The inglorious task of AM antenna array maintenance

AM radio stations are rough customers. They frequently operate on the margins, both in terms of ratings and revenue. Their transmitter plants are complex and very often have been on a reduced maintenance schedule for years, sometimes decades.  Those of us that understand the operation of AM transmitter plants and all their quirky behaviors are getting older.  I myself, feel less inclined to drop everything and run off to the AM transmitter site when things go awry.  Seldom are such efforts rewarded, much less acknowledged.  Station owners are also finding that their previous demands are unrealistic.  For example, time was that any work that takes the station off the air had to be done after midnight.  These days, I can tell you, I will not be working at your radio station after midnight.  You can find somebody else to do that work.

Thus, today, we took this particular AM station off the air from Noon until 3 pm to diagnose and repair a problem with the four-tower daytime array.  Once again, this involved a shift in common point impedance and a drastic change in one tower’s current ratios.

Antenna Tuning Unit, mice have made a mess
Antenna Tuning Unit, mice have made a mess

In all fairness to the current owner, this ATU reflects years of neglect. At some point, mice made a home in there and created a mess. The ATU smells of mouse shit, piss, and mothballs.  It is full of mouse droppings, grass seeds, and fur.  All of the ATUs in this array are in similar condition.

Paper wasp, inside ATU
Paper wasp, inside ATU

It was warm enough that the wasps were active, if not a little bit lethargic.

Broken stand off insulators in ATU
Broken stand-off insulators in ATU

This coil is being held up by the tubing that connects it to other components. When the ATU was built, no nylon or cork bushings were used between the insulators and the wall of the ATU they were mounted on. Heat cycling eventually did all of the insulators in.

Catwalk to the other towers
Catwalk to the other towers

Catwalks to the other towers. At least the swamp grass has been cut this year, it is only four feet tall instead of ten.

Tower base
Tower base

The tower bases are all elevated above the theoretical maximum water level. The ATUs are also up on stands with platforms build for maintenance access.

ATU Work "platform"
ATU Work “platform”

I cannot even blame the current owner, who has to spend considerable money to make repairs and upgrades to this site. It is very difficult and very expensive to catch up with deferred maintenance. Sadly, most AM stations we encounter have similar or worse problems.

I think it is too late to save many of these AM stations.  The technical issues, lack of revenue, perceived poor quality, and lack of good programming are all taking their toll.  At this point, the hole is so deep there is no hope of ever getting out.  The FCC’s faux interest in “revitalization” followed by two years of stony indifference seems to be a final, cruel joke.

Winter! Is upon us….

What better time to take the gondola to K-1? None, none at all.  We do work for the two radio stations that are on the peak of Mount Killington, near Rutland, Vermont.  In the summer, usually, we can drive up there in a four-wheel drive truck.  In the winter, the gondola is the way to go.  On this day, there was a 48-56 inch base, light north winds, and air temperature around 10° F (-12° C) .

Ride up to Killington Peak
Ride up to Killington Peak
View from Killington Peak
View from Killington Peak
View from Killington Peak
Transmitter buildings on Killington Peak
View from Killington Peak
View from Killington Peak
View from Killington Peak
Tower from Killington Peak
Killington STL dishes
Killington STL dishes
ERI antenna, WZRT/WJJR Killington VT
ERI antenna, WZRT/WJJR Killington VT

The reason for the trip today; is repair work on the Nautel VS2.5 transmitter. All three power supplies and the power supply summing board needed to be replaced.

Cleaning up

We removed this old Harris BC5HA transmitter recently:

Harris BC5HA, WROW Albany, NY
Harris BC5HA, WROW Albany, NY

It was installed new in 1974 when the station moved to this site from another one a few miles up the road. It functioned as a main transmitter until the BE AM5E was installed in late 2001. The BE transmitter, other than a power supply issue, has been a solid, reliable unit. Truth be told, the last time the BC5HA ran was in 2006. After that, the unit refused to run, and a bad modulation transformer was suspected. It was deemed not worth it to repair, thus, out the door it goes. We ended up giving it to a local contractor who scrapped the metal in lieu of payment for his labor.  The only thing he could not take was the aforementioned modulation transformer, which is full of PCBs.  That will have to be hauled away by a licensed disposal company.

Broadcast Electronics AM5E, WROW Albany, NY
Broadcast Electronics AM5E, WROW Albany, NY

We may be getting a second hand Nautel transmitter from another station as a backup transmitter.  If that comes to fruition, then a couple of racks can be added to the end of the Phasor/transmitter/transmitter row and the wiring for the remote control and STL can be simplified and neatened up.

Dog Days of Summer

That saying originates from Greek and Roman times, when Sirius, the Dog Star, aligned with the Sun during July and August and was thought to bring extra heat to the earth.  The Dog Days are evil times; seas boil, wine turns sour, dogs grow mad, and all other creatures became languid; causing to man, among other diseases, burning fevers, hysterics, and phrensies.

Bad news, indeed.  Add to that; air conditioners fail, general managers become cranky, and transmitters overheat causing damage to sensitive control circuits, which is even worse.

We shall be busy dealing with things like this:

AC condenser frozen dryer and piping
AC condenser frozen dryer and piping

Air conditioning condenser with low refrigerant. This unit either has a leak or was not charged properly. I would hazard the former.

AC condenser broken fan
AC condenser broken fan

Fan blade on condenser coil failed due to metal fatigue. I have seen this in more than one place.

Bard 5 ton wall mount AC unit
Bard 5 ton wall mount AC unit

These wall-mount Bard AC units are pretty reliable, however, even they fail from time to time. The best course of action is to have a maintenance plan, a backup plan, and the number of the best HVAC contractor that can be found.