ISS Crossband Repeater Active

[WB2UZR]

The crossband repeater on the International Space Station has been active the last couple of days. Listen on 145.800 when it's in your area. I worked through it last night with my handheld and 2.5 watts. I believe there is going to be a certificate available for working through it or hearing it for the 25th anniversary of hams in space.

Scott/WB2UZR

[Bill_White]

ARISS to Celebrate 25 Years of Amateur Radio in Space with Special Events:
http://www.arrl.org/news/stories/2008/12/01/10481/?nc=1

[bearcat012]

Originally Posted by WB2UZR

The crossband repeater on the International Space Station has been active the last couple of days. Listen on 145.800 when it's in your area. I worked through it last night with my handheld and 2.5 watts. I believe there is going to be a certificate available for working through it or hearing it for the 25th anniversary of hams in space.

Scott/WB2UZR

Scott,

What is the Xmit freq?

Thanks,

[mancow]

Found this but don't know if it's correct for the uplink... I did hear the 145.800 downlink several times yesterday.

The uplink is UHF (437.800 MHz) which can have up to 10 KHz of Doppler either side of the center frequency.

Downlink is 145.800 MHz. No PL tone.

[WB2UZR]

The uplink is 437.800, +/- doppler. There is some good info at:http://www.southgatearc.org/news/oct...es_popular.htm

I worked it earlier with 1W and the handheld, a bit of a challenge, but it is doable. It was almost an overhead pass.

Good Luck!

Scott/WB2UZR

[LarryMax]

Are any of guys getting sstv or is it all voice?

I've monitored 2 passes today and haven't heard a thing. I will have 3 very close passes during the rest of the afternoon. I hope to get some pics.

[ka3jjz]

Remember that during spacewalks and other functions (such as Soyuz docking), the radio is taken off line.

Here is an article - from 2004 - on how to work the cross band repeater. While a few of the details might be a bit dated, there's enough tech data here - like how to adjust for Doppler - that makes keeping this around worthwhile...

http://www.arrl.org/news/features/2004/10/06/1/?nc=1

73 Mike

[WB2UZR]

Originally Posted by LarryMax

Are any of guys getting sstv or is it all voice?

I've monitored 2 passes today and haven't heard a thing. I will have 3 very close passes during the rest of the afternoon. I hope to get some pics.

SSTV has not been active for a bit now, it has been all crossband repeater the last 3 days or so. It has been quite strong here, shouldn't be a problem.

Scott/WB2UZR

[kb9hgi]

I heard the ISS this moring while in range but was ob packet. Darn my luck! not setup for packet no more was hoping to catch then on voice. Anyone know if they have a schedule between voice and packet?

[ka3jjz]

Not exactly a schedule per se - the crew are performing various experiments with the current gear which vary each week. See the following for a better explanation;

http://www.amsat.org/amsat-new/index.php

Interestingly there's a L band test coming up. I wonder if they're using a downconverter, because the Kenwood doesn't cover that band.

73 Mike

[WB2UZR]

I have to look around, but I think they are using a D700, which has wideband receive, I believe.

Scott/WB2UZR

[WB2UZR]

As an FYI, the ISS has been using packet for several days at least now. It has been back and forth between 1200 and 9600 baud, check both 145.800 and 1456.825 for activity. The crossband voice repeater should be reactivated next week as per the AMSAT site info.

[ka3jjz]

From the description on the Universal website, you're right - it goes from 118 Mhz-1.3 ghz, which would cover the L band. I guess they're going to try out some of those new antennas that went up on a shuttle mission during the summer. Interesting for the satellite folks...73 Mike

[WB2UZR]

Some technical stuff from the SAREX reflector:



All
For those of you that may be considering trying to make a contact with
the ISS on L band, here is the data you need to help you decide on how
to do it.
The measured sensitivity of the L band receiver on a D700 is -105dBm
for full quieting. The cable loss from the radio to the antenna is
9.3db. The antenna gain is zero db.
The polarization is LHCP. The path loss at the horizon on L band is
-160dB. That means the required EIRP for a full quieting contact at
the horizon is 65dBm. The path loss decreases by 15dB at 80 degrees
elevation so that means you can get full quieting with 50dBm in that
case. To further elaborate if you use a 20dB gain antenna ( a small
dish).
You can do it with 32 watts at the horizon or 1 watt at 80 degrees
elevation.

Good luck with your efforts.
I will try to answer your questions.


Lou McFadin
W5DID
ARISS US Hardware manager

[thom]

At 1:55-2:00 EST, have been receiving a female voice continuously calling Houston on 143.625. She couldn't connect.

[WB2UZR]

Someone reported that as well locally here in Florida. That is the VHF-1 frequency, usually used for comms to Moscow apparently.

Scott/WB2UZR

[WB2UZR]

Originally Posted by thom

At 1:55-2:00 EST, have been receiving a female voice continuously calling Houston on 143.625. She couldn't connect.

PS
That voice was crew member Sandy Magnus.

Scott/WB2UZR

[thom]

If I remember correctly, I used to listen to MIR on this frequency.

[KA6RBJ]

Originally Posted by WB2UZR

The uplink is 437.800, +/- doppler. I worked it earlier with 1W and the handheld, a bit of a challenge, but it is doable. It was almost an overhead pass.

The autopatch code is *1 to go off-hook, and *0 to hang up. Calls are restricted to non-Earth intergalactic phone calls only.

73's,
KA6RBJ

[ka3jjz]

Originally Posted by thom

If I remember correctly, I used to listen to MIR on this frequency.

And it's use is problematic at best. I remember the late Ron Parise playing a tape recording from the 80s using a handheld to listen to that frequency. It was horribly clobbered with intermod from Mexican taxi drivers using illegal (and mis-adjusted) 2m amps and radios. What a mess! 73 Mike