Next HARC TEK NET will be…..

August 25th at 8pm –

  • How to use a multimeter

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WELCOME all to the Henderson Amateur Radio Club’s   TEK NET

This is where we will have the TEK NET’s subjects listed and accompanying photos to go along with the discussion.

This is a new adventure and is open to everyone’s suggestions and ideas. The more discussions and and comments the better. There are many hams with years of hands-on experience to share and many without that knowledge who wants to gain a better understanding of some of the many facets of amateur radio, communications or electronics in general.

Some of the subjects that have been asked to cover will be listed below. Subjects that have already been discussed will be displayed in GREEN text to show it has been archived. Those will be at the bottom of the current discussion listed by date, for easy reference should anyone have a question to bring up.

We will have a round table type of QSO on any of the linked HARC repeaters. A roll will be established for that evenings net, for record keeping purposes.

After each photo, diagram or comment, I will ask for anyone’s comment or question .We may change the way this works, depending on what helps to make it flow smoothly. The photos, drawings and diagrams found here will assist with visually understanding the subject for that net. The subject for the next net will listed, as soon as is available so you can look over the net’s topic for the upcoming Tek Net come Sunday night.

Participation is what will make this a success. 

Subjects for discussion: (No particular order)

  • Aug 11,2019 – Power supplies- operation and failures – analog type

  • Power supplies- operation and failures –  switching types

  • Grounding around the shack

  • What is D-star

  • Stealth or disquised antennas in an HOA

  • DTMF or Touch-tone, what is it really

  • Aug 18th,2019 – How does Allstar work

  • Using commercial radios on Ham frequencies

  • Ham swap meets, do you go?

  • Mounting mobile antennas for better performance

  • Have you ever built or owned a repeater

  • What do you think of the audio on most repeaters

  • What does it take to have a successful repeater

  • Building your own antennas

  • How to use a multimeter

  • What does a swr meter really tell you

  • What do we know about Hoover dam power plant

  • Why should I turn my radio on other than for nets

  • Do you have or know about Solar power

  • Since being licensed, how have you seen amateur radio change


Next Net will be…..

August 25th at 8pm –

How to use a multimeter


#1  Digital LCD or LED multimeter

Some of the cheapest LCD digital meters have a sensitivity of Megohms per volt, making them very attractive when measuring a high impedence circuit.  (Polarity)


#2 Display driver circuit LCD


Display driver circuit LED




#3  Analog Multimeter 

Quality meter movements sensitivity was 20,000 per volt, which depending on the circuit would change the tuning or measurement by loading the circuit down.

To a circuit it could look like you just connected a 20K resistor in the circuit.

images (1)


The DArsonval movement is a DC moving coil-type movement in which an electromagnetic core is suspended between the poles of a permanent magnet. This was first called a galvanometer before the development of the D Arsenval movement. They were the first instruments used to detect and measure small amounts of electric currents.


Note…that when using an analog meter the Polarity or Positive and Negative leads MUST be hooked up correctly or the meter movement will deflect the needle in the opposite direction and can damage the movement.


#5 What are some of the uses of a typical multimeter?

* DC voltages when checking a battery or power supply output.

* Checking the charging voltage that your car’s alternator produces.

* Checking the AC voltage at an outlet in your home.

* Determining what AC voltages an unmarked transformer is producing.

* Measuring the ohms of a resistor or potentiometer.

* Checking the voice coils of a speaker.

* Checking a fuse or lamp to see if it is open.

* Measuring the current that a circuit is drawing from its power source.

* Measuring the charging current to a battery being charged.

* Use as a continuity checker with an audible tone.

#6 AC and DC jpg

#7 Current jpg

#8 Resistance jpg

#9 Continuity (low resistance) jpg












August 18th at 8pm –

  • How does Allstar work




Allstar node located at Pleasants Pk., California WB6MIE repeater 446.120MHz






Hardware improvements from the Pi 3 to Pi 3 B+

The Pi 3 Model B+ is based on the same quad-core, 64-bit processor, as the Pi 3Model B. Like the Model B, the B+’s is based on a Arm Cortex A53 architecture. However, the B+ ups the speed of the CPU to 1.4GHz from 1.2GHz in the original Model B, an increase of 16.7%.Mar 14, 2018


August 11, 2019 

Astron analog power supply









#5 Adjustable regulator board


#6 & #7 Surplus equipment