New  Equipment
Used Equipment
Our Office
What We Do
Web Links
Tech Tips
Engineer's Log
Contact Us

Radio Broadcast Technical Consulting and Sales
10032 Island Drive, Brainerd, MN  56401   

Bemidji, Minnesota

Facility Upgrade in 2010

September 2010:  It was time to upgrade old wiring and an old transmitter to a new setup at KBUN AM Radio in Bemidji, Minnesota. 

The work involved having an electrician come in to install new electrical wiring and drill holes through concrete walls with a hammer drill. 

Things really go well when the right tools are available.

Yes, he is wearing ear plugs while operating the hammer drill. 

A fluorescent lamp fixture on the ceiling had to be moved to a new location. 

The original bolts in the concrete ceiling were frozen in place so some had to be removed with a hand-grinder.   

Three-inch copper strap was run across the ceiling and into two equipment racks. 

Quote of the day:  You can never have too much grounding.    

You can see the rear of a new transmitter-to-antenna 1 KW RF switch with four RG-213 cables leading to it. 

Below that is an STL receiver and above a Sine remote control.

The finished setup has an MW-1A Transmitter on the left, which is no longer supported by Harris

Next is a custom RF filter box to keep a nearby 1360 KHz station out of this 1450 KHz station, and then an equipment rack on the right with a new Broadcast Electronics AM1A 1000 Watt Transmitter. 

At the top of the rack is a Marti STL-8 Receiver.  Below it is a 1 KW RF switch, Sine remote control, audio processing, and the new transmitter. 

At the very bottom of the rack you can see 3-inch copper strap that has been silver soldered joining all of the equipment for lightning protection.   

The back of this new rack-mounted transmitter has coils of cable. 

On the right are the power and RF output cables with ferrite cores. 

The combination of coiling the cables and the cores is good engineering practice to keep lighting out of the equipment. 

Control and metering lines coil twice through white colored cores on the left in this photo.

The project worked out well and the new transmitter passed FCC required occupied bandwidth and RF harmonic tests.

March 6, 2011 e-mail:  Very nice upgrade there at KBUN.  Steve in Green Bay, Wisconsin.

The KBUN telephone number is 218-444-1500.

   Email Mark Persons: teki@mwpersons.com    

     Return to Home Page

page last edited 02/16/2016