• Category Archives: Projects

1296 MHz 4 Way Power Divider

Hello 2 all.

Want to introduce one of my UHF projects. It’s a 4 way power divider for 23 cm band which can be used to make antenna stack arrays for contests or EME.
I made many of this dividers and always they have very good performance. To make this divider you need to have a simple skills of drilling, soldering and understanding of microwave principles.
You will need:

  • – enclosure by HAMMOND – 1 pc
  • – 1/8 brass rod by K&S Engineering – 1 pc (12″)
  • – N-type connector – 5 pcs
  • – M3 or 4-40 screws – 20 pcs
  • – digital caliper

That’s all. Now time to show a technical details. It’s very easy just follow all steps.

4-way power divider. Click to enlarge.

Click to enlarge.

Here is pictures of assembly procedure.

Good luck!

Alex K6VHF

ICOM IC-7100, IC-703, IC-706MK2/G Headset Adapter

IC-7100 HEADSET ADAPTER HS-02C

THIS ADAPTER 100% COMPATIBLE WITH:
IC-7100, IC-703, IC-706MK2/G
This amazing headset adapter HS-02C is great for field day, contesting or make your rig more portable
with a headset and foot switch. The adapter has EMI filter which protects against RFI and internal RC
filter makes your audio clean.  I use this adapter with my IC-703+ in portable operation with light weight
headset and always happy. The headset adapter is short (2”), light and ready to use.
SPECIFICATIONS:
– Cable Length – 2”
– Standard 3.5 mm Stereo Female
– RJ-45 Connector
– EMI Ferrite Filter
– Assembled in USA
HS-02C

HS-02C

IC-703 with HS-02C

IC-703 with HS-02C

Feel free to ask me. Support 24/7.

de Alex K6VHF

The Lightning Protection for Antenna Rotors

ASSEMBLED and TESTED BOARD – $29.99 with Free Shipping USA only.

INTERNATIONAL BYERS MUST CONTACT ME FOR INQUIRY AND SHIPPING INFORMATION

CURRENT VERSION – V2

Manual can be download HERE (in PDF)

Hello 2ALL. This is a fresh and new design of Lightning Protection for Antenna Rotors (LPR) by Ivan RA3WDK.
What is the LPR?
LPR – Lightning Protection for Antenna Rotors.
It’s the electrical circuit which connects between a rotor and control unit. The circuit has relays and other parts which help to protect your
control unit against the static and dangerous voltage during the lightning storm or thunderstorm.
What do I need it for?
You need it for protection. Without the proper protection of your rotor and control unit the chance to get damage during a lightning is very high. There is a few important steps that needs to be done before rotor installation. Some people prefer disconnect the all cables during the lightning storm but that is only option and it’s not a right way to do.
If your system is not GROUNDED or hasn’t any lightning protection the cable disconnecting won’t work.
The lightning strike is the natural hazard. Stay smart!

some words from Ivan RA3WDK

  • I hope you thinking about protection your antenna rotors and station. How many HAMs ground or disconnect their rotor cables?
  • So much information has been posted on lightning protection for Rotor in Internet, but not many HAMs used those recommendations. Isn’t good idea!
  • You have to be always prepared. It’s better spend $$ for protection instead spend your $$$$ for repairing and replacing.

Let’s read some interesting article from DX Engineering

The primary goal in any lightning protection system is to control the massive energy generated during a lightning strike so it will dissipate before it can enter our homes. Lightning contains awesome levels of energy in a wide range of frequencies, and travels fast (1ns per foot) with very fast rise times. It can travel through the power lines, coax feed line, control lines, telephone, CATV or satellite coax and our equipment looking for the easiest path to ground unless we can provide a better path for it to follow. To control this energy, we have to provide a better path to ground than anything else around. A single, low inductance ground point system can ensure a simultaneous rise and fall of the currents across all of our equipment, so no current will flow across the equipment in search of ground potential.

Build a ground system that uses conductors with low inductance and impedance across a wide frequency spectrum to provide a good path for the energy to follow. A wide and thin conductor like copper strap is better than wire or cable for longer runs. A heavy solid, rather than stranded, wire will work if the connection is direct and short.

Even with a well designed ground system, some of the current generated during a lightning event may flow along feed lines, control and equipment grounds and AC power lines. Lightning protectors should therefore be used on all of these lines before they enter our house. Lightning protectors work by diverting the surge to a low inductance ground path that we must provide.

                                                         DX Engineering, Inc

Lightning Protection for the Rotors (LPR)

LPR V1

LPR V1

Description

  • Easy to install, have TVS-diode/Gas tube Arrestor and relays to disconnect the rotor from control unit.
  • TVS diode shunts RF current and voltage over 18V, Gas Tube Arrestor shunts voltages over 80v. The relay connects the rotor only for work period.
  • It’s very simple circuit but could save your time and money.

The LPR compatible with many types of rotors:

Type COMPABILITY Notes
YAESU G-250 X
YAESU G-450A X
YAESU G-650A X
YAESU G-800DXA(SA) X
YAESU G-1000A(DX,SDX) X
YAESU G-2800A X
YAESU G-550 X
YAESU G-5500 X [*] Available with restrictions
KENPRO KR-400 (RC) X
KENPRO KR-500 X
KENPRO KR-600 (RC) X
HY-GAIN  HDR-300A X
HY-GAIN  T-2x (T-2xx) X Also for use with DCU-3
HY-GAIN  AR-40 (500) X Available for other old models of rotors and models with digital controller (DCU-1, e.t.c.)
HY-GAIN  HAM-V (VX)HAM IV with DCU-3

with digital controller

X

[*] recommend use of two LPR to increase protection
If you don`t see in the table your rotor or controller please contact Ivan RA3WDK or me

Connection Diagram

Connection Diagram

IMPORTANT INFORMATION ABOUT GROUNDING:

  • Amateur radio equipment should be grounded in the single ground point (better outside of house/shack).
  •  You must connect PLR ground wire to that ground point.
  • TURN OFF and UNPLUG the control rotor equipment and TRX (included PS) before start grounding.

The Schematic Diagram of LPR V2 (please click to enlarge or left button SAVE IS to save it to your PC)

Schematic Diagram

Schematic Diagram

Typical LPR Connection Diagram for Yaesu G-250A rotor:

LPR connection diagram for Yaesu G-250

LPR connection diagram for Yaesu G-250

Table of connection LPR to Yaesu G-250 rotor

CONTROL UNIT LPR OUTPUT ROTOR LPR INPUT
Pin 1 B1 Pin 1 A1
Pin 2 B2 Pin 2 A2
Pin 3 B3 Pin 3 A3

For other types rotors and their connections to LPR V2 please download the LPR manual

–         Current LPR version V2 -available from May 2014

–         Previews version V1 is discounted since April 2014

 

For more information please contact 24/7:

    Alex K6VHF – alex_nersesyan@yahoo.com

    Ivan RA3WDK – ra3wdk@gmail.com

 

LPR author and designer – Ivan RA3WDK

Support and USA official distributor – Alex K6VHF

MADE IN USA

EMI-LPF Filter for the headsets or microphones

Hello everyone. Here is my another project for headsets or microphones. It’s an EMI-LPF filter.

EMI-LPF filter

EMI-LPF filter

It’s a complete and finish device which you can use to protect your microphone against the EMI. There is a simple circuit for the EMI filtering and also has a LPF (Low Pass Filter) which rejects all frequencies below 300 Hz.

You can make it or buy in my ebay store

Thanks.

73’s,
Alex K6VHF

Automatic Fan Controller Circuit

This circuit will turn on/off 12V DC fan or CPU fan when temperature above normal temperature.You can set turn on temperature by adjust VR1. This circuit use an NTC (Negative temperature coefficient)which is a thermistor is one in which the zero-power resistance decreases with an increase in temperature. So If temperature increate the voltage at pin 3 on LM311 will decreated .The resistance of NTC is about 10K at 25’c.

VR1 should be multi-turn potentiometer type such 10K/25 turn

Automatic Fan Controller Circuit

Automatic Fan Controller Circuit

73’s,
Alex K6VHF