OK, must have missed his first post where he mentions the fact.   But why does the report back mechanism has to work in order for doppler correction to work ? SatPC32 just calculates the correct frequencies based on satellite data and current position / relative movement. It then sends the set frequency command to the radio, regardless what it's current frequency is. It does that in adjustable intervals. So IMHO it wouldn't be necessary to read the current frequency back from the FT 847. In fact I am not sure if SatPC32 even does read the frequency from the radio, even if it can.   Andreas - VK4TH

________________________________ From: "kq6ea@verizon.net" kq6ea@verizon.net To: hawat1@yahoo.com; w1pa@hotmail.com; amsat-bb@amsat.org Sent: Wednesday, 29 May 2013 9:51 AM Subject: Re: [amsat-bb] Re: a cheap LEO tracker for single op

Guys, in his FIRST post he mentioned he had a very early FT-847.

The early FT-847's did NOT support two-way CAT communication for frequency and mode. You could command the radio, but it lacked the capability to report the frequency back to the control software.

Yaesu modified the radios, but that was a long time agao, and if the radio didn't get modified then, you're out of luck as there are no more parts.

The change over point is somewhere in the 8G05xxxx range.

73, Jim  KQ6EA

On 05/28/13, Andy Kellnerhawat1@yahoo.com wrote:

FT 847 no computer assisted doppler ? Why ?

My FT 847 happily gets its doppler correction from SatPC32 - all you need is a cable.

Add a cheap tv rotor and a bit of homebrew software and you are all set ! ( http://evolution2enterprises.com/sat/sat.html )

This system works well for me for about 2 years now. Have since upgraded to higher gain antennas, though.

Cheers,

Andreas - VK4TH

________________________________ From: Bill (W1PA) w1pa@hotmail.com To: amsat-bb@amsat.org Sent: Wednesday, 29 May 2013 12:54 AM Subject: [amsat-bb] a cheap LEO tracker for single op

Again, thinking to FD...

- My FT-847 predates bi-directional CAT  i.e. no computer assisted Doppler - I may be the only one at the station i.e. no helper to man the antenna (Arrow), so I may need to do everything. - assume the transponder LEO birds

Has anyone tried this?:

1) mount a standard TV antenna horizontal 2) align the horizontal rotor axis 90 deg to the orbit   tilt (inclination?) of the intended bird (so if the bird went directly overhead, a beam mounted on the mast would track) 3) but, mount the antenna on the horizontal mast such that it can be set tilted off the mast   0 to 90 degs to the mast axis (from horizon to zenith, and in practice set it to the maximum elevation of the intended pass) 4) operation: set the rotator (in 2) and aim the beam to the AOS   point of the pass (in 3), pan the orbit remotely from the operator position. 5) the rotator axis and angle of the beam to mast would have to be set for each pass.

Do-able?

Bill W1PA

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