Transcript
Tips & Tricks And tales from the trenches
Suggestions taken from NUG registration • AUI (20 requests in total) – – – –
Familiarization (9) Updates and update notifications (6) SNMP (3) Secure email (3)
• DRM and HD Radio (5 requests) • Dynamic Carrier Control (4 requests) • Maintenance tips (10 requests) – – – –
Cooling/air handling (3) Common Failures (2) What modules can be swapped? When is rebalance of modules required?
• Lightning Protection (4 requests)
AUI
There will be a two hour presentation by the Engineering team starting at 1:30 pm
DRM and HD Radio™ • Will be covered in an upcoming presentation. • “Digital Radio Update” with Hal Update Kneller, at 11:10
DRM and HD Radio™ • Points to consider: – Cost of implementation • Overall cost, including STL, studio changes and licensing • Cost of various injection methods, up front and ongoing.
– Total system requirements • Data path to transmitter site and impact on installation • Processing for additional audio signals • Studio needs for multiple simultaneous audio feeds
DRM and HD Radio™ •
Draw a signal flow diagram – Show analog and HD audio, as well as RF chain – Don’t forget g data vs. audio and include telemetry y
Dynamic Carrier Control Will be discussed briefly at 11:20 – MDCL and HD Radio, with Brian Walker •
Points to consider: – Effect on audio and/or signal quality • AMC has the least impact, but less improvement in savings. • DAM-6 has the most impact, but also the greatest impact on operating costs. • The algorithm that works best may be different, depending on your specific situation (i.e., local audience in a metro area vs. a spread out rural audience; cost of electricity, program material, etc.)
– Cost of implementation • Free for newer NX series transmitters, or most systems operating with HD Radio™ technology • May be higher for older systems, but weighed against power savings could show a significant long term reduction in operating costs.
Dynamic Carrier Control •
For older ND and XL series transmitters not equipped with AM-IBOC, some upgrades are required. – – –
RF and Mod (PDM) drivers need to be replaced an interface board needs to be installed to interface to a DCC unit a DCC unit will need to be installed
“I have had the opportunity to evaluate the effects of the MDCL operation on the signal firsthand and … well… I haven’t detected any.” - Cris Alexander, Crawford Broadcasting
Maintenance Tips •
General Maintenance – Keep p it cool • A 10°C (18°F) decrease in ambient temperature from 30° (86°F) to 20° (68°F) can double fan life and significantly decrease component failures.
– Keep it clean • Dust can conduct electricity, causing arcs. • It also reduces the effectiveness of heatsinks and blocks airflow through filters, decreasing fan life and resulting in higher operating temperatures.
– Check hardware • Compression connections (such as AC entry points and circuit breaker connections) can loosen over time, as wires compress. • Filter connections and grounds should also be checked (fan/blower vibration and heating/cooling cycles can also cause these to loosen)
Maintenance Tips AMPFET Series (1-10kW AM) •
Clean Connectors Use DeOxit and a toothbrush Do NOT use an abrasive, such as ScotchBrite™
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Check hardware security in RF filter Focus on capacitor p connections – especially the screws that hold the end plates in place on the caps
Maintenance Tips (AMPFET 25/50) • •
Check filter and all power supply connections Verify that all power amplifiers are contributing – Remember that the current meters on front of the modules are only a relative indication – Measure the PA volts from the modulator FET cases to ground • All should be roughly equal • Take care not to short the meter lead to the front of the power module!
– Schedule some off air time, remove modules one at a time and check electrolytic caps for swelling or leakage.
Maintenance Tips ND Series (1-50kW AM) •
For all ND series transmitters, power module retaining nuts must be “nutdriver tight” or intermittent spurious alarms may result.
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y indicate temperature p PA and MOD ‘B’ alarms at same time usually trips. Check fan, clean filter. (applies to models with NAP16 power modules – built in 1991 or later)
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For ND2.5/5/10 built in 1991 or later, if power is decreased and there is an audible “clicking”, check the 40A fuses on the floor of the transmitter ((right g hand cabinet for ND10). )
Maintenance Tips ND Series (1-50kW AM) •
Capacitor hardware
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Transformer screws
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Power Module retaining hardware
Maintenance Tips J1000 •
Surge protection is very important – Consider our in-house protector • Contains MOV protection for AC transients and for decoupling antenna strikes to AC lines (more on that later) • Contains C t i fferrites it for f additional dditi l surge protection t ti on AC and d RF lines li • Contains a 1:1 isolation transformer for RF cable
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Fan filters are frequently overlooked, but very important A Annually, ll check h k RF Filt Filter connections ti
Maintenance Tips XL Series (12-60kW AM) PA contains eight FETs in H bridge configuration Freewheel diodes on each pair To check any of the FETs the gate leads must be carefully removed from all of the FETs.
The freewheel diodes can be tested while the gate leads are removed.
Ensure a good E d coating ti off thermal th l compound is applied to the bottom of the amplifier before installation in a module.
Maintenance Tips XR Series (3-50kW AM) •
Power modules are very similar to XL series – Resistance measurements can be found in troubleshooting manual – FET test and troubleshooting procedures can also be found here
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Before troubleshooting, always set exciter and power module automatic changeover to OFF. Set power scheduler to MANUAL
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If system is equipped with NX-Link (an optional item, available from Customer Service as a field upgrade for existing systems), a lot of information can be collected over the IP link,, much easier than scrolling through front panel display.
Maintenance Tips NX Series (25kW-2MW AM) •
AUI allows display of several parameters simultaneously, for example, power module operating parameters.
Maintenance Tips FM Series (3.5-10kW FM) • •
All models – replace batteries with AC energized, especially important with FM10 FM10 – ALARM RESET clears LEDs – theyy will come on again g if p problem still present – PROTECT RESET clears fault latches – MODULE RESET clears power supply inhibits
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FM3.5-8 – If there is a PA fault alarm, check fuses in rear of transmitter before assuming it’s a PA failure – Occasionally IPA Input Power Probe connections fail – gives IPA OUTPUT and INPUT alarms – IPA OUTPUT alarm is only significant if there are no other alarms
Maintenance Tips Q Series (10 and 20kW FM) •
Q series transmitters have metal panels over the control, display and distribution boards, located on the back of the front door and inside left wall. These are used as heat shields (among other things) to absorb heat from power module exhaust and should be left in place l d during i operation. ti
• There are also airflow directors mounted on each power module and IPA, to force exhaust air upwards – these also need to be in place for reliable operation.
Maintenance Tips V Series (1-10kW FM) •
There was a field upgrade (FM08011) issued in 2008 to decrease IPA output level, to prevent overdriving of PA input stages (applies to V3.5-V40 transmitters equipped q pp with NAPA16 Power Amplifiers). p ) – Most of these were either sent to the customers affected, or done during the course of site visits. – If you are experiencing power module failures and seeing signs of overheating of resistors in the PA, it might be a good idea to check with tech support and see if this mod applies.
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Note that FM08011 only applies to transmitters being operated in analog l mode, d as d drive i llevels l ffor IBOC are significantly i ifi tl llower.
Maintenance Tips NV Series (3.5-40kW FM) •
As with the NX series, AUI allows simultaneous display of several parameters (from the Meter screen, just click the “i” symbol
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g, be sure to remove the p power module shipping pp g bolts When installing,
Maintenance Tips VS Series (300W – 2.5kW FM) •
Following customer requests for clarification (and some discussion on the Public Radio technical
[email protected]), @ p g), we’ve realized that the VS series handbook has an error listserver – p regarding digital status output connections. The documentation is being corrected. Correct pinout is as follows:
per docs Status 1 Status 2 Status 3 Status 4 Status 5 Status 6 Status 7 Status 8
actual
(1) [1] (2) [2] (14) [3] ((16)) [[4]] [5] ground (17) [6] (18) [7] (19) [8] (3) [9] [10] ground
per docs Status 9 Status 10 Status 11 Status 12 Status 13 Status 14 Status 15 Status 16
actual
(4) [11] (6) [12] (7) [13] ((8)) [[14]] [15] ground (9) [16] (11) [17] (12) [18] (13) [19] [20] ground
Thanks to William Fawcett, James Madison University, for sticking to his guns!
Cooling and Air Handling • Points to Consider – If using forced air: – intake air must be filtered – draw in more air than is exhausted, to maintain positive pressure – exhaust more air than the transmitter airflow requirement – allow for redundancy (use louvres to allow warm air to heat room in cold weather, use multiple blowers to avoid overheating in the event of a failure) – If using chilled air (air conditioning): – allow sufficient headroom for building convection (heat from sun, and other equipment in building – use redundant systems… systems if you require 5T of air conditioning conditioning, consider using two three ton units and alternate the main monthly – remember maintenance (clean filters and condenser coils as required)
Cooling and Air Handling AIRFLOW DIRECTION IS CRITICAL!!!
IN
OUT
IN
OUT
Grounding and Lightning Protection • Penetrate below the frost line • Moist soil or the water table
22 Feet
• Diameter 3/8” or larger g • Connected with Cad welded or silver soldered copper straps
10 Feet
11 Feet
• Copper or copper clad steel Electrode Interface Hemisphere Grounding Conductor
Grounding and Lightning Protection Ferrites Feed Return
• When feed and return currents are equal and opposite, the ferrite is inert. • When a surge occurs on one conductor, a magnetic field is induced around the ferrite, causing current to be induced in the opposing line, effectively cancelling the surge. • Also acts as a troubleshooting tool – a warm ferrite indicates a current imbalance (feed and return currents not equal), which usually means a grounding problem – either a poor ground, or a loop.
Grounding and Lightning Protection Ferrite Choke Locations ON the coax near the transmitter ON the coax near the input to the antenna tuning unit (ATU) ON audio cables near their termination point only twisted pair, shielded cables should be used ON the AC to the transmitter all AC phases and AC ground go through the same ferrite ON the remote control cables only twisted pair, shielded cables should be used ON AC cables to any external equipment
Grounding and Lightning Protection Building Ground Ring
Ferrites on AC and Coax Lines
Transmitter
Audio Rack
Antenna Ground Radials
Surge Protector
Station Reference Ground Coax to Antenna
AC Power P
Lightning Li ht i energy
Grounding and Lightning Protection Reroute the coax to allow a short ground strap, a longer coax is better!
Improve the station reference ground point
Lightning g g energy gy
Grounding and Lightning Protection Protection At The AM Antenna
From Transmitter
DC Bl Blocking ki Capacitor Static Drain Choke
To Antenna
Properly Set Spark Gap
Antenna Reference Ground
Grounding and Lightning Protection A regular visual inspection of the ATU and lightning protection components t helps h l tto preventt damage d caused db by ffailures il lik like this.
General Questions from sign-ups Why doesn’t Nautel make a shortwave transmitter? How do you configure a preset for a second audio source? What modules are safe to swap? When is rebalancing of modules needed? H How d do you change h tto diff differentt RF or HD llevels? l ? What’s up with the remote digital outputs on the VS series???
Learn More / Stay in touch • Nautel Waves Newsletter http://www nautel com/newsletter/ http://www.nautel.com/newsletter/ • Webinars http://www.nautel.com/webinars/ • YouTube http://www.youtube.com/user/NautelLtd • Nautel N t l St Store http://store.nautel.com/
Nautel Major j Product Families NXSeries MW 25kW – 2.0MW NX25
VSSeries FM 300W – 2.5kW
NX50
NX100
NX200
NX300
NX400
NX800
Advanced User Interface (AUI)
NVSeries FM 3.5kW – 88kW
Thank You
