satellite communications. Rechecking, I found that it had
drifted up to 3.8 KHz. That is well within normal parameters, but I dialed
it back to 3.2 KHz again. I did not have time to do any A/B testing, but at
least what I did was not harmful.
>From a communication standpoint, not so much. I did hear someone else bring
up the repeater, and caught "N5???" twice, but each time the repeater
dropped after the first two syllables. N5UXT???
I have a couple of things to test should they do this again. My lessons
learned are that:
(a) You MUST be on frequency, much closer than when operating through normal
satellite repeaters. The usual manual tuning just does not work in
practice. It is good to check the actual mode L output, however you get
there, since 2-3 KHz error is critical. My TX transverter has a few KHz
error in the LO, but I just put the measured numbers into SATPC32, and it
does the correct tuning for me.
(b) Your deviation needs to be optimum, with less being better than more.
(c) You need significantly more power than the usual mode UV or VU, but not
unreasonable ERP.
Thanks to NASA and the ARISS team. Lets do it again sometime.
Alan
WA4SCA
------------------------------
Message: 7
Date: Fri, 02 Jan 2009 10:19:23 -0500
From: Curt Nixon <cptcurt@xxxxx.xxx>
Subject: [amsat-bb] Question adding RHCP to Cheap Yagi
To: AMSAT-BB <amsat-bb@xxxxx.xxx>
Message-ID: <495E307B.2090401@xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Good Morning All:
I've been using a 10el version of Kent Britain's Cheap yagi for my 70cm
downlink antenna. It suffers from deep fades so I am going to add the
second yagi with physical offset to get to RHCP in the x config.
Question is:
normally I would reverse the coax connections to a dipole driver but
this is a hairpin (half of a folded dipole. )
Do I reverse the connections as normal? Kents instructions just say
offset the elements and feed in phase.
Thanks
Curt
KU8L
------------------------------
Message: 8
Date: Fri, 2 Jan 2009 10:01:32 -0600
From: "Alan P. Biddle" <APBIDDLE@xxxxxx.xxx>
Subject: [amsat-bb] Re: Delfi-C3 / DO-64 status update January 2nd
2009 14:00 UTC
To: "'Wouter Jan Ubbels'" <wjubbels@xxxxx.xxx>, "'Amsat-Bb@xxxxx.
Org'" <amsat-bb@xxxxx.xxx>
Message-ID: <80295BC69CCC4B0AA1F6A1B14E4A09F8@xxxxxx>
Content-Type: text/plain; charset="us-ascii"
Wouter,
Thanks for the New Year present. It is working perfectly, and does handle a
much wider range of inputs.
73s,
Alan
WA4SCA
------------------------------
Message: 9
Date: Fri, 2 Jan 2009 16:13:14 -0000
From: "Howard Long" <howard@xxxxxxxxxx.xxx>
Subject: [amsat-bb] Re: Question adding RHCP to Cheap Yagi
To: "'Curt Nixon'" <cptcurt@xxxxx.xxx>, "'AMSAT-BB'"
<amsat-bb@xxxxx.xxx>
Message-ID: <49B198652C974B91A3686FEA040C981E@xxxxxxx>
Content-Type: text/plain; charset="us-ascii"
Hi Curt.
Either way will work.
http://www.g6lvb.com/AO-40%2070cm%20uplink%20antenna.htm
I have had superb success with mine, in fact during the days of AO-40 I
worked the world with it as an uplink antenna with 50W.
http://www.g6lvb.com/3A2%20ops.htm
http://www.g6lvb.com/dayton_demo_2002.htm
73, Howard G6LVB
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of Curt Nixon
Sent: 02 January 2009 15:19
To: AMSAT-BB
Subject: [amsat-bb] Question adding RHCP to Cheap Yagi
Good Morning All:
I've been using a 10el version of Kent Britain's Cheap yagi for my 70cm
downlink antenna. It suffers from deep fades so I am going to add the
second yagi with physical offset to get to RHCP in the x config.
Question is:
normally I would reverse the coax connections to a dipole driver but this is
a hairpin (half of a folded dipole. )
Do I reverse the connections as normal? Kents instructions just say offset
the elements and feed in phase.
Thanks
Curt
KU8L
_______________________________________________
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: 10
Date: Fri, 2 Jan 2009 16:24:04 +0000
From: Dimitrios Pallis <mc90606@xxxxxxx.xxx>
Subject: [amsat-bb] FT 736 Question
To: <amsat-bb@xxxxx.xxx>
Message-ID: <COL111-W80D13D8090D5FE19CD4856F8E20@xxx.xxx>
Content-Type: text/plain; charset="Windows-1252"
I wish happy new year to the group.I would like to ask if i can use lower step
than 100 hz in sat mode on FT 736.I cannot turn on the clar on sat mode!thank
youDimitrios Pallis (JIMMY)73 de SW1JGWwww.sw1jgw.com
_________________________________________________________________
It?s the same Hotmail?. If by ?same? you mean up to 70% faster.
http://windowslive.com/online/hotmail?ocid=TXT_TAGLM_WL_hotmail_acq_broad1_122
008
------------------------------
Message: 11
Date: Fri, 2 Jan 2009 08:44:38 -0800
From: "wa6fwf" <wa6fwf@xxxxxxxxx.xxx>
Subject: [amsat-bb] Re: G-5500 stuck problem
To: <amsat-bb@xxxxx.xxx>
Message-ID: <0F467A7D2DFB4E9DA751C6564D6A8A75@xxx>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Hi Greg,
Yes these will burn up on their own, page 2 of the manual states that the
maximum continuous run time is 5 mins, but when
normally tracking a sat were talking little movements of a couple of seconds.
I was measuring current with a standard VOM set for AC current and I had
no way of measuring the PF so what you say could be
correct and I wasn't seeing the real current, and I'm not a motor guru but
from what I understand the capacitor and the winding
90deg out of phase are only needed to get the motor spinning and turning in
the direction that you want, that once the motor is up
to speed you could disconnect the capacitor and 90 deg winding and the motor
would keep running, also the capacitor value needed to
start vs. the most efficient to run at "if you were going to leave the
circuit engaged" are two completely different values, and
the current rise at run speed are caused by the mis-match.
So when you lock the rotor you are in start mode at x current and when your
up to speed your seeing the mismatch/inefficiency and
the increased current flow.
Maybe there is someone on here that could do a better job of explaining why
this motor works like this.
I don't remember the original sites I went to but a couple links that you
might want to check out...
http://www.lmphotonics.com/single_phase_m.htm
http://www.allaboutcircuits.com/vol_2/chpt_13/9.html
73 Kevin
WA6FWF
----- Original Message -----
From: "Greg D." <ko6th_greg@xxxxxxx.xxx>
To: <wa6fwf@xxxxxxxxx.xxx>; <amsat-bb@xxxxx.xxx>
Sent: Thursday, January 01, 2009 11:08 PM
Subject: RE: [amsat-bb] Re: G-5500 stuck problem
Hi Kevin,
So, my take-away here is that it's not the stall itself that is the problem;
the motor is practically designed to self-destruct.
Simply running the rotor back and forth enough times will do the same thing.
In fact, probably worse, given the higher draw.
One thing just occurred to me... AC current measurements assume a specific
phase relationship between voltage and current - power
factor, I think they call it. This is a highly inductive load, and the phase-
shift capacitor throws another unknown into the
puzzle. I wonder if the two measurements you took are real? It could be that
you think that the running current is higher, when it
may just be a measurement error. How were they measured?
Greg KO6TH
------------------------------
Message: 12
Date: Fri, 02 Jan 2009 11:50:08 -0500
From: Curt Nixon <cptcurt@xxxxx.xxx>
Subject: [amsat-bb] Re: Question adding RHCP to Cheap Yagi
To: Howard Long <howard@xxxxxxxxxx.xxx>
Cc: 'AMSAT-BB' <amsat-bb@xxxxx.xxx>
Message-ID: <495E45C0.8000206@xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Hi Howard:
Thanks..I've looked at alot of your info on-line--especially the
sub-500GBP AO-40 setup.
I guess I still don't get it..if I just feed them in-phase with both
connections same polarity, what controls RH v. LH?
Or is it RH if the front half loop is to the right and LH if the front
half-loop is to the left?
Thanks
Curt
Too cold to not get it right on the first try!!
Howard Long wrote:
> Hi Curt.
>
> Either way will work.
>
> http://www.g6lvb.com/AO-40%2070cm%20uplink%20antenna.htm
>
> I have had superb success with mine, in fact during the days of AO-40 I
> worked the world with it as an uplink antenna with 50W.
>
> http://www.g6lvb.com/3A2%20ops.htm
> http://www.g6lvb.com/dayton_demo_2002.htm
>
> 73, Howard G6LVB
>
> -----Original Message-----
> From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
> Behalf Of Curt Nixon
> Sent: 02 January 2009 15:19
> To: AMSAT-BB
> Subject: [amsat-bb] Question adding RHCP to Cheap Yagi
>
> Good Morning All:
>
> I've been using a 10el version of Kent Britain's Cheap yagi for my 70cm
> downlink antenna. It suffers from deep fades so I am going to add the
> second yagi with physical offset to get to RHCP in the x config.
>
> Question is:
>
> normally I would reverse the coax connections to a dipole driver but this is
> a hairpin (half of a folded dipole. )
>
> Do I reverse the connections as normal? Kents instructions just say offset
> the elements and feed in phase.
>
> Thanks
>
> Curt
> KU8L
>
>
> _______________________________________________
> 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: 13
Date: Fri, 02 Jan 2009 11:55:09 -0500
From: Curt Nixon <cptcurt@xxxxx.xxx>
Subject: [amsat-bb] Re: Question adding RHCP to Cheap Yagi
To: Howard Long <howard@xxxxxxxxxx.xxx>
Cc: 'AMSAT-BB' <amsat-bb@xxxxx.xxx>
Message-ID: <495E46ED.20300@xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
OK..I think I have it..RH v. LH depends on which half loop is to the
left or right--I just had the view from the wrong end. I'll do it like
your pic.
Thanks Again
Curt
Howard Long wrote:
> Hi Curt.
>
> Either way will work.
>
> http://www.g6lvb.com/AO-40%2070cm%20uplink%20antenna.htm
>
> I have had superb success with mine, in fact during the days of AO-40 I
> worked the world with it as an uplink antenna with 50W.
>
> http://www.g6lvb.com/3A2%20ops.htm
> http://www.g6lvb.com/dayton_demo_2002.htm
>
> 73, Howard G6LVB
>
> -----Original Message-----
> From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
> Behalf Of Curt Nixon
> Sent: 02 January 2009 15:19
> To: AMSAT-BB
> Subject: [amsat-bb] Question adding RHCP to Cheap Yagi
>
> Good Morning All:
>
> I've been using a 10el version of Kent Britain's Cheap yagi for my 70cm
> downlink antenna. It suffers from deep fades so I am going to add the
> second yagi with physical offset to get to RHCP in the x config.
>
> Question is:
>
> normally I would reverse the coax connections to a dipole driver but this is
> a hairpin (half of a folded dipole. )
>
> Do I reverse the connections as normal? Kents instructions just say offset
> the elements and feed in phase.
>
> Thanks
>
> Curt
> KU8L
>
>
> _______________________________________________
> 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: 14
Date: Fri, 2 Jan 2009 09:04:56 -0800 (PST)
From: Mark Spencer <mspencer12345@xxxxx.xx>
Subject: [amsat-bb] Re: FT 736 Question
To: Dimitrios Pallis <mc90606@xxxxxxx.xxx>, amsat-bb@xxxxx.xxx
Message-ID: <966261.30331.qm@xxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=windows-1252
This may not be the answer you are looking for but SAT32PC tunes my 736 in 20
hz steps.
________________________________
From: Dimitrios Pallis <mc90606@xxxxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Sent: Friday, January 2, 2009 8:24:04 AM
Subject: [amsat-bb] FT 736 Question
I wish happy new year to the group.I would like to ask if i can use lower step
than 100 hz in sat mode on FT 736.I cannot turn on the clar on sat mode!thank
youDimitrios Pallis (JIMMY)73 de SW1JGWwww.sw1jgw.com
_________________________________________________________________
It?s the same Hotmail?. If by ?same? you mean up to 70% faster.
http://windowslive.com/online/hotmail?ocid=TXT_TAGLM_WL_hotmail_acq_broad1_122
008
_______________________________________________
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
__________________________________________________________________
Yahoo! Canada Toolbar: Search from anywhere on the web, and bookmark your
favourite sites. Download it now at
http://ca.toolbar.yahoo.com.
------------------------------
Message: 15
Date: Fri, 2 Jan 2009 17:12:04 -0000
From: "Howard Long" <howard@xxxxxxxxxx.xxx>
Subject: [amsat-bb] Re: Question adding RHCP to Cheap Yagi
To: "'Curt Nixon'" <cptcurt@xxxxx.xxx>
Cc: 'AMSAT-BB' <amsat-bb@xxxxx.xxx>
Message-ID: <EE3CA2D20AEA438EBCB5D771526CB0F6@xxxxxxx>
Content-Type: text/plain; charset="us-ascii"
Hi Curt
There are several ways to skin the same cat.
Although they are fed in phase, they are orthogonally mounted and with their
spatial separation a 90 degree phase delay is created, thus creating CP.
If the elements are still orthogonal but are at the same location along the
boom, then the delay would need to be inserted electrically, with an
electrical 1/4 wave section of 50 ohm coax. Some CP antennas use a
combination of both spatial and electrical phase difference.
To switch RHCP to LHCP can be achived by any of the following three means:
O Insert an additional 180 degree electrical delay between one arm of the
power splitter and the antenna, with an electrical lambda/2 50 ohm coax
section;
O Physically move one set of elements 180 degrees forward or behind;
O Turn one of the driven elements 180 degrees so the loop is on the other
side of the antenna, but maintain the same electrical connections.
This may (of may not!) help... http://www.g6lvb.com/remotepolarization.htm
It takes a bit of lateral thinking, but once you've figured it out it's a
bit like learning to ride a bike in that you don't forget, although in later
years I find one may become a little wobbly.
73, Howard G6LVB
-----Original Message-----
From: Curt Nixon [mailto:cptcurt@xxxxx.xxxx
Sent: 02 January 2009 16:50
To: Howard Long
Cc: 'AMSAT-BB'
Subject: Re: [amsat-bb] Question adding RHCP to Cheap Yagi
Hi Howard:
Thanks..I've looked at alot of your info on-line--especially the sub-500GBP
AO-40 setup.
I guess I still don't get it..if I just feed them in-phase with both
connections same polarity, what controls RH v. LH?
Or is it RH if the front half loop is to the right and LH if the front
half-loop is to the left?
Thanks
Curt
Too cold to not get it right on the first try!!
Howard Long wrote:
> Hi Curt.
>
> Either way will work.
>
> http://www.g6lvb.com/AO-40%2070cm%20uplink%20antenna.htm
>
> I have had superb success with mine, in fact during the days of AO-40
> I worked the world with it as an uplink antenna with 50W.
>
> http://www.g6lvb.com/3A2%20ops.htm
> http://www.g6lvb.com/dayton_demo_2002.htm
>
> 73, Howard G6LVB
>
> -----Original Message-----
> From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx
> On Behalf Of Curt Nixon
> Sent: 02 January 2009 15:19
> To: AMSAT-BB
> Subject: [amsat-bb] Question adding RHCP to Cheap Yagi
>
> Good Morning All:
>
> I've been using a 10el version of Kent Britain's Cheap yagi for my
> 70cm downlink antenna. It suffers from deep fades so I am going to
> add the second yagi with physical offset to get to RHCP in the x config.
>
> Question is:
>
> normally I would reverse the coax connections to a dipole driver but
> this is a hairpin (half of a folded dipole. )
>
> Do I reverse the connections as normal? Kents instructions just say
> offset the elements and feed in phase.
>
> Thanks
>
> Curt
> KU8L
>
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
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>
>
>
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End of AMSAT-BB Digest, Vol 4, Issue 5
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