RF-Tight Steel Enclosure
The steel box is 18-1/2" wide x 10" deep x 3-1/2" high and includes an internal divider spot welded in place creating a 4" wide compartment for the included power supply. The power transformer puts out 8.5 vac @ 0.5 amps and 22 vac @ 0.5 amps. Mounted on the back panel are a 5 volt, 1.5 amp regulator and a 1.5 amp, 18 volt regulator on a small heatsink.
Filter capacitors are 22,000mF at 16 volts and 470mF at 50 volts. The end result is a linearDC +5 volts @ 1.0 amps and +18 volts @ 1.0 amps supply that can supply power for many different projects. A 1/2 amp slo-blow fuse and holder are included as well as the SJT 18/3 power cord.
Each cabinet also includes a 'Logic Board' and an 'RF Module'. See the description below of what this was for. There is a 40" long cable with 5 pin male "DIN" connnectors on each end. Also included is a 40" RG-59 cable with male "F" connectors on each end. A great project box with some usable parts for a bargain price. Shipping weight = 16 lbs.
The NABU Network was the City of Ottawa Canada's step into the future well before its time. Please read the historical perspective on this very early bi-directional home/business access network. We were able to acquire the set-top converter / controllers for this network. This equipment provided the interface between the 117 MHz cable signals that were exchanged between the DEC server and the user's TV. There was probably a keyboard type device used with this for selecting services and interaction.
In addition to the power supply described above there are 2 modules inside the unit. There is an RF module that down-converted signals from the cable connection and up-converted requests to be sent to the server. This also provided the TV signal to the user's set. All sections of this unit are enclosed in another RF-tight box. There are 4 circuit boards for frequency synthesis, data in and out and RF conversion and dual helical coil bandpass filters. All parts on these boards are descrete components and include some LS and CMOS chips. This module is mounted on a 4 3/8" x 8 1/2" one-quarter inch thick heatsink.
The logic module includes 4 socketed chips: a TR1865CL-04, a full duplex UART, a SC87253P 8 bit microprocessor, a N8X60N FIFO I/O controller and a pre-programmed ROM. The remainder of the parts on this board are numerous 74LS series logic ICs.
While there are a lot of components included on these boards they are literally antique and more of a curiousity than anything else. Keep in mind that at the time these boxes were made, there was no internet. Only BBSs and teletext services. By the way, if you are familiar with the service these boxes were used for, let us know so we can share the information with others.
I just received the NABU steel enclosure and what a great project box it is. I will use it to install a 500 watt Stereo amplifier, a special switching power supply and an equalizer. Thank you for a great find.
-- Robert Chatelain E045576
Rain Tight Case
Rain Tight Case (cont'd)
Rain Tight on Budget
• 5-1/4" x 19" x 8"
• Two internal spaces: 9" x 4-3/4" x 2-3/4"
and 6" x 6" x 4"
Cabinet & Electronics
- Outside: 15-3/8" x 10" x 5-3/4"H
- Inside: 14-5/16" x 9-1/8" x 4-1/4"H
Empty Film Reel
|Fingerstock for positive RF sealing of compartment|