Telex SPK-300L Portable Desktop Speaker User Station w/ A4F Headset Connector

BH #TESPK300LA4F • MFR #F.01U.118.506
Telex
Telex SPK-300L Portable Desktop Speaker User Station w/ A4F Headset Connector
Key Features
  • Comes with Built-In Speaker
  • Used as a Public Listen Box
  • Channel Select Switch
  • Call Light
The SPK-300L Portable Desktop Speaker User Station w/ A4F Headset Connector from Telex is a portable speaker station used in the TW Intercom System. Each station is a communication unit along a multi-conference bus. The SPK300L includes the following functional components: a microphone preamplifier with limiter, an electronic microphone switch, a bilateral current source line driver, a listen volume control, a headphone amplifier, a speaker amplifier, a speaker switch and a channel selector switch.

The SPK 300L is designed in a rugged all metal housing perfect for table-top operation. Some features include channel select switch, call light, speaker on/off switch and dual-purpose portable desktop volume control.

Special Order
Expected availability: 3-7 business days
$939.00

Important Notice

  • This item is noncancelable and nonreturnable.

Telex SPK-300L Portable Desktop Speaker User Station w/ A4F Headset Connector

Daniel A., B&H Pro Audio Expert

True Know-How

Ask Our Experts

800.606.6969

Telex SPK300L A4F Overview

  • 1Description
  • 2Microphone Preamplifier/Limiter
  • 3Bilateral Current Source
  • 4Channel Selector Switch
  • 5Volume Control
  • 6User Station Voltage Regulator
  • 7Operational Controls

The SPK-300L Portable Desktop Speaker User Station w/ A4F Headset Connector from Telex is a portable speaker station used in the TW Intercom System. Each station is a communication unit along a multi-conference bus. The SPK300L includes the following functional components: a microphone preamplifier with limiter, an electronic microphone switch, a bilateral current source line driver, a listen volume control, a headphone amplifier, a speaker amplifier, a speaker switch and a channel selector switch.

The SPK 300L is designed in a rugged all metal housing perfect for table-top operation. Some features include channel select switch, call light, speaker on/off switch and dual-purpose portable desktop volume control.

Microphone Preamplifier/Limiter

The microphone preamplifier/limiter converts the small microphone signal to a strong line level signal conditions the signal strength from loud and soft talkers to be almost the same sends the signal to the line via the microphone switch and a bilateral current source

Bilateral Current Source

The bilateral current source adds signal, via the channel select switch, to the line without affecting any signals already on the line. The bilateral current source also extracts the listen signal from the line and sends it to the headphone amplifier via the volume control. Some of the user's own voice signal (sidetone) is also fed to the headphone amplifier

Channel Selector Switch

The channel selector switch selects the channel on which the user will talk and listen. The headphone amplifier output drives the user's headphones

Volume Control

The volume control also feeds the speaker amplifier via the speaker switch and the speaker dim network

User Station Voltage Regulator

The user station voltage regulator takes power from channel 1, regardless of the channel selector switch setting (exception: local power option units). The regulator not only supplies regulated power to the user station, but also prevents unwanted interaction between the user station and the intercom line which is supplying the power. Because the regulator takes power from channel 1, channel 2 can be expanded into many channels by using a switch and, for each channel, a separate wire and a termination network consisting of a 200 ohm resistor and a 10 microfarad capacitor in series

Operational Controls

Channel select switch / latching-action microphone on-off toggle switch / momentary-action microphone on-off push-button switch / speaker-headphone volume control / call switch-indicator / speaker on-off switch / sidetone adjustment
UPC: 800549425162

Telex SPK300L A4F Specs

VoltageAudio line voltage: 1 volt, peak (0 dBm voltage-equivalent)
RangeAverage speech level range: -20 dBV to -10 dBV
Absolute maximum speech level: 3 volts, peak (linear limit)
ImpedanceAudio line impedance, nominal: 50 ohms, 75Hz-20kHz system will continue to operate from 50-300 ohms
DC Current RequirementsNominal: 32 V DC
Operational range: 18-35 V DC
Steady state without damage: -1.5-36 V DC
Transient: 200 V, 8ms or less (after this time, power supply and user station fuses will open)
Quiescent (per station): 10-40 milliamps
Dynamic (per station): 50 milliamps (w/ 25 ohm headphones); 70 milliamps (w/ 25 ohm headphones and lights); 100 milliamps (w/ 8 ohm speaker)
Start-up current: 1.25 amperes, 50 units, all kinds
Fault current:
4.0 amperes, power supply at voltage >12 volts
1.0 amperes, power supply at voltage <12 volts
Operating DistanceMaximum DC limit: 5000' (1524 m) distance along cable, power supply to single station #22 gauge wire - DC voltage drop limitation
Maximum AC limit: 10,000' dry pair, power supply at each end, #22 gauge wire
System capacitance: 0.3 microfarads (cumulative effect of 10,000' (3048 m) of maximum cable at 30 picrofarads/foot)
Inputs/OutputsDynamic microphone type headset or handset
Carbon microphone type headset or handset
Line input (ties the station to the intercom line)
Loop/extension (allows another station to access the line through the first station. Also called loop-through
DC VoltageUser station specifications:
20-35 V DC, operating from -200-36 volts DC without damage
DC Current RequirementsUser station specifications:
DC current:
Quiescent, 10-40 milliamps
50 milliamps, typical (w/ 25 ohms headphones)
75 milliamps, typical (w/ 25 ohms headphones + lights)
100 milliamps, typical (w/8 ohm speaker)
ImpedanceUser station specifications:
10,000 ohms typical; 2000 ohms worst case dynamic operation
TemperatureUser station specifications:
Operating: 0-140°F (0-60°C)
Storage: -67-257°F (-55-125°C)
NoiseUser station specifications:
One unit: -75 dBu
Ten unit: -67 dBu
Panel Microphone PreampInput impedance: 470 ohms
Source impedance: 200 ohms, nominal
Maximum input level: 150 millivolts
Voltage gain: 54 dB
Frequency response: 100-10,000Hz, 3 dB
Limiter range: 50 dB
Carbon mic excitation current: 10 milliamps, nominal
CurrentTransfer ratio: 5 milliamps / 1.5 V
Output: 5 milliamps into 200 ohms
Headphone AmpOverall voltage gain: 24 dB
Overall voltage gain: 9 V peak-to-peak into 25 ohms
Output power headset station: 1/2W into 25 ohms
Speaker station: 2W into 8 ohms
Frequency response: 150-8000Hz, 3 dB
Headphone impedance range: 25-600 ohms
Sidetone adjustment range: 20 dB to full on
Call Light LevelsSignaling frequency: 20,000kHz 3dB
Flashing rate: 3Hz, 2Hz
ColorGrey
Dimensions (H x W x D)4 x 8 x 8" (101.6 x 203.2 x 203.2mm)
Weight3.5 lb. (1.6kg)
Packaging Info
Package Weight5.4 lb
Box Dimensions (LxWxH)13.8 x 11 x 5.5"
See any errors on this page? Let us know

YOUR RECENTLY VIEWED ITEMS

Browsing History

Close

Close

Close