Ceduna L-band
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From: <Brett.Reid_at_email.protected>
Date: Wed, 08 Aug 2012 14:43:13 +1000
Hi All,
Warren Hankey and I made some progress towards the end of July at Ceduna
on the L-band system installation.
Jamie McCallum remotely performed some tests with a scan on on a source
revealing Tsys something like 1200 Jy and the beam is reasonably
centered. He also obtained fringes to Hobart.
We took some video and pictures of the mechanical arrangement. Links
below. Google search for Ceduna L-band will also find it.
It is at a stage where it can again be enabled by Warren or I for the
September VLBI run for serious tests. Changes to or from L-band will
take an hour currently. Once we automate it, it will take only a few
minutes.
We need to eliminate some of our own RFI, that showed up at frequencies
like 1426 and 1596 MHz, prior to some serious tests. An oscillating
power supply voltage regulator is causing at least one of these problems
and should be easy to fix. We also need to implement a circularly
polarised signal injector to aid adjusting the inputs to the quadrature
hybrid for dual pol circular outputs.
Video:
http://vimeo.com/46930203
This is one of 4 short videos. The other 3 show up at the same site.
In the comments for the videos above is a link to still photos which are
here:
http://users.on.net/~cdadsl/Lband/
While we were there testing, Jamie reported:
>Hi everyone,
>We've just managed to get L-band fringes between Ceduna and Hobart on 0537-441 with Chris's help. http://www.evlbi.atnf.csiro.au/RtFC/Jul2012/t12207/02:03:10/CD-HO-1.png has the images - this was with a 0.5 second integration time using the standard VSOP mode and some variety of linear polarisations.
Regards,
Brett
Date: Wed, 08 Aug 2012 14:43:13 +1000
Hi All,
Warren Hankey and I made some progress towards the end of July at Ceduna
on the L-band system installation.
Jamie McCallum remotely performed some tests with a scan on on a source
revealing Tsys something like 1200 Jy and the beam is reasonably
centered. He also obtained fringes to Hobart.
We took some video and pictures of the mechanical arrangement. Links
below. Google search for Ceduna L-band will also find it.
It is at a stage where it can again be enabled by Warren or I for the
September VLBI run for serious tests. Changes to or from L-band will
take an hour currently. Once we automate it, it will take only a few
minutes.
We need to eliminate some of our own RFI, that showed up at frequencies
like 1426 and 1596 MHz, prior to some serious tests. An oscillating
power supply voltage regulator is causing at least one of these problems
and should be easy to fix. We also need to implement a circularly
polarised signal injector to aid adjusting the inputs to the quadrature
hybrid for dual pol circular outputs.
Video:
http://vimeo.com/46930203
This is one of 4 short videos. The other 3 show up at the same site.
In the comments for the videos above is a link to still photos which are
here:
http://users.on.net/~cdadsl/Lband/
While we were there testing, Jamie reported:
>Hi everyone,
>We've just managed to get L-band fringes between Ceduna and Hobart on 0537-441 with Chris's help. http://www.evlbi.atnf.csiro.au/RtFC/Jul2012/t12207/02:03:10/CD-HO-1.png has the images - this was with a 0.5 second integration time using the standard VSOP mode and some variety of linear polarisations.
Regards,
Brett
-- Brett Reid Observatory Manager, Radio Astronomy Group University of Tasmania, School of Mathematics and Physics Phone +61 3 6248 5285 Mobile 0407 955 283 email brett.reid_at_utas.<!--nospam-->edu.au web http://users.on.net/~cdadslReceived on 2012-08-08 14:43:47