PATCH BAY WIRING GUIDE

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To help order a system that fully meets your requirements,
read the following descriptions of patch bay conventions and terms.


1. Jacks and Plugs 
There are two sizes of patch bay jacks and plugs.
The bays used with approximately 1/4" diameter 
plugs are known as Longframe, while the 
bays used with 11/64" diameter plugs are 
known as Bantam, TT, or Tiny Telephone. 
A Whirlwind Longframe bay has 24 jacks per 
row providing 48 patch points 
(also referred to as a 48 point patch 
bay). A Whirlwind TT bay has two rows 
of 48 jacks each, providing 96 patch points.

2. Wiring
The convention for patch bay wiring is that 
they are configured with two rows of jacks, 
one above the other, with the top row wired to 
equipment outputs, and the bottom row wired to 
equipment inputs. The jacks are numbered in 
a standard left to right,top to bottom scheme
(Top Row: 1-24 LONGFRAME or 1-48 TT, Bottom Row: 25-48 
LONGFRAME or 49-96 TT).

3. Normalling 
Typically patch bays are wired so that with no patch cables inserted, 
each jack in the top row is automatically connected to the jack 
immediately below it in the bottom row. By planning your wiring 
in advance, this arrangement will let you connect the outputs of 
equipment (wired to the top row jacks) to the inputs of other 
equipment (wired to the bottom row jacks) in the most often used 
configuration. Then, when you need to do something special, 
you can insert a patch cord and change the way signals are connected. 
Normalling is the term used to describe this configuration 
(you have pre-selected your "Normal" signal routing).There are 
two common forms of normalling: HALF NORMAL and FULL 
NORMAL. HALF NORMAL (HN) connects the top row (output) 
jack to switching contacts on the (input) jack just below it. When 
you plug a patch cord into the top (output) jack on an HN patch 
bay, the output signal wired to that top jack stays connected to 
the (input) jack below it and therefore continues to be connected 
to the equipment wired to that input jack. At the same time, the 
output signal from the top jack is now connected to your patch 
cord and can be plugged into another input jack on the patch bay. 
The result is one output going to two inputs. When you plug a p
atch cord into a bottom row (input) jack on an HN patch bay, 
however, the "Normal" connection between that input jack and 
the (output) jack just above it is disconnected. Using the patch 
cord, you can route that input to a different output. FULL 
NORMAL (FN) uses switching contacts in both rows of jacks. 
Plugging a cord into either the top row (output) or the bottom 
row (input) of a full normalled bay disconnects the "Normal" signal 
flow from the top jack to bottom jack. Patch cords connected to 
the top jack have access to the output signal of the device wired to that 
jack. Patch cords connected to the bottom jack have access to the 
input of the device wired to that jack.

4. Grounding
Grounding throughout a patch bay wiring system can become a very 
complicated issue. To keep ground-loop induced hum from entering 
your system, it is important to decide on a uniform method of 
interconnecting equipment chassis grounds and audio shields. There 
are several schools of thought regarding what type of grounding 
configuration is most effective. Consequently, we offer a number 
of standard shield termination configurations, including four options 
for the termination of shields at the patch bay. These options are 
designated ST, SB, SS, and SN.

The ST (Shields Terminated) designation indicates that the shield 
for each wire will be terminated only at the jack terminal. Shield wires 
do not interconnect from jack to jack.

The SB (Shields Bussed) designation indicates bussed shields. 
Each row of jacks has a buss bar that connects all shield connections 
from that row together and is brought out with a single ground-wire 
lead.

The SS (Shields Strapped) designation indicates strapped shields, 
meaning that the shield of each top row output jack is connected to 
the shield of the input jack directly below it. This connection remains 
whether or not patch cables are inserted into the jacks.

The SN (Shields Normalled) designation requires a special patch bay 
using jacks with shield normalling switch contacts. These contacts 
allow the shield to be either half or full normalled from a jack in the 
top row to the jack immediately below it. This is the least common 
of these grounding schemes.

5. Termination The wiring to connect the patch bay to your equipment can be done in several ways: Cables can be pre-wired to the jacks in your patch bay and left blunt cut or trimmed and prepped as required. Connectors can be soldered onto "cable tails" (shielded pair wires soldered to the jacks in your patch bay and long enough to reach your equipment) for direct connection to your gear. It is possible to specify the ground scheme at the equipment connectors. For individual XLRs, 1/4", or RCA connectors, the shield is connected to the appropriate terminal of the connector. The GL (Ground Lift) designation indicates that the shield is left disconnected at the connector. Inline or chassis multipin connectors can be wired to short lengths of cable soldered to the jacks in your patch bay. You then connect cables between these connectors and your equipment. This arrangement allows you to easily remove the patch bay from your system while leaving the basic wiring from your equipment to the patch bay intact. Whirlwind MPB punch blocks are available pre-wired to the jacks of your patch bay for rapid, solderless "insulation displacement" field termination of wires running to your equipment. 6. Cleaning Whirlwind recommends cleaning patch bays by inserting a clean plug five or six times into a jack. The use of chemical cleaners or compressed air is not recommended. 7. Labelling Dezzy strip software from ADC (PPDS-1) produces professional designation strips for all ADC and Whirlwind patch bays. The program allows you to choose the font size and style as well as the background color, and runs on *Windows 95TM or NT platforms. The model number for Whirlwind patch bays is formed by completing each block from the categories below. For non-standard configurations, please call.

Catalog Number
1 2 3 4 5
Match number to chart
TERMINATION
5
W4C (O) Whirlwind W4 chassis: wired in Output configuration
W4C (I) Whirlwind W4 chassis: wired in Input configuration
W4I (O) Whirlwind W4 inline: wired in Output configuration
W4I (I) Whirlwind W4 inline: wired in Input configuration
T For 96 point patch bays wired to 1-48 top row
B For 96 point patch bays wired to 49-96 bottom row
S For 96 point patch bays wired to 24 top row jacks and 24 corresponding bottom row jacks
For 96 point patch bays, with two MASS connectors or multiples of Elco, please apply the appropriate suffix to the multipin indicated above:
E2CM Elco chassis male wired to 24 jacks
E2CF Elco chassis female wired to 24 jacks
E2IM Elco inline male wired to 24 jacks
E2IF Elco inline female wired to 24 jacks
T Apply as in W4 above with jack # designations
B Apply as in W4 above with jack # designations
S Apply as in W4 above with jack # designations
MPB58 Whirlwind MASS Punch Block (1 per 48 jacks)
MPB28 Whirlwind MINI Punch Block (1 per 24 jacks)
MPB-16 Punch Block, MASS Micro Punch, 16 channel (1 per 24 jacks)
MPB16MH Punch Block, mounting hardware, MPB-12 (1 per 24 jacks)
MPBMHPunch Block, mounting hardware, MPB, MPB-58 and MPB-24 (1 per 24 jacks)
BC Blunt cut cable, Brady markers for IP; MP, and I J use color or number code
BP Blunt cable prepped for punch down in the MPB termination - specify type
F2 Female WI3F XLR wired pin 1 shield, pin 2 to the tip of the jack, pin 3 to the ring of the jack
F3 Female WI3F XLR wired pin 1 shield, pin 3 to the tip of the jack, pin 2 to the ring of the jack
M2 Male (WI3M) XLR wired pin 1 shield, pin 2 to the tip of the jack, pin 3 to the ring of the jack
M3 Male (WI3M) XLR wired pin 1 shield, pin 3 to the tip of the jack, pin 2 to the ring of the jack
S TRS 1/4" plug wired tip to tip, ring to ring, shield to shield
U TS 1/4" plug wired tip to tip, ring and shield tied at plug
R Male RCA phono plug wired tip to tip, ring and shield tied at plug
NOTE: GL (Ground Lift) suffix can be applied to termination options F2, F3, M2, M3, S, U, and R above. This suffix will designate that the shield is not connected to any pin in the connector. Examples: F3GL, M2GL, UGL, etc. The shield is still connected at the patch bay jack.
BAY
1
WLF481 48 point longframe 1 rack space (ADC P-KIT 1)
WLF482 48 point longframe 2 rack spaces (ADC P-KIT 3)
WTT961 96 point Bantam 1 rack space (ADC P-KIT B)
NORMALLING
2
NN no normal connections
HN half normal wiring
FN full normal wiring
GROUND SCHEME
3
ST shields connected at jack only
SS shield strapped from top jack to the one below it
SB all top row shields are bussed together, all bottom row shields bussed together
SN shield half or full normalled via special jacks in top and bottom rows (non-standard)
CABLE AND LENGTH
4
 IP individual pieces of 8451, 9451, 1266A, etc
 MP Whirlwind standard multipair with heatshrunk fanouts
 IJ individually jacketed multipair











































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