HOME MADE MOTOR POWERING MOUNTING BRACKET

This is my experimental mounting bracket for mobile antenna using car POWER WINDOW's motor . The construction is simple, you can see it, the only hard job is positioning the axle of motor and hinge, it must be one line. You may change the hinge with simpler and light one. My purpose putting the hinge is only for keeping the load of antenna, not at the motor. I make an octagonal hole, just like a 19 mm spanner by filing as arm adapter for matching to the gear at power window. Don't do welding because the gear inside is made from such kind of plastic material.

 It is more detail picture of motor, arm coupling and 90 degree stopper. The long bolt is for coupling adjustment or replacement.

You can see the plate connection from motor to the hinge for connector placement. Don't forget to make stopper for hinge rotation, I make 90 degree operation.

The total weight is around 1 kg, so you must consider about it.

This is maximum position for standing.

and it is minimum position.

I am using a simple motor speed controller with some adjustment, but still need improvement for movement. because down speed  movement is faster than up movement ( because of antenna self weight ), so I add Resistor to keep slower for down movement ( same speed is the best ),
I am sure you know better for this matter to solve it.

ANOTHER 40 M MOBILE ANTENNA

RESONATOR COIL

MATCHING COIL

WINDING CONFIG.

GDO

GDO is my project starter in this year 2012, even it is actually not a new one. I only grade  up my old gdo that I built from plastic box and have only 2 band coil , for 80 m and 40 m. Now it can be used for HF band from 1.6 up to 30 Mhz. The schematic I take from " Modern GDO " ( QST May 2003 ), but I use only the oscillator.

The box is made from PCB with final touch of  paint, and coil core is from sewing thread that I put audio connector to make easy to plug in to GDO. I use heat shrink rubber to keep the coil fix in the position and for nice looking. The dial mark I used from transparent paper by mirror printing then glued with silicone paste.
                   

          
  

                                                         

The lowest frequency should be lower than that , seeing that my project is still around 3.5 - 21 Mhz only, for the moment I just put in any limit for lowest and highest frequency for hf operation, and if my project needs lower or higher , I will re-wind the coil then.

This Frequency Counter I built totally from IK3OIL
( schematic and source code ).For normal operation it can measure up to 50 Mhz, and needs prescaler  for higher measurement. I like IK3OIL project ( FC ), because he provides some variables choice for the PIC Program, eg. X-tal, prescaler division , etc. so I can use any X-tal from the junk and prescaler IC, as well. I know, to get prescaler IC is not easy unless importing from other countries. Another way to get it, is, by cascading two ic LB 3500 ( 1/8 prescaler ) , it becomes 1/64 prescaler. Even it is only 150 Mhz, but better than not.