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CX2SA > SATDIG 17.06.15 19:17l 1142 Lines 39375 Bytes #999 (0) @ WW
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Today's Topics:
1. Re: EO-80 FM Transponder Tested (Andrew Koenig)
2. Re: EO-80 FM Transponder Tested (Paul Stoetzer)
3. Re: EO-80 FM Transponder Tested (Andrew Koenig)
4. Re: EO-80 FM Transponder Tested (Zach Leffke)
5. Re: EO-80 FM Transponder Tested (noise floor?) (Robert Bruninga)
6. Re: EO-80 FM Transponder Tested (noise floor?) (Paul Stoetzer)
7. EO-80 FM Transponder Tested (noise floor?) (Nicholas Mahr)
8. Re: EO-80 FM Transponder Tested (noise floor?) (Joe)
9. Re: EO-80 FM Transponder Tested (noise floor?) (Paul Stoetzer)
10. Re: EO-80 FM Transponder Tested (noise floor?) (Paul Stoetzer)
----------------------------------------------------------------------
Message: 1
Date: Wed, 17 Jun 2015 09:43:56 -0500
From: Andrew Koenig <ke5gdb@xxxxx.xxx>
To: Paul Stoetzer <n8hm@xxxx.xxx>
Cc: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>, Nicholas Mahr
<nicholasmahr1@xxxxx.xxx>
Subject: Re: [amsat-bb] EO-80 FM Transponder Tested
Message-ID:
<CAFingdMPAYuWe7=djyKEE4tTvR1u4-DL+g73WztGOLgnvNYEGg@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
*9dB (typo)
On Wed, Jun 17, 2015 at 9:42 AM, Andrew Koenig <ke5gdb@xxxxx.xxx> wrote:
> Can you explain the 6dB advantage 2m has over 70cm? I've seen it here on
> the amsat-bb, and in the mesh realm when comparing 2.4GHz and 5.8GHz WiFi
> gear, but it still hasn't "clicked."
>
> 73 de KE5GDB
>
> On Tue, Jun 16, 2015 at 6:56 PM, Paul Stoetzer <n8hm@xxxx.xxx> wrote:
>
>> Nick,
>>
>> It should be even stronger than AO-27's 500 mW, AO-27 had a 70cm
>> downlink, the EO-80 downlink is on 2 meters, so EO-80's signal should
>> be up to 9 dB stronger than AO-27 (12 dB stronger if they run it at 1
>> watt).
>>
>> 73,
>>
>> Paul, N8HM
>>
>> On Tue, Jun 16, 2015 at 7:49 PM, Nicholas Mahr <nicholasmahr1@xxxxx.xxx>
>> wrote:
>> > Thats very good news, Hopefully the two get activated before field day?
>> Im
>> > most looking forward to EO-80, It should be like AO-27 with 500Mw or 1W.
>> > Good to know both are working well and wish a long life to them.
>> >
>> > 73 KE8AKW
>> > _______________________________________________
>> > Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
>> > to all interested persons worldwide without requiring membership.
>> Opinions expressed
>> > are solely those of the author, and do not reflect the official views
>> of AMSAT-NA.
>> > Not an AMSAT-NA member? Join now to support the amateur satellite
>> program!
>> > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>> _______________________________________________
>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
>> to all interested persons worldwide without requiring membership.
>> Opinions expressed
>> are solely those of the author, and do not reflect the official views of
>> AMSAT-NA.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>>
>
>
>
> --
> Andrew Koenig
>
--
Andrew Koenig
------------------------------
Message: 2
Date: Wed, 17 Jun 2015 10:51:22 -0400
From: Paul Stoetzer <n8hm@xxxx.xxx>
To: Andrew Koenig <ke5gdb@xxxxx.xxx>
Cc: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>, Nicholas Mahr
<nicholasmahr1@xxxxx.xxx>
Subject: Re: [amsat-bb] EO-80 FM Transponder Tested
Message-ID:
<CABzOSOrR4DUbaZy6mR92xLq0QPsXL84ZDGTzoDPzWoc-_74cQg@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
Free space path loss is dependent on frequency. All things being equal
(distance, antenna gain on both ends, etc), a 2 meter signal has about
a 9 dB advantage over a 70cm signal.
Here's an explanation:
http://www.radio-electronics.com/info/propagation/path-loss/free-space-formula
-equation.php
73,
Paul, N8HM
On Wed, Jun 17, 2015 at 10:42 AM, Andrew Koenig <ke5gdb@xxxxx.xxx> wrote:
> Can you explain the 6dB advantage 2m has over 70cm? I've seen it here on the
> amsat-bb, and in the mesh realm when comparing 2.4GHz and 5.8GHz WiFi gear,
> but it still hasn't "clicked."
>
> 73 de KE5GDB
>
> On Tue, Jun 16, 2015 at 6:56 PM, Paul Stoetzer <n8hm@xxxx.xxx> wrote:
>>
>> Nick,
>>
>> It should be even stronger than AO-27's 500 mW, AO-27 had a 70cm
>> downlink, the EO-80 downlink is on 2 meters, so EO-80's signal should
>> be up to 9 dB stronger than AO-27 (12 dB stronger if they run it at 1
>> watt).
>>
>> 73,
>>
>> Paul, N8HM
>>
>> On Tue, Jun 16, 2015 at 7:49 PM, Nicholas Mahr <nicholasmahr1@xxxxx.xxx>
>> wrote:
>> > Thats very good news, Hopefully the two get activated before field day?
>> > Im
>> > most looking forward to EO-80, It should be like AO-27 with 500Mw or 1W.
>> > Good to know both are working well and wish a long life to them.
>> >
>> > 73 KE8AKW
>> > _______________________________________________
>> > Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
>> > to all interested persons worldwide without requiring membership.
>> > Opinions expressed
>> > are solely those of the author, and do not reflect the official views of
>> > AMSAT-NA.
>> > Not an AMSAT-NA member? Join now to support the amateur satellite
>> > program!
>> > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>> _______________________________________________
>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
>> to all interested persons worldwide without requiring membership. Opinions
>> expressed
>> are solely those of the author, and do not reflect the official views of
>> AMSAT-NA.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>
>
>
>
> --
> Andrew Koenig
------------------------------
Message: 3
Date: Wed, 17 Jun 2015 09:55:24 -0500
From: Andrew Koenig <ke5gdb@xxxxx.xxx>
To: Paul Stoetzer <n8hm@xxxx.xxx>
Cc: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>, Nicholas Mahr
<nicholasmahr1@xxxxx.xxx>
Subject: Re: [amsat-bb] EO-80 FM Transponder Tested
Message-ID:
<CAFingdM7ihTzCpE-7q-X3w-mt19bWjEGPYnjCL+8t3ogQHr31A@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
Thanks! That website explained it very well, and seeing the formulas really
helped.
73 de KE5GDB
On Wed, Jun 17, 2015 at 9:51 AM, Paul Stoetzer <n8hm@xxxx.xxx> wrote:
> Free space path loss is dependent on frequency. All things being equal
> (distance, antenna gain on both ends, etc), a 2 meter signal has about
> a 9 dB advantage over a 70cm signal.
>
> Here's an explanation:
>
>
>
http://www.radio-electronics.com/info/propagation/path-loss/free-space-formula
-equation.php
>
> 73,
>
> Paul, N8HM
>
> On Wed, Jun 17, 2015 at 10:42 AM, Andrew Koenig <ke5gdb@xxxxx.xxx> wrote:
> > Can you explain the 6dB advantage 2m has over 70cm? I've seen it here on
> the
> > amsat-bb, and in the mesh realm when comparing 2.4GHz and 5.8GHz WiFi
> gear,
> > but it still hasn't "clicked."
> >
> > 73 de KE5GDB
> >
> > On Tue, Jun 16, 2015 at 6:56 PM, Paul Stoetzer <n8hm@xxxx.xxx> wrote:
> >>
> >> Nick,
> >>
> >> It should be even stronger than AO-27's 500 mW, AO-27 had a 70cm
> >> downlink, the EO-80 downlink is on 2 meters, so EO-80's signal should
> >> be up to 9 dB stronger than AO-27 (12 dB stronger if they run it at 1
> >> watt).
> >>
> >> 73,
> >>
> >> Paul, N8HM
> >>
> >> On Tue, Jun 16, 2015 at 7:49 PM, Nicholas Mahr <nicholasmahr1@xxxxx.xxx
> >
> >> wrote:
> >> > Thats very good news, Hopefully the two get activated before field
> day?
> >> > Im
> >> > most looking forward to EO-80, It should be like AO-27 with 500Mw or
> 1W.
> >> > Good to know both are working well and wish a long life to them.
> >> >
> >> > 73 KE8AKW
> >> > _______________________________________________
> >> > Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
> >> > to all interested persons worldwide without requiring membership.
> >> > Opinions expressed
> >> > are solely those of the author, and do not reflect the official views
> of
> >> > AMSAT-NA.
> >> > Not an AMSAT-NA member? Join now to support the amateur satellite
> >> > program!
> >> > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> >> _______________________________________________
> >> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
> >> to all interested persons worldwide without requiring membership.
> Opinions
> >> expressed
> >> are solely those of the author, and do not reflect the official views of
> >> AMSAT-NA.
> >> Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> >> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> >
> >
> >
> >
> > --
> > Andrew Koenig
>
--
Andrew Koenig
------------------------------
Message: 4
Date: Wed, 17 Jun 2015 11:23:18 -0400
From: Zach Leffke <zleffke@xx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] EO-80 FM Transponder Tested
Message-ID: <558190E6.4000504@xx.xxx>
Content-Type: text/plain; charset=windows-1252; format=flowed
Paul beat me to the punch as I was typing up my response, but I'm
sending it anyway:
Path Loss. -> function of lambda (wavelength) squared.
So all other things being equal (antenna gains, power levels, range,
etc.), you can look at the power ratio of the two.
Rough calculation (going from 2m to 70cm):
10log[(0.70/2)^2] = -9.1 dB
OR
Rough calculation (going from 70cm to 2m):
10log[(2/0.7)^2] = +9.1 dB
The thing to watch out for is antenna gains on the ground. The arrow
for example has more gain on 70cm (7el) than it does on 2m (3el). So
while 2m has a 9-ish dB improvement over 70cm in terms of path loss, the
receiver may not see the full 9dB because of the difference in gains on
the antenna between the two bands.
Again VERY rough approximation (for demonstration purposes only):
3el yagi -> call it 7.5 ish dB of gain
7el yagi -> call it 11.5 ish dB of gain
so, about 4 dB of LOST gain (going from 70cm to 2m using the arrow example).
So net gain going from 70cm to 2m (all other things equal except the
gains on the arrow antenna)
9dB - 4dB = 5dB
so your typo was actually fairly close :-) for those planning to use
their existing setup for the new birds.
-Zach, KJ4QLP
On 6/17/2015 10:43 AM, Andrew Koenig wrote:
> *9dB (typo)
>
> On Wed, Jun 17, 2015 at 9:42 AM, Andrew Koenig <ke5gdb@xxxxx.xxx> wrote:
>
>> Can you explain the 6dB advantage 2m has over 70cm? I've seen it here on
>> the amsat-bb, and in the mesh realm when comparing 2.4GHz and 5.8GHz WiFi
>> gear, but it still hasn't "clicked."
>>
>> 73 de KE5GDB
>>
>> On Tue, Jun 16, 2015 at 6:56 PM, Paul Stoetzer <n8hm@xxxx.xxx> wrote:
>>
>>> Nick,
>>>
>>> It should be even stronger than AO-27's 500 mW, AO-27 had a 70cm
>>> downlink, the EO-80 downlink is on 2 meters, so EO-80's signal should
>>> be up to 9 dB stronger than AO-27 (12 dB stronger if they run it at 1
>>> watt).
>>>
>>> 73,
>>>
>>> Paul, N8HM
>>>
>>> On Tue, Jun 16, 2015 at 7:49 PM, Nicholas Mahr <nicholasmahr1@xxxxx.xxx>
>>> wrote:
>>>> Thats very good news, Hopefully the two get activated before field day?
>>> Im
>>>> most looking forward to EO-80, It should be like AO-27 with 500Mw or 1W.
>>>> Good to know both are working well and wish a long life to them.
>>>>
>>>> 73 KE8AKW
>>>> _______________________________________________
>>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
>>>> to all interested persons worldwide without requiring membership.
>>> Opinions expressed
>>>> are solely those of the author, and do not reflect the official views
>>> of AMSAT-NA.
>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
>>> program!
>>>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>>> _______________________________________________
>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
>>> to all interested persons worldwide without requiring membership.
>>> Opinions expressed
>>> are solely those of the author, and do not reflect the official views of
>>> AMSAT-NA.
>>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>>>
>>
>>
>> --
>> Andrew Koenig
>>
>
>
------------------------------
Message: 5
Date: Wed, 17 Jun 2015 12:26:08 -0400
From: Robert Bruninga <bruninga@xxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] EO-80 FM Transponder Tested (noise floor?)
Message-ID: <c4b86a1e3e378e5569f7d66b5c7f8959@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
I also am a proponent ot using 2m for weak downlinks because of the 9 dB
advantage. But it has been pointed out to me that there is a higher
background noise component that needs to be considered. I have not done
this. My assumption is that the noise floor at 2m is maybe about 3 dB
worse than at 70cm?
So 2m still wins, but I'm not sure of what the real noise floor is.
Bob, WB4aPR
-----Original Message-----
From: AMSAT-BB [mailto:amsat-bb-bounces@xxxxx.xxxx On Behalf Of Zach
Leffke
Sent: Wednesday, June 17, 2015 11:23 AM
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] EO-80 FM Transponder Tested
Paul beat me to the punch as I was typing up my response, but I'm sending
it anyway:
Path Loss. -> function of lambda (wavelength) squared.
So all other things being equal (antenna gains, power levels, range,
etc.), you can look at the power ratio of the two.
Rough calculation (going from 2m to 70cm):
10log[(0.70/2)^2] = -9.1 dB
OR
Rough calculation (going from 70cm to 2m):
10log[(2/0.7)^2] = +9.1 dB
The thing to watch out for is antenna gains on the ground. The arrow for
example has more gain on 70cm (7el) than it does on 2m (3el). So while 2m
has a 9-ish dB improvement over 70cm in terms of path loss, the receiver
may not see the full 9dB because of the difference in gains on the antenna
between the two bands.
Again VERY rough approximation (for demonstration purposes only):
3el yagi -> call it 7.5 ish dB of gain
7el yagi -> call it 11.5 ish dB of gain
so, about 4 dB of LOST gain (going from 70cm to 2m using the arrow
example).
So net gain going from 70cm to 2m (all other things equal except the gains
on the arrow antenna) 9dB - 4dB = 5dB
so your typo was actually fairly close :-) for those planning to use their
existing setup for the new birds.
-Zach, KJ4QLP
On 6/17/2015 10:43 AM, Andrew Koenig wrote:
> *9dB (typo)
>
> On Wed, Jun 17, 2015 at 9:42 AM, Andrew Koenig <ke5gdb@xxxxx.xxx> wrote:
>
>> Can you explain the 6dB advantage 2m has over 70cm? I've seen it here
>> on the amsat-bb, and in the mesh realm when comparing 2.4GHz and
>> 5.8GHz WiFi gear, but it still hasn't "clicked."
>>
>> 73 de KE5GDB
>>
>> On Tue, Jun 16, 2015 at 6:56 PM, Paul Stoetzer <n8hm@xxxx.xxx> wrote:
>>
>>> Nick,
>>>
>>> It should be even stronger than AO-27's 500 mW, AO-27 had a 70cm
>>> downlink, the EO-80 downlink is on 2 meters, so EO-80's signal
>>> should be up to 9 dB stronger than AO-27 (12 dB stronger if they run
>>> it at 1 watt).
>>>
>>> 73,
>>>
>>> Paul, N8HM
>>>
>>> On Tue, Jun 16, 2015 at 7:49 PM, Nicholas Mahr
>>> <nicholasmahr1@xxxxx.xxx>
>>> wrote:
>>>> Thats very good news, Hopefully the two get activated before field
day?
>>> Im
>>>> most looking forward to EO-80, It should be like AO-27 with 500Mw or
1W.
>>>> Good to know both are working well and wish a long life to them.
>>>>
>>>> 73 KE8AKW
>>>> _______________________________________________
>>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum
>>>> available to all interested persons worldwide without requiring
membership.
>>> Opinions expressed
>>>> are solely those of the author, and do not reflect the official
>>>> views
>>> of AMSAT-NA.
>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
>>> program!
>>>> Subscription settings:
>>>> http://www.amsat.org/mailman/listinfo/amsat-bb
>>> _______________________________________________
>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum
>>> available to all interested persons worldwide without requiring
membership.
>>> Opinions expressed
>>> are solely those of the author, and do not reflect the official
>>> views of AMSAT-NA.
>>> Not an AMSAT-NA member? Join now to support the amateur satellite
program!
>>> Subscription settings:
>>> http://www.amsat.org/mailman/listinfo/amsat-bb
>>>
>>
>>
>> --
>> Andrew Koenig
>>
>
>
_______________________________________________
Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available to
all interested persons worldwide without requiring membership. Opinions
expressed are solely those of the author, and do not reflect the official
views of AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 6
Date: Wed, 17 Jun 2015 12:32:34 -0400
From: Paul Stoetzer <n8hm@xxxx.xxx>
To: Robert Bruninga <bruninga@xxxx.xxx>
Cc: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] EO-80 FM Transponder Tested (noise floor?)
Message-ID:
<CABzOSOri34WJxriEhc9a9ksGaK8+biK6a9CnNP5-OA_i97g1uQ@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
That is definitely true. I have terrible noise in certain directions
here in southwest Washington, DC (especially at night - the lighting
on the north fence of my apartment building puts out a hash that
completely wipes out 2m, but is OK on 70cm). The noise level doesn't
affect FM as much, though.
73,
Paul, N8HM
On Wed, Jun 17, 2015 at 12:26 PM, Robert Bruninga <bruninga@xxxx.xxx> wrote:
> I also am a proponent ot using 2m for weak downlinks because of the 9 dB
> advantage. But it has been pointed out to me that there is a higher
> background noise component that needs to be considered. I have not done
> this. My assumption is that the noise floor at 2m is maybe about 3 dB
> worse than at 70cm?
>
> So 2m still wins, but I'm not sure of what the real noise floor is.
>
> Bob, WB4aPR
>
> -----Original Message-----
> From: AMSAT-BB [mailto:amsat-bb-bounces@xxxxx.xxxx On Behalf Of Zach
> Leffke
> Sent: Wednesday, June 17, 2015 11:23 AM
> To: amsat-bb@xxxxx.xxx
> Subject: Re: [amsat-bb] EO-80 FM Transponder Tested
>
> Paul beat me to the punch as I was typing up my response, but I'm sending
> it anyway:
>
> Path Loss. -> function of lambda (wavelength) squared.
> So all other things being equal (antenna gains, power levels, range,
> etc.), you can look at the power ratio of the two.
>
> Rough calculation (going from 2m to 70cm):
> 10log[(0.70/2)^2] = -9.1 dB
> OR
> Rough calculation (going from 70cm to 2m):
> 10log[(2/0.7)^2] = +9.1 dB
>
> The thing to watch out for is antenna gains on the ground. The arrow for
> example has more gain on 70cm (7el) than it does on 2m (3el). So while 2m
> has a 9-ish dB improvement over 70cm in terms of path loss, the receiver
> may not see the full 9dB because of the difference in gains on the antenna
> between the two bands.
>
> Again VERY rough approximation (for demonstration purposes only):
> 3el yagi -> call it 7.5 ish dB of gain
> 7el yagi -> call it 11.5 ish dB of gain
> so, about 4 dB of LOST gain (going from 70cm to 2m using the arrow
> example).
>
> So net gain going from 70cm to 2m (all other things equal except the gains
> on the arrow antenna) 9dB - 4dB = 5dB
>
> so your typo was actually fairly close :-) for those planning to use their
> existing setup for the new birds.
>
> -Zach, KJ4QLP
>
> On 6/17/2015 10:43 AM, Andrew Koenig wrote:
>> *9dB (typo)
>>
>> On Wed, Jun 17, 2015 at 9:42 AM, Andrew Koenig <ke5gdb@xxxxx.xxx> wrote:
>>
>>> Can you explain the 6dB advantage 2m has over 70cm? I've seen it here
>>> on the amsat-bb, and in the mesh realm when comparing 2.4GHz and
>>> 5.8GHz WiFi gear, but it still hasn't "clicked."
>>>
>>> 73 de KE5GDB
>>>
>>> On Tue, Jun 16, 2015 at 6:56 PM, Paul Stoetzer <n8hm@xxxx.xxx> wrote:
>>>
>>>> Nick,
>>>>
>>>> It should be even stronger than AO-27's 500 mW, AO-27 had a 70cm
>>>> downlink, the EO-80 downlink is on 2 meters, so EO-80's signal
>>>> should be up to 9 dB stronger than AO-27 (12 dB stronger if they run
>>>> it at 1 watt).
>>>>
>>>> 73,
>>>>
>>>> Paul, N8HM
>>>>
>>>> On Tue, Jun 16, 2015 at 7:49 PM, Nicholas Mahr
>>>> <nicholasmahr1@xxxxx.xxx>
>>>> wrote:
>>>>> Thats very good news, Hopefully the two get activated before field
> day?
>>>> Im
>>>>> most looking forward to EO-80, It should be like AO-27 with 500Mw or
> 1W.
>>>>> Good to know both are working well and wish a long life to them.
>>>>>
>>>>> 73 KE8AKW
>>>>> _______________________________________________
>>>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum
>>>>> available to all interested persons worldwide without requiring
> membership.
>>>> Opinions expressed
>>>>> are solely those of the author, and do not reflect the official
>>>>> views
>>>> of AMSAT-NA.
>>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
>>>> program!
>>>>> Subscription settings:
>>>>> http://www.amsat.org/mailman/listinfo/amsat-bb
>>>> _______________________________________________
>>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum
>>>> available to all interested persons worldwide without requiring
> membership.
>>>> Opinions expressed
>>>> are solely those of the author, and do not reflect the official
>>>> views of AMSAT-NA.
>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
>>>> Subscription settings:
>>>> http://www.amsat.org/mailman/listinfo/amsat-bb
>>>>
>>>
>>>
>>> --
>>> Andrew Koenig
>>>
>>
>>
>
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available to
> all interested persons worldwide without requiring membership. Opinions
> expressed are solely those of the author, and do not reflect the official
> views of AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
expressed
> are solely those of the author, and do not reflect the official views of
AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 7
Date: Wed, 17 Jun 2015 12:42:00 -0400
From: Nicholas Mahr <nicholasmahr1@xxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] EO-80 FM Transponder Tested (noise floor?)
Message-ID:
<CAGu+VYsX4MBpWAcos4nWCbj2Ca+d5LsfEBC-4LB5szAKj=_iKg@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
I notice 2M has a high noise floor when im working AO-7, Theres a few same
spots on the passband that have these giant swooshing sounds/etc, It wont
be a problem on EO-80 as I as well have found it dosent affect me on FM,
maybe EO-79. Looks like we wont have to wait for FOX-1 in september to
cover for SO-50... Its really hard to do portable FM operations here where
I live, theres lots of trees, so it makes working SO-50 very difficult
because of its 250 mw power, I wish they would just increase the power on
the thing.
73 KE8AKW
------------------------------
Message: 8
Date: Wed, 17 Jun 2015 11:43:16 -0500
From: Joe <nss@xxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: Re: [amsat-bb] EO-80 FM Transponder Tested (noise floor?)
Message-ID: <5581A3A4.20604@xxx.xxx>
Content-Type: text/plain; charset=windows-1252; format=flowed
why can we not get an old skool mode "A" back?
Joe WB9SBD
Sig
The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com
On 6/17/2015 11:26 AM, Robert Bruninga wrote:
> I also am a proponent ot using 2m for weak downlinks because of the 9 dB
> advantage. But it has been pointed out to me that there is a higher
> background noise component that needs to be considered. I have not done
> this. My assumption is that the noise floor at 2m is maybe about 3 dB
> worse than at 70cm?
>
> So 2m still wins, but I'm not sure of what the real noise floor is.
>
> Bob, WB4aPR
>
> -----Original Message-----
> From: AMSAT-BB [mailto:amsat-bb-bounces@xxxxx.xxxx On Behalf Of Zach
> Leffke
> Sent: Wednesday, June 17, 2015 11:23 AM
> To: amsat-bb@xxxxx.xxx
> Subject: Re: [amsat-bb] EO-80 FM Transponder Tested
>
> Paul beat me to the punch as I was typing up my response, but I'm sending
> it anyway:
>
> Path Loss. -> function of lambda (wavelength) squared.
> So all other things being equal (antenna gains, power levels, range,
> etc.), you can look at the power ratio of the two.
>
> Rough calculation (going from 2m to 70cm):
> 10log[(0.70/2)^2] = -9.1 dB
> OR
> Rough calculation (going from 70cm to 2m):
> 10log[(2/0.7)^2] = +9.1 dB
>
> The thing to watch out for is antenna gains on the ground. The arrow for
> example has more gain on 70cm (7el) than it does on 2m (3el). So while 2m
> has a 9-ish dB improvement over 70cm in terms of path loss, the receiver
> may not see the full 9dB because of the difference in gains on the antenna
> between the two bands.
>
> Again VERY rough approximation (for demonstration purposes only):
> 3el yagi -> call it 7.5 ish dB of gain
> 7el yagi -> call it 11.5 ish dB of gain
> so, about 4 dB of LOST gain (going from 70cm to 2m using the arrow
> example).
>
> So net gain going from 70cm to 2m (all other things equal except the gains
> on the arrow antenna) 9dB - 4dB = 5dB
>
> so your typo was actually fairly close :-) for those planning to use their
> existing setup for the new birds.
>
> -Zach, KJ4QLP
>
> On 6/17/2015 10:43 AM, Andrew Koenig wrote:
>> *9dB (typo)
>>
>> On Wed, Jun 17, 2015 at 9:42 AM, Andrew Koenig <ke5gdb@xxxxx.xxx> wrote:
>>
>>> Can you explain the 6dB advantage 2m has over 70cm? I've seen it here
>>> on the amsat-bb, and in the mesh realm when comparing 2.4GHz and
>>> 5.8GHz WiFi gear, but it still hasn't "clicked."
>>>
>>> 73 de KE5GDB
>>>
>>> On Tue, Jun 16, 2015 at 6:56 PM, Paul Stoetzer <n8hm@xxxx.xxx> wrote:
>>>
>>>> Nick,
>>>>
>>>> It should be even stronger than AO-27's 500 mW, AO-27 had a 70cm
>>>> downlink, the EO-80 downlink is on 2 meters, so EO-80's signal
>>>> should be up to 9 dB stronger than AO-27 (12 dB stronger if they run
>>>> it at 1 watt).
>>>>
>>>> 73,
>>>>
>>>> Paul, N8HM
>>>>
>>>> On Tue, Jun 16, 2015 at 7:49 PM, Nicholas Mahr
>>>> <nicholasmahr1@xxxxx.xxx>
>>>> wrote:
>>>>> Thats very good news, Hopefully the two get activated before field
> day?
>>>> Im
>>>>> most looking forward to EO-80, It should be like AO-27 with 500Mw or
> 1W.
>>>>> Good to know both are working well and wish a long life to them.
>>>>>
>>>>> 73 KE8AKW
>>>>> _______________________________________________
>>>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum
>>>>> available to all interested persons worldwide without requiring
> membership.
>>>> Opinions expressed
>>>>> are solely those of the author, and do not reflect the official
>>>>> views
>>>> of AMSAT-NA.
>>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
>>>> program!
>>>>> Subscription settings:
>>>>> http://www.amsat.org/mailman/listinfo/amsat-bb
>>>> _______________________________________________
>>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum
>>>> available to all interested persons worldwide without requiring
> membership.
>>>> Opinions expressed
>>>> are solely those of the author, and do not reflect the official
>>>> views of AMSAT-NA.
>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
>>>> Subscription settings:
>>>> http://www.amsat.org/mailman/listinfo/amsat-bb
>>>>
>>>
>>> --
>>> Andrew Koenig
>>>
>>
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available to
> all interested persons worldwide without requiring membership. Opinions
> expressed are solely those of the author, and do not reflect the official
> views of AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
expressed
> are solely those of the author, and do not reflect the official views of
AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>
>
>
------------------------------
Message: 9
Date: Wed, 17 Jun 2015 12:59:24 -0400
From: Paul Stoetzer <n8hm@xxxx.xxx>
To: Nicholas Mahr <nicholasmahr1@xxxxx.xxx>
Cc: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] EO-80 FM Transponder Tested (noise floor?)
Message-ID:
<CABzOSOpKzooWnEH+4SaXhssJsd8ojgWQ96+i2LA3snvXaaVuaw@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
The noise peaks on AO-7 are actually coming through the transponder,
not local interference. I don't know if they've always been there or
not, but often the noise peaks are stronger than any of the signals in
the passband.
As far as SO-50, the transmitter running at just 250 mW is probably
part of the reason why the batteries have lasted 13.5 years. AO-27
could only operate the FM transmitter for short periods during it's
orbit and AO-51's batteries lasted only 7 years.
Keep in mind that you'll be able to hear EO-80 and Fox-1 much better
through the trees, but now your uplink signal will be impacted more by
the trees. One medium deciduous tree attenuates signals on 70cm by up
to 10.5 dB.
SO-50 is lots of fun, but it can be frustrating because so many people
just can't hear it and continue to transmit anyway. I hope lots of the
problems we see day-to-day using SO-50 will be reduced by the stronger
signals of EO-80 and the Fox-1 series. One minor thing is that tuning
the uplink will be a bit trickier than tuning the downlink for
stations that are running half duplex. They'll have to remember to
tune the transmit frequency up 5 kHz about 4 times during the pass.
Anyone who wants to program memories for EO-80 should follow this plan:
EO-80 AOS - TX 435.070 MHz 210.7 Hz CTCSS, RX 145.840 MHz
EO-80 2 - TX 435.075 MHz 210.7 Hz CTCSS, RX 145.840 MHz
EO-80 TCA - TX 435.080 MHz 210.7 Hz CTCSS, RX 145.840 MHz
EO-80 4 - TX 435.085 MHz 210.7 Hz CTCSS, RX 145.840 MHz
EO-80 LOS - TX 435.090 MHz 210.7 Hz CTCSS, RX 145.840 MHz
73,
Paul, N8HM
On Wed, Jun 17, 2015 at 12:42 PM, Nicholas Mahr <nicholasmahr1@xxxxx.xxx>
wrote:
> I notice 2M has a high noise floor when im working AO-7, Theres a few same
> spots on the passband that have these giant swooshing sounds/etc, It wont
> be a problem on EO-80 as I as well have found it dosent affect me on FM,
> maybe EO-79. Looks like we wont have to wait for FOX-1 in september to
> cover for SO-50... Its really hard to do portable FM operations here where
> I live, theres lots of trees, so it makes working SO-50 very difficult
> because of its 250 mw power, I wish they would just increase the power on
> the thing.
>
> 73 KE8AKW
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
expressed
> are solely those of the author, and do not reflect the official views of
AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 10
Date: Wed, 17 Jun 2015 13:05:13 -0400
From: Paul Stoetzer <n8hm@xxxx.xxx>
To: Joe <nss@xxx.xxx>
Cc: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Subject: Re: [amsat-bb] EO-80 FM Transponder Tested (noise floor?)
Message-ID:
<CABzOSOpfiB0Uh-x22a8VmwkQzveBo4LkeisLurR+26g8-nAhwQ@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=UTF-8
Mode A would be fun, but equipment to work VHF/UHF is so common these
days, I'm not sure there's much point in a 10m downlink. Mode B and
Mode J are really not that much more difficult than working Mode A and
have advantages (noise floor and antenna size, especially).
The real problem is deploying a good 10m antenna from a cubesat to
produce a decent signal on the ground. 10m uplinks, on the other hand,
are something to look into (as W2RS has presented in numerous forums).
With NO-84, we now have a good experimental 10m uplink to test out.
Since ground stations can usually increase power to compensate from a
loaded antenna on the satellite, the use of a short antenna from a
cubesat for an uplink receiver isn't as much of a problem.
73,
Paul, N8HM
On Wed, Jun 17, 2015 at 12:43 PM, Joe <nss@xxx.xxx> wrote:
> why can we not get an old skool mode "A" back?
>
> Joe WB9SBD
> Sig
> The Original Rolling Ball Clock
> Idle Tyme
> Idle-Tyme.com
> http://www.idle-tyme.com
>
> On 6/17/2015 11:26 AM, Robert Bruninga wrote:
>>
>> I also am a proponent ot using 2m for weak downlinks because of the 9 dB
>> advantage. But it has been pointed out to me that there is a higher
>> background noise component that needs to be considered. I have not done
>> this. My assumption is that the noise floor at 2m is maybe about 3 dB
>> worse than at 70cm?
>>
>> So 2m still wins, but I'm not sure of what the real noise floor is.
>>
>> Bob, WB4aPR
>>
>> -----Original Message-----
>> From: AMSAT-BB [mailto:amsat-bb-bounces@xxxxx.xxxx On Behalf Of Zach
>> Leffke
>> Sent: Wednesday, June 17, 2015 11:23 AM
>> To: amsat-bb@xxxxx.xxx
>> Subject: Re: [amsat-bb] EO-80 FM Transponder Tested
>>
>> Paul beat me to the punch as I was typing up my response, but I'm sending
>> it anyway:
>>
>> Path Loss. -> function of lambda (wavelength) squared.
>> So all other things being equal (antenna gains, power levels, range,
>> etc.), you can look at the power ratio of the two.
>>
>> Rough calculation (going from 2m to 70cm):
>> 10log[(0.70/2)^2] = -9.1 dB
>> OR
>> Rough calculation (going from 70cm to 2m):
>> 10log[(2/0.7)^2] = +9.1 dB
>>
>> The thing to watch out for is antenna gains on the ground. The arrow for
>> example has more gain on 70cm (7el) than it does on 2m (3el). So while 2m
>> has a 9-ish dB improvement over 70cm in terms of path loss, the receiver
>> may not see the full 9dB because of the difference in gains on the antenna
>> between the two bands.
>>
>> Again VERY rough approximation (for demonstration purposes only):
>> 3el yagi -> call it 7.5 ish dB of gain
>> 7el yagi -> call it 11.5 ish dB of gain
>> so, about 4 dB of LOST gain (going from 70cm to 2m using the arrow
>> example).
>>
>> So net gain going from 70cm to 2m (all other things equal except the gains
>> on the arrow antenna) 9dB - 4dB = 5dB
>>
>> so your typo was actually fairly close :-) for those planning to use their
>> existing setup for the new birds.
>>
>> -Zach, KJ4QLP
>>
>> On 6/17/2015 10:43 AM, Andrew Koenig wrote:
>>>
>>> *9dB (typo)
>>>
>>> On Wed, Jun 17, 2015 at 9:42 AM, Andrew Koenig <ke5gdb@xxxxx.xxx> wrote:
>>>
>>>> Can you explain the 6dB advantage 2m has over 70cm? I've seen it here
>>>> on the amsat-bb, and in the mesh realm when comparing 2.4GHz and
>>>> 5.8GHz WiFi gear, but it still hasn't "clicked."
>>>>
>>>> 73 de KE5GDB
>>>>
>>>> On Tue, Jun 16, 2015 at 6:56 PM, Paul Stoetzer <n8hm@xxxx.xxx> wrote:
>>>>
>>>>> Nick,
>>>>>
>>>>> It should be even stronger than AO-27's 500 mW, AO-27 had a 70cm
>>>>> downlink, the EO-80 downlink is on 2 meters, so EO-80's signal
>>>>> should be up to 9 dB stronger than AO-27 (12 dB stronger if they run
>>>>> it at 1 watt).
>>>>>
>>>>> 73,
>>>>>
>>>>> Paul, N8HM
>>>>>
>>>>> On Tue, Jun 16, 2015 at 7:49 PM, Nicholas Mahr
>>>>> <nicholasmahr1@xxxxx.xxx>
>>>>> wrote:
>>>>>>
>>>>>> Thats very good news, Hopefully the two get activated before field
>>
>> day?
>>>>>
>>>>> Im
>>>>>>
>>>>>> most looking forward to EO-80, It should be like AO-27 with 500Mw or
>>
>> 1W.
>>>>>>
>>>>>> Good to know both are working well and wish a long life to them.
>>>>>>
>>>>>> 73 KE8AKW
>>>>>> _______________________________________________
>>>>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum
>>>>>> available to all interested persons worldwide without requiring
>>
>> membership.
>>>>>
>>>>> Opinions expressed
>>>>>>
>>>>>> are solely those of the author, and do not reflect the official
>>>>>> views
>>>>>
>>>>> of AMSAT-NA.
>>>>>>
>>>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
>>>>>
>>>>> program!
>>>>>>
>>>>>> Subscription settings:
>>>>>> http://www.amsat.org/mailman/listinfo/amsat-bb
>>>>>
>>>>> _______________________________________________
>>>>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum
>>>>> available to all interested persons worldwide without requiring
>>
>> membership.
>>>>>
>>>>> Opinions expressed
>>>>> are solely those of the author, and do not reflect the official
>>>>> views of AMSAT-NA.
>>>>> Not an AMSAT-NA member? Join now to support the amateur satellite
>>
>> program!
>>>>>
>>>>> Subscription settings:
>>>>> http://www.amsat.org/mailman/listinfo/amsat-bb
>>>>>
>>>>
>>>> --
>>>> Andrew Koenig
>>>>
>>>
>>
>> _______________________________________________
>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available to
>> all interested persons worldwide without requiring membership. Opinions
>> expressed are solely those of the author, and do not reflect the official
>> views of AMSAT-NA.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>> _______________________________________________
>> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
>> to all interested persons worldwide without requiring membership. Opinions
>> expressed
>> are solely those of the author, and do not reflect the official views of
>> AMSAT-NA.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>>
>>
>>
>
> _______________________________________________
> Sent via AMSAT-BB@xxxxx.xxx. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Subject: Digest Footer
_______________________________________________
Sent via amsat-bb@xxxxx.xxx.
AMSAT-NA makes this open forum available to all interested persons worldwide
without requiring membership. Opinions expressed
are solely those of the author, and do not reflect the official views of
AMSAT-NA.
Not an AMSAT member? Join now to support the amateur satellite program!
http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
End of AMSAT-BB Digest, Vol 10, Issue 168
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