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CX2SA > SATDIG 22.04.10 20:07l 750 Lines 22706 Bytes #999 (0) @ WW
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From: CX2SA@CX2SA.LAV.URY.SA
To : SATDIG@WW
Today's Topics:
1. Re: N3FJP Amateur Contact Log and LoTW (David - KG4ZLB)
2. Re: Arecibo on 432 MHz Moon Bounce (some calculations) (Idle-Tyme)
3. Re: Arecibo on 432 MHz Moon Bounce (some calculations)
(Fabio Azzarello)
4. Re: W1RJA EME event, Echoes of Apollo (Luc Leblanc)
5. Re: Arecibo on 432 MHz Moon Bounce (some calculations)
(Stephen Melachrinos)
6. Re: Arecibo on 432 MHz Moon Bounce (some calculations) (Idle-Tyme)
7. Re: Arecibo on 432 MHz Moon Bounce (some calculations)
(Nigel Gunn G8IFF/W8IFF)
8. OZ7SAT? Off the air? (Mark L. Hammond)
9. Re: OZ7SAT? Off the air? (Bent OZ6BL)
10. UHF/VHF Polarization Switch (Peter Portanova)
11. Re: Arecibo on 432 MHz Moon Bounce (some calculations)
(Edward Cole)
12. Re: Arecibo on 432 MHz Moon Bounce (some calculations)
(Edward Cole)
13. Re: OZ7SAT? Off the air? (Mark L. Hammond)
14. Re: Arecibo on 432 MHz Moon Bounce (some calculations) (i8cvs)
----------------------------------------------------------------------
Message: 1
Date: Wed, 21 Apr 2010 22:34:12 -0400
From: David - KG4ZLB <kg4zlb@xxxxxxxxxx.xxx>
Subject: [amsat-bb] Re: N3FJP Amateur Contact Log and LoTW
To: amsat-bb@xxxxx.xxx
Message-ID: <4BCFB5A4.2010409@xxxxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"
This will help; from the LoTW site:
*Mar 25, 2010: Synching or Downloading Log data* -- Some LoTW users who
use N3FJP AC Log to upload their logs to Logbook of The World have been
experiencing difficulty. The solution is to configure the logging
software to connect to the LoTW server.
Open N3FJP AC Log program.
1. Select the "LoTW" tab at the top of the log form.
2. Select the tab "LoTW Server Settings" in the upper right of the
LoTW form.
3. In the box marked "LoTW Download URL:" replace the current URL
with this new URL
https://p1k.arrl.org/lotwuser/lotwreport.adi?login=
Click DONE.
1. Make sure that all other settings such as own call, username and
password, and station location are correct.
2. Now you should be able to upload and download data to LOTW using
the logging software utility.
The N3FJP site < http://n3fjp.com/ > offers support for this program.
Hope that helps
David
KG4ZLB
On 4/21/2010 21:14, Michae J. Wolthuis wrote:
> Is anyone else having problems downloading data from LoTW for N3FJP's AC
> Log?? I have not been able to download data for about 2 weeks. I can
> upload.
>
>
>
> I get an error saying:
>
> The data file did not complete normally. Please try downloading the file
> again.
>
>
>
> I have tried about 25 times.
>
>
>
> Any ideas? It has been working so well!
>
>
>
> Mike
>
> Kb8zgl
>
>
>
> _______________________________________________
> 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
>
>
--
David
KG4ZLB
www.kg4zlb.com
------------------------------
Message: 2
Date: Wed, 21 Apr 2010 22:08:33 -0500
From: Idle-Tyme <nss@xxx.xxx>
Subject: [amsat-bb] Re: Arecibo on 432 MHz Moon Bounce (some
calculations)
To: Nigel Gunn G8IFF/W8IFF <nigel@xxxxx.xxx>
Cc: amsat-bb@xxxxx.xxx
Message-ID: <4BCFBDB1.1020202@xxx.xxx>
Content-Type: text/plain; charset=UTF-8; format=flowed
Yes this is the original made by the person that made and trained most
of the assemblers all those years ago. Read the history page it's
pretty interesting.
The plastic junk one was a license on our patent. We thought of it like
a Mc Donalds quarter pounder with cheese vs a nice sirloin steak at a 5
star steak house. They are both Beef. but there IS a big difference.
Joe
The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com
On 4/21/2010 7:08 PM, Nigel Gunn G8IFF/W8IFF wrote:
> Is it the original?
>
> I had a mass produced plastic one (with a 50Hz motor) back in the
> early 1980's (or earlier).
> Unfortunately, your web site doesn't appear to give dates.
>
> On 21-Apr-10 23:28, Idle-Tyme wrote:
>
>>
>> The Original Rolling Ball Clock
>> Idle Tyme
>> Idle-Tyme.com
>> http://www.idle-tyme.com
>
>
------------------------------
Message: 3
Date: Thu, 22 Apr 2010 07:45:24 +0200
From: Fabio Azzarello <iw8qku@xxxxx.xxx>
Subject: [amsat-bb] Re: Arecibo on 432 MHz Moon Bounce (some
calculations)
To: amsat-bb@xxxxx.xxx
Message-ID:
<j2m2b3cc8c11004212245gadbf00edh4d38a640cabe6a79@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Hi all,
I'm pleased of all those replies... but
as I wrote in my previous email ( I agree with Mr. Bruninga ) "ERP is about
243 MW" and
that comes from the conversion from dBi to dBd. That's all.
No Losses. No difference in decimals punctuation.
That's my conclusion... think it is the right one.
Thanks for the comments.
73s
Fabio
IW8QKU
On Wed, Apr 21, 2010 at 1:46 PM, Fabio Azzarello <iw8qku@xxxxx.xxx> wrote:
> Hello,
> thanks for the reply, but now I have another question.
> I'm not good enough with those numbers!
>
> If the calculated ERP is about 243 MW... which derives from changing from
> dBi to dBd (60dBi - 2.14),
> the part I don't understand is:
>
> "*Since the given ERP is 243,902,443 Million Watts (see below)
> and since 60 dB is equivalent to 1000000 (one Million) time in
> power it comes out that the power reaching the feed of the dish is:
> 243902443 / 1000000 = 243 watt
>
> The rest of the power 400-243 = 157 watt is lost in the feed line.*"
>
> How do they have feeder losses?
> thanks in advance,
>
> 73s
> Fabio
> iw8qku
>
>
>
> On Wed, Apr 21, 2010 at 8:45 AM, Mateusz <sq7dqx@xxxxxx.xxxx.xx> wrote:
>
>>
>> 60dBi is abt 57dB
>> It means 10exp5,7
>> ERP was 400x10exp5,7 W
>>
>> ----- Original Message ----- From: "Fabio A" <iw8qku@xxxxx.xxx>
>> To: <AMSAT-BB@xxxxx.xxx>
>> Sent: Tuesday, April 20, 2010 8:26 PM
>> Subject: [amsat-bb] Re: Arecibo on 432 MHz Moon Bounce (some calculations)
>>
>>
>> Hello all,
>>> just a curiosity, how did you found that the ERP is "... 243,902,443
>>> Million
>>> Watts".
>>>
>>> Thanks
>>>
>>> 73s
>>> Fabio
>>> iw8qku
>>>
>>>>
>>>>
>>>> ... snip ...
>>>>
>>>
>
------------------------------
Message: 4
Date: Thu, 22 Apr 2010 01:15:22 -0400
From: Luc Leblanc <lucleblanc6@xxxxxxxxx.xx>
Subject: [amsat-bb] Re: W1RJA EME event, Echoes of Apollo
To: amsat-bb@xxxxx.xxx
Message-ID: <4BCFA32A.11295.4A6697B@xxxxxxxxxxx.xxxxxxxxx.xx>
Content-Type: text/plain; charset=US-ASCII
On 21 Apr 2010 at 18:32, n1jez@xxxxxxxxxxxxxxxxx.xxx wrote:
Date sent: Wed, 21 Apr 2010 18:32:59 -0400
From: n1jez@xxxxxxxxxxxxxxxxx.xxx
Subject: [amsat-bb] Re: W1RJA EME event, Echoes of Apollo
To: amsat-bb@xxxxx.xxx
Send reply to: n1jez@xxxxxxxxxxxxxxxxx.xxx
> Luc,
>
> 2 x 31 el K1FO yagis with a preamp on the splitter and an 8938 running ~ 1
> KW.
>
> 73,
> Mike, N1JEZ
> AMSAT 29649
> "A closed mouth gathers no feet"
>
> ----- Original Message -----
> From: "Luc Leblanc" <lucleblanc6@xxxxxxxxx.xx>
> Subject: [amsat-bb] W1RJA EME event, Echoes of Apollo
>
>
> > W1RJA EME event, Echoes of Apollo
> >
> > Aside of the "Pickle dipole" did any one have an idea of their setup?
>
> _______________________________________________
Thank's Mike
I will now do my maths i have a lot of reference now...But result seems to
match the theory a single 24 elements K1FO style yagi beam
+preamp and 50 watt was a bit short here.
"-"
Luc Leblanc VE2DWE
Skype VE2DWE
www.qsl.net/ve2dwe
DSTAR urcall VE2DWE
WAC BASIC CW PHONE SATELLITE
------------------------------
Message: 5
Date: Thu, 22 Apr 2010 05:20:06 -0500 (CDT)
From: Stephen Melachrinos <melachri@xxxxxxx.xxx>
Subject: [amsat-bb] Re: Arecibo on 432 MHz Moon Bounce (some
calculations)
To: amsat-bb@xxxxx.xxx
Message-ID:
<6738722.664104.1271931606464.JavaMail.root@xxxxxx.xxxxxxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
Ah, but this focuses on my question: Why is ERP referenced to a dipole? Why
did someone assume that Arecibo's stated gain of 60 dB was dBd and not dBi?
I've never seen the gain of a dish antenna used in satellite work quoted in
dBd. All of the references for calculating gain are based on the isotropic
reference. And all of the usages I have seen (in professional satellite
work) use ERP and EiRP interchangeably, and the i in EiRP is used to
explicitly state "referenced to isotropic."
In fact, the amateur community is the only place where there is a
fascination with the dipole reference.
The dBd specs are useless for any real calculation purposes. Satcom
engineering is much simpler if everyone quotes isotropic, and all
commercial/government/military satellite link budgets are based on isotropic
references.
Steve Melachrinos
W3HF
(Professional) Satcom Engineer since 1979
> "ERP is about 243 MW" and
> that comes from the conversion from dBi to dBd.
------------------------------
Message: 6
Date: Thu, 22 Apr 2010 08:07:34 -0500
From: Idle-Tyme <nss@xxx.xxx>
Subject: [amsat-bb] Re: Arecibo on 432 MHz Moon Bounce (some
calculations)
To: i8cvs <domenico.i8cvs@xxx.xx>
Cc: AMSAT-BB <amsat-bb@xxxxx.xxx>
Message-ID: <4BD04A16.8080009@xxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
On 4/21/2010 8:25 PM, i8cvs wrote:
>> Comma or no comma, shouldn't matter
>> 1000 mega watts or 1,000 Mega watts is still one thousand million
>> watts! NOT one thousands watts. true?
>>
>> The Original Rolling Ball Clock
>> Idle Tyme
>> Idle-Tyme.com
>> http://www.idle-tyme.com
>>
>>
> Hi Idle-Tyme
>
> I don't agree with your statement:
>
> 1000 mega watt are one thousand million watt
> 1,000 mega watt or 1.000 mega watt is only one million watt because
> zero after the comma means nothing like 1,0000000000000 is still
> one million watt or 1 MW
>
NO! it's a comma, not a decimal point! it's one thousand, one thousand
written 1000 or 1,000 is still one thousand they are exactly the same.
------------------------------
Message: 7
Date: Thu, 22 Apr 2010 13:14:39 +0000
From: Nigel Gunn G8IFF/W8IFF <nigel@xxxxx.xxx>
Subject: [amsat-bb] Re: Arecibo on 432 MHz Moon Bounce (some
calculations)
To: w3hf@xxxx.xxx
Cc: amsat-bb@xxxxx.xxxx Stephen Melachrinos <melachri@xxxxxxx.xxx>
Message-ID: <4BD04BBF.4050804@xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8; format=flowed
I guess because it's impossible to build an isotropic radiator and therefore
just as impossible to measure it.
Why would I believe, or want to use, something I can neither have, use or
measure?
An isotropic antenna doesn't exist.
On 22-Apr-10 10:20, Stephen Melachrinos wrote:
> In fact, the amateur community is the only place where there is a
fascination with the dipole reference.
>
--
Nigel A. Gunn, 1865 El Camino Drive, Xenia, OH 45385-1115, USA. tel +1 937
825 5032
Amateur Radio G8IFF W8IFF (was KC8NHF), e-mail nigel@xxxxx.xxx www
http://www.ngunn.net
Member of ARRL, GQRP #11396, QRPARCI #11644, SOC #548, Flying Pigs QRP
Club International #385,
Dayton ARA #2128, AMSAT-NA LM-1691, AMSAT-UK 0182, MKARS, ALC,
GCARES, XWARN.
------------------------------
Message: 8
Date: Thu, 22 Apr 2010 10:05:35 -0400
From: "Mark L. Hammond" <marklhammond@xxxxx.xxx>
Subject: [amsat-bb] OZ7SAT? Off the air?
To: Amsat - BBs <amsat-bb@xxxxx.xxx>
Message-ID:
<l2j5d8cecfe1004220705u7f3e1980w6a11539d5f86af2d@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Does anybody (Ib ;) ) know if OZ7SAT is off the air? I haven't seen
any telemetry updates in over a week.
http://www.amsat.dk/oz7sat/tlm/
Thanks,
--
Mark L. Hammond [N8MH]
------------------------------
Message: 9
Date: Thu, 22 Apr 2010 16:41:02 +0200
From: Bent OZ6BL <oz6bl@xxxx.xx>
Subject: [amsat-bb] Re: OZ7SAT? Off the air?
To: amsat-bb@xxxxx.xxx
Message-ID: <4BD05FFE.1010308@xxxx.xx>
Content-Type: text/plain; charset=UTF-8
On 2010-04-22 16:05, Mark L. Hammond wrote:
> Does anybody (Ib ;) ) know if OZ7SAT is off the air? I haven't seen
> any telemetry updates in over a week.
>
> http://www.amsat.dk/oz7sat/tlm/
>
>
It has been off the air for some days (I blew a software update ;-()
It should be up again now.
73 de Bent/OZ6BL
AMSAT-OZ hostmaster
------------------------------
Message: 10
Date: Thu, 22 Apr 2010 10:48:34 -0400
From: Peter Portanova <roic@xxxxxxxxx.xxx>
Subject: [amsat-bb] UHF/VHF Polarization Switch
To: AMSAT-BB@xxxxx.xxx
Message-ID: <74EF7E07F1C24D058E7BC4B81C77E9D2@xxxx>
Content-Type: text/plain; format=flowed; charset=iso-8859-1;
reply-type=original
Hello,
I've been asked by a club member if anyone has any experience using an M2
VHF/UHF Polarization Switch, and what their opinion of it may be. I can't
seem to find any reviews on field performance, thank you.
73's Pete
WB2OQQ
www.massapequanyweather.com
------------------------------
Message: 11
Date: Thu, 22 Apr 2010 07:46:33 -0800
From: Edward Cole <kl7uw@xxxxxxxxx.xxx>
Subject: [amsat-bb] Re: Arecibo on 432 MHz Moon Bounce (some
calculations)
To: w3hf@xxxx.xxxx amsat-bb@xxxxx.xxx
Message-ID: <201004221546.o3MFkfcg051030@xxxxxx.xxxxxxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"; format=flowed
At 02:20 AM 4/22/2010, Stephen Melachrinos wrote:
>Ah, but this focuses on my question: Why is ERP referenced to a
>dipole? Why did someone assume that Arecibo's stated gain of 60 dB
>was dBd and not dBi? I've never seen the gain of a dish antenna used
>in satellite work quoted in dBd. All of the references for
>calculating gain are based on the isotropic reference. And all of
>the usages I have seen (in professional satellite work) use ERP and
>EiRP interchangeably, and the i in EiRP is used to explicitly state
>"referenced to isotropic."
>
>In fact, the amateur community is the only place where there is a
>fascination with the dipole reference.
>
>The dBd specs are useless for any real calculation purposes. Satcom
>engineering is much simpler if everyone quotes isotropic, and all
>commercial/government/military satellite link budgets are based on
>isotropic references.
>
>Steve Melachrinos
>W3HF
>(Professional) Satcom Engineer since 1979
>
>
> > "ERP is about 243 MW" and
> > that comes from the conversion from dBi to dBd.
>_______________________________________________
>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
In fact the first gain number published over a month ago was 58
dBi. Then I suppose a bunch of hams complained that they didn't
understand isotropic gain so the Arecibo folks kindly converted the
number to 60 dBd. (i.e. unity isotropic gain, dBi=0, is what a true
omni-directional antenna produces in free space)
Does anyone on this reflector know the formula for calculating gain
of a parabolic dish (Yes, I know-I'm asking if you know)? Did you
know that Arecibo dish is spherical and not parabolic? So we can
only use the gain number they provide (BTW the UHF line-feed corrects
for spherical aberration of the dish surface at Arecibo). Arecibo
can track a small amount of angle "because" the dish is
spherical. It is my understanding (might be wrong on this) the
line-feed can adjust for the amount of surface irradiated (which will
change the gain).
The formula normally used in radio astronomy and mw engineering is in
terms of dBi. Most (not all) eme hams use dBi vs dBd.
I am really amazed at this thread on amsat-bb. I thought the
satellite community was more globally oriented (International). The
different convention in expressing decimal numbers (aka using comma
or period) is pretty well known (I thought). US/UK use period and
most EU use comma.
Most antenna analysis sw express gain in dBi
73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ 500 KHz - 10-GHz www.kl7uw.com
EME: 144-600w, 432-100w, 1296-60w, 3400-fall 2010
DUBUS Magazine USA Rep dubususa@xxxxxxx.xxx
======================================
------------------------------
Message: 12
Date: Thu, 22 Apr 2010 08:08:21 -0800
From: Edward Cole <kl7uw@xxxxxxxxx.xxx>
Subject: [amsat-bb] Re: Arecibo on 432 MHz Moon Bounce (some
calculations)
To: w3hf@xxxx.xxxx amsat-bb@xxxxx.xxx
Message-ID: <201004221608.o3MG8Shh068953@xxxxxxx.xxxxxxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"; format=flowed
At 07:46 AM 4/22/2010, Edward Cole wrote:
>At 02:20 AM 4/22/2010, Stephen Melachrinos wrote:
> >Ah, but this focuses on my question: Why is ERP referenced to a
> >dipole? Why did someone assume that Arecibo's stated gain of 60 dB
> >was dBd and not dBi? I've never seen the gain of a dish antenna used
> >in satellite work quoted in dBd. All of the references for
> >calculating gain are based on the isotropic reference. And all of
> >the usages I have seen (in professional satellite work) use ERP and
> >EiRP interchangeably, and the i in EiRP is used to explicitly state
> >"referenced to isotropic."
> >
> >In fact, the amateur community is the only place where there is a
> >fascination with the dipole reference.
> >
> >The dBd specs are useless for any real calculation purposes. Satcom
> >engineering is much simpler if everyone quotes isotropic, and all
> >commercial/government/military satellite link budgets are based on
> >isotropic references.
> >
> >Steve Melachrinos
> >W3HF
> >(Professional) Satcom Engineer since 1979
> >
> >
> > > "ERP is about 243 MW" and
> > > that comes from the conversion from dBi to dBd.
> >_______________________________________________
> >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
>
>In fact the first gain number published over a month ago was 58
>dBi. Then I suppose a bunch of hams complained that they didn't
>understand isotropic gain so the Arecibo folks kindly converted the
>number to 60 dBd. (i.e. unity isotropic gain, dBi=0, is what a true
>omni-directional antenna produces in free space)
>
>Does anyone on this reflector know the formula for calculating gain
>of a parabolic dish (Yes, I know-I'm asking if you know)? Did you
>know that Arecibo dish is spherical and not parabolic? So we can
>only use the gain number they provide (BTW the UHF line-feed corrects
>for spherical aberration of the dish surface at Arecibo). Arecibo
>can track a small amount of angle "because" the dish is
>spherical. It is my understanding (might be wrong on this) the
>line-feed can adjust for the amount of surface irradiated (which will
>change the gain).
>
>The formula normally used in radio astronomy and mw engineering is in
>terms of dBi. Most (not all) eme hams use dBi vs dBd.
>
>I am really amazed at this thread on amsat-bb. I thought the
>satellite community was more globally oriented (International). The
>different convention in expressing decimal numbers (aka using comma
>or period) is pretty well known (I thought). US/UK use period and
>most EU use comma.
>
>Most antenna analysis sw express gain in dBi
hmm dBi = dBd +2.15. Gain of dipole = 1.64 10Log(1.64) = 2.15 dB
so what gives here? is it 58 dBd and 60 dBi? Sorry if I wrote that
backwards. Or we just playing around with significant numbers and
gain is approx 58 to 60 dB (somethings).
Pat, Joe? can you please clear up this mess and state for everyone
what the gain is for Arecibo on 432-MHz?
73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ 500 KHz - 10-GHz www.kl7uw.com
EME: 144-600w, 432-100w, 1296-60w, 3400-fall 2010
DUBUS Magazine USA Rep dubususa@xxxxxxx.xxx
======================================
------------------------------
Message: 13
Date: Thu, 22 Apr 2010 12:26:28 -0400
From: "Mark L. Hammond" <marklhammond@xxxxx.xxx>
Subject: [amsat-bb] Re: OZ7SAT? Off the air?
To: Bent OZ6BL <oz6bl@xxxx.xx>, Amsat - BBs <amsat-bb@xxxxx.xxx>
Message-ID:
<s2h5d8cecfe1004220926k8bcfb46secbf46ae470b87ab@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Thank you Bent and OZ7SAT. I find it very useful and have come to
depend on it ;)
73,
Mark N8MH
On Thu, Apr 22, 2010 at 10:41 AM, Bent OZ6BL <oz6bl@xxxx.xx> wrote:
> On 2010-04-22 16:05, Mark L. Hammond wrote:
>> Does anybody (Ib ;) ) know if OZ7SAT is off the air? ?I haven't seen
>> any telemetry updates in over a week.
>>
>> http://www.amsat.dk/oz7sat/tlm/
>>
>>
> It has been off the air for some days (I blew a software update ;-()
> It should be up again now.
>
> 73 de Bent/OZ6BL
> AMSAT-OZ hostmaster
>
> _______________________________________________
> 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
>
--
Mark L. Hammond [N8MH]
------------------------------
Message: 14
Date: Thu, 22 Apr 2010 19:26:30 +0200
From: "i8cvs" <domenico.i8cvs@xxx.xx>
Subject: [amsat-bb] Re: Arecibo on 432 MHz Moon Bounce (some
calculations)
To: <w3hf@xxxx.xxx>, "AMSAT-BB" <amsat-bb@xxxxx.xxx>, "Edward Cole"
<kl7uw@xxxxxxxxx.xxx>, <melachri@xxxxxxx.xxx>
Message-ID: <007001cae240$f36be800$0201a8c0@xxx.xx>
Content-Type: text/plain; charset="iso-8859-1"
----- Original Message -----
From: "Edward Cole" <kl7uw@xxxxxxxxx.xxx>
To: <w3hf@xxxx.xxx>; <amsat-bb@xxxxx.xxx>
Sent: Thursday, April 22, 2010 5:46 PM
Subject: [amsat-bb] Re: Arecibo on 432 MHz Moon Bounce (some calculations)
Hi Ed, KL7UW
You writes:
> In fact the first gain number published over a month ago was 58
> dBi. Then I suppose a bunch of hams complained that they didn't
> understand isotropic gain so the Arecibo folks kindly converted the
> number to 60 dBd. (i.e. unity isotropic gain, dBi=0, is what a true
> omni-directional antenna produces in free space)
>
> 73, Ed - KL7UW, WD2XSH/45
Ed , you have reversed dBi with dBd
58 dBi cannot be converted to 60 dBd because the gain of a dipole
over the isotropic antenna is 2.14 dB then 60 dBd is corresponding to
60 + 2.14 = 62.14 dBi
By the way 58 dBd is corresponding to 60.14 dBi rounded to 60 dBi
wich is the official gain given for Arecibo at 432 MHz
73" de
i8CVS Domenico
------------------------------
_______________________________________________
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 5, Issue 184
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