Hi Drew!

The range of audio levels coming out of the SQRX on SSB is difficult to match to the FM transmitter. If you recall we've had problems with too strong stations on SSB up causing the FM transmitters to behave poorly and overdeviate. I can only imagine it would be 100 times worse on Field Day. It's a good mode when everyone behaves though!

I guess I've missed those passes you mentioned. The issues I've heard working the cross-mode V/U passes tends to be centered on stations aligning their uplink signals to be heard by the SQRX receiver while compensating for Doppler. Even at 2m, that can be a challenge with an uplink receiver that has filtering to pass - I think - 4 kHz in SSB. Not the same as working FO-29 or HO-68 in SSB with the larger passbands.

It is interesting that an organization like AMSAT, one that is trying to increase membership and raise funds for a new satellite, would try to limit the usefulness of its prime satellite to a few dozen stations (number based on WA4SCA's message from earlier today regarding L/U activity during Field Day last year) during the busiest on-air activity for hams across North America. Yes, V/U may be chaotic, no matter if the uplink mode is FM or SSB for Field Day. Work 20m SSB during Field Day, and that is also chaotic. We don't try to have ARRL rule out using SSB or CW on 20m during that weekend. Even V/U FM on AO-51 is a "good mode when everyone behaves", ;-)

Again, just some thoughts and observations. It is good to see the discussion about something related to satellite operation here on the -BB. 73!

Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/

..... Good Stuff Clipped ......

One option that hasn't been floated is trying a mode switch on the early AM Sunday pass. We could go from L/U to V/U very easily. If we do this, I'd like to work with Bruce and actually count the number of QSOs reported per mode.

73, Drew KO4MA

That's a novel idea! I would support a mode change. They kept things interesting on AO-13 during Field Day.

73, Joe kk0sd

The trouble with V/S is that any clueless group trying to make a sat contact will be blindly transmitting on the 2m uplinks. Since nothing is being heard on the UHF downlink, they think the bird is open, so call CQ even more. Their thinking mode V/U, it totally blows away the S band D/L. This happened 3 or 4 years ago. The whole pass was people calling CQ FD without listening to the mode s D/L. A disaster. I don't think I heard even 1 contact being made on several east coast passes I tried. We have to remember there are a lot of groups trying to make a sat contact for the points, that don't read this SIG, so they just try calling on the V/U frequencies. I'm for L/U. It would be cool to try L/S, but I think I was told it isn't possible because it wouldn't leave a channel for control?

73 Jeff kb2m

-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Alan P. Biddle Sent: Wednesday, May 05, 2010 8:50 AM To: AMSAT-BB Subject: [amsat-bb] Re: Field Day AO-51 configuration - another option

One thing I would like to see tried, perhaps for one FD as a test, would be to relax the restrictions on FM mode contacts where one or both of the frequencies is above 70 cm. That would certainly encourage people to try L/U or V/S. Based on last year's numbers, every L/U station could have worked every other station easily, given the shortness of a FD QSO. Considering that people manage to work these modes portable, and in the case of N5AFV, mobile, it is relatively easy to get on. The mode-S downlink is truly loud, easily overcoming the general 2.45 GHz QRM/QRN.

Alan WA4SCA

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With other birds like AO-27 and SO-50 already in V/U FM mode and FO-29 VO-52 and possible AO-07 in SSB mode, I vote for L/U or V/S. The reason is during FD, we end up with stations/operators that have NEVER worked satellites before and end up adding to the already unusable uplink. It will also add flavor to the mix for FD.

I feel that AO-51 during FD ends up being a contest of WHO HAS THE MOST POWER! WHO CAN FIND THE BIG AMP. Those are the few stations that end up making the contacts.

----- Original Message ----- From: "Mike Benonis" mailinglists@benonis.net To: "BB" amsat-bb@amsat.org Sent: Wednesday, May 05, 2010 10:50 AM Subject: [amsat-bb] Re: Field Day AO-51 configuration - another option

I would vote for switching from L/U to V/U. I would love an opportunity to work a satellite on L band, if only for the technical challenge of it. Mode S would be harder to do, as I'd have to build a downconverter to hear it (though such a project would not be totally out of the question).

My feeling is this--with 7(?) other birds up there, variety is a good thing.

73 de Mike KI4RIX

On 05 May 2010, at 07:19, Andrew Glasbrenner wrote:

...

No one is trying to limit the the usefulness. Exactly the opposite, the idea is to pick the mode that is the MOST useful. It's a quantity versus quality problem. On a typical V/U FM Field Day pass, very few contacts actually get made, and most of the pass (at least on the east coast) is nothing but a fragmented dogpile of pieces of calls, whistles, blowing in the mike, etc. Some people enjoy that, others walk away in disgust, and think "why would I want to be part of that mess".

It's my contention that we pick a mode on AO-51 that provides a more challenging goal for the technically inclined portion of the hobby, encourages clubs to actively seek help from their local AMSAT types, and provides a more civilized environment on just one of the eight LEOs likely to be active that weekend. Think of it as showcasing what amateur satellites can be like on days other than Field Day. By limiting the accessibility, we improve the quality of the experience for those actively participating, and just listening. Again, AO-51 is one of many satellites. If it were just AO-51, we wouldn't even be having this conversation.

One option that hasn't been floated is trying a mode switch on the early AM Sunday pass. We could go from L/U to V/U very easily. If we do this, I'd like to work with Bruce and actually count the number of QSOs reported per mode.

73, Drew KO4MA

73, Drew KO4MA

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Best regards,

Mike Benonis mike@benonis.net KI4RIX

---

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Hi Drew!

Thanks for your reply. Having this discussion out in the open is a good thing.

No one is trying to limit the the usefulness. Exactly the opposite, the idea is to pick the mode that is the MOST useful. It's a quantity versus quality problem. On a typical V/U FM Field Day pass, very few contacts actually get made, and most of the pass (at least on the east coast) is nothing but a fragmented dogpile of pieces of calls, whistles, blowing in the mike, etc. Some people enjoy that, others walk away in disgust, and think "why would I want to be part of that mess".

As with any other part of the hobby, if operators choose not to cooperate, problems like that will occur. The same thing happens on HF during a contest or trying to work a DXpedition. With cooperation, at least 40 or more QSOs could be completed on a 15-minute AO-51 V/U FM pass. It is unfortunate that some (many?) do not take the time to get familiar with satellite operating before Field Day weekend. In a less-than-perfect situation those operators who are able to complete the QSOs would be a great example of what the situation could be if we were in an emergency situation instead of a weekend operating exercise or "contest".

It's my contention that we pick a mode on AO-51 that provides a more challenging goal for the technically inclined portion of the hobby, encourages clubs to actively seek help from their local AMSAT types, and provides a more civilized environment on just one of the eight LEOs likely to be active that weekend. Think of it as showcasing what amateur satellites can be like on days other than Field Day. By limiting the accessibility, we improve the quality of the experience for those actively participating, and

.... and possibly paint an inaccurate picture of amateur satellite operation on days other than Field Day, to someone listening to the activity?

If only a few dozen stations are going to be able to use an L/U configuration throughout Field Day weekend, and even fewer an L/S configuration, is this really what amateur satellites are like on days other than Field Day? Beyond my own recordings of passes I have worked and listened to since early 2005, K8YSE has an archive of MP3 recordings of FM satellite activity over the past several weeks. Many passes that are not way out over an ocean will have more activity than an L/U or L/S pass will be able to offer with the current numbers of stations capable of those configurations. Right now, it is a "chicken and egg" situation - with only one satellite with L or S capability, not many will add these to their stations unless there were more options to use the gear. S is easier to deal with than L, with the strong downlink signals from AO-51 copyable with downconverters and simple S-band antennas, but still a smaller number of stations on S than V/U using FM, SSB, CW, etc.

Your response from earlier this morning included my comments about AMSAT and its fundraising goals and increasing its membership. I appreciate that you, as one who wears many hats for AMSAT (director, officer, volunteer, and probably a few others), picked up on that. AMSAT should be interested in ensuring that it is an organization interested in building up its membership. This, in turn, will help in the fundraising efforts. Otherwise, catering to a few dozen stations for Field Day weekend may turn off more people from taking up this part of our hobby than a crowded pass might. Judging from the numbers of unique callsigns in my log, I contend that the chaotic V/U FM passes during past Field Day weekends haven't kept people from getting out and trying the FM satellites.

If the scheduling caters to that small number of stations that can work L/U or L/S, this may cause some to think AMSAT is an elitist organization. I hear that from time to time at the hamfests I attend, whether I'm talking with some who were active in the days or AO-10, AO-13, or even in AO-7's first life in the 70s.

just listening. Again, AO-51 is one of many satellites. If it were just AO-51, we wouldn't even be having this conversation.

Since AO-51 has the flexibility that the other satellites lack, we are able to have this discussion regardless of the status of other satellites. If AO-51 was the only satellite, there would probably still be some discussion due to this satellite's flexibility.

One option that hasn't been floated is trying a mode switch on the early AM Sunday pass. We could go from L/U to V/U very easily. If we do this, I'd like to work with Bruce and actually count the number of QSOs reported per mode.

Now this would be interesting. There would need to be a command station available during the weekend - either a west-coast station during the last Saturday evening pass, or an east-coast station for the first Sunday morning pass - to make this work. Could you please check with the command stations, and see if this is something that you (or one of the other command stations) could commit to? Let's see if this is even possible, before the discussion shifts to which 2 modes will AO-51 have during Field Day.

Unfortunately, relatively few logs are submitted for AMSAT Field Day. Using additional resources like recordings from passes like those K8YSE has archived and information from stations that worked those passes would be useful.

Thanks for your time in having a discussion here on the -BB. I'm looking forward to seeing you in Dayton, and attending the AMSAT events over that weekend. 73!

Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/