Running DELAYS:
Make sure all antennas are online and operating well
Correct any errors (sub-reflector errors, etc.)
Check that nothing is off in C-Band (sub-reflector, front end, etc)
Check that reference antenna being used has no problems
In SYSSTART (make sure all antennas on source before starting and when switching between bands)
Make sure you are in the F display on Monty

On Op3, run DELAYS:
  $ JOB
  $ DELAYS (uses the values displayed in the current F display)
    Sub Array:    1  (usually 1)
    Ref Antenna: 22, 6   (VLBI reference antenna, check bulletin board for current one)

The program will make three iterations of the calculation, printing out the information on LA2 (top printer)
The program will tell you when it has finished
(Always "SKIP 1 0" out of delays, unless proceeding on to DELEDT)
Check printouts – if lots of *’s (asterisks indicate good solutions), apply the changes using DELEDT
Note: If you get suspicious results (see examples below), choose a different reference antenna. Do a "SKIP  1  0"  and run delays again.

Printout handling:
Separate Delays Summary, the last page(s), from the printout. Circle the date and band. These will be cut down to 81/2” x 11” and put in red Delay Summary Output binder on console. The body of the printout goes in the appropriate Startup File folder in the hanging file located under the console.

Running DELEDT:

 $  JOB
 $  DELEDT  x   (where x is the desired band)
 Program will prompt you regarding the date of the data it is going to use (check that the right data will be used).
 After answering Y to the above prompt, the data will be displayed on the monitor.
 Make any exclusions at this time using the commands below.
          EXC ?     excludes solutions marked with ?
          REM #    does not apply solutions for the antenna, where # is the number of the antenna
          HELP      online help manual
After making any exclusions, continue through process by entering
 $  EXIT
The following prompts will appear:
  prompt>  Create new file?    1/ yes   or   2/ no (enter the number 1 or 2 as desired)
  prompt>   New file?  /R = yes     /A = no  (enter /R or /A as desired)
 

After exiting deledt, enable changes with a SKIP  1  0  (this will also take you out of delay mode)
$  ctrl+A
> SKIP  1  0

In F display, check that no antennas drop out or have other problems. If everything looks correct, do another pass with Delays. If the first solution looks good (meaning no antennas show up as needing to be altered), it is not necessary to wait for the next 2 solutions; cancel out with the following command:  ctrl + a  then  /A   (abort)
If antennas appear as needing correction, wait for the next iteration or two to monitor the values. If any errors persist, DELEDT can be run again to apply corrections.

The DELAYS/ DELEDT process is continued in the other bands in the order listed below:

       C      $10 or $19
       L      $13 or $22
       X      $14 or $23
       X ptg  $15 or $24  (don't run DELAYS; a pointing determination is done by this source)
       Q      $16 or $25  (remember that not all antennas have Q-band!)
       K      $17 or $26
       U      $18 or $27

Repeat process:

$ ctrl + a
> SKIP  1  $13 (or $22)
> DELAYS
 etc…
 

Miscellaneous Notes:

• On the X-band pointing source, do not run delays. It will print the message,

“Begin pointing determination” on LA2 (top printer).  When done (a few minutes) it will print the message, “End pointing determination”.  Let this process run twice. Printed output can be tossed.
• Q-band not installed on all antennas (refer to Antenna Status report for current list), so you will get many spurious error messages. These can be ignored (if they are for the antennas without Q-band)
• Q-band is very weather dependent; never use “?” solutions. On the 2nd delays run check the error values with the 1st delays run. If the numbers are fluctuation wildly, give it up!
• Q-band signal values are not scaled, so don’t be surprised at widely ranging values
• IAT 00:00 will cause source change. Don’t be in delays at this time or you will be thrown out
• Keep observing log as you go, noting the time of the band changes and any unusual occurrences
• The D10 display can be used to look at a 2-antenna baseline and see what step the delays program is on. Access this display through the F display. With the window active (mouse cursor must be anywhere in the window), enter a question mark ? (shift + forward slash key) for a listing of the necessary commands.
• When running Delays, If you make a typo when entering the sub-array number or reference antenna number and you need to abort, do a SKIP 1 0 before starting delays again.

Examples of suspicious behavior:

• Noted T-sys fluctuations in L band on IF A on antenna 19. Therefore, did not use the suggested solutions.
• DELAYS show all antennas having large error values for IF D in K-band. This suggests a problem with the reference antenna being used in K-band. Run delays again with a different reference antenna.
• DELAYS show all antennas having errors of same value for IF B in U-band. Suggests a problem with the reference antenna.  Run delays again with a different reference antenna.