hi All- To follow up on the "Rx suite" selection issue which I
mentioned in the commissioning meeting this morning: we need to think
through how we will rotate receivers through the year and which
receivers will go in which holes in the turret.  There are 8 holes

1 with d=48''
3      d=36''
4      d=24''

The current arrangement nominally is

48: L 
36: S
24: C
24: X
24: Ku
24: K
36: Q
36: holo

We are planning 4 additional receivers: Ka, W, Penn Array, and W2
(90-116 GHz).  It will be desirable for these to be up for as much of
the winter as feasible.  Packaging on *all* of these receivers is
currently negotiable.  The notional Q-band tertiary is what motivated
the 36'' slot for this receiver; as a possible constraint on this and
other receivers this design needs more careful consideration.

I propose a nominal arrangement as a starting point.  In this
arrangement we have a "low frequency season" (~ 01May - 01 Sep) and a
"high frequency season" (the other 8 months).  There will be a set of
receivers up, more or less the same each year, in each season; we will
plan on individual swap outs, however, to accomadate projects or
blocks of them (VLBI, radar, particular LST ranges, holography, etc)
"out of season".  The rationale for the uneven split is that we want
to be ready for good conditions when they come, wheras most lower
frequency observations can easily be scheduled in advance via the
above mechanism.

Here's what I propose:

Low Frequency Season       
48: L 			   
36: S			   
24: C			   
24: X			   
24: Ku			   
24: K			   
36: Holo		   
36: Q			   
			   
High Frequency Season      
48: L 			   
36: S -> W		   
24: C-> Ka                 
24: X 			   
24: Ku -> (W2 eventually)  
24: K			   
36: Holo -> Penn Array             
36: Q                      

One possibility which would buy some flexibility is to make one or
more "mating plates" to fit 24'' Rx's in 36'' holes.

I welcome any and all comments, especially from those more familiar
with operational constraints and the current science demand. To be
clear what I am trying to define now are receiver packaging
constraints.  A missing piece of the puzzle is a real tertiary
design(s).

 -Brian