Are those who are working AO-51 mode L/S mostly using rotors and tracking software? What are you using to keep the antennas pointed for mode L/S and what are you using for antennas?
Eric
Eric,
Are those who are working AO-51 mode L/S mostly using rotors and tracking
software?
Yes, though in some cases the rotators are "Armstrong Rotators." That is, hand-held antennas.
What are you using to keep the antennas pointed for mode L/S and what are
you using for antennas?
Any AZ-EL array will work fine. The beam widths are not that narrow. For the S-band side, most people use a small dish, though AO-51 is so loud that even a modest Yagi or loop Yagi is fine. For the L-band, a linear Yagi or a helix. NOVA, SATPC32, Ham Radio Deluxe, or something like a TrakBox will easily handle for pointing the antennas.
At these frequencies, the real need is for computer frequency control to compensate for the Doppler. It can be done manually, but if you don't have that, you are going to be spending a lot of time talking yourself back on frequency, and giving and asking for repeats. SATPC32 of course works perfectly, and the new, improved Ham Radio Deluxe has performed well.
Alan WA4SCA
On 13 Nov 2008 at 11:01, Eric Fort wrote:
Are those who are working AO-51 mode L/S mostly using rotors and tracking software? What are you using to keep the antennas pointed for mode L/S and what are you using for antennas?
Eric
Hi eric here is my setup
On 2.4GHZ Vagi Series WiMAX Directional Antenna 2500 to 2700 MHz Operation.....She seems to perform not too badly at 2.4! Features o Compact, Low Profile 16 dBi Antenna Gain Kind of double row yagi!!! very odd design o Lower cost compared to other 16dBi Gain Antennas 70$+- o Very Low Wind Loading. Aesthetic design o QuikClamp Bracket for 1.0" to 1.5" Pole Diameter o 45 Deg tilt and 360 Deg rotation adjustments o Vertical or Horizontal Polarization o 30" Pigtail with Type N Female or N Male Connector o Rugged, Lightweight and Waterproof
On L band
25 elem loop yagi from Directive system with about 18W at the antenna.
I have orbitron tracking in azimuth and i manually control the elevation
I finally found a way to fully doppler control the doppler on both uplink and downlink using 2 programs as HRD does not work with my Yaesu FT-847 one of the first put on the market with the one way CAT system.
I am in a learning process with the PC assisted doppler control and i will try to implement doppler control on S and L band but i will have to tweak and play with the IF'S on the downconverter and transverter...and this will not an easy task!
BTW manual doppler adjustment is possible on S/L mode but it's like a circus juggler you have to get some practice but when you became familiar with the process you can have a full pass QSO.
"-"
Luc Leblanc VE2DWE Skype VE2DWE www.qsl.net/ve2dwe WAC BASIC CW PHONE SATELLITE
Hi Eric,
Yes, especially for S-band, but that's because my antennas are both narrow beamwidth. I suppose that you could use something much more blunt, given the lower altitude of AO-51, as compared with my setup which was designed for AO-40. I only have 10 watts at shack-level on L-band, and with an 18 turn helix it's plenty, even after all that cable. My configuration has an active Az/El rotor system, controlled by my Linux PC, running predict software and a homebrew controller.
Greg KO6TH
Date: Thu, 13 Nov 2008 11:01:59 -0800 From: eric.fort@gmail.com To: amsat-bb@amsat.org Subject: [amsat-bb] ao-51 mode L/S
Are those who are working AO-51 mode L/S mostly using rotors and tracking software? What are you using to keep the antennas pointed for mode L/S and what are you using for antennas?
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participants (4)
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Alan P. Biddle -
Eric Fort -
Greg D. -
Luc Leblanc