Improving the MFJ-2990 Vertical antenna.

     I have owned the MFJ-2990 vertical antenna since May of 2009.  It has been a great performer but it has some design flaws.
     First of all, the sections of aluminum tubing are held in place by hose clamps.  These tend to loosen with time and vibration.  Once I had the thing adjusted and tunable on all the bands I work on the radio,  I put a sheet metal screw in each section near the hose clamp to make sure the sections don't slide down and de-tune the antenna.
     An antenna this long (43 ft.) tends to vibrate in the wind especially if it has guy ropes attached to it.  I would not recommend installing it without guy ropes, especially in windy climates like Illinois has.  The vibration tends to loosen clamps and other components.
     The balun box is poorly designed.  The box is held in place at the base of the antenna by two hose clamps which also serve as contact points to the antenna.  This is not a good thing because the clamps tend to get dirt behind them and the aluminum of the antenna tends to corrode there.  To fix this issue, I disconnected the wire that feeds signal to the hose clamps and terminated it to a stainless steel bolt which I installed in the side of the box.  See figure 1.  The cable I used for the outside connection to the antenna is plain old #12 copper wire. The cable you see in this photo is the center conductor of LMR-400 coax. It dry-rotted over time and I had to replace it.  I then connected the other end of the cable to the antenna by means of a 10-32 stainless steel screw tapped into the side of the antenna.

Figure 1.

     The next thing I did was to take out the two blue capacitors and mount them to a circuit board and re-solder them into the box.  One time I could not figure out why the antenna would not tune, so I looked inside the balun box and discovered that one of the wires from the capacitors had broken off! This was puzzling to me, but I figured out that it must have been vibration that caused the connection to weaken.  Putting the capacitors on a circuit board then soldering in some heavier wire for the connection to the coax connector cured the problem.  See figure 2.

     Next, I found that the ground wire connection to the base plate of the antenna was not very good.  I had mistakenly used a zinc terminal on the end of the earth ground wire to connect to the base plate.  These two metals don't like each other.  I took the terminal off and installed a connector made of an alloy that is friendly with copper and aluminum.  I bolted it on with a stainless steel bolt and then polished up the end of the ground wire with sandpaper.  Then, before inserting the end of the copper ground wire, I smeared some Gardner-Bender No-Ox on the end of the wire.  Then I tightened the connector's set screw.  See figure 3.

                                                                       Figure 3.

     Make sure you don't forget to insert the black wire from the bottom of the balun box into the connector as shown.

     These improvements have made a big difference in keeping the antenna in good condition and functioning normally.  Remember that using stainless steel bolts and other hardware are the only way to go when constructing antennas.  They don't corrode or rust and you won't have to replace them unless they break.

73.  Your comments are welcome.

Weather Stations - You Get What You Pay For...Most of the Time.

     Last August my LaCrosse Technologies Weather Station model WS-2812U-IT went belly-up after just over one year of use.  The anemometer quit on me.  I opened up the anemometer to see if there was any kind of damage, but I only found that the batteries were dead.  I found out the hard way that taking the thing apart is difficult due to one part in particular.  It is a little piece of black plastic in an L shape that covers 5 little LEDs.  If you break this little piece of plastic, you are SCREWED!  A black plastic disk goes in between it and the LEDs to sense the wind speed.  The plastic disk is on the shaft for the wind cups.  I tried to fix my anemometer but failed.  I contacted the company and sent the whole thing back.  They returned it with a new anemometer inside for free.  I set it all back up again and found that the new anemometer DID NOT WORK right out of the box!  I was thoroughly disgusted, to say the least, so I decided "I am done with this company!"
     I went on-line and searched for weather stations of different brands and found one that suits my needs.  It cost me $200 but I found it was well worth it.  It is made by Meade Instruments and it is the model TE923W-M.  This puppy has the usual indoor/outdoor temp and humidity, barometer, wind speed and direction, and rainfall, plus a UV sensor for sunburn risk, moon phase, sunrise/sunset times, and wind chill.  It even has a remote!  You can even have it backlit in blue, but the backlight only stays on for about 30 seconds or so.  The barometer has a bar graph that constantly updates showing you changes in pressure.  It comes with software for making charts and graphs of weather data.  It is called Weather Capture Advance V 1.2.  It is pretty darn cool!  I had no trouble at all setting it up.  This program also saves the weather data in an archive file so you can access it as needed.  I used to have a weather station made by MFJ Enterprises a few years ago and it had a nasty software program called Heavy Weather.  It took me forever to figure that program out!
     In summary, let me say that I am very pleased with this new weather station.  I think I got a good value for my money.  LaCrosse will not see another dime from me, tho.
      Here is an update on the Meade weather station.  When I updated my computer to Windows 7, I found that the Meade software would not work.  I went on-line to the Meade website and found that they don't provide updates to their software packages!  I tried looking elsewhere on-line for software that might work but I had no luck.  By this time, the weather station was showing its age and battery life was getting shorter, so I decided to go shopping for yet another weather station.
     I ended up with a nice one from Acurite, which cost $225.  The outside unit was an all-in-one outfit and it sends data wirelesssly to a receiving unit inside the house and that unit is connected to my router, which sends the data to a website from which I can access my data from any Wi-Fi hotspot or standard internet connection.  THAT is COOL!  The display unit is a full-color LCD outfit with back-lighting. I usually have to change batteries in the sending unit about every 4 months.  I did not put the sending unit up very high this time.  It is about 12 ft. off the ground on a self-supporting mast and works fine there.