Saturday, 26 October 2013

WCBN's new transmitter pt. 1

The installation of our new transmitter and antenna has begun!

WCBN is soon going to be broadcasting at 3000 watts instead of our current 200 watts.
We hope to be on the air at 3000 watts by the end of November, if all goes well.

We are at the end of a long process that required FCC approval, engineering studies, coordinating with the UM AEC , the EEDRC, various UM Plant Dept. Units and external contractors and engineers.

In order to support a bigger antenna mast to hold our bigger antenna, the UM Plant Dept. engineered a way to add I-beam parts to the existing roof structure to create a solid base to which Great Lakes Tower company will attach our new antenna mast and antenna.

Today - Saturday Oct. 26, 2013 - the fine folks from the UM Plant Dept. carried a handful of I-Beam pieces (up to 400 lbs!) and antenna tower sections up to the very topmost roof of the Dennison building, where our antenna lives (photo below).

You can see a 360 panorama with Jim checking the antenna mast sections that I took on the roof.  If you view it on an iPhone or iPad, click the little gyro icon in the bottom left corner of the screen and you can turn around and look up and down just as if you were there on the roof!  Or you can just spin around and up & down with your fingers.

And DO NOT miss the chance to view it in a very fun way.  At the top of the screen you will see 2 round buttons and one bowtie button.  Click the round button on the right for a full bird's eye view!

If you just view it on a computer, you can only spin around in circles.  Sorry.

And please forgive the "transporter accident" mis-alignments.
It was the best I could do in a cold and windy spot.  With a cell phone.

Oh, and both in the photo below, the pano and some other shots, you can see our current antenna, which is on a simple pipe-like support mast.  In the shot below, it is the one on the right.


Here on the roof are the I-beam parts that will be embedded in the roof to support the pieces of our new tower, whose 3 sections are also on the roof.  The red circle is where the new antenna tower will sit.


Here are shots of most of the parts that will make up our new antenna array.

One of 2 sections that will support the actual antenna elements.

A close-up showing a TIG weld between brass and copper.

Close-up of the 'antenna tuners'.
The rods on the left slide in and out to fine-tune for a
specific FM frequency once the antenna is assembled.

One of the 2 actual antenna elements that create the pattern of our broadcast footprint.
The 2 elements are arranged one above the other on the antenna mast.
Their orientation with each other and the world determine our broadcast pattern and coverage.

Close-up of the "Phillystran" non-conductive guy wire that keep the antenna mast stable.
 Our new tower will have 3 guy wires, just like our current one.

One of the 'connectors' that capture and hold the end of the guy wires at the rooftop attachment points.
It gets braided with the actual guy wire to form a very strong grip.

Finally, here's Jim Campbell with some shots of the parts of our new transmitter!

The parts that will go in the rack.

The 150 watt FM Exciter.
It's actually a low power transmitter that feeds
the input of the 3000 watt transmitter.

The 3000 watt transmitter!
It's designed thoughtfully: it has multiple power amp modules,
so if one fails all the others continue - although with a lesser power output.
The bad amp block can be replaced without turning off the transmitter, too!

I'll post more updates as the work continues.

-t



7 comments:

  1. Congratulations, wCBN....
    Cool pictures, Tom.

    I made the mistake of trying to view the "flat image". Now my mind hurts.
    Where is this building?
    Somewhere I have a picture of the even older 10-watt antenna on the roof of the P&A building on central campus.

    - Phloyd

    ReplyDelete
    Replies
    1. this is the building you are thinking of - the Dennison Building formerly Physics and Astronomy Building

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  2. I'm going to miss the static, pop, and hiss I get from 3 miles from campus with the current transmitter. It has always been a reassuring and familiar part of listening for decades to WCBN.

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  3. This blog shows how essential a component roofing is to just about anything, including technology. Being adjustable and made of stern stuff can help it aid a transmitter. Such contraptions demand specifics, and even an overhaul. That is just about right.

    Sarai @ Edmunds General Contracting

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  4. I was driving out of Stockbridge and hit my preset 88.3 and the station miraculously came in...i was like "whoa" is the antenna operational ?? or is the atmosphere playing tricks...
    why is Special k so warm on the radio but a bit frigid in person?

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  5. Soundbelter- we were testing the new xmtr last Friday from 1-2 and then 3-4. If you were listening then, you heard it. Not on the air full time with it yet.

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  6. You are, the Electrician!!! now WCBN can enslave even more brains! Such progress since those halcyon days of 10 watt world domination in 1979. er, sez the old geezer - Git off may lawn!!

    ReplyDelete