Safety Warning
To prevent the possibility of electrocution, always be aware of nearby electric power lines and mount the transmitter far enough away such that if the antenna fell down, there would be no chance of contact.

Grounding Warning
The Procaster™ has a built-in lightning protection device that safely shunts electrical charge to ground under adverse conditions. It is important that a proper ground be attached to the copper lug on the underside of the transmitter for this device to work properly. Consult your local electrical safety standards.

FCC Warning
Changes or modifications not expressly approved by ChezRadio could void user's authority to operate the equipment.

Quick Setup

1. Set transmit frequency and other options using the internal option switch.
Use the highest “clear” frequency available for best range. (“clear” means no music or talking – static is OK).
(Note: the Procaster™ comes with the frequency set at 1610 kHz).

2. Assemble the 3 antenna sections by lining up the black dot on one section with the edge of the mating section. Secure sections with the provided hose clamps.

3. Remove the white protective bolt tubes and discard them and attach the antenna to the side of the transmitter using the 2 locknuts provided.

4. Mount the transmitter vertically as high as possible in a clear area away from trees, power lines and other obstructions.

5. Connect a 14 gauge or larger solid copper wire from the ground lug to a suitable ground. (grounding rod in the earth, water pipe, existing electrical ground, metal roof etc.).

6. Run the 4 conductor wire from the Procaster to the Studio Interface and connect as follows at both ends: RED to +12V, GREEN to 0V, BLACK to AUD-, YELLOW to AUD+.
Note: to minimize induced static pickup, run the cable along walls, fences etc., rather than hanging in the open air if possible. Use only enough cable as is necessary and do not leave coiled up.

7. Plug the wall adapter into the Studio Interface (do not connect the audio yet).

8. Using a small bladed flat screwdriver, adjust trimmer capacitor C18 (small yellow circular component near the yellow antenna wire) until a maximum reading is seen on the tuning meter. Important: keep large metal objects such as elevating work platforms (Skyjacks) and yourself away from the antenna while doing this. Optimum range depends on proper tuning!

9. Close up the Procaster™. Tighten the 2 cover screws evenly until the foam seal on the underside of the cover is moderately compressed – don’t over-tighten!

10. Connect audio.

11. It may be necessary to adjust the gain control on the Studio Interface to suit the audio source being used. Some headphone jacks on MP3 players have a low output voltage. To increase gain on the Studio Interface, adjust the gain control CW using a small screwdriver.

Detailed Setup

Step 1. Choose a Quiet Channel
Drive around your chosen broadcast area and listen for clear channels. Note: car radios are usually more sensitive than portables, so that should be considered too. If you want to broadcast at night, you would have to check if the channel is clear then. It's more difficult to broadcast at night because skywaves from higher-powered radio stations reach into your broadcast area and will reduce your effective transmit range; so bear that in mind. Try to choose one of the highest 43 channels available for the Procaster™ by setting the option switch accordingly. The higher the frequency, the better the range because of the restrictive short antenna length.

Step 2. Choose a Location for Installation
Locate the Procaster™ in as clear an area as possible away from metal structures, trees and other obstructions which can absorb and deflect your signal. Higher mounted antennas work best and give best range. Mounting methods vary - see Step 4. Ensure you can access the transmitter for tuning once it is in its final position. A good height above earth ground is about 25 feet. The roof of a 2-storey building is a good choice.

Step 3. Assemble Antenna
The antenna consists of 3 aluminum tubes (large 5/8", medium 1/2" and small 3/8") which are assembled together. These sections are held together using 2 stainless steel pipe clamps located at the mid-point of the slots. Refer to Fig. 1.

• Join the large tube to the medium tube
  • insert the medium tube into the slotted end of the large tube
  • line up the black dot on the medium tube with the edge of the large tube
  • tighten pipe clamp snugly using a 1/4" nut driver
    
• Join the small tube to the medium tube
  • insert the small tube into the slotted end of the medium tube
  • line up the black dot on the small tube with the edge of the medium tube
  • tighten pipe clamp snugly using a 1/4" nut driver
    
• Fasten the assembled mast to the transmitter using (2) locknuts

Antenna assembly is now complete

Fig. 1 - Assembling the antenna

Step 4. Mount External Transmitter
In all mounting cases, make sure you can reach the unit for tuning once installed!

Direct wall mounting
The Procaster™ can be mounted directly to a flat vertical surface using the 4 holes in the case mounting plate. Make sure that there is sufficient space between the antenna mast and the rear wall such that snow/ice does not cause a short.

Direct wall mounting with standoff brackets
If you need to install the Procaster™ further away from the wall, use Radio Shack brackets # 15-883. This will give an extra 4" of clearance.

Pole mounting
For pole mounting use a pair of 2" spacing U-bolts with formed curved backing plates as shown. These types of clamps are commonly used on automobile exhaust applications. The backing plate prevents the case mounting plates from bending when tightening onto the pole and makes for a more secure installation.

Fig. 2 - U-bolt with backing plate

Step 5. Install Ground
Connect the copper grounding lug shown in Fig. 3 below to a suitable ground using a 14 gauge or larger solid copper wire.

Fig.3 - Copper grounding lug

Good grounding is extremely important and required for safe operation of the lightning protection circuitry and also an important part of optimum antenna performance. Typical grounds include:

Copper clad steel grounding rod at least 8 ft into earth ground. If you cannot go down 8ft, use more rods
Water pipe ground; preferably where it enters the ground
Radial ground system; more details can be found on the Internet
Metal roof; make sure metal roof sections are electrically connected together
FCC rules (47 part 15.219) state:” the total length of the transmission line, antenna and ground lead (if used) shall not exceed 3 meters.” [3 meters = 118 inches]

The Procaster™ has an attached 103 inch antenna. It has no transmission line. A 15 inch maximum ground lead is allowed from the grounding lug to a ground (for example, which can be a steel pole used for mounting).

Step 6. Connect Power and Audio Wiring
The Procaster™ connects to the studio interface with the supplied 4 conductor CAT3 wire (telephone wire). Because the audio is balanced and the power consumption is low, several hundred feet of wire can be used without issue. Referring to Fig. 4 below, connect as follows:

• Open the Procaster™ cover by removing the 2 screws
• Insert 4 conductor CAT3 wire through liquid-tight grommet on the underside
  
• Connect as follows:
  • RED: +12V
  • GREEN: 0V
  • YELLOW: AUD +
  • BLACK: AUD -
    
• Tighten nut on liquid-tight grommet

Fig. 4 - Wiring the Procaster™

Step 7. Connect to indoor Studio Interface Module
Bring the 4 conductor CAT3 cable into the studio area. Refer to Fig. 5.

• Remove the 4 screws from the studio interface enclosure
• Remove the cover
• Pass the 4 conductor CAT3 cable through the hole near the terminal block
  
• Connect as follows:
  • RED: +12V
  • GREEN: 0V
  • YELLOW: AUD +
  • BLACK: AUD -
    

When using the wall adapter, the jumper SV1 is set to the 'AC' (normal operation)
When using 12V battery power, move the slide switch to the 'BAT' position
Replace the cover and screws
Warning: Powering the Procaster™ with the wall adapter in the BAT position could cause damage to the unit

Fig. 5 - Wiring the studio interface

Step 8. Connect an audio source
The Procaster™ is fitted with a universal 3.5mm stereo input jack. It has been designed to accept stereo left and right audio channels and mix them into a mono signal. If you only have a mono signal, you can apply it to either the left or the right input connection.

The built-in audio processor has a fairly wide accomodation range and will automatically adjust audio level for optimum sound quality. In addition there is an input audio level adjustment control (normally set at mid-point) accessible through the front panel using a small jewellers screwdriver. The audio level can be set from approximately 200mV to 3V which will accomodate most audio devices.

Step 9. Power Up the Procaster ™
Connect the AC wall adapter or 12V DC power source.

Step 10. Choose Channel Frequency
Using the 10-position option switch (Fig. 6), choose the desired broadcast frequency and other features. Note: always choose the highest clear frequency possible. The short length of the antenna is more efficient at higher frequencies and you will get better range.

Switches S1 - S6 allow selection of 1 of 43 broadcast channels
Switch S7 selects 1 of 2 audio processor response rates (music or voice)
Switches 8 and 9 turns the audio processor on or off (when external processing is used)
Switch 10 turns on the treble boost

Fig. 6 - Option switch

Note: frequencies in shaded area are recommended for best range

Once the broadcast channel is set, turn the antenna tuning capacitor (this is the yellow circular component labelled C18 near the yellow antenna wire) using a small bladed screwdriver until a maximum reading is seen on the tuning meter. Make sure to stand clear of the antenna as body capacitance will affect tuning. If the reading is not "sharp" and strong, re-check your ground connection.

Failing to tune C18 properly is the leading cause of poor range!

Choosing a lower frequency will result in a lower reading on the tuning meter - this is normal. Antenna tuning is now complete. (Now that was easy!)

Step 12. Final Checkout & Adjustments
Check your sound level and range by listening on a radio. The broadcast signal should be clear and strong when closer to the transmitter, with more noise heard the further you move away.

The built-in audio processor is what makes the Procaster™ sound like a big station. If you want to use your own external audio processing equipment, the Procaster™ audio processor can be disabled by changing the option switch.

The Procaster™ audio processor can be adjusted to suit personal preferences by adjusting the Compression and Modulation Depth controls using a small bladed screwdriver (Fig. 7).

Fig.7 Audio Processor Controls

Fig. 7 - Compression and modulation depth controls
Compression: Turning the compression control CW boosts quieter parts of the audio to be more equal to the louder parts. This makes the overall audio louder resulting in a stronger signal and greater range. The tradeoff is the subjective audio quality depending on the level of compression. Default is midway.

Modulation Depth: Turning the modulation depth control CW increases the audio modulation level of the AM signal. Some additional over modulation (depending on your application) adds 'punch' to the received audio resulting in a stronger, louder signal and greater range. Default is midway.

Limiting: Limiting is automatic to prevent sideband 'splatter' and both the above adjustments have no affect on the 'hard limiter' built into the audio processor.

Step 13. Secure cover
Close up the Procaster. Tighten the 2 cover screws evenly until the foam seal on the underside of the cover is moderately compressed – don’t over-tighten!

Congratulations! You have set up your broadcast station.

Did you know?...
Multiple Transmitters - Synchronization
Many people ask if the Procaster™ can be synchronized such that larger areas can be covered using multiple transmitters. The answer is no - the Procaster™ was designed to be a "standalone" unit which can be installed by the novice. Synchronizing is a difficult and complex process requiring specialized knowledge - here is basically what is involved:

A master transmitter is setup with the desired channel frequency.
This frequency is fed to the slave transmitters by several methods - here are some common ones:

1. a wired connection (often not possible due to distances/obstructions)
2. a radio connection (microwave - line of sight)
3. a special dedicated telephone line (recurring rental costs)
   
   Due to differing distances, the propagation of the signal takes different times to arrive at the slave units. This causes the signal to be out of phase and must be corrected to prevent one transmitter from "fighting" against another with the possibility of reducing the overall signal strength. This requires walking around the site with a field strength meter and making adjustments to each individual slave transmitter.

Similarly, the audio takes differing times to propagate to each transmitter, and if not delayed may result in an undesirable echo effect to the listener.

Internet Streaming
Many radio broadcasters already stream their programs over the Internet. Connecting a Procaster™ to the audio output of a PC receiving the program stream is quite straightforward and easy to do. Using a device called an Exstreamer from www.barix.com ,this little box will connect to the Internet and "pull" an audio file from a server with a fixed IP address and convert that stream to high quality audio which can be fed directly to the Procaster™. The Exstreamer is very reliable and will "re-try" the connection to maintain service. If the Procasters™ are spaced far apart, then each installation operates independently and there is no interference. If you want to cover a continuous area, then you would set up the transmitters such that their fringes meet.

Listeners in that fringe area may witness some unusual events:

"beating" - this can be minimized by adjusting the Procaster™ clocks using the trimmer capacitor
"echoes" - caused by differing delays of the streaming packets as they traverse the Internet

This is a good solution to create a large reliable broadcast area. The coverage area can be national - a cluster in one city/town another cluster somewhere else. For example: a chain of supermarkets might have a Procaster™/Exstreamer setup all over the country to service their parking lots with program audio content controlled from a single location.