1. Recommended Installation Procedures for Performance / Life
Module 1 covers NV series product overview and installation requirements.
After the slide presentation do a show & tell using the transmitter pointing out the various PWBs, power supplies, RF modules, etc.

2. Overview Transmitters often reside in harsh environments.
Site planning and best practical installation techniques increase a transmitter’s life cycle.
Increased reliability = Less maintenance costs = Longer life
Can move between analog and HD or DRM at the touch of a button.

3. Topics Heating and Cooling Ferrite Toroids AC Surge Protection
Room Considerations
Miscellaneous
Can move between analog and HD or DRM at the touch of a button.

4. Cooling - Open Configuration
Ambient Temperature between 0°C (32°F) and 50°C (122°F)
De-rate by 3°C / 500 m (2°F / 1,000 ft.)
Draw cool (intake) air in the back via filters. Air circulates throughout the transmitter and then exhausted up through opening in the top.

5. Cooling - Closed Configuration
For closed air ventilation, cool (intake) air is drawn through the grill or duct at the top of the transmitter.
The air circulates inside the transmitter and exhausts in the same manner as the
open air ventilation system.
Air must be well filtered to prevent dust and insects from entering the transmitter.

6. Air handling is very much a cost vs. benefits discussion
Points to Consider
Air handling is very much a cost vs. benefits discussion
In hot, dusty environments, air conditioning is sometimes the only viable solution
In cooler climates, with sufficient incoming air filtration, cooling with outside air can be quite acceptable
Airflow direction should ideally be cooler air coming into the transmitter/equipment intakes, not shooting past it or coming into the opposite end of the building
Positive pressure – more air should be brought into the building than is exhausted
If the transmitter is ducted, exhaust airflow should be greater than the airflow throughput of the transmitter
Read information on slide.
1 watt = BTU
1 Ton of AC = 12,000 BTU 6

7. Poorly Designed Cooling
The gray rack is the transmitter.
The silver pipe is the incoming air – directed away from the transmitter
The hole below the silver pipe is the exhaust fan – pulling air AWAY from the transmitter air intake (the rear of the transmitter, or left side of the photo)
This site was plagued with PA and power supply failures.
Rerouting the airflow has solved that problem.

8. Cooling Options Often a gap is left between the hood and transmitter.
If case of exhaust fan failure, some heat can vent into the room.
The air gap prevents possible ground loops through the ventilation duct work.

9. Not so cool! Dummy load air intake is from the left and right sides
Exhaust at the rear towards the wall
The dummy load is unable to vent the heat

10. Ferrite Toroids Various sizes of ferrites are available
Install over the coax near the transmitter (size permitting)
Install over the group of incoming AC wires
Remote control / audio / Ethernet paths need protection too
Double up and loop where possible

11. AC Wires
Read information on slide.

12. AC Wires
Explain AUI

13. Ferrites can also be a troubleshooting tool
Ferrites Over Coax
Ferrites on coax help reduce lightning susceptibility
- They should always be installed between the coax ground at cable entry and the equipment being protected
Ferrites can also be a troubleshooting tool
- If there is an imbalance between feed and return currents (common at AM transmitter sites), a ferrite on the coax will get warm – or even hot!
Read information on slide.

14. AC Surge Protection
Too many grounds can cause ground loops, circulating currents, hums, buzzes and increased lightning damage.
Single point (star) grounding is the key
As much as possible, each piece of equipment should have one ground connection, going back to a reference point.
If there are multiple rooms in a site, establish a reference ground for each room, then connect all rooms to the site reference ground point
In a room with a lot of equipment, a “tree” system (a reference ground for each rack, with each rack connected to reference point) can also be made to work.

15. AC Surge Protection Buss bar for AC grounds
Tied to station reference ground
All primary equipment connected
Bulkhead ground for coax cables
Best done where cables enter building
Connected to station reference ground
Keep ground leads as short as possible

16. AC Surge Protection
Star ground to the common ground is better than daisy chaining
NOTES: Explain diagram.

17. Ac Surge Protection
This site installed a surge box for each transmitter
Remember to install the ground connection to the common point
Read information on slide.

18. Room Considerations
Determine the floor space required and entrance door opening before the transmitter arrives
Skyscrapers often have floor weight limits
Conductive floors may provide unwanted ground paths
Most transmitters allow AC entrance from the floor or top
Levelers and seismic anchoring available on higher powered transmitters

19. Room Considerations
Leave space around the transmitter for future maintenance:
- To remove / install RF modules and power supplies
- To install / remove the AC transformer
- To remove the combiner ‘pipe’ in NX transmitters
- For general safety and space to work!
Keep the manual at the site
The site ideally has adequate lighting, tools and a workbench

20. Room Considerations Copper strap is used as the RF ground.
But it is touching the chassis and reducing the benefit of our internal grounding system
Read information on slide.

21. Room Considerations These transmitter cabinets are touching each other
Uncontrolled grounds can lead to disaster
Read information on slide.

22. Miscellaneous Be aware of falling ice!
This roof has a wooden shield as additional protection
The RF feed to the tower should have a shield
Read information on slide.

23. Miscellaneous Add a drip loop!
The loops prevent water from running back to the feed-through insulator
It also acts as a lightning choke
Read information on slide.

24. Miscellaneous Ground the guy wires!
Prior to the lowest turn-buckle, ground the guy wires
Otherwise, lightning energy can cause the concrete to fail
Read information on slide.

25. Miscellaneous Soil Erosion!
The concrete base is almost washed away by tidal changes
The lagoon (background) provides good AM grounding
Read information on slide.

26. Miscellaneous Spark ball spacing!
These balls are too far apart to ever trip
Note at least 3” wide copper ground straps used
Read information on slide.

27. Miscellaneous Making a solid connection!
Termination of radials must be mechanically and electrically strong
Wrapping the wire is ineffective
Read information on slide.

28. Miscellaneous Don’t cheat!
This customer soldered a wire across the fuse
This is extremely dangerous
Read information on slide.

29. Miscellaneous Control local vegetation!
This transmitter was always shutting back with VSWR alarms
Read information on slide.

30. Miscellaneous
That’s better!
Read information on slide.

31. Conclusions Prepare your site Monitor and Maintain
Keep it cool, keep it clean
Be safe!
Can move between analog and HD or DRM at the touch of a button.