[amsat-bb] Geostationary & HEO Satellites

[Jim Sanford]

Very much what  I see with my satellite internet -- if I ping something, 
I see delay between 600 - 800 msec.

Jim

wb4gcs at amsat.org


On 2/8/2019 4:20 PM, Paul Andrews wrote:
> Simon,
>
> I spent 20 years building data circuits using geosynchronous satellites.
> During that time, my definition of round trip was
> uplink-dowlink-uplink-downlink or 4 x 150ms (plus or minus a small amount
> of Doppler).
>
> Yes - you're correct - the loopback delay is 300ms.  But if you communicate
> with another person on Earth, the round trip delay is 600ms.
>
> If you tell someone a joke, you won't hear the laugh until after a 600ms
> delay.  This is only true for a good joke.  Tell a bad joke and the delay
> will be infinite.  :O
>
> 73 - Paul - W2HRO
>
>
>
>
> On Fri, Feb 8, 2019, 16:09 Simon Brown <simon at sdr-radio.com> wrote:
>
>> Paul,
>>
>> Unless there's significant latency inside the satellite, I think you're
>> out by a factor of two. Round trip is 2 x 40,000 km (*) = 80,000 km total.
>> Speed of light and radio latency says we're looking at closer to 300 ms.
>>
>> (*) depending on where you are on the mother planet.
>>
>> Simon Brown, G4ELI
>> www.sdr-radio.com
>>
>>
>> -----Original Message-----
>> From: AMSAT-BB <amsat-bb-bounces at amsat.org> On Behalf Of Paul Andrews
>> Sent: 08 February 2019 19:27
>> To: Les Rayburn <les at highnoonfilm.com>
>> Cc: AMSAT BB <amsat-bb at amsat.org>
>> Subject: Re: [amsat-bb] Geostationary & HEO Satellites
>>
>> GEOSATs have another interesting characteristic.   600 ms round trip
>> delay due to the longer distance.
>>
>> Does anyone remember when MCI first started providing a discounted long
>> distance telephone service?
>>
>> This will make voice QSOs a little unnatural but certainly not impossible.
>>
>> 73 - Paul - W2HRO
>>
>>
>>
>>
>>
>> On Fri, Feb 8, 2019 at 12:21 PM Les Rayburn <les at highnoonfilm.com> wrote:
>>> I’m also a newcomer to the birds, but very excited about it. Likewise, I
>> responded to the survey, but wanted to comment further regarding
>> geostationary and HEO satellites.
>>> In the camp of “Both, please.” The HEO birds would once again offer the
>> possibility of DXCC and make WAS more realistic—it also offers more
>> operating challenges.
>>> But a geostationary amateur satellite would have many interesting
>> benefits:
>>> Provide an easier introduction to satellite operation, and attract new
>> operators.
>>> Excellent tool for emergency communications during a natural disaster.
>>> Opportunity to experiment with microwave operations.
>>> The ability to enjoy satellite operation any time of the day/night. The
>> band is always open.
>>> I’m grateful for anyone who incorporates amateur radio into their
>> satellites, but feel that birds should include either linear, digital, or
>> FM transponders whenever possible. Designers are asking a lot of hams when
>> they solicit our monitoring their telemetry signals, and using amateur
>> spectrum for their purposes without much tangible benefit to us. My opinion
>> only.
>>> It’s wonderful that they asked us. Dialogue is the key to most human
>> accomplishment.
>>>
>>> 73,
>>>
>>> Les Rayburn, N1LF
>>> Maylene, AL
>>> EM63nf
>>> AMSAT #38965, ARRL Life Member, CVHS Life Member, SVHF Member
>>>
>>>
>>>
>>>
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>> _______________________________________________
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>> _______________________________________________
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>> to all interested persons worldwide without requiring membership. Opinions
>> expressed
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> _______________________________________________
> Sent via AMSAT-BB at amsat.org. 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

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