[Milsurplus] ART-13B Questions
Morrow, Michael A.
[email protected]
Wed, 15 Oct 2003 17:50:30 -0500
Robert wrote of the AN/ART-13B and CDA-T:
> I have the installation instructions ... But there's nothing so far as
I can
> recall in the installation instructions about a control box.
The schematic for the T-412/ART-13B (from T.O. 12R2-2ART13-2, 30MAR56)
shows a crystal bank select relay control line connected to pin 25 of
the control box connectors, and a switch added to the C-87/ART-13 that
grounds this line to select B-bank crystals in the CDA-T. No such
switch is shown on that same schematic for the C-405/A control panel,
nor do late-model control panels like the C-740/ART-13 have such a
switch. The C-740/ART-13 is obviously a USN design intended to match
the C-733/ARR-15 control panel for the USN's AN/ARR-15, and I doubt the
USN employed AN/ART-13s with a CDA-T.
A quirk of the T-412 remote bank selection circuit is that if control is
remoted to a control box/panel without the A-B switch, only bank A
crystals can be selected even if the local A-B switch on the CDA-T is
position B. The local A-B switch on the CDA-T is disabled when remote
control is selected.
I have no schematic which shows the presence of the LF Extended Range
switch on the CDA-T, and T.O. 12R2-2ART13-2/30MAR56 (Maintenance
Instructions) does not mention its use in the CDA-T operation section.
But T.O. 12R2-2ART13-1/15DEC56 (Operating Instructions) clearly
describes its use in that manual's CDA-T operation section as being
required for operating an HF channel between 1.67 to 2 mcs. Possibly
this switch was added on later models of the CDA-T. I'd be curious to
know exactly what that switch did to the CDA-T circuit.
73,
Mike / KK5F