Galcom Cornerstone Transmitters

Galcom Technicians Allan McGuirl, Jr. and Neil Woods have recently designed a new ultra low-power FM transmitter that incorporates many new technology features at a very competitive cost.  It is a base unit for higher powered FM transmitters.  What we once purchased from other suppliers, we will now be able to produce at a reduced price.

For more information you can visit the Cornerstone Transmitter Forum.

Cornerstone Transmitter

Galcom’s new rugged Cornerstone Transmitter enables low power FM radio transmission for churches, conferences, speech translation, the mission field or commercial stations.

The Cornerstone Transmitter includes attachable wings allowing installation in a standard 19” rack.

The Cornerstone Transmitter includes a Mixer Mode. This mode allows two microphones and two auxiliry inputs, such as a CD player or MP3 player, to be mixed using slide controls.

Setup and monitoring of all features is easy using the touch screen LCD display. The backlight display is viewable in all lighting conditions from direct sunlight to a darkened room.

Features and Specifications

FM 88 MHz – 108 MHz
2.0 mW Output
 - Connects to 1 Watt Amplifier
 - Connects to 50 Watt Amplifier
Stereo Encoder
Audio Processor
6 Channel Input
 - 2 Balanced Line Inputs
 - 4 Component Inputs
SCA (Subsiduary Communications Authority Encoder)
Touch Screen Control
SWR Monitoring
Temperature Monitoring
Complete Digital Design
Optional Internal Ethernet Card
Complete mixing of inputs
Pre-emphasis
Save and restore all settings

Expansion Features

1 Watt Amplifier
    - Broadcast to a village

45 Watt Amplifier
    - Broadcast to a city

Planned Expansion Features

450 Watt amplifier

Ethernet Card
- Remote monitoring
- Remote control
- Stream audio to the internet
- Broadcast an internet stream

Technical Specifications:  Transmitter Model:  CT-X

Power Input
- 5.0 VDC (Includes 110V / 220V adapter)
- Regulated Voltage
- 5.5mm Cannon plug
- Internal self-resetting 1.2 Amp fuse
- Power switch
- 2.5 Watt power supply
- Power light on front of case
- Current Draw:  70mA @ 110 Volts

Chassis
- Rugged design
- Powder coated steel
- Wing attachments to fit in a 19” rack (3 Units)
- 45 degree leg attachments for desk use

Display
- 320 x 240 Resolution
- Black and White
- Backlight
- Transflective (Can be used in sunlight or total darkness)
- Contrast adjustment

Touchscreen
- High resolution touchscreen panel
- Single point, pressure sensitive touch
- Can use stylus or finger

Digital IO Port
- Provides communication to other Galcom components such as 50 Watt amplifier
- Future expansion (such as a Galcom radio programmer)

RF Output
- Output Power:   -8 dBm, .09 V RMS, 160uW (into 50 Ohm Load)
- Over voltage protection
- Low pass filter
- FM Stereo
- FM Mono
- FM Subcarrier
- BNC jack
- Digitally synthesized output
- Frequency Stability:  +/- 0.3 kHz over temperature range
- Subcarrier Frequency Stability:  +/- 0.3 kHz

Optional Ethernet Card
- Stream audio to the internet
- Stream audio from the internet
- Built in web page
- Remote control of transmitter from any web browser
- Remote software upgradeable

Audio Inputs
- Audio Input #1 Left and #1 Right
   2 x Dual XLR / ¼” jack
   Balanced on unbalanced
   Mono or stereo ¼” plug
   10K Ohm Line level 
   600 Ohm Microphone level

- Audio Input #2 Left and #2 Right
   2 x RCA jack (L & R)
   Unbalanced component input
   10K Ohm

- Audio Input #3 Left and #3 Right
   2 x RCA jack (L & R)
   Unbalanced component input
   10K Ohm

Audio Processing:
- Pre-emphasis
   Switchable: 50 us, 75 us or none

- Compression

- Dynamic Range Compression

Audio Mixing
- 8 Input channels (1L, 1R, 2L, 2R, 3L, 3R, Internet L, Internet R)
- 6 Output channels (FM L, FM R, SCA1, SCA2, Internet L, Internet R)
- Mix any input or combination of input channels to any output channel

Software includes a ‘Mixing Mode’ program
- One screen mixes two microphones and two auxiliary audio inputs to the FM output
- Adjustable on-screen sliders
- Entire radio show can be mixed from the touch screen of the transmitter

Temperature
- Monitor the ambient temperature
- Monitor the DDS temperature
- Warn when high temperature (Audio and visual warning)
- Auto-Shutdown of the transmitter in case of over temperature
- Operational between 0 Celsius to 50 Celsius (Recommended below 25 Celsius)

Time and Date clock
- Record time and date of errors (such as over temperature)

Includes:
- Durable padded carrying case
- Telescoping antenna
- Touchscreen Stylus
- AC Adapter (110V/220V with many common worldwide plugs)
- Instruction Book
- Rackmount wings
- 45 degree legs

Technical Specifications:  45 Watt Amplifier Model:  CT-45

Power
- Switchable 120 Volt or 220 Volt AC
- Voltage selector on back
- Power switch on front
- Power light on front
- Current Draw:  930 mA @ 110 Volts (Includes the CT-X Exciter)

Chassis
- Powder coated steel
- Rugged design
- 19” Rack mount (3 Units)
- Quiet fan design

Digital IO
- Connection to control amplifier via the Cornerstone CT-X
- Must be connected in order to power up the amplifier

RF Input
- BNC input

RF Output
- Type N output
- FM Signal to Noise:  -75dB
- AM Signal to Noise:  -69dB
- FM Signal to Noise below 50Hz:  -75dB
- Frequency Stability:  +/- 0.3 kHz over temperature range

Temperature
- Temperatures monitored via cornerstone CT-X
- Monitor the ambient temperature
- Monitor power supply temperature
- Monitor final amplifier temperature
- Warn when high temperature (Audio and visual warning)
- Auto-Shutdown of the amplifier in case of over temperature
- Operational between 0 Celsius to 50 Celsius (Recommended below 25 Celsius)

Output Power
- >45 Watts Output (88 – 108 MHz)
- SWR monitored via the cornerstone CT-X
- Monitor forward power at the amplifier
- Monitor reflected power at the amplifier
- Monitor the SWR at the amplifier
- Output power light on front
- Warn when high SWR
- Shut down the amplifier in case of SWR >2.5:1