The General Instrument DSR-4000 is a satellite TV receiver designed for CATV headends and other installations of that sort. The chassis fits into a standard 19-inch equipment rack.

I took an interest in the DSR-4000 while looking for a cheap DigiCipher 2 receiver for "free-to-air" use. There are several dozen DCII signals on the satellites visible from North America, and many of them have at least some unencrypted (or "zero-key") streams embedded within them. DSR 4000s, once the top of their line, are now dumped on the used equipment market for very reasonable prices, often under $50. If you just want to play with some FTA DCII and don't need something TOO fancy, this is a pretty good unit. The DSR-4200v set-top box seems to be more popular among FTA enthusiasts, but when they pop up for sale, they tend to have a heftier price tag attached. Consumer "4DTV" boxes like the DSR-922 do not appear to be useful for FTA.

The DSR-4000 is capable of receiving DigiCipher 2 signals at symbol rates of 1830, 2440, 3250, 4880, 7320, 9760, 14600, 19510 and 29270 symbols/sec. That covers almost every signal currently on the birds, but there are a handful running oddball symbol rates that the '4000 can't lock onto. Few (if any) of them have any FTA content, so it's a moot point. Additionally, it can receive analog signals, and seems to be fairly hot at it. It supports mono and discrete stereo, but does not appear to do matrix stereo. I know of no analog broadcasts currently using matrix stereo, so that doesn't matter much either.

Despite my best efforts, I have been unable to find any documentation whatsoever on this receiver online, so I am attempting to gather information on its use here. I've only had it for about 2 months and I still haven't figured out much about it, so if you know the answer to any of the many questions posed throughout this page, please send me an e-mail.

Rear panel overview
The DSR-4000 is quite different from a typical set-top box in terms of its rear-panel connections, owing to both its age and its origins as a headend unit.

Power connector: Same as typically found on computer equipment.
L-band splitter: Connect the coax from your LNB(s) to the "in" jack. The "DC blocked" outputs will only pass the IF signal, whereas the "Out4" jack will pass DC voltage. See the "example configuration" section for notes.
Video out: 75Ω BNC connectors. "Y" and "C" provide an S-Video compatible signal, whereas Video 1 and Video 2 are composite signals. When enabled in the menus, Video 2 will show various diagnostic displays. Note that the S-Video output is active only when receiving digital video, it will not pass analog.
BB output: 75Ω BNC connector, provides "baseband" analog video. This output is always active, and is always in analog mode. That is, you will only see static when receiving a digital signal. See the "Receiving analog TV" section for notes.
Port 0/1: IF input from your LNB. Provides 18v DC power. Can be switched via the menus. Both are identical, there is no significance to the polarization listed next to each connector.
Audio out: Screw terminals. Each is a balanced output ("+", "-", "gnd"). To connect an unbalanced line, just run one side to either "+" or "-" and the other to "gnd". You could use a balun transformer if you wanted to get fancy, but it's not necessary.
Remote: 6P6C modular jacks, function unknown.

Lower left:

• Relay 1 and 2: Internal SPDT relays. If configured to do so via the menus, relay 1 will be activated when the "Alarm" LED is on. Both relays can also be manually controlled.
• Cue tone: unknown
• Async/Sync data: unknown
• HS data: unknown, possibly the "hyperport" used for external HDTV decoders?

Example configuration
Since the DSR-4000 doesn't support most of what is needed to control a modern feed setup (i.e. voltage switching, 22kHz tone, DiSEqC, etc...), I recommend configuring it as a "slave", with a DVB-S FTA receiver controlling the LNB.

This, of course, is only one possible configuration.

• LNB: Feedline from the dish is connected to the input of the DSR-4000's splitter. The #4 output, which passes DC, is run to the LNB input jack on the DVB-S box. One of the DC-blocked outputs is connected to one of the DSR-4000's LNB ports. Note that if your DVB-S box has an IF passthrough jack (like the one in the diagram), you can simply connect the dish directly to its LNB input like usual, then connect the IF output to one of the DSR-4000's ports.
• Audio: Take an RCA patch cable or the cord from an old pair of headphones and cut it in half. For each channel, connect the center conductor to the "+" terminal, and the shield braid to the "gnd" terminal.
• Video: For composite video (BB out or Video 1/2), use a BNC-RCA adapter. For S-Video (Y+C), use a dual BNC-mini DIN cable. The output from the DVB-S box's RF modulator can be used to navigate its menus while preparing the LNB as described below.

Configured this way, the DVB-S receiver is responsible for powering and configuring the feed, and the DSR-4000 only acts as a passive receiver. On the DVB-S box, tune to a transponder on the same band and polarization as the analog or DCII transponder you want to receive (or just program in a dummy channel if there is none). Leave the DVB-S tuner on and switch your TV to the input the DSR-4000 is connected to.

The DSR-4000's myriad configuration menus are displayed on a 40x2 LCD on the front panel, and navigated using the buttons to the right of said display. The currently usable buttons are shown in the lower-left corner of the display.

General navigation:

• From the main menu, select a submenu with the up and down buttons, and press "E" to enter the submenu.
• In a submenu, use the left and right buttons to move the cursor. When the leftmost option is selected, use the up and down buttons to move between pages, or "E" to go back to the main menu.
• Any option with an arrow next to the name can be configured. Select it, press "E", then use the up and down buttons to change the setting.

Installation
Tuning, subcarrier configuration, output levels, and some various one-time settings.

ManualTune

Port (0, 1): Selects which of the LNB ports to use.

Type (C-Band, Custom, Ku-Custom): C-Band lets you specify a transponder by number. Custom and Ku-Custom let you specify a transponder by frequency.

Xpndr (1-24): Channel number for "C-Band" mode.

L_Freq (950.0-1550.0): IF frequency for "Custom" and "Ku-Custom" mode. fL = fLO - fC or fL = fKu - fLO, where fLO is 5150, 9750, 10600 or 10750. Example: 5150 - 3800 = 1350.

PortSetup

Port (0, 1): Selects LNB port. The currently active port can only be viewed, the other can be manually edited.

Satellite: 3-character satellite identifier. Will be overwritten when a DCII signal is received.

Polarity (V/RHP, H/LHP): Identifies the polarity for the selected LNB. Does not change voltage. Will be overwritten when a DCII signal is received.

Modulation

Mode (Auto, Manual): "Auto" will automatically detect symbol rate and FEC encoding for DCII transponders. "Manual" allows you to select from a list.

Symbol Code Format: Select the transponder's symbol rate and FEC configuration from the list.

Offset

Fine_Tune: Displays detected carrier offset from specified frequency?

FM_Filter (Wide, Narrow): Selects bandwidth for analog reception?

Relay

Cntrl (Auto, Manual): "Manual" allows direct control of the internal relays. "Auto" lets the receiver control the relays according to configuration.

Relay0/Relay1 (Off, On): Displays or sets the status of the internal relays.

Relay1Config (Alarm, Relay): "Alarm" activates Relay 1 whenever an alarm condition is present. "Relay" allows Relay 1 to behave like Relay 0.

Alarm

Alarm_Cause (No Video Present, No Authorization, (Alarm) Disabled): Displays the status of each alarm condition. Selecting one with "E" will set the "Alarm" light on the front panel (and possibly Relay #1) to respond to that condition.

Control_Line

On_State (On=Low, On=High): Unknown

Mode (Off(Local), On(Local), Remote): Unknown

Subcarrier

Mode (Mono, Stereo): Analog audio mode. The DSR-4000 does not appear to support matrix stereo.

Gain (-15-0 dB): Analog audio volume. Output is quite strong, -15 dB is about right for my soundcard's line input.

Freq_L/Freq_R: Analog stereo audio frequencies. 6.20 MHz for Left and 6.80 MHz for Right are the norm for NTSC signals.

Freq_M/Freq_Cue: Analog mono audio frequency. For NTSC, 6.80 MHz is usually the main channel, with alternate audio on 5.80 MHz. I am unfamiliar with the "Cue" carrier.

Dig_Audio_Gain

ALL/L1/R1/L2/R2 (-15-0 dB): Digital audio volume. Can be set for all outputs or individually. Levels are about the same as with analog.

Audio1/Audio2

DialNorm (On, Off): Unknown.

AudioMix (Mono, Dual Mono, Stereo, Surr Stereo): Audio upmix/downmix mode. The specifics of the "Surr Stereo" mode are unknown.

Compress (Off, Moderate, Heavy): Dynamic range compression.

Graphics

Display (Video 1 & 2, Video 2 only): Unknown.

Video_Out_Format

525_Lines (NTSC, PAL M): TV standard to use for 525-line digital video.

625_Lines (PAL D,G,B, PAL I, PAL N): TV standard to use for 625-line digital video.

Aspect_Ratio

Input: Displays the aspect ratio of the digital video currently being received. Blank for analog or audio-only signals.

Output_for_16:9_In (16:9, 4:3 (PAN), 4:3 (Center)): How to handle widescreen digital video. Note that the DSR-4000 can not decode HDTV.

IRD

Contrast (0-31): Analog video contrast?

Reset (No, Yes): Resets unit to default settings, clears all stored VCTs.

Firmware: Displays firmware revision. My unit shows "0000008C". Newer firmware does exist, I have seen mention of an "F2" update. Unknown how to obtain or update firmware.

Multidrop

Station# (64-128): Unknown.

Language(Lenguaje)

Select(Seleccione) (English(Inglés), Spanish(Español)): Menu language.

Ch_Select

VCT (0-99999): The VCT of the mux you want to receive. Unknown VCTs will show parentheses.

Xpndr: 8-character description of the transponder being received. Set by the provider.

Chnl (0-9999): The mux channel you want to receive. Channels not in the mux (or previously seen in a mux with the same VCT) will show parentheses.

VCTs Avail: List of all VCTs known by the receiver.

Lang1/Lang2

Dspl (Status/Avail/All): "Status" prevents editing. "Avail" allows you to select from lists. "All" allows free entry.

Left/Right: Audio language

Sub: Subtitle/closed caption language?

Text: Unknown.

EMM_ID

ID_Number (0-FFFF): Unknown.

Status1

Ntwk: Provider-defined descriptive tag.

Channel/Name: Mux channel number or provider-defined tag. "FM" when receiving analog TV.

Level (0-100): Unknown if this is a strength, SNR or BER/'quality' display. 0: LNB off. 40: some DCII signals decode. 55: watchable analog video. 75: typical for DCII. 100: seen occasionally on stronger transponders. Select and press "E" for a bar graph display.

Status2

Sat: User- (analog) or provider-defined (DCII) satellite ID

Freq: Current IF frequency

Symb/Code/Format: DCII symbol rate and FEC configuration

Diag

Menus (Off, On): toggles on-screen diagnostic menus on Video 2. The meaning of the information on these screens is unknown.

Scroll_Scrn: Flips through the diagnostic menus

Clear_Cntrs: Clears counters

Addrs

Unit_Address: Unit address for DCII programming authorization.

TVPass_Card: If a CA unit is installed (behind the door to the left of the LCD), displays pass card info.

AudioTestSignal

L1/R1/M1 / L2/R2/M2 (Off, 1000, 4040,3960): Generates audio test tones, either a pure 1000 Hz tone or a 3960/4040 Hz pair.

Full_Field_Video_Test_Sig

Pattern (Program, 525Composit, 525Combo, 525ColorBar, 525 Y Ramp, 525Matrix, 525 VP Test, 625CCIR 17, 625CCIR 18, 625CCIR 330, 625CCIR 331, 625Matrix, 625 VP Test): Generates video test patterns.

VITS

Waveform (Transmitted, Disabled, 525Composit, 525Combo, 525ColorBar, 525 Y Ramp, 625CCIR 17, 625CCIR 18, 625CCIR 330, 625CCIR 331): Unknown.

DCII_Cue_Tone_Test

Test (Off, On): Unknown.

The DSR-4000 is capable of receiving analog TV. Operation is very straightforward: just aim the dish, then go to Installation → ManualTune → Xpndr and select your desired transponder. If a good signal is present, the receiver should lock on within 10 seconds.

Some caveats to note:

• The "Video 1" and "Video 2" outputs, as well as the audio output, are "squelched". If the receiver does not think a valid signal is present, it will black out the video and mute the audio. This does not appear to be directly related to signal strength, as it will sometimes refuse to unsquelch even when a strong and perfectly watchable signal is present. Power-cycling the receiver will usually get it to work properly in these cases.
• The "baseband" output is not squelched, as such it can be used to locate the desired satellite if you aren't sure exactly where it is (assuming the receiver has tuned to the requested frequency).
• As noted in the Installation section above, the S-Video output is NOT used for analog video, it will show only a black screen even when the receiver has detected a good analog signal.
• Occasionally, the receiver will simply refuse to tune to another channel if a strong analog signal is currently being received. Shutting off the LNB momentarilly will usually get the receiver to cooperate in these cases.

The primary purpose of the DSR-4000 is to receive DigiCipher 2 digital TV broadcasts. The process for getting this going is a little more involved, as you have to get quite a few settings right, and there is no on-screen guide (or even a scan function) to make it easy.

Here are the general steps to get it going:

1. Aim the dish and set up the LNB.
2. Go to Installation → ManualTune and tune in the desired transponder. For C-Band transponders on multiples of 20 MHz (e.g. 3800, 3820, 3840, etc) you can just use "C-Band" and tune by transponder number. Otherwise, calculate and enter the IF frequency as explained under "Menu System" above.
3. Once the receiver locks on (may take 10-40 seconds), go to Channel Selection and enter the VCT and channel numbers.
   • On LyngSat, the VCT is the green number in the ONID-TID column on the first row, and the channel number will be black number in the VPID column in the channel's row.
   • If the VCT isn't listed, go to VCTs Avail → ID_Number, press "E" and then down once. This will usually be the VCT of the last mux you tuned in. If not, try each one in the list until you find one that works (assuming you have the right channel number).
4. If everything's good so far, and the channel is unencrypted, the "Authorized" light should come on after about a second, and you'll be watching digital TV!