Some General Guidelines to Working the Birds with Omni Antennas: (My opinion for what it's worth; others may disagree.)
A lot of people are using omni antennas. Some use preamps and some do not. The important thing to remember when using omni antennas is that you will be getting into the bird much better than you can hear it, if you can hear it at all. A preamp will really help.
If you have a full duplex radio and can't hear yourself on the ssb downlink, there's a problem. If you can hear others, try calling them and see if you can make a contact. Don't call CQ if you can't hear yourself. You may be calling on top of a qso and if you are not doppler controlled, you will likely drift into a qso and cause interference. If you hear others on the bird, try to find yourself and determine your offset. Setting your uplink and downlink manually is challenging but not impossible. Use a program like SatPC32 to help you determine what tx frequency corresponds to the receive frequency. Ultimately, use the program to control your radio. Once you calibrate your uplink to your downlink, you will make more qso's. Make sure your computer clock is set to a few seconds of the correct time and your keps are current. If these are not set, you will not have the proper doppler control, especially when the bird is overhead and the frequency is changing rapidly. If you can only manage to change one of the frequencies, change the one that is higher (e.g. tx (UHF) on VO-52 and rx (UHF) on FO-29). The UHF frequency changes much faster than the VHF frequency.
On the FM birds, don't announce yourself unless you are full duplex, can hear yourself and there is little or no activity on the bird. Wait until you can hear other stations and then call someone you can copy. They will likely come back to you. Once you make a qso, others will call you so pay attention. If you are in an inactive grid, expect a pileup. Use a recorder so you don't have to write anything down. Don't disappear after your initial qso. Stay with it as long as you can hear. You will make more qso's.
There is always activity on any daylight pass of AO27 and AO51. If you don't hear anyone, you are likely not hearing the satellite.
As the bird comes over the horizon, adjust your fm rx frequency 10 KHz higher than the published center frequency. As the bird moves toward you, lower the frequency in 5 KHz steps. The bird should be on the center frequency when overhead and then -5KHz as it moves away and then -10KHz as it gets closer to the horizon. No computer control is necessary on the FM birds. When the audio sounds a little distorted, it's time to change the frequency. Use your ears; a computer is not necessary. It is not necessary to change your uplink (145 MHz) tx frequency.
Working the birds with omni antennas is challenging. As long as you know your limitations and operate accordingly, you will be fine. But don't expect to be able to hear very well. If omni antennas worked that well, everyone would be using them, and there would be a lot more than 21 stations that have 350 or more grids confirmed on satellite VUCC.
John K8YSE
Message: 2 Date: Tue, 4 Aug 2009 13:41:27 +0000 (UTC) From: aa2tx@comcast.net Subject: [amsat-bb] Re: FO-29 and VO-52 To: Jean-Fran?ois M?nard jf.va2ss@gmail.com Cc: AMSAT-BB@amsat.org Message-ID:
87800968.8532491249393287738.JavaMail.root@sz0024a.westchester.pa.mail.comcast.net
Content-Type: text/plain; charset=utf-8
Hello Jean-Francois,
I have worked VO-52 with omni antennas and an FT-817
on SSB with no problem at all. FO-29 should work?too as long
as there are no high-power stations pumping the satellite AGC.
73,
Tony AA2TX
----- Original Message ----- From: "Jean-Fran?ois M?nard" jf.va2ss@gmail.com To: AMSAT-BB@amsat.org Sent: Tuesday, August 4, 2009 8:53:17 AM GMT -05:00 US/Canada Eastern Subject: [amsat-bb] ?FO-29 and VO-52
Hi,
I would like to know if I'm dreaming, but will it be possible for me to use these two satellites with my pair of FT-817 running on SatPC32??
Am I asking too much for my 5W only radios ?? I'm using 2 Eggbeater antenna from M?... EB-144 and EB432 with AR? preamps on both antennas feed with heliax.
73
-- Jean-Fran?ois M?nard VA2SS
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On 4 Aug 2009 at 16:14, John Papay wrote:
Some General Guidelines to Working the Birds with Omni Antennas: (My opinion for what it's worth; others may disagree.)
A lot of people are using omni antennas. Some use preamps and some do not. The important thing to remember when using omni antennas is that you will be getting into the bird much better than you can hear it, if you can hear it at all. A preamp will really help.
With marginal receiving set up on SSB transponder sat there is a tendency to often use a lot of power to be able to hear their downlink signal. It's often the case on CW as it is a more effective mode it is not unusual to see the passband signals moving at the CW speed high power station.
I try to answer back a station on FO-29 using about 5W (O power setting on the Yaesu 847) the station who was calling CQ in SSB never get back to me until i increased my TX power to 50W on a 14 element cross yagi and he gave me a 55 report with a weak signal comment... I was receiving his signal near S9 here...
Another way to evaluate your receiving system is to be able to copy the satellite beacon. If you hear your downlink and not the beacon it is an indication that you "could be using too much power on the uplink"
A transponder satellite is a kind of sharing system a lot stations can use it at the same time providing they all use the lowest power. It takes only one station to scap the whole passband signals. I personally contact the "offending" station to advised him about the facts some times it works but there is still some who seems to never cares as i always see them returning to their high power habits.
On AO-40 LEILA was there to watch the offenders it was not perfect but it helps controlling the uplink powers. I try to find out my old recording of the LEILA siren but i only found the beacon signal if someone still has a recording on his web page just let us know it will at least makes us remember the HEO era. "-"
Luc Leblanc VE2DWE Skype VE2DWE www.qsl.net/ve2dwe WAC BASIC CW PHONE SATELLITE
Hi Luc and all,
I often listen to RS-22 and RS-30, and I can copy them as high as 1 or 2 degres with my setup. Iwas amazed the first time that I can copy beacon at a lower elevation like this. I don't know much about RS-22 and RS-30 beacon, but I use it as my reference for receiving.
I did my best that I can afford the moment in my setup..... heliax 0.5, AR² preamps at the top... and only 2 FT-817 at the bottom.
Be sure that I read all guidelines that people post. I know how important ham must follow good technique and habit for proper operation up there !! :-)
I'm still experimenting SSB calibration when using 2 half duplex controled radio.... It is a little bit tricky, but I will survive !! :-) I'm using CW for testing and calibrating.... using my headphone with a VHF TX CW sidetone in one ear and my UHF RX CW sidetone is another hear... I'm trying to zero beat as close as possible to know how much I must compensate between the rig. CW is less harmfull when doing this experiment.... and at 5W MAX only.
I'm already thinking for my next generation setup... when I will use beam and rotor... and a real full duplex satellite rig... ;-)
73
2009/8/5 Luc Leblanc lucleblanc6@videotron.ca:
On 4 Aug 2009 at 16:14, John Papay wrote:
Another way to evaluate your receiving system is to be able to copy the satellite beacon. If you hear your downlink and not the beacon it is an indication that you "could be using too much power on the uplink"
participants (3)
-
Jean-François Ménard -
John Papay -
Luc Leblanc