UBS Axcera 325A 500-Watt VHF Low-band Television Transmitter User Manual

UBS-Axcera 500-Watt VHF Low-band Television Transmitter Title Page

a href="https://usermanual.wiki/UBS-Axcera" itemprop="url"> UBS Axcera >

Chapter 4

500-Watt VHF Low Band Transmitter          Chapter 4, Installation and Setup Procedures325A, Rev. 0 4-1Chapter 4Installation and Setup ProceduresThere are special considerations thatneed to be taken into account before the325A can be installed. For example, if theinstallation is completed during coolweather, a heat-related problem may notsurface for many months, suddenlyappearing during the heat of summer.This section provides planninginformation for the installation and set upof the transmitter.4.1 Site ConsiderationsThe transmitter requires an AC input lineof 220 VAC with a rating of 40 amps forthe exciter/amplifier cabinet. Make surethat the proposed site for the transmitterhas the necessary voltage requirements.The 325A is designed and built to providelong life with a minimum of maintenance.The environment in which it is placed isimportant and certain precautions mustbe taken. The three greatest dangers tothe transmitter are heat, dirt, andmoisture. Heat is usually the greatestproblem, followed by dirt, and thenmoisture. Over-temperature can causeheat-related problems such as thermalrunaway and component failure. Eachamplifier tray in the transmitter containsa thermal interlock protection circuit thatwill shut down that tray until thetemperature drops to an acceptable level.A suitable environment for thetransmitter can enhance the overallperformance and reliability of thetransmitter and maximize revenues byminimizing down time. A properlydesigned facility will have an adequatesupply of cool, clean air, free of airborneparticulates of any kind, and noexcessive humidity. An ideal environmentwill require temperature in the range of40° F to 70° F throughout the year,reasonably low humidity, and a dust-freeroom. It should be noted that this israrely if ever attainable in the real world.However, the closer the environment isto this design, the greater the operatingcapacity of the transmitter.The fans and blowers designed and builtinto the transmitter will remove the heatfrom within the trays, but additionalmeans are required for removing thisheat from the building. To achieve this, afew issues need to be resolved. The firststep is to determine the amount of heatto be removed from the transmitterroom. There are generally three sourcesof heat that must be considered. The firstand most obvious is the heat from thetransmitter itself. This can be determinedby subtracting the average power to theantenna (350 watts) from the AC inputpower (3500 watts). This number inwatts (3150) is then multiplied by 3.41,which gives 10,741, the BTUs to beremoved every hour. 12,000 BTUs perhour equals one ton, so a 1-ton airconditioner will cool a 500-watttransmitter.The second source of heat is otherequipment in the same room. Thisnumber is calculated in the same way asthe equation for BTUs. The third sourceof heat is equally obvious but not assimple to calculate. This is the heatcoming through the walls, roof, andwindows on a hot summer day. Unlessthe underside is exposed, the floor isusually not a problem. Determining thisnumber is usually best left up to aqualified HVAC technician. There are fartoo many variables to even estimate thisnumber without reviewing the detaileddrawings of the site that show all of theconstruction details. The sum of thesethree sources is the bulk of the heat thatmust be removed. There may be othersources of heat, such as personnel, andall should be taken into account.Now that the amount of heat that mustbe removed is known, the next step is to
Download:
Mirror Download [FCC.gov]
Document ID265276
Application IDx4m/3vp4IYWlMuqAIdiA0Q==
Document DescriptionChapter 4
Short Term ConfidentialNo
Permanent ConfidentialNo
SupercedeNo
Document TypeUser Manual
Display FormatMicrosoft Word - pdf
Filesize17.82kB (222721 bits)
Date Submitted2002-08-23 00:00:00
Date Available2002-10-16 00:00:00
Creation Date2002-08-23 10:47:55
Producing SoftwareAcrobat Distiller 4.0 for Windows
Document Lastmod2002-08-23 10:47:56
Document TitleChapter 4
FCC ID Filing: OUS325A

Navigation menu