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CX2SA > SATDIG 13.05.13 21:41l 854 Lines 29044 Bytes #999 (0) @ WW
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Today's Topics:
1. Re: J-Pole Antenna (Art McBride)
2. Re: ISS HamTV Frequencies (Art McBride)
3. Re: ISS HamTV Frequencies (Daniel Schultz)
4. Satellite Demonstration Passes for Dayton 2013 (Keith Pugh)
5. Re: J-Pole Antenna (gordonjcp@xxxx.xxxx
6. Re: Satellite Demonstration Passes for Dayton 2013 (Rodney Waln)
7. Re: ISS HamTV Frequencies (I0ELE)
8. Re: ISS HamTV Frequencies (M5AKA)
9. Re: Satellite Demonstration Passes for Dayton 2013
(Stephen E. Belter)
10. Re: ISS HamTV Frequencies (range gain) (Robert Bruninga)
11. Re: ISS HamTV Frequencies (Greg Dolkas)
12. Re: J-Pole Antenna (Gregg Wonderly)
13. J-Pole Antenna (Werner, HB9BNK)
14. Re: J-Pole Antenna (Robert Bruninga)
----------------------------------------------------------------------
Message: 1
Date: Sun, 12 May 2013 21:22:13 -0700
From: "Art McBride" <kc6uqh@xxx.xxx>
To: "'Jeff Moore'" <tnetcenter@xxxxx.xxx>, <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: J-Pole Antenna
Message-ID: <FC8EDADDBE174296AA2ED1D8C121CD6B@xxxxxx>
Content-Type: text/plain; charset="us-ascii"
Jeff,
You are correct, a J Pole is an end fed dipole on its side. Max gain at the
horizon and extinction at 90 degree elevation. The J section is for matching
and does not radiate. Gain = 2.1 dBi at the horizon.
Art,
KC6UQH
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of Jeff Moore
Sent: Sunday, May 12, 2013 10:48 AM
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: J-Pole Antenna
I wouldn't recommend a J-pole for satellite work unless you expect to
only work sats on the horizon. The J-Pole antenna has a low take-off
angle and almost NO radiation overhead, an plain 1/4 wave ground plane
antenna would work better for the sats.
J-poles are great terrestrial communications antennas, not so much for
working overhead satellite passes. An Eggbeater or quadrifiliar antenna
would be a better choice.
7 3
Jeff Moore -- KE7ACY
On 5/12/2013 8:00 AM, Werner, HB9BNK wrote
> Thank you all for your valuable hints and advices !
>
> I will now build such an antenna and then supply here the results.
>
> 73 Werner, HB9BNK
_______________________________________________
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: 2
Date: Sun, 12 May 2013 21:43:36 -0700
From: "Art McBride" <kc6uqh@xxx.xxx>
To: "'Roger'" <Rogerkola@xxx.xxx>, <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: ISS HamTV Frequencies
Message-ID: <5C7B0384F6074FF5943E58136B182E73@xxxxxx>
Content-Type: text/plain; charset="us-ascii"
Roger,
A SWAG, (Wild Guess) 1 degree per second at a Zenith of 90 degrees. Anything
less than 90 degrees will be slower with several minutes spent near the
horizon. You can use an orbital program to get exact numbers. With a wide
beam width antenna, the lag overhead may never require the antenna to move
with the object, as there will be time for the antenna system to catch up
after passing overhead.
Art,
KC6UQH
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of Roger
Sent: Sunday, May 12, 2013 2:34 PM
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: ISS HamTV Frequencies
Anybody off the top of their heads know how many degrees a second swing
are (is?) required for direct aim at the ISS? I know there are beam
width tolerances, altitude variations and degree above horizon
variations but I'm looking at Bob B's fixed antenna aiming of 15-20
degrees above horizon to evaluate swinging a dish without torque eating
up the drive train...
Roger
WA1KAT
On 5/12/2013 5:01 PM, M5AKA wrote:
> The AMSAT-UK page at http://amsat-uk.org/2013/05/12/hamtv-from-the-iss/
provides the links, they are:
>
> Facebook https://www.facebook.com/Hamtvproject
>
> More information at http://www.amsat.it/Amsat-Italia_HamTV_brochure.pdf
> and http://www.amsat.it/Amsat-Italia_HamTV.pdf
>
> The HamTV.pdf gives the link budget, looks like there's 7dB of
coax/connector losses to overcome between the ISS transmitter and the
antenna. That document indicates a 90cm dish should be sufficient.
>
> I believe that it's going up on ATV 4 which is currently slated for June
5.
>
> 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: 3
Date: Mon, 13 May 2013 00:46:11 -0400
From: "Daniel Schultz" <n8fgv@xxx.xxx>
To: <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: ISS HamTV Frequencies
Message-ID: <914RemetL3600S07.1368420371@xxxxx.xxx.xxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
------------- Original Message -------------
>> Right. But what is that in terms of what normally gets described?
>> For example, I have a Digital TV card for my computer (Pinnacle PCTV
>> HD). It says it does "ATSC digital TV (HDTV up to 1080i, and SDTV)"
>> and "Clear QAM (unencrypted digital cable)".
>>
>> Am I even close?
>>
>> Greg KO6TH
No, you are not even close.
ATSC (Advanced Television Systems Committee) is the proprietary over-the-air
television broadcast standard used in North America. It is fundamentally
incompatible with the open source "DVB-T" broadcast standard that the rest of
the world uses for domestic TV. (The fact that it was designed by a committee
should tell you all that you need to know about that particular political
sausage.) The "Cheap and Easy SDR" article in January QST requires using a
DVB-T USB dongle which you need to purchase from a supplier that knows that
you want to use it for SDR. The ATSC USB devices sold at Best Buy or other
retail stores in the USA cannot be used for this purpose.
QAM is used only by cable TV and is never broadcast over the air. (Most cable
systems use encrypted QAM so you will still need to rent the decoder box from
the cable company).
DVB-S is the digital satellite TV standard that the "free to air" (FTA)
satellite receivers use. We are not talking about Direct TV or Dish TV, but
the C band services. If you watch NASA TV or the foreign language TV
broadcasts directly from your C band dish, you are using DVB-S. This standard
has been used for terrestrial ham ATV in some US cities. It would be best to
contact the ATV experts directly to see what receivers they are using. I don't
know which FTA receivers will work with the ISS ham TV.
Bottom line is: ATSC and QAM decoders are not useful for receiving the ISS ham
TV signals, and DVB-S is not widely used in the USA except by dedicated "free
to air" hobbyists. If you bought your receiver card or dongle from any US
consumer retail store, it almost certainly is not what you need for ISS ham
TV.
Dan Schultz N8FGV
------------------------------
Message: 4
Date: Mon, 13 May 2013 00:03:08 -0500
From: "Keith Pugh" <w5iu@xxxxxx.xxx>
To: <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Satellite Demonstration Passes for Dayton 2013
Message-ID: <000c01ce4f97$2959cc90$7c0d65b0$@xxxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"
Here are the Satellite Demonstration Passes for Dayton 2013, 17-19 May.
Times are in UTC. We will work as many of these passes as possible -
weather and equipment permitting. The days are Friday, 17 May, through
Sunday, 19 May. The original plain text file is attached with the original
formatting. See you on the "Birds" at Dayton 2013 this weekend.
73 - Keith, W5IU
AMSAT DAYTON HAMVENTION DEMOS - 2013
TZ = UTC
N 39.820328 W 84.255224 ELEV. 296 M
MIN ELEV. = 10 DEG
GRID = EM79ut
WinAos QTH: -84.3/39.8 T#: 12920 Sat.: 6 [Standard]
----------------------------------------------------------
Day Object AOS (U) LOS Period maxEl AZ
----------------------------------------------------------
17.05.2013 AO-07 13:19 13:26 07 15 341 - 279
17.05.2013 ISS 13:50 13:53 03 12 347 - 043
17.05.2013 VO-52 14:07 14:10 03 13 319 - 267
17.05.2013 HO-68 14:19 14:31 12 32 036 - 159
17.05.2013 FO-29 14:39 14:51 12 33 032 - 160
17.05.2013 SO-50 15:00 15:08 08 70 202 - 036
17.05.2013 ISS 15:26 15:32 06 28 327 - 094
17.05.2013 HO-68 16:07 16:20 13 48 003 - 220
17.05.2013 FO-29 16:24 16:36 12 43 001 - 224
17.05.2013 SO-50 16:42 16:49 07 17 276 - 006
17.05.2013 ISS 17:03 17:09 06 34 290 - 154
17.05.2013 AO-07 20:30 20:44 14 35 121 - 357
18.05.2013 ISS 13:01 13:02 01 11 347 - 020
18.05.2013 FO-29 13:48 13:51 03 11 068 - 101
18.05.2013 SO-50 13:48 13:55 07 20 158 - 063
18.05.2013 HO-68 14:03 14:13 10 24 043 - 146
18.05.2013 ISS 14:37 14:42 05 20 332 - 079
18.05.2013 SO-50 15:28 15:36 08 45 234 - 022
18.05.2013 FO-29 15:29 15:42 13 77 015 - 191
18.05.2013 HO-68 15:50 16:03 13 62 008 - 212
18.05.2013 ISS 16:13 16:20 07 60 302 - 137
18.05.2013 FO-29 17:15 17:24 09 19 344 - 256
18.05.2013 HO-68 17:41 17:45 04 12 326 - 287
18.05.2013 AO-07 19:34 19:42 08 16 081 - 012
19.05.2013 VO-52 13:02 13:09 07 60 004 - 205
19.05.2013 AO-07 13:11 13:20 09 16 345 - 273
19.05.2013 HO-68 13:47 13:55 08 18 052 - 134
19.05.2013 ISS 13:48 13:52 04 16 342 - 066
19.05.2013 SO-50 14:15 14:23 08 53 193 - 041
19.05.2013 FO-29 14:35 14:46 11 31 034 - 157
19.05.2013 ISS 15:24 15:30 06 66 313 - 120
19.05.2013 HO-68 15:33 15:46 13 79 013 - 203
19.05.2013 SO-50 15:57 16:03 06 21 267 - 008
19.05.2013 FO-29 16:19 16:31 12 44 001 - 222
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------------------------------
Message: 5
Date: Mon, 13 May 2013 08:00:16 +0100
From: gordonjcp@xxxx.xxx
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: J-Pole Antenna
Message-ID: <20130513070016.GB25782@xxxx.xxx>
Content-Type: text/plain; charset=iso-8859-1
On Sun, May 12, 2013 at 09:22:13PM -0700, Art McBride wrote:
> Jeff,
> You are correct, a J Pole is an end fed dipole on its side. Max gain at the
> horizon and extinction at 90 degree elevation. The J section is for matching
> and does not radiate. Gain = 2.1 dBi at the horizon.
Absolutely perfect for the ISS though, especially at these latitudes up
around 56?N.
--
Gordonjcp MM0YEQ
------------------------------
Message: 6
Date: Mon, 13 May 2013 00:04:29 -0700 (PDT)
From: Rodney Waln <kc0zhf@xxxxx.xxx>
To: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Satellite Demonstration Passes for Dayton 2013
Message-ID:
<1368428669.2289.YahooMailNeo@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
hi forgive me if i am wrong but is HO-68 operational again for SSB,FM ...ect
during your demo, i thought that they were still haveing problems with it,
or is it back to normal?
i am going so i will stop by,
Rodney
kc0zhf
------------------------------
Message: 7
Date: Mon, 13 May 2013 09:16:54 +0200
From: I0ELE <emanuele.dandria@xxxxx.xx>
To: Farrell Winder <fwinder@xxxx.xxx>, AMSAT BB <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: ISS HamTV Frequencies
Message-ID: <51909366.8@xxxxx.xx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Farrell,
HAMTV equipment will be delivered to the ISS in August (TBC) by the
Japanese HTV-4 cargo.
You can check on the web the exact date.
Then we will start the commissioning soon and we will start the
transmissions soon after.
Information on the transmission plan will be delivered on this BB.
Emanuele, I0ELE
Rome, Italy
Il 13/05/2013 2.03, Farrell Winder ha scritto:
> Dear Emanuele,
> Thanks for the detailed information on the HAMTV stream. Is the
> DTV-S equipment aboard the ISS now complete and ready to start
> transmissions?
> Is there a target date as to when 2.4 GHz transmissions might begin?
> Thanks for any information.
>
> Farrell Winder, W8ZCF
> Cincinnati, Ohio, USA
> --------------------------------------------------
> From: "I0ELE" <emanuele.dandria@xxxxx.xx>
> Sent: Sunday, May 12, 2013 6:32 PM
> To: "Greg D" <ko6th.greg@xxxxx.xxx>
> Cc: <amsat-bb@xxxxx.xxx>
> Subject: [amsat-bb] Re: ISS HamTV Frequencies
>
>> HAMTV stream will be transmitted at 1.3 MSym/s or at 2.0 MSym/s.
>> Technical specs of the set-top box indicate the range of the decoded
>> stream. Generally this range is from 2 to 45 MSym/s, therefore if you
>> need to buy it, you should select one that can guarantee a range from
>> 1 to 45 MSym/s.
>>
>> Emanuele I0ELE
>>
>>
>> Il 13/05/2013 0.15, Greg D ha scritto:
>>> For the digital TV challenged, what means "Any DVB-S Decoder which
>>> can decode a 1.3 MSym/s TV signal"? How would I know if I have such
>>> a thing, or what I would need to get if I don't.
>>>
>>> Greg KO6TH
>>>
>>>
>>> I0ELE wrote:
>>>> Certainly!
>>>> You can find the nominal link budget on
>>>> http://www.amsat.it/HAMTV_Link-budget-IARU.pdf and all the relevant
>>>> information http://www.amsat.it/Amsat-Italia_HamTV_brochure.pdf.
>>>> However
>>>>
>>>> * Recommended Antenna gain > 25 dB
>>>> * RHCP
>>>> * Low noise down converter i.e. Kuhne LNC 25 or LNC 25 TM NF 0.7 dB
>>>> * Any DVB-S Decoder which can decode a 1.3 MSym/s TV signal
>>>>
>>>> 73, Emanuele, I0ELE
>>>> President AMSAT Italia
>>>> _______________________________________________
>>>> 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
>>
>> _______________________________________________
>> 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: 8
Date: Mon, 13 May 2013 08:56:41 +0100 (BST)
From: M5AKA <m5aka@xxxxx.xx.xx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: ISS HamTV Frequencies
Message-ID:
<1368431801.35108.YahooMailClassic@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
Typo on my earlier email I meant HTV-4 not ATV-4 and so launch date is
different around August ?
ARISS Antennas Installed on Columbus http://www.ariss-eu.org/columbus.htm
73 Trevor M5AKA
------------------------------
Message: 9
Date: Mon, 13 May 2013 06:02:20 -0400
From: "Stephen E. Belter" <seb@xxxxxx.xxx>
To: Rodney Waln <kc0zhf@xxxxx.xxx>
Cc: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] Re: Satellite Demonstration Passes for Dayton 2013
Message-ID: <76A68372-CA39-4C65-A7FF-681A1C981FBB@xxxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"
Only the beacon works on HO-68. The satellite is very useful for testing
your tracking and Doppler correction setup, and to demonstrate *receiving*
an amateur satellite.
73, Steve N9IP
--
Steve Belter, seb@xxxxxx.xxx
On May 13, 2013, at 3:06 AM, "Rodney Waln" <kc0zhf@xxxxx.xxx> wrote:
> hi forgive me if i am wrong but is HO-68 operational again for SSB,FM ...ect
> during your demo, i thought that they were still haveing problems with it,
or is it back to normal?
> i am going so i will stop by,
> Rodney
> kc0zhf
> _______________________________________________
> 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: Mon, 13 May 2013 08:52:27 -0400
From: Robert Bruninga <bruninga@xxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: ISS HamTV Frequencies (range gain)
Message-ID: <74de2fd3b2c0a9f03fa7732c9ced3355@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
One needs to also realize duration. The time say above 70 degree
elevation (where rates are highest) are less than 2% of the total pass
times. Not worth worrying about. Similarly, a LEO satellite spends 70%
of its time below about 22 degrees. (but it is far away and needs max
gain). So simply design for the best operation for most of the time when
the link will work.
Remember, the satellite is 3000 km away on the horizon and very weak, but
as it gets into say 1500 km it is twice as close and 4 times (6 dB)
stonger which is a heck of a lot of gain. When it goes directly overhead
it is another 6 dB closer which is more than *ten* times the signal on the
horizon, so don't worry about the 2% of the time it is going to be above
70 degrees. The signa is 10 times stronger and easy to deal with.
Bob, WB4APR
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of Art McBride
Sent: Monday, May 13, 2013 12:44 AM
To: 'Roger'; amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: ISS HamTV Frequencies
Roger,
A SWAG, (Wild Guess) 1 degree per second at a Zenith of 90 degrees.
Anything less than 90 degrees will be slower with several minutes spent
near the horizon. You can use an orbital program to get exact numbers.
With a wide beam width antenna, the lag overhead may never require the
antenna to move with the object, as there will be time for the antenna
system to catch up after passing overhead.
Art,
KC6UQH
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of Roger
Sent: Sunday, May 12, 2013 2:34 PM
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: ISS HamTV Frequencies
Anybody off the top of their heads know how many degrees a second swing
are (is?) required for direct aim at the ISS? I know there are beam width
tolerances, altitude variations and degree above horizon variations but
I'm looking at Bob B's fixed antenna aiming of 15-20 degrees above horizon
to evaluate swinging a dish without torque eating up the drive train...
Roger
WA1KAT
On 5/12/2013 5:01 PM, M5AKA wrote:
> The AMSAT-UK page at
> http://amsat-uk.org/2013/05/12/hamtv-from-the-iss/
provides the links, they are:
>
> Facebook https://www.facebook.com/Hamtvproject
>
> More information at
> http://www.amsat.it/Amsat-Italia_HamTV_brochure.pdf
> and http://www.amsat.it/Amsat-Italia_HamTV.pdf
>
> The HamTV.pdf gives the link budget, looks like there's 7dB of
coax/connector losses to overcome between the ISS transmitter and the
antenna. That document indicates a 90cm dish should be sufficient.
>
> I believe that it's going up on ATV 4 which is currently slated for
> June
5.
>
> 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
_______________________________________________
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: 11
Date: Mon, 13 May 2013 07:18:38 -0700
From: Greg Dolkas <ko6th.greg@xxxxx.xxx>
To: Daniel Schultz <n8fgv@xxx.xxx>, amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: ISS HamTV Frequencies
Message-ID: <cb6e5eb5-7acf-4f3d-a64b-88284e56946a@xxxxx.xxxxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
Thanks, Dan. That helps a lot.
Is there something about the DVB-S modulation that makes it astoundingly
better for this application? For something that is intended to be widely
received, they sure are making it difficult...
Greg. KO6TH
--
Sent from my new toy... Please ignore tupos.
Daniel Schultz <n8fgv@xxx.xxx> wrote:
>------------- Original Message -------------
>>> Right. But what is that in terms of what normally gets described?
>>> For example, I have a Digital TV card for my computer (Pinnacle PCTV
>
>>> HD). It says it does "ATSC digital TV (HDTV up to 1080i, and SDTV)"
>
>>> and "Clear QAM (unencrypted digital cable)".
>>>
>>> Am I even close?
>>>
>>> Greg KO6TH
>
>No, you are not even close.
>
>ATSC (Advanced Television Systems Committee) is the proprietary
>over-the-air
>television broadcast standard used in North America. It is
>fundamentally
>incompatible with the open source "DVB-T" broadcast standard that the
>rest of
>the world uses for domestic TV. (The fact that it was designed by a
>committee
>should tell you all that you need to know about that particular
>political
>sausage.) The "Cheap and Easy SDR" article in January QST requires
>using a
>DVB-T USB dongle which you need to purchase from a supplier that knows
>that
>you want to use it for SDR. The ATSC USB devices sold at Best Buy or
>other
>retail stores in the USA cannot be used for this purpose.
>
>QAM is used only by cable TV and is never broadcast over the air. (Most
>cable
>systems use encrypted QAM so you will still need to rent the decoder
>box from
>the cable company).
>
>DVB-S is the digital satellite TV standard that the "free to air" (FTA)
>satellite receivers use. We are not talking about Direct TV or Dish TV,
>but
>the C band services. If you watch NASA TV or the foreign language TV
>broadcasts directly from your C band dish, you are using DVB-S. This
>standard
>has been used for terrestrial ham ATV in some US cities. It would be
>best to
>contact the ATV experts directly to see what receivers they are using.
>I don't
>know which FTA receivers will work with the ISS ham TV.
>
>Bottom line is: ATSC and QAM decoders are not useful for receiving the
>ISS ham
>TV signals, and DVB-S is not widely used in the USA except by dedicated
>"free
>to air" hobbyists. If you bought your receiver card or dongle from any
>US
>consumer retail store, it almost certainly is not what you need for ISS
>ham
>TV.
>
>Dan Schultz N8FGV
------------------------------
Message: 12
Date: Mon, 13 May 2013 09:25:43 -0500
From: Gregg Wonderly <w5ggw@xxx.xxx>
To: Jeff Moore <tnetcenter@xxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: J-Pole Antenna
Message-ID: <5190F7E7.3040204@xxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Yes, any 1/2wave or 5/8 wave antenna system doubles the horizontal power by
eliminating the power going up. So, it is more like a donut in emission
pattern, whereas the 1/4 antenna is a hemispherical (half a ball) emission
pattern.
With satellites, you clearly need to go "up".
As has been said many times, most satellite passes are never "directly
overhead", but rather on some inclination across the sky. A 5 element yagi
antenna, at a 35 degree angle from the horizon, with only an asmuth rotator,
will let you work far more satellites for the money spent.
Gregg Wonderly
On 5/12/2013 12:48 PM, Jeff Moore wrote:
> I wouldn't recommend a J-pole for satellite work unless you expect to only
work
> sats on the horizon. The J-Pole antenna has a low take-off angle and
almost NO
> radiation overhead, an plain 1/4 wave ground plane antenna would work
better
> for the sats.
>
>
>
> J-poles are great terrestrial communications antennas, not so much for
working
> overhead satellite passes. An Eggbeater or quadrifiliar antenna would be a
> better choice.
>
> 7 3
>
> Jeff Moore -- KE7ACY
>
> On 5/12/2013 8:00 AM, Werner, HB9BNK wrote
>> Thank you all for your valuable hints and advices !
>>
>> I will now build such an antenna and then supply here the results.
>>
>> 73 Werner, HB9BNK
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
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------------------------------
Message: 13
Date: Mon, 13 May 2013 18:26:43 +0200
From: "Werner, HB9BNK" <hb9bnk@xxxx.xx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] J-Pole Antenna
Message-ID: <51911443.2010008@xxxx.xx>
Content-Type: text/plain; charset=ISO-8859-15; format=flowed
The antenna, that I want to build, is described in a paper
(probably 20 years old) by Dick, WD4FAB, titled 'Antennas for
microsat ground stations', and the paper describes the large time,
a LEO remains at low elevations - about 76 % below 20 degrees -
and then concludes, that this is fine for a J-Pole.
I am aware of the fact, that the microsats (AO-16 et.al.) had a
mean altitude of 800 km, while my 'targets' fly (sometimes) at
higher altitudes. So, some problems are to be expected.
(In fact, I was working with a small yagi with fixed elevation of
about 15? for several years but my rotor has problems and the
access to it is complicated and the repair also, so that I decided
to try something simpler until the rotor is fixed - or replaced.
Living in a tight environment, I cannot put up a nice antenna
system, but to compromise is part of our hobby.)
So, I keep you informed about my results.
73 Werner, HB9BNK
------------------------------
Message: 14
Date: Mon, 13 May 2013 12:29:03 -0400
From: Robert Bruninga <bruninga@xxxx.xxx>
To: Jeff Moore <tnetcenter@xxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: J-Pole Antenna
Message-ID: <575cfa6107c1a6367b9c0af6bdc8a256@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
> As has been said many times, most satellite passes are never
> "directly overhead", but rather on some inclination across the sky.
> A 5 element yagi antenna, at a 35 degree angle from the horizon,
> with only an asmuth rotator, will let you work far more satellites for
the money spent.
Except that the correct angle is 15 degrees not 30 or 35. At 15
degrees, the main gain lobe of the antenna still has excellent gain on the
horizon where you need it most and an equal gain all the way up to 30
degrees or so. Below 30 degrees is where satellites spend 80+% of their
in-view times. This is where you need the gain most. But when the
satellite is above 30 degrees, the satellite is at least 6 to 10 dB closer
and so it makes no sense to sacrifice gain on the horizon (where you need
it most) by placing it at 30 degrees where you need it least.
See http://aprs.org/rotator1.html
Ignore the topic of the page but look very carefullyl at the SCALE drawing
(Yes, that is drawn to scale) of a LEO satellite pass Notice how 95% of
all satellite access times are below 50 degrees and 70% of the time they
are below 22 degrees. That is where you need the gain. Do not waste it
by tilting the antenna up more than 15 degrees.
The only exception is that if your beam antenna cannot see the horizon
anyway, then, yes, tilt it up a little more since you wont hear the low
stuff anyway...
Bob, WB4aPR
Gregg Wonderly
On 5/12/2013 12:48 PM, Jeff Moore wrote:
> I wouldn't recommend a J-pole for satellite work unless you expect to
> only work sats on the horizon. The J-Pole antenna has a low take-off
> angle and almost NO radiation overhead, an plain 1/4 wave ground
> plane antenna would work better for the sats.
>
>
>
> J-poles are great terrestrial communications antennas, not so much for
> working overhead satellite passes. An Eggbeater or quadrifiliar
> antenna would be a better choice.
>
> 7 3
>
> Jeff Moore -- KE7ACY
>
> On 5/12/2013 8:00 AM, Werner, HB9BNK wrote
>> Thank you all for your valuable hints and advices !
>>
>> I will now build such an antenna and then supply here the results.
>>
>> 73 Werner, HB9BNK
>
> _______________________________________________
> 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
>
_______________________________________________
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
------------------------------
_______________________________________________
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 154
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