News from Maxwell Communications

For the latest news updates and comments, see our BLOG at www.maccuss.com/blog

Current Events - August 2009

It has been a month reflective of the economic crisis surrounding radio. One friend in Romania joked that they don't have an economic problem there, because they didn't have an economy to begin with! Ouch!

Several recent projects involved

AM NRSC-2 occupied bandwidth measurements for four radio stations of Salem Communications
Measuring the products of a combined TV and radio system for Georgia Public Broadcasting
Troubleshooting the diversity delay and power metering of the Georgia Tech radio station (with help from Harris)
Reviewing parts of an update to the Harris 3DX50 technical manual.
Writing a few blogs
Selling things like a Motu 896mk3 which was integrated into a computerized audio analysys package. If anyone has a desire to learn how to use a high quality sound card to measure audio quality, please contact us and we will be glad to give recommendations.

Web Site updates - July 2009

When the economy is down we spend time restructuring and reordering and, well, cough, digging deeper. It has been a joy to redesign the web site to show updated services where our goal is to be "Maxwell Smart" and not only "good to the last drop" but also efficient in the airwaves. Electromagnetic propagation has always been a favorite occupation for Daniel Maxwell though Maxwell's equations and their use are unfortunately credited to a long lost distant relative, James Clerk Maxwell. Daniel's oldest son is named James, by the way.

Please keep tuned as new projects will show up, new services offered and more detail is given to the web site. It is a pleasure serving you!

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HT-35FM PA Cavity Repair - June 2009

One very distinct job recently was to disassemble the heart of a very powerful FM transmitter and put it all back together again without making any mistakes. There are literally hundreds of small parts and the project involves a wide discipline of skills. The engineer on site was very helpful with background history, observations, disassembly and reassembly, logistics, cleaning materials and most of all with patience.

The first step was to look at the damaged plate blocker and try to analyze why they might be failing and the next step was to tear it all apart. The transmitter was already apart prior to our arrival so we could not test on the original configuration. Along the way, it appeared as if we were astronauts working with small pieces with large gloves on. Hot humid outside aire condensing through the ventilation duct and dripping down into the PA from above didn't help matters. That part is now resolved.

The new plate blocker assembly is "hot off the press" so to speak because it includes newly machined side rails to isolate the kapton from the edges of the PA cavity. These rails are stiff and sturdy and consistent from one machining batch to another. In addition, the new plate blocker anode plate has a ridge of fingerstock like coductive material which effectively raised the anode plate on the tube wall about 1/16". This may explain why we had to move the PA deck up 1/4" to recover tuning range.

The network's Agilent E4402B was used to neutralize the transmitter's power amplifier, canceling out internal parasitic capacitances as best as possible. A good part of time in this work is spent working as a mechanic or technician but then suddenly we find ourselves switching into some kind of "Maxwell Smart" electromagnetic fields and waves expert with high power 4CX2000D tubes rated for 35 thousand watts of energy at 100MHz.

The job ended well and it looks like the 15 year old transmitter will get a second wind.

Ethiopia Projects - February to May 2009

Installation help and a day of training for a 3DXD-100:

This job was under a contract with Harris Corporation as are many of the jobs performed by Maxwell Communications. The people of Ethiopia are grand in many ways, having a history rich in ideals and cultural jewels. Here we are having a very brief time to explore transmitter operation and "mock-troubleshooting" exercises.