It has been about a month now since AO-51 was commanded back to its normal orientation. But many are reporting that they are having more trouble hearing it now than they did before the first re-orientation.
It does seem to me that some stations that usually hear very well are not hearing that well now. This morning's pass (9Feb2010 1045z) of AO-51 seemed to bear that out. AF6RF, KB1RVT, KE3LB, WD0X?, KJ4CBC, K5QXJ, WB2IOL and YF6BFE were on the pass and with a few exceptions, all were not able to hear at some point during the pass. There are also a few noisy uplink transmissions as well.
The recording can be downloaded at: http://www.papays.com/AO-51_09Feb2010_104452za.mp3 (there are no signals in the first minute of the recording)
Is anyone else having trouble hearing AO-51 as well as they heard it before the flip experiment?
73, John K8YSE
Hi John,
Have you looked to see what power levels we were running at the comparision times? Maybe that's part of it...
The orientation should be "back to the way it was" before the flip experiments. What might be differnet is power budget and therefore signal strength.
Anyhow, it's good to ask and compare notes!
73,
Mark
On Tue, Feb 9, 2010 at 10:47 AM, John Papay john@papays.com wrote:
It has been about a month now since AO-51 was commanded back to its normal orientation. But many are reporting that they are having more trouble hearing it now than they did before the first re-orientation.
It does seem to me that some stations that usually hear very well are not hearing that well now. This morning's pass (9Feb2010 1045z) of AO-51 seemed to bear that out. AF6RF, KB1RVT, KE3LB, WD0X?, KJ4CBC, K5QXJ, WB2IOL and YF6BFE were on the pass and with a few exceptions, all were not able to hear at some point during the pass. There are also a few noisy uplink transmissions as well.
The recording can be downloaded at: http://www.papays.com/AO-51_09Feb2010_104452za.mp3 (there are no signals in the first minute of the recording)
Is anyone else having trouble hearing AO-51 as well as they heard it before the flip experiment?
73, John K8YSE
Sent via AMSAT-BB@amsat.org. 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
By the way, John--a handy place to spot check power levels at various dates is here:
http://www.amsat.dk/oz7sat/tlm/view.php?sat=ao51 Just put in the dates you want to see.
And the full telemetry archive is on the AMSAT FTP server, so folks can grab, decode, and and analyze anything they want, for any telemetry that's been collected.
73,
Mark N8MH
On Tue, Feb 9, 2010 at 12:35 PM, Mark L. Hammond marklhammond@gmail.com wrote:
Hi John,
Have you looked to see what power levels we were running at the comparision times? Maybe that's part of it...
The orientation should be "back to the way it was" before the flip experiments. What might be differnet is power budget and therefore signal strength.
Anyhow, it's good to ask and compare notes!
73,
Mark
On Tue, Feb 9, 2010 at 10:47 AM, John Papay john@papays.com wrote:
It has been about a month now since AO-51 was commanded back to its normal orientation. But many are reporting that they are having more trouble hearing it now than they did before the first re-orientation.
It does seem to me that some stations that usually hear very well are not hearing that well now. This morning's pass (9Feb2010 1045z) of AO-51 seemed to bear that out. AF6RF, KB1RVT, KE3LB, WD0X?, KJ4CBC, K5QXJ, WB2IOL and YF6BFE were on the pass and with a few exceptions, all were not able to hear at some point during the pass. There are also a few noisy uplink transmissions as well.
The recording can be downloaded at: http://www.papays.com/AO-51_09Feb2010_104452za.mp3 (there are no signals in the first minute of the recording)
Is anyone else having trouble hearing AO-51 as well as they heard it before the flip experiment?
73, John K8YSE
Sent via AMSAT-BB@amsat.org. 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]
--- On Tue, 2/9/10, John Papay john@papays.com wrote:
From: John Papay john@papays.com Subject: [amsat-bb] AO-51 Signal Strength Post Flip To: amsat-bb@amsat.org Received: Tuesday, February 9, 2010, 8:47 AM It has been about a month now since AO-51 was commanded back to its normal orientation. But many are reporting that they are having more trouble hearing it now than they did before the first re-orientation.
It does seem to me that some stations that usually hear very well are not hearing that well now. This morning's pass (9Feb2010 1045z) of AO-51 seemed to bear that out. AF6RF, KB1RVT, KE3LB, WD0X?, KJ4CBC, K5QXJ, WB2IOL and YF6BFE were on the pass and with a few exceptions, all were not able to hear at some point during the pass. There are also a few noisy uplink transmissions as well.
The recording can be downloaded at: http://www.papays.com/AO-51_09Feb2010_104452za.mp3 (there are no signals in the first minute of the recording)
Is anyone else having trouble hearing AO-51 as well as they heard it before the flip experiment?
<snip>
In the past few weeks, I've often had problems hearing AO-51 here in DO33. A year ago, signals of at least S3 on my FT-817ND were common. Now they are weaker.
As well, I get the impression that the signal polarity has changed. Formerly, I could hold my Arrow dual-band Yagi with the 2 m elements nearly horizontal and still hear the satellite. Now, I have to turn it nearly 90 degrees, sometimes changing the orientation more than once during a pass.
Some of that I might attribute to my operating a portable station within a residential area in the city, but I definitely noticed a significant difference between what I hear from AO-51 now and what it was before the satellite was flipped.
73s
Bernhard VA6BMJ @ DO33FL
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Thanks for the reports.
Again, I encourage you all to research the power levels OUT at the comparison times. That has to at least be considered in the discussion.
For example:
Power is "watts" out
Date 435.150 435.300 Battery V
Before flips
2009-02-09 19:27:04 oz7sat 0 0.779 0.859 7.660 <--- 859 mW one year ago! compare to today, listed below!
2009-10-25 18:17:01 oz7sat 0 0.452 0.617 7.868
2009-11-25 17:41:51 oz7sat 0 0.361 0.744 7.581 <-- 745 mW before the flip!
2010-01-15 18:45:31 oz7sat 0 0.437 0.462 7.892
Currently:
2010-02-09 17:19:06 oz7sat 0 0.452 0.475 7.752 <-- 475 mW today!
We are running a few hundred milliwatts below what we were running pre-flip, and a good bit less than we were able to run a year ago. So you all may be seeing the difference between 600-850 mW and 475 mW. It's real.
Yes, the bird is aging, and we're doing the best we can to manage the resources available on-board (the limits now are orbit and battery condition) . The full illumination periods in the last year or two have taken their toll on the batteries. What will be interesting is to see what happens when we return to periods of eclipse!! Personally, I don't expect the situatio to improve, although it might be that the batteries will cool and some capacity will return. But we'll need it with eclipses.
73,
Mark N8MH
In the past few weeks, I've often had problems hearing AO-51 here in DO33. A year ago, signals of at least S3 on my FT-817ND were common. Now they are weaker.
As well, I get the impression that the signal polarity has changed. Formerly, I could hold my Arrow dual-band Yagi with the 2 m elements nearly horizontal and still hear the satellite. Now, I have to turn it nearly 90 degrees, sometimes changing the orientation more than once during a pass.
Some of that I might attribute to my operating a portable station within a residential area in the city, but I definitely noticed a significant difference between what I hear from AO-51 now and what it was before the satellite was flipped.
73s
Bernhard VA6BMJ @ DO33FL
__________________________________________________________________ Yahoo! Canada Toolbar: Search from anywhere on the web, and bookmark your favourite sites. Download it now http://ca.toolbar.yahoo.com. _______________________________________________ Sent via AMSAT-BB@amsat.org. 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
You are on-the-nose John.
Currently, I AOS and LOS AO-51 at higher elevations than before the initial flip. During high passes, the downlink is no longer DFQ or is as strong as before, and there are more fades (was better with leaves still on the trees!).
I have questioned my antenna calibration; it appears to be where it was previously. Clock, Keps, etc., all good too.
So that's my observation--jives with John's. Of course I am appreciative of the team keeping her chugging, but feedback is helpful I'm sure.
73, Elan WB2IOL
Also, would like to thank John for recording and posting downlink audio files. They're not only useful in evaluating signal quality, they're fun to listen to when I can't be in the shack!
Funny to hear myself mangle the call of the last station--still half-asleep--hi hi.
Didn't hear you at all John, but had less than 1 deg left in the pass.
Just read the explanation of our observations--makes perfect sense and again, thanks to those of you keeping the old girl kickin'
Elan
Another observation from DO33 (yo Bernhardt), I've always had trouble hearing this bird well enough to work from my home station, as I have my antennas at fixed elevation, and manually-rotated via channelmaster... AO-51 has been consistently easier to hear AFTER it has passed overhead on ascending passes. Between AOS and peak-elevation, it's always just above my noise. I don't have any observations about descending passes because I'm not up early enough to try those;) . I also can't say how that compares to pre-flip, as I never heard it well enough to work, except on very low passes, and didn't keep notes. I actually had the bird all to myself a few weeks ago, while everyone from the USA already had LOS, and I had almost full-quieting for many minutes in a row that time, until my LOS. This is what struck me as being a significant observation!
I hope this helps,
73's Auke ----- Original Message ----- From: "John Papay" john@papays.com To: amsat-bb@amsat.org Sent: Tuesday, February 09, 2010 8:47 AM Subject: [amsat-bb] AO-51 Signal Strength Post Flip
It has been about a month now since AO-51 was commanded back to its normal orientation. But many are reporting that they are having more trouble hearing it now than they did before the first re-orientation.
It does seem to me that some stations that usually hear very well are not hearing that well now. This morning's pass (9Feb2010 1045z) of AO-51 seemed to bear that out. AF6RF, KB1RVT, KE3LB, WD0X?, KJ4CBC, K5QXJ, WB2IOL and YF6BFE were on the pass and with a few exceptions, all were not able to hear at some point during the pass. There are also a few noisy uplink transmissions as well.
The recording can be downloaded at: http://www.papays.com/AO-51_09Feb2010_104452za.mp3 (there are no signals in the first minute of the recording)
Is anyone else having trouble hearing AO-51 as well as they heard it before the flip experiment?
73, John K8YSE
Sent via AMSAT-BB@amsat.org. 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
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--- On Tue, 2/9/10, Auke de Jong, VE6PWN sparkycivic@shaw.ca wrote:
From: Auke de Jong, VE6PWN sparkycivic@shaw.ca Subject: [amsat-bb] Re: AO-51 Signal Strength Post Flip To: amsat-bb@amsat.org Received: Tuesday, February 9, 2010, 9:42 PM Another observation from DO33 (yo Bernhardt),
Greetings. It's nice to hear from a fellow Edmontonian.
I've always had trouble
hearing this bird well enough to work from my home station, as I have my antennas at fixed elevation, and manually-rotated via channelmaster... AO-51 has been consistently easier to hear AFTER it has passed overhead on ascending passes. Between AOS and peak-elevation, it's always just above my noise. I don't have any observations about descending passes because I'm not up early enough to try those;) . I also can't say how that compares to pre-flip, as I never heard it well enough to work, except on very low passes, and didn't keep notes.
I live beside one of the biggest shopping centres in the city and I've got no obstructions from due N to nearly due NW for lower elevation passes. At much higher angles, I can follow it from nearly directly overhead to SSW.
In the past, I could tell when AO-51 was within view because the background noise would drop significantly. Since I'm operating a portable station, I use that to track it. Lately, it hasn't been as easy.
I actually had the bird all to myself a fewweeks ago, while everyone from the USA already had LOS, and I had almost full-quieting for many minutes in a row that time, until my LOS. This is what struck me as being a significant observation!
I've noticed that it's been rather quiet during later morning passes (say, after 1500 UTC).
<snip>
BTW, were you at the flea market at the Yellowhead Inn this past Saturday? I've been to each one since I got my callsign 5 years ago and I'm sure that this one had the most people. I was looking for a manual HF + 6 m tuner but couldn't fine one, but there were lots of other items that I bought that I could use.
It was a good opportunity to meet hams in person that I'd spoken to by radio, including some from local nets. It was certainly a good way to spend two hours.
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participants (5)
-
Auke de Jong, VE6PWN -
B J -
Elan Portnoy -
John Papay -
Mark L. Hammond