Paul Thurst – Page 44 – Engineering Radio

North Adams Tower update II

Work continues on rebuilding the North Adams tower after the collapse of March 2014. Over last winter, a new tower was erected. This is a fairly substantial tower.

New North Adams tower on ground — New North Adams tower on the ground

In the interim, a new Shively 6810 four bay half wave spaced antenna was ordered. This antenna will be combined for two stations, WUPE-FM and WNNI using a Shively 2630-2-06 branched combiner. The 70 foot utility pole next to the building will be retained as a backup facility for both stations. The Shively Antenna went up in stages.

New WUPE-FM and WNNI Shively 6810 antenna

Tower climbers rigging tower for new antenna

Prescott Tower from Rutland Vermont was on site to do the tower work. They were the primary contractor for installing the new tower and did a really nice job of it.

New North Adams tower ice bridges to various shelters

Hanging the top two bays of new antenna — Hanging the top two bays of the new antenna

Lift of bottom two bays and first tuning section

Securing bottom section and bolting bays together — Securing the bottom section and bolting bays together

After that, there were twenty feet of rigid line, another tuning section, then the 1 5/8 inch heliax into the transmitter room. The antenna was tuned and the load looks very good. We are waiting for the electrician to finish wiring up the new racks and we will move both stations into their new home.

Hearing test

This was in the Wheatstone newsletter a few months ago. NPR has an interesting test to see if one can hear the difference between various quality .mp3 and .wav files. There are six cuts with three versions each; a 128 kbps .mp3, a 256 kbps .mp3, and a .wav file in no particular order.

That NPR article can be found here: How Well Can You Hear Audio Quality?

I listened to all of them and found the 128 kbps .mp3 was pretty easy to pick out. On the newer material, it was sometimes difficult to tell the difference between the .wav file and the 256 kbps .mp3. Keep in mind that most radio stations stream at 64-128 kbps. Online music services like Pandora (64 kbps for free listeners, 192 kbps for subscribers), Spotify (96-160 kbps for free listeners, 320 kbps for subscribers), and Apple (256 kbps for everybody) offer slightly better quality, especially for paid subscribers.

It is too bad one cannot simulate 15 IPS analog tape. I would bet that a well-mastered recording on analog tape would stand out above anything even remotely compressed.

Others have compared streaming audio to analog FM audio and found that fairly high bit rates are needed to make the quality equal: What bitrate is needed to sound like analog FM?

One more thing to keep in mind, HD Radio runs 96-144 kbps on the main channel and 20-60 kbps on the sub-channels.

Installation Check Lists

On the subject of project management; oftentimes, we need to keep track of the small details that can derail a project, blow the budget, and upset schedules. A quick checklist can help to identify things that might not have been planned for. I developed a checklist mentality in the military. There, we had checklists for everything. Simple day-to-day things like disposing of garbage over the side, or pumping the CHT (sewage) tank to complex evolutions like entering or leaving port all had a checklist. On the aforementioned CHT tank; the Coast Guard cutter I was on had a vacuum flush system to conserve water. Emptying the CHT tank involved a complex set of valve openings and closings to route compressed air into the vacuum tank and literally blow the sewage overboard. Anyone can see the danger in such a design. Failure to follow the exact procedure resulted in raw sewage blowing out of the nearest toilets, which were unfortunately (or perhaps humorously) in the lower-level officer’s staterooms.

But I digress.

I have made a series of outlines for different project types. These can be used as general guidelines for project planning and management. Of course, each project is different, but these are flexible enough that they can be adapted on a project-by-project basis.

Transmitter installation outline (.docx)
Studio installation outline (.docx)
Automation system installation outline (.docx)

These are for general use and should be adapted for your own purposes. Don’t forget to document and label all the wire runs, etc.

Also, do not forget the transmitter site maintenance checklists: FM transmitter site maintenance list, AM transmitter site maintenance list. I have used these reliably at many different sites since I committed them to writing in late 1999.

Copper Thieves

If you are the type of person that drives around to transmitter sites and steals things; fuck you. You have no idea the problems you are causing to get a few extra dollars worth of scrap copper.

I have a feeling that most of these copper thefts can be attributed to out-of-town tower contractors removing old cellular equipment from towers. Notice, only the buss bar and copper ground wire is missing. They did not try to cut the transmission lines. In other words, they seemed to know what they were doing. I have noticed around here that when a particular contractor, employed by an unnamed large company that rhymes with glint, would work at a site, things would be missing afterward.

Perhaps it is just a coincidence. I have never been able to catch anyone pinching things. However, if this is you, and I catch you, you can rest assured that I will block you in with my car, then walk down the road and call the police.