Back in 2002, AO-40 was running K Band down (24,048 MHz)
G3WDG and I both had K band receivers. Charlie was running a ~10' dish? and I had just a 0.5m dish.
Charlie used circular polarization, so his receive signal didn't suffer from spin modulation. I was using a linear feed, so the signal would fade out for 2-3 secs or so as the polarization shifted from horizontal that I was running.
Here's my reception of Charlie's signal - our first successful L/k contact:
https://drive.google.com/file/d/1J_U7GIdrCr7A12XTqYmgs9L4HATyaMOJ/view?usp=s...
Here's Charlie's audio of me:
https://drive.google.com/file/d/13ffNjzyZcWNwino06wTFQn-5NVBBbmaF/view?usp=s...
Mike, N1JEZ
On 7/16/2018 6:21 PM, Zach Leffke wrote:
I think historically there have been some birds that operate in the higher bands. AO-40 comes to mind with downlinks in multiple microwave bands topping out at 24 GHz (didn't miss a period there...that was twenty four gigahertz, not two point four gigahertz, though AO-40 had that too). (ref: http://www.ne.jp/asahi/hamradio/je9pel/ao40freq.htm) There may be some others from the Phase 3 era with microwave uplink/downlinks, but I'm not as sure of the history there..
-Zach, KJ4QLP
Research Associate Aerospace Systems Lab Ted & Karyn Hume Center for National Security & Technology Virginia Polytechnic Institute & State University Work Phone: 540-231-4174 Cell Phone: 540-808-6305
On 7/16/2018 5:40 PM, Eric Fort wrote:
As one goes up in frequency the Doppler goes up. That said, these would be great on a geostationary bird or something that moved much slower than the short Leo passes for most of our satellites. There are some satellites build and pending launch for amsat phase IV in geosynchronous orbit. Those launches are not cheap though and rides are much more difficult to come by. At least a few of the sats awaiting launches will use the microwave bands you speak of for their uplink and downlink. The advantage of using that spectrum is multiple MHZ of passband (think the entirety of all amateur spectrum 6m and below easily on one transponder 24x7x~365.25 to anyone in the footprint. It would be nice if amsat would provide better support for these projects and the teams that work on them.
Eric
Sent using SMTP.
On Jul 16, 2018, at 5:29 AM, Samudra Haque [TTLLC] [email protected] wrote:
Hi, I am experimenting with RF carriers above 2 GHz in my lab. According to FCC and ITU tables there are several AMATEUR-SATELLITE bands allocated above 2 GHz, to very very high frequencies.
What is the status of those frequencies in terms of past, present or planned utilization on AMSAT / other satellites ?
If those bands haven't been used, should they be not used or plans to use them to protect them from being de-assigned to other services? Is there room for experimental RF super high frequency and extremely high frequency payloads on any mission to make some use of these great resource?
73 de Samudra N3RDX