Crud and Other Stuff

| May 24, 2013

By Thomas R. Ray, III CPBE, AMD, DRB
Tom Ray Consulting
President   
TALKERS
Technical Editor

First the Crud

NEW YORK — So I was working on this transmitter today.  Seriously – I know this starts off like a joke.  Problem was actually a bad air switch.  All transmitters have a way to sense air flow.  If there is no air flow in the transmitter, if, for example, the blower motor quits, it will shut down.  In the case of a tube transmitter, this is to prevent the final amplifier deck from melting down and starting a fire.  In a solid state transmitter (which also uses temperature sensing in the final amplifier), it prevents the transistors from self destructing causing a fire and/or other severe damage to the amplifier.

Anyway, this isn’t related to the air switch, but it could be (the air switch in this case was 33 years old – it simply had enough).  The air filters on the transmitter were caked with crud.

The air filters are there to keep crud out of the transmitter (obviously, in this case, they did their job).  In a tube transmitter, crud can cause an arc over in the high voltage areas.  In solid state transmitters that do not have high voltage inside, the crud acts like a blanket holding heat into the transistors.  Heat is an electronic device’s worst enemy.

If the filters are caked with crud, the transmitter has trouble breathing.  Pinch your nose.  Inhale.  Now you know how your transmitter feels.

Caked up air filters can cause a lack of air flow – if this occurs, the transmitter will shut down.   This lack of air flow can also cause the temperature inside the box to increase.  This can also shut down the transmitter.

It’s an easy fix, and one that you could do yourself.  Some transmitters use a foam filter over the air intake (usually located on the back door).  I hate these, because as the foam ages and dries out, it starts to disintegrate and generates its own crud that gets pulled into the transmitter.  But, if the foam is in good shape, remove the filter temporarily, put it in a sink, and give it a good bath.  Let it dry out thoroughly, then put it back on the transmitter.

You can also measure the filter space with a tape measure, and go to your favorite home or hardware store.  Go to the filter aisle and grab a couple of air conditioning/furnace filters.  Not the fiberglass kind – those won’t filter out the dirt particles well enough.  Grab the pleated paper types.  They range in price from a couple of bucks per to $20 each.  You don’t need the $20 ones, and you don’t need  one that’s super thick, which can affect air flow.  Grab several and change them once a month or so.  Your transmitter will thank you.  It’s cheap insurance to staying on the air.

Now the Other Stuff

Changing topics – while the slate has not come out yet, I am running for Board of Directors for the Society of Broadcast Engineers.  I have already spent 6 years on the board previously – and I’m not asking for votes here (though I hope if you’re an SBE member, you would be so inclined).

A questionnaire goes out to each candidate with a series of questions so members know who you are.  The first question is:

What goals should be set for the Society this coming year that you will support and work for?

My response is:  “I think the Society is and has been on the right track with its education initiatives.  That being said, there needs to be more emphasis on IT for Broadcast Engineers.  Everything at NAB this year was IT based.  I would fully support furthering the IT education of our members.  No IT?  You’ll be left behind.”

None of us in Broadcast Engineering can deny that our jobs and our job duties have changed drastically in the past 5-10 years.  The IT train has left the station and it’s not slowing down.

First, encourage your station engineer to either join and/or attend SBE meetings.  SBE is dedicated to the education of the engineer.  It’s no longer about RF, audio and video.  It’s about all these, plus IT.

Encourage your engineer to attend seminars and perhaps classes on IT.  The more he knows, the better your station will function.

Broadcast IT has one major difference from “normal” IT work.  Broadcast stations function 24 hours a day, seven days per week, 365 days per year.  There need to be backup systems, and any system maintenance needs to be done at odd hours or ways need to be developed to do system maintenance without causing a major disruption on the air.

I have friends who tell me constantly about the IT department needing to do “system maintenance” and just taking the network down at 1:00 pm – and these people can’t get any work done until IT says OK.  How would that fly at your station?  No spots for several hours because “system maintenance” is being performed.  You’re right.  It won’t.  Broadcast IT requires a different mindset, and broadcast engineers are trained and have been conditioned to keep the station on 24/7/365.  Again, the more your engineer knows about the IT world, the better.

And, yes, I dare say it – perhaps the station may consider assisting the engineer with any certifications, classes and seminars he may attend – ie, pick up the costs.  Give him/her the time off they require to attend education events, such as SBE Ennes Workshops.  This is an investment in the future and in the infrastructure of the company.  Maybe even fund his/her SBE membership – after all, SBE is a professional organization, much like many of your sales persons may belong to professional organizations.  The more encouragement you can give your engineer, the better the station will perform IT wise.

I’ll be talking about IT quite a bit in the coming months – it has become pervasive in our portion of the world, and our on air survival depends on it.

tbugk

Thomas R. Ray, III CPBE, AMD, DRB is president of Tom Ray Consulting and Technical Editor of Talkers. He can be phoned at 845-418-5065 or emailed at tomray@tomrayconsulting.com.  His website is www.tomrayconsulting.com.  Meet Tom Ray at TALKERS New York 2013 on Thursday June 6.    

 

 

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Category: Technical