[asac][Fwd: A major change request has received final approval]

[Al Wootten]

Folks,

For your information...H2D+ will now be accessible to ALMA.  For the 
full discussion, follow the link in almaedm.  I've added the final few, 
listing performance expectations, for your information.

Al
-------- Original Message --------
Subject: A major change request has received final approval
Date: Wed 07 Jul 2004 21:48:48 -0700
From: almaedm at nrao.edu
To: Distribution at orval.tuc.nrao.edu

A major change request that you authored, were informed of, were a 
reviewer for, or issued a decision on has been approved.

http://almaedm.tuc.nrao.edu/forums/alma/dispatch.cgi/changereq/showFolder/100225/def/def/582781

___________________________________________________________
Forum: CRE - Change Requests

Entry: 81.  (modified)
From: Al Wootten
Date: 2004-03-24 10:56
Workflow state: approved - major cr (Change Request Process)

Subj: Request to extend upper frequency limit on Band 7

CRE Number :
ALMA-40.02.07.00-003-A-CRE

Description :
The upper frequency edge of Band 7 is now 370 GHz.  An increase of this 
edge to 373 GHz is requested.  As with other Band extensions, 
performance need not be guaranteed in this extension, for which the 
atmosphere has poor transmission.


Author:
awootten

Date decision required:
2004-04-01 09:00

Name of supervisor who authorized the submittal of this change request:
Al Wootten


Entry: 81.8.
From: Gie Han Tan
Date: 2004-05-10 06:21
Subj: Follow up on CCB meeting of 2004-04-28

In a further discussion with the Band 7 cartridge group at IRAM it has 
been agreed that they will investigate to what extent the Band 7 upper 
frequency limit can be extended with guaranteed specs and at no extra 
costs.

Spec items that have been identified to detoriate above 370 GHz are Rx 
noise temperature and image rejection ratio. The possibility of other 
specs detoriating above 370 GHz will be investigated.

For the noise temperature a reduced noise spec of 300 K between 370 and 
373 Ghz has been tentatively proposed by IRAM.

IRAM will do this further investigation in June '04, after their PDR.
-------------------------------------

Entry: 81.9.
From: Bill Shillue
Date: 2004-06-04 10:40
Subj: Comments from B. Shillue

Since this change requires the first LO reference frequency to change 
from 94.3-120.7 to 94.3-121.7, it changes the photomixer specification 
and the laser synthesizer and microwave synthesizer frequency coverage 
requirement.  These are all small changes to specs only, the 
instrumentation will be expected to cover the frequency range in any case.
-------------------------------------

Entry: 81.10.
From: Christoph Haupt
Date: 2004-07-01 00:49
Subj: Response by GHT via email on 2004-06-30

Dear Dick / Christoph,

After consultation with IRAM, I can confirm that the ALMA Band 7 upper
frequency limit can be increased from 370 GHz to 373 GHz. The receiver 
noise
temperature limit over this extended band, 370 - 373 GHz, will be 300 K. 
The
limit for image rejection ratio over this band will be 7 dB instead of 
10 dB.

First LO coverage over this extended range should according to Charles 
be no
problem.

Last but not least, IRAM agrees to these extended specs without any cost
increase.

In the next update of the Band 7 cartridge technical specification this 
change
will be incoporated.

Best regards,


Gie Han