Archive for February, 2013

My Arduino I will be using to count freq and do some line select inputs and math.

RGB back light dispaly by Adafruit.com for my freq display

These are the freq I measured coming out of the three RCA jacks on the back of the TS-520S ham radio. I need to count these freq and do some math to know the freq the radio is using.

I can measure the VFO and BFO with the Arduino directly but not the HFO. I will need to use a prescaler to divide the HFO by 8 before it gets to the Arduino.

The library I’m using is coded to use just the one input so my plan is to use a line select chip to multiplex the three signals to this single Arduino input.

For a test of the Arduino measuring the BFO freq level directly I just created a nice clean 0-5v square wave at 3.395MHz on my freq generator and put it into the input pin the Arduino is coded to use per the library. As you can see it can count this just fine.

I use my leader to validate the Arduino is correct.

I then double check the Leader and Arduino with my HP counter. All instruments agree to within 1Hz. WOW. Nice.

For the HFO I have to use a MFJ-259 SWR antenna analyzer to generate the higher 10 to 40 MHz signal for testing the Arduino.

However this instrument only outputs a 1 to 1.1V peak wave which is too low of a voltage level for the Arduino to count.

Even at the 5MHz level the Arduino only outputs 0 back to the serial monitor on the PC. It could measure the 5MHz but not at the low voltage levels. I will need to build an amplifier before the Arduino can use the SWR antenna analyzer output for testing.

On to testing the divide by 8 prescaler. I output a 4MHz square wave 0-5 v from my function generator.

I then pipe this 4MHz into the 4 bit binary ripple counter in 3 bit mode. It should output a clean divide by 8 signal at 500KHz

My Leader records the 4MHz in and the HP records the 500KHz out of the chip so we can compare to the Arduino freq count output.

The Arduino reads spot on with the HP at 499,997Hz

This just shows that the Arduino can then do some math to multiply what it counted back to 4MHz with (frq*8) code.

This shows the Leader which is counting the source at 4Mhz agrees with the Arduino’s math to within +/-4Hz. NICE! I only need to be within 100Hz in the end for this to work as a ham radio freq display

That is it for part one. Part two will start with signal amplification then multiplexing and more. I’m not sure how many parts this will end up being but it is fun to share and I hope fun to follow along.

My bench stool is upside down. Add some oil between the two pipes.

Sand the inner pipe if it is not smooth.

Add some clean bearing grease.

Make sure the bearing grease goes as far down as the stool goes.

Add some more oil to the pivit point of the air ram. Clean up before returning the stool to the house.

My office chair upside down.

Oil the spring. Mine is inside the large knob so I put lots on and let it set for an hour.

Add oil to the pivit points.

Remove the clip that holds the legs to the air ram.

Remove these bearings and clean them before applying clean bearing grease. Put some grease on the air ram too.

When the chair is right side up put a little oil between the spring knob and base.

Put your air ram retention clip back on and add more bearing grease to this point.

Office chair is now squeak free.

Use an Allen wrench or whatever you need to really tighten up all the fasteners so you don’t get any hardware squeaks.

My bench stool is now squeak free too!. Thanks for joining.