[evlatests] Standing Wave in IF 'A'

[Joseph P. McMullin]

Hi Jim,

>From the perspective of the ongoing science observations, we can endure this
for a while. My understanding was that it would be a 2-day endeavor to
resolve
the issue and given the current churning on 3-bit testing, it wasn't clear
to me
if this was coming anytime soon.

Joe

On Wed, Apr 20, 2011 at 8:14 AM, Jim Jackson <jjackson at nrao.edu> wrote:

> Having heard no objection to the contrary, Rick and myself are both
> inclined to leave this DTS module in place in EA22 for the duration
> of the 3-bit testing.  We will live with the bandpass ripple in the 8
> bit path on IF-A and repair this module later.
>
> Jim
>
> At 01:31 PM 4/19/2011, Jim Jackson wrote:
> >In that case, this requires an upper management decision. Is this
> >problem bad enough to warrant removing the 3-bit equipped DTS module
> >from EA22 and delaying the 3-bit testing or can we live with it this
> >way for a while?
> >
> >Jim
> >
> >At 01:21 PM 4/19/2011, Eric Chavez wrote:
> > >I just came from ant 22 and swapped the entire signal path between D301
> > >and D302. We wiggled cables connectors etc and the problem was always in
> > >IF-A. I talked to Kerry Shores while doing this test and I am convinced
> > >that the problem is between the input to the D301 and the correlator. No
> > >matter what I tried in the LO/IF path, the ripple always stayed the same
> > >in IF-A.
> > >
> > >Rob Long
> > >
> > >Rick Perley wrote:
> > > >     Bandpass solutions at L, S, and X bands show a 32 MHz-period
> > > > periodicity, of amplitude 1.5 dB, in IF 'A' only.  Presumably, a bad
> > > > match in the T304?
> > > >
> > > > _______________________________________________
> > > > evlatests mailing list
> > > > evlatests at listmgr.cv.nrao.edu
> > > > http://listmgr.cv.nrao.edu/mailman/listinfo/evlatests
> > >
> > >_______________________________________________
> > >evlatests mailing list
> > >evlatests at listmgr.cv.nrao.edu
> > >http://listmgr.cv.nrao.edu/mailman/listinfo/evlatests
> >
> >
> >_______________________________________________
> >evlatests mailing list
> >evlatests at listmgr.cv.nrao.edu
> >http://listmgr.cv.nrao.edu/mailman/listinfo/evlatests
>
>
> _______________________________________________
> evlatests mailing list
> evlatests at listmgr.cv.nrao.edu
> http://listmgr.cv.nrao.edu/mailman/listinfo/evlatests
>
>


-- 
Dr. Joseph P. McMullin
EVLA
Ph: +1 575 835 7315
E-mail: jmcmulli at nrao.edu
http://science.nrao.edu/evla/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listmgr.nrao.edu/pipermail/evlatests/attachments/20110420/aa1bde69/attachment.html>