JK Audio AutoHybrid User manual

AutoHybrid
Auto-Answer Hybrid
JK Audio
User Guide

2
Introduction
The JK Audio AutoHybrid is a simple, passive, auto-answer /
disconnect telephone line hybrid. AutoHybrid allows simul-
taneous send and receive audio through analog telephone
lines. Not just another half duplex auto-coupler, this is a full
duplex AutoHybrid. Perfect for remote monitoring, IFB feeds,
and many simple studio, conferencing, and PA telephone
interface applications.
AutoHybrid's dual transformer hybrid circuit provides a nomi-
nal 20 dB separation of send and receive audio. This
means that the level of your send audio on the caller output
jack will be approximately 20 dB less than your transmit
level.
Balanced XLR input and output jacks provide easy connec-
tion to your professional audio equipment and the detach-
able screw terminal block provides easy access to remote
features.

3
Features
This small desktop unit easily converts to a rack-mount unit
using the optional RA4 Rack Panel.
The RA4 holds four AutoHybrids in a 1U rack space.

4
Features (continued)
1 2 3 4 5
6 7 8 9 10

5
Features (continued)
1. Call Button - Press this button to answer or place a tele-
phone call (takes the line off-hook).
2. OH LED - Lit when you are on line with a call (Off-
Hook).
3. Drop Button - Press this button to drop (hang up) a call.
4. Auto-Answer - Press this switch to enable the AutoHy-
brid to automatically answer an incoming call and then
disconnect after the caller hangs up. Auto answer will
occur on the first ring.
5. Null Adjust - Used to adjust the level of Send audio that
is present on the Caller output jack.
6. Line Jack - Connect to a standard, single line, analog
telephone line.
7. Phone Jack - Connect a single line analog telephone for
call setup and dialing.
8. Remote Screw Terminals -
Call - Momentary + 5 VDC to seize phone line.
Drop - Momentary + 5 VDC to release phone line.
OH pulled to ground for OH LED.
9. Caller Output - Male balanced line level XLR output
contains audio from the phone line.
10. Send Input - Female balanced line level XLR input for
signals going into the phone line.

6
Connection
Connecting Cables
Phone Line - Connect the supplied RJ-11 phone line cable
between the jack marked "Line" and your wall jack. Be sure
this phone line can support standard analog telephone opera-
tion.
Send Audio - Connect audio you wish to send into the phone
line to the balanced line level XLR Send jack.
Caller Audio - Connect the balanced line level Caller XLR jack
to a line level input on your audio equipment. The Caller out-
put contains audio coming from the phone line. This audio sig-
nal will contain the caller's voice and any audio you send into
the phone line at approximately 20 dB less than your transmit
level.
Auxiliary Telephone
Connect an auxiliary telephone to this jack to dial calls. After
connecting a call, press the Call button on the AutoHybrid and
you may then hang up the telephone. When you are finished
with the call, press the Drop button to release the phone line
(place the line on hook).
Please note: When you drop a call, any audio delivered to the
Send jack of AutoHybrid will still appear on the Caller output
jack. AutoHybrid does not mute your Send audio when the
phone line is On Hook.

7
Auto-Answer
When the Auto-Answer button is in the "in" position, AutoHy-
brid will answer on the first ring. AutoHybrid will look for a
CPC disconnect signal from the phone company to determine
when a call has disconnected. This will generally take only
several seconds but can take up to a minute. If you are using
a simulated analog phone line provided by a PBX system, the
system must be configured to send a disconnect signal for the
AutoHybrid's auto-disconnect function to operate. The CPC
disconnect signal must be set at 300 ms minimum.
Detachable Remote Screw Terminal
The detachable remote control screw terminal block on the
back of the AutoHybrid provides connection to switch contacts
for remote operation.
A momentary + 5 VDC applied to Pin 1 takes the phone line
off-hook. Another momentary + 5 VDC applied to Pin 2 will
drop the call.
Pin 3 is an open collector opto-isolator terminal that is pulled
to ground while AutoHybrid is off-hook. This terminal is pro-
tected by a 220 ohm series resistor. You can light a remote
LED by simply connecting your LED from +5 VDC to pin 3.
Screw Terminal Pinout:
Pin 1: Call
Pin 2: Drop
Pin 3: OH LED
Pin 4: Ground
Operation

8
Operation (continued)
Null Adjust
The Null Adjust is a 15 turn pot used to determine how
much of your Send audio is delivered to the Caller output
jack. Use a small flatblade screwdriver to make adjust-
ments to this control.
To find the absolute null for any telephone line, follow this
procedure:
1. Place a call to a quiet location.
2. Send a signal into the AutoHybrid Send jack at a mod-
erate level. A test signal or tone works best.
3. Connect the Caller output jack to a meter or scope, or
listen to this signal through your external audio equip-
ment.
4. Try to remember the position of the adjustment screw-
driver blade and the number of turns you are making
as you first adjust clockwise, then back to the original
position, then counter clockwise.
When the level of this signal is at a minimum, you have
achieved the maximum null for the phone line. The maxi-
mum null you can achieve is approximately 20 dB.

9
Operation (continued)FAQ’s
?Does AutoHybrid work with Vonage IP telephony?
!Yes, however customers have reported one glitch in the
Vonage system. If the AutoHybrid is set to auto-answer
or if the call is manually answered on the first ring there
will be a considerable amount of noise on the call. This
can be avoided by initiating the call from your location or
manually answering after the second ring. If auto-answer
is an integral part of your application you may contact
Vonage directly to downgrade to a previous version of
their firmware. This information is valid as of January 23,
2006. We have no direct connection with Vonage and
therefore will not know when this particular problem is
resolved.

10
FCC Part 15 Compliance
This equipment has been tested and found to comply with the limits for a
Class A digital device, pursuant to Part 15 of the FCC Rules. These
limits are designed to provide reasonable protection against harmful
interference when the equipment is operated in a commercial
environment. This equipment generates, uses, and can radiate radio
frequency energy and, if not installed and used in accordance with the
instruction manual, may cause harmful interference to radio
communications. Operation of this equipment in a residential area is
likely to cause harmful interference in which case the user will be required
to correct the interference at his own expense.
Changes or modifications not expressly approved by JK Audio can void
the user's authority to operate the equipment.
Input:
Transmit XLR: Balanced Female XLR, 800 ohms, 1 volt RMS
(+4 dBv max)
Insertion Loss: 11dB Send XLR to Phone Line
Maximum transmit level at Phone Line -3 dBm
Output:
Receive XLR: Balanced Male XLR, 600 ohms, 200 mV RMS
(-15 dBm nom)
Phone Line Connector: RJ11C
1500 VAC Isolation
0.8B REN
Aux Phone Connector: RJ11C
Screw Terminals:
Off-Hook Control: +5 VDC momentary
Release Control: +5 VDC momentary
OH LED Signal: Pulled to ground on OH
CPC Disconnect: 300 ms minimum
Size: 4" x 5" x 1.5" (10.5 x 13 x 4 cm)
Weight: 11 ounces
Specifications