AO-85 Amazing foot print

[VK4WDM]

I just monitored an amazing AO-85 pass from Townsville. I first heard the announcement from the satellite when it was crossing the south coast near the WA/SA border, heard it several times more as it moved north over central Australia and heard it for the final Time as it crossed the coast of West Papua. What an amazing foot print!

Unfortunately I did not work or hear any stations during the pass.

73

Wayne VK4WDM

[VK2AVR]

that's a great orbit. definitely will have to work this bird!

when you say "heard it" - is there a periodic beacon (FM/CW ident)? Or are you full duplex and hearing yourself on the downlink?

[VK4WDM]

Hi Geoff

FM. A YL announces "Hi, this is amateur radio satellite Fox 1" several times during the pass. It does not seem to get a lot of use. I have worked VK2 (VK2ZAZ seems to be the most active) and VK3 and heard VK6. I am using just split mode, I haven't got full duplex sorted as yet, to my terrestrial horizontal yagis.

73

Wayne VK4WDM

[VK7ZA]

It does not seem to get a lot of use.

I had a look again today and g-predict still doesn't show the satellite even after an update. Hopefully that will be resolved soon. If the other tracking applications rely on the same datasets, that may account for the lack of people working through it.

[VK4WDM]

Very low-tech prediction programs here. Heavens Above and NY2YO.com with manual tracking

73

Wayne VK4WDM

[VK2XTC]

Can I confirm the operating frequencies are:

Uplink 145.950
Downlink 435.8520

????


Brian

[VK4WDM]

Hi Brian

435.180 MHz uplink, 145.980 MHz downlink. FM. No tone needed.

73

Wayne VK4WDM

[VK3MQ]

Hi All,

To answer a few questions from the previous posts:

To include AO-85 in Gpredict it is necessary to download the tle's from AMSAT-NA
http://www.amsat.org/amsat/ftp/keps/cur ... sabare.txt
This file contains all the amateur sats. of interest as well and could be set as the default update location instead of CELESTRAK.

The uplink frequency is closer to 435.170MHz but the onboard AFC will counter any errors to some extent.

Whilst the downlink signal is very strong a failure of the receive antenna on launch means that it is far less sensitive than desireable. It is still posible to access the bird with 5 watts on an overhead pass but I find that at least 30 watts into my M2 30 element cross yagi is required.

A 67Hz tone is needed to trigger the transponder mode but I am told by Geoff VK2ZAZ that no tone is needed after that. I normally leave the tone on.

FOX-1 C & D will launch this year providing some more FM satellites with a switchable 23 cm uplink option

For my money the SSB birds are still the best performers and well worth the effort required to setup a good ground station.

Cheers,
Rob
VK3MQ

[VK3ANZ]

With regard to not getting an update for AO-85, I have the same issue with my "Satellite Tracker" (disclosure: this is an iPhone/iPad program that I sell) and some kind user (forget the name as I'm not on my home computer right now) found out why.
I use the celestrak.com web site for the TLEs for my program. Dr T S Kelso looks after that site and his explanation was that the satellite was launched on a "classified" (or some such name) rocket. While the satellite it launched is not classified in any way, the fact that it was on a classified rocket means that the TLE cannot be published officially (I think that web site gets the TLEs form NORAD). Dr Kelso has tried to get that decision altered (after all this is an amateur radio satellite) but the decision stands.
It could well be that the default web site that gpredict uses has the same restriction on it.
I'm guessing here but the underlying reason might be that the satellite's location might give some clue to the location of the payload(s) that are actually classified.
Whether or not you think this is nuts (after all the TLEs are published elsewhere) that is the situation.
Susan

[VK3ALB]

. . . . .

Whilst the downlink signal is very strong a failure of the receive antenna on launch means that it is far less sensitive than desirable. It is still possible to access the bird with 5 watts on an overhead pass but I find that at least 30 watts into my M2 30 element cross yagi is required.

. . . . . .

Cheers,
Rob
VK3MQ

I reckon I heard you calling once or twice last night Rob right in the middle of the passband. Very weak to me.

[VK3MQ]

Hi Lou,

Not last night, most of my operation is on the daytime passes. Right now I am waiting for Fuji Oscar 29 to appear -26 minutes to go!

Cheers,
Rob

[VK2XTC]

That's interesting ,

I've updated the keps and told the app to use the defaults.

I'm using MacDoppler and shows the uplink as 145.9800 and the downlink as 435.1800.

complete reverse... very strange... but explains why I never hear the bird !!



Brian

[VK3KGR]

From the AMSAT UK site.

"Measurements made by Alan Biddle WA4SCA indicate the downlink is consistently 1.400 kHz low at 145.9786 MHz. Reports indicate the uplink may be 10 kHz low of nominal frequency – 435.170 MHz."

Geoff

[VK7ZA]

To include AO-85 in Gpredict it is necessary to download the tle's from AMSAT-NA
http://www.amsat.org/amsat/ftp/keps/cur ... sabare.txt
This file contains all the amateur sats. of interest as well and could be set as the default update location instead of CELESTRAK.

Thanks Rob, that worked a treat!

[VK2CSW]

With regard to not getting an update for AO-85, I have the same issue with my "Satellite Tracker" (disclosure: this is an iPhone/iPad program that I sell) and some kind user (forget the name as I'm not on my home computer right now) found out why.
I use the celestrak.com web site for the TLEs for my program. Dr T S Kelso looks after that site and his explanation was that the satellite was launched on a "classified" (or some such name) rocket. While the satellite it launched is not classified in any way, the fact that it was on a classified rocket means that the TLE cannot be published officially (I think that web site gets the TLEs form NORAD). Dr Kelso has tried to get that decision altered (after all this is an amateur radio satellite) but the decision stands.
It could well be that the default web site that gpredict uses has the same restriction on it.
I'm guessing here but the underlying reason might be that the satellite's location might give some clue to the location of the payload(s) that are actually classified.
Whether or not you think this is nuts (after all the TLEs are published elsewhere) that is the situation.
Susan

I suspect this is an "ITAR" issue. ITAR is the International Traffic in Arms Regulations and is a set of United States Government regulations on the export and import of defence related articles and services. It is used to cover a bunch of stuff it was never designed to do, but that is what governments do, isn't it?

Unfortunately, it gets applied to just about anything that is installed on or carried by US military means. It is awfully hard to get it un-ITARed once it happens. I kid you not, I have worked on washing machines and hobart mixers that have been covered by ITAR - these are commercially available units but because the US supplied them on naval vessels we bought from them, they are assumed to be covered by ITAR.

I get to deal with this crap each and every day (Lucky me!!)

To answer your question:
I don't think it's nuts - I know it is.

[VK2GFR]

To include AO-85 in Gpredict it is necessary to download the tle's from AMSAT-NA
http://www.amsat.org/amsat/ftp/keps/cur ... sabare.txt
This file contains all the amateur sats. of interest as well and could be set as the default update location instead of CELESTRAK.
VK3MQ

Hi Rob, I have downloaded the program & updated the keps (as above), but I don't see (& yes my glasses are on) the AO-85 sats details.
Maybe it'll be under the NORAD cat number?
But also I can't list the Amateur sats as seperate from ALL sats to have in the "Favourites List".
Have I lost the polt?
Any help greatly appreciated.

[VK4WDM]

I am glad I am a low tech nerd. I just use "Heavens Above" and the N2YO predictor with manual tracking but I am started to get hooked so I probably need to learn about the more high tech stuff. I heard my first ZL on AO-35 yesterday but the bird disappeared before I could get in contact.

73

Wayne VK4WDM

[VK3MQ]

Hi Mark,

Sorry about the delay in replying, I am not monitoring this forum as much as I should,hi!

My version of Gpredict is running on a linux platform so my experience is only relevant to that. However the configuation files will be the same on Microsoft Windows but in a different directory structure.

The place to look will be in your home directory and in my case this will be:

/home/robert/.config/Gpredict/satdata/

Note the dot in the .config indicates a hidden directory tree. Your file manager can be set to make it visble.

The file of interest will be 40967.sat and should look something like this in a text editor:

[Satellite]
VERSION=1.1
NAME=AO-85
NICKNAME=AO-85
TLE1=1 40967U 15058D 15363.38242379 .00002253 00000-0 24809-3 0 00855
TLE2=2 40967 064.7803 043.6761 0216948 257.3619 100.3083 14.74602293011944

Note the "Name" and "Nickname" settings as these will be the ones appearing in the satellite list and on the maps. It is ok to edit this file and the files in the trsp directory but don't do it to the "modules" files.

With the above setting It should be visible as AO-85 in the satellite list. I wouldn't worry about the invisibilty of the amateur list as long as you can find the sats in the overall list.

Hope this helps. Gpredict has been a great program for me.

Cheers,
Rob
VK3MQ

[VK2GFR]

No worries Rob.
I did reload the keps but still no reference to the sat.
BTW I might try another tracking program as Gpredict appears not to have a screen predict like Gorbtrak did (& that was very handy too.)
Anyway thanks for your help with the prgm & edit keps info.
73 Mark.

[VK3MQ]

Hi Mark,

Gpredict does have a feature that could be described as a predict screen of sorts which you might have found already. Place your mouse pointer on the satellite of interest on the map or in the satellites table below the map and right click. This will bring up a dialog box with an option to show "Future passes". Select the one of interest with a right click and this will present the pass details in numerical, polar and Az/El formats.

Good luck and hope to hear you on a pass soon, I am QRV on all the sats.

Cheers,
Rob
VK3MQ