Includes:

- Interface cable (0.5metres) to connect to 950 transceiver.
- Telephone cable (2 metres) with RJ-45 connectors.
- 961 operation and installation manual.

Barrett 961 phone patch

The Barrett 961 HF telephone interface (phone patch) interfaces a
Barrett 530, 550, 930 or 950 transceiver to the telephone network,
allowing HF stations to be connected to subscribers on the telephone
network and visa versa.

A caller on the HF network indicates to the HF base station operator
the telephone number required. The HF base station operator dials the
number on the line connected to the 961 interface unit, using the
telephone connected to the 961. When the telephone subscriber
answers, the HF base station operator switches the 961 to "CONNECT",
the automatic VOX is activated and the call between the HF network
station and the telephone subscriber proceeds, the HF transmitter
being keyed by the telephone subscribers voice. At the completion of
the call the HF base station operator switches the 961 to
"DISCONNECT".

The unit is packaged in a compact desk-top enclosure designed to fit
under a standard telephone set so that no desk space is lost. Front
panel switches are widely-spaced to allow easy one-hand operation;
front panel indicators make the Barrett 961's operational status
simple to monitor. All connections to the radio system and telephone
line are made via the units rear panel connectors.

The Barrett 961 uses a unique adaptive hybrid to convert the
four-wire audio from the transmitter and receiver to the two-wire
audio for the phone line. This hybrid represents a true technological
breakthrough to the problem of interfacing an HF radio network to a
telephone system.

Conventional hybrids used in all existing phone patches can provide
good balance at only one frequency into a complex impedance such as a
telephone line. As a result, signals leak across conventional hybrids
at all other frequencies causing oscillation in full duplex systems
and unreliable VOX (Voice Operated Xmit (transmit)) operation in
half-duplex systems.