MFJ 993B Switch Problem

  I own a MFJ 993B antenna tuner and have suffered from the dreaded on/off power switch failure. The antenna tuner functioned properly for about 4 to 6 months and then it would not power on. When the on/off switch was pressed it would have power and then shut off. I did some research on the internet and found that this was a common problem. I emailed MFJ and they sent me a couple of switches to replace the bad switch at no charge.
  Well I have replaced the switch at least four times and this would have been the fifth time. I started checking the internet for a better solution then to just keep replacing the switch. I found some switches at some suppliers on the internet such as Jameco and Digi-Key. I then came across a person that decided to replace the switch with a toggle switch.
  I checked my junk parts and found some on/off toggle switches that are 2amp 125vac, which will easily handle the current and voltage. My next step was to ohm out the six pin power switch to determine what the pin outs were doing. I found that 4 pins were either on or off depending on the switch position. I removed the defective switch from the smaller front board. I looked at the traces and found the two pins were shorted by a trace as well as the other two pins. The last two pins have no trace on either side of the board. I shined a light behind the board and found there are no traces at all going to those pins. They seem to be just for support.
  I should say it is a little tricky removing the small front board, because there is a grey ribbon cable connecting the small front board to the main board. I soldered two wires to the two holes that have the traces shorted. I the drilled a hole in the lower right side of the front panel. I pretty much eyeballed it because the bottom case does slide in under it. I did put some electrical tape on the bottom under the switch just to make sure nothing shorts out. I then soldered the two wires to the toggle switch.
  I powered on the antenna tuner to see if it powered on properly. It powered on and off properly and the meter needles moved properly. I closed it up and connected back in place with my antenna switch and my ts2000 radio. I then tested it in the system and it is working properly. The best thing is if I ever have to replace the toggle switch it will be much easier to replace.
  Thanks for reading 73s from KC2YTI.

9-6-2019 This is an update on the Mfj 993B Antenna Tuner I own. I just wanted to let everyone know that the antenna tuner is still working fine. I have not had to replace the toggle switch.
     

Working on the 6 meter cubical quad antenna.

  Started work on building the 6 meter cubical quad antenna. Cut about 8 pieces of the grey 3/4 inch pvc tubing into 18 inch lengths. Then I put a 3/4 inch pvc cap on one end of the tube. Cut a 3/4 inch piece of poplar dowel rod into the tube and drilled a 5/16 hole in the end and 6 inches into the dowel rod. I will then place the 4 foot fiberglass driveway marker into it. These will be placed into a 5 way pvc fitting. These will make up the spreaders for the reflector and the director. I will then place each of these crosses on the grey pvc boom. I am going to place a piece of metal conduit inside the boom for extra strength. If this causes any problems with the antenna, then I will replace the metal conduit with a piece of 3/4 inch dowel rod. Still deciding on the type of matching I will use. I am going to use two stainless steel adjustable clamps and some tuning to string the antenna wire around the crosses.
  Thanks for reading and 73s from KC2YTI.

Home Brew A 6 Meter Quad Antenna

  I am starting to build a 6 Meter Quad Antenna. I have chosen this mainly because it will fit my area comfortably. The first thing to do is check the internet for as much information as possible. Youtube has a variety of videos out there to get ideas for building the antenna. There are also many sites with excellent pics to get various ideas as to the construction of the antenna. I also tend to write different ideas down on graph paper for future reference.
  Once I had a plan in mind I decided as to where I would get materials from. There are places out there that sell fiberglass tubes of varying sizes to make the spreader arms. Some of the places I would suggest are dx engineering and max gain systems. I decided in my case due to a lack of funds I would go with grey electrical pvc conduit pipe. It will not be very heavy due to the small size of the antenna. It would work well for other antennas such as 2 meters. The grey pvc conduit pipe is also uv resistant. The pvc conduit is always available at Lowes and Home Depot.
 In trying to make the antenna as light as possible I am extending fiberglass driveway markers out of the 1.5ft pieces of pvc conduit pipe. These are also available from Lowes and Home Depot and are not very expensive. The also have some flexibility which will help in case of wind. I have seen some different techniques for stringing the antenna around the quad ends of the spreaders. What I will try using are two small hose clamps and a piece of the black outer part of some coax cable. Inside the pvc conduit I am going to place a 1 foot piece of dowel rod and mount the fiberglass driveway marker into it. This would also provide some adjustment for the spreaders if needed.
  The next part to tackle is what to make the boom out of. Since I am using the grey electrical pvc conduit pipe I bought some 5 way pvc connectors online from the Green House Mega Store online. They fit the 3/4 inch grey pvc electrical pipe properly. To reinforce the grey pvc pipe I am going to try one of two options. I may use a piece of 3/4 inch dowel rod or 3/4 inch metal pvc pipe. I may design a clamp assembly of some sort to clamp the antenna to the mast.
  The wire for the quad antenna can be interesting as well. Some individuals use scrap wire or even heavy duty speaker wire. I am going to use 14 gauge stranded copper antenna wire with relaxed pvc insulation for uv protection. It seems to be flexible enough for my situation. This was purchased from dx engineering online. There are a number of other ham radio supply sites out there that sell this wire as well as other types and sizes of antenna wire.
  On a final thought once I get this together and tune it properly I will let all my readers know the results. Well everyone out on the air waves take care and 73s.