Digital Store and Forward Device
The Model 55B is essentially a recording device for storing pages received from a paging terminal for later transmission.
Sequencing without zone addressing
When the coverage area of multiple remote transmitters overlap, interference can cause garbled or missed pages. Standard solutions to this problem include simulcasting and zone sequencing. Simulcasting requires expensive transmitters and control equipment. Sequencing is less costly, but some paging terminals are not capable of repeating pages with different zone addresses. By replaying pages from a remote link after transmission, the Model 55B provides a way to sequence overlapping transmitters without using zone addressing.
Remote control of shared channels
When the remote transmitter is being controlled via a simplex link such as RF or microwave, the remote site cannot notify the paging terminal when the channel is busy. This is a problem for shared paging frequencies, because the paging terminal might instruct a transmitter to key-up when the frequency is already in use. Because the Model 55B can monitor a receiver tuned to the paging frequency at the transmitter site, it can prevent transmission of pages when the channel is busy.
Paging terminals with no page storage
The Model 55B is an ideal add-on for a paging terminal with limited buffering capabilities. The Model 55B can store excess pages when the terminal or channel is already busy. This eliminates putting a caller on hold or sending a busy signal until the paging terminal or channel is free to receive new pages.
Paging terminals sharing remote transmitters
The Model 55B will allow two paging terminals to share one remote transmitter. By tying together two Model 55B Page Buffers at the transmitter site, each communicating with a different paging terminal, both terminals can page into one area without interfering with each other.
Analog paging channel repeater
The Model 55B can also be used to
buffer analog pages from a receiver listening to the paging channel
itself (eliminating the need for any link equipment). The pages are
then retransmitted when the channel is clear. Since all
transmissions on the paging channel are repeated, this only works
when the paging channel is not being shared with other applications.
|Size||1.75" H x 19" W x 2
|Temperature Range||0 to +60 degrees C., 32
|Power Input||120 VAC, 50/60 Hz (10 W nominal) using optional modular transformer; 12 -14 VDC (600mA maximum). Internally fused at 2A|
|Frequency Response||Flat +/- 1.75 dB, 300 Hz to 3400 Hz; jumper-selectable -6dB / octave decompensation|
|RADIO INTERFACE, TO /FROM PAGING TERMINAL|
|Dynamic Range||-20 to +5 dBm|
|Audio||Balanced or unbalanced (jumper selectable); 600 ohm or 7k ohm (jumper selectable)|
|PTT-REQ Input||Relay closure to ground or HCMOS levels (jumper selectable); Optional 10k ohm pullup (jumper selectable); jumper selectable polarity|
|INHIBIT Output||2 form C relay, 1A max. @ 28V. Active when buffer becomes full|
|VOX Detector||Activates when signal > -23 dB|
|Sample Rate||8,000 times per second audio 32,000 times per second digital|
|RADIO INTERFACE, TO/FROM TRANSMITTER|
|Audio||+5 dBm into high
+1 dBM into 600 ohm load; AC coupled
(no offset); Balanced or single-ended (jumper-selectable)
|PTT Output||2 form C relay, 1A max. @ 28V|
|COR Input||Relay closure to ground or HCMOS levels (jumper selectable); Optional 10k ohm pullup (jumper selectable); jumper selectable polarity|
WISCO International, Inc. -
MIAMI, FL U.S.A.
Fax: E-mail: firstname.lastname@example.org