NELSON END FED 80 – 6M PORTABLE HF ANTENNA MATCHBOX

NELSON END FED 80 – 6M PORTABLE HF ANTENNA MATCHBOX

        

  This unit will allow you to run an end fed long wire on almost any band (80 – 6M) with just a single wire and radio plus antenna tuner. 

I have successfully used this Antenna Matchbox to tune into from 40m – 6m (I have not checked it on 80m but I am sure it would also tune to 80m).

                      

I have used 33 feet of wire with this antenna matchbox and it perfectly tunes from 40m – 6m with equal to or less than 1:1.5 provided you also use an antenna tuner with it.

              
I am using ICOM IC-7300 and the antenna tuner is MFJ – 941E.

73,
KISHORE (VU2JXL)   

MY WOODEN YAGI SWL ANTENNA

        This SWL antenna in the form of YAGI antenna was constructed by me in Nov 2011. I used this antenna with my SANGEAN (ATS-909) receiver. Performance was OK, although I could not compare it with a DIPOLE antenna.

       This is basically an experimental antenna therefore I would not recommend it. Instead a random length DIPOLE antenna is better option for SWL purpose.

MY AWARDS AND MEMBERSHIP CERTIFICATES

AS VU2-002SWL

 

 

AS VU3INK

 AS VU2JXL

MY MORSE KEYS

MY SINGLE LEVER PADDLE

     This Single Lever Paddle was given to me on loan by OM Paddy (VU2PEP) on 11 Aug 2014.

     This paddle was actually developed by OM Dev Rama Prabhu (VU2DEV), who gave one piece to OM Paddy for testing. Subsequently the paddle was passed on to me by Paddy to practice CW and give feedback about its performance. It took me more than a month's rigorous practice to get accustomed to this paddle.

     I have been using this paddle since 27 Apr 2015 for regular CW QSOs.

MY STRAIGHT KEY

     This Straight Key was gifted to me by OM LM Rajeev (VU2OCY) on 05 Mar 2008.

     I basically used this key to practice Morse Code for my ASOC (General Grade) exam.

     As a tribute to my membership to SKCC (Straight Key Century Club), I used this key 22-26 Apr 2015 to make regular CW QSOs.

MY HOMEBREW STRAIGHT KEY

     I homebrewed this Straight Key in the year 2011.

     This key was never used for making regular CW QSOs. Its meant only for use with my JAMMER-20 QRP CW transmitter.

73 !!

V KISHORE

VU2JXL

EX-VU3INK

10 WATTS HF LINEAR AMPLIFIER USING IRF530 FOR 20M

10 WATTS HF LINEAR AMPLIFIER USING IRF530 FOR 20M

BY VAGISETTY KISHORE (VU3INK)

1.         This is an easy to build 10 watts HF linear amplifier for 20M. The MOSFET used is IRF530. Based on my experience I have found that IRF530 is more resistant to ‘Thermal Runaway’ than IRF510. Though ‘Input Capacitance’ of IRF530 (700pF) is higher than IRF510 (135pF), I have comfortably used it on 14 Mhz.

2.         I had taken references from the following :

            (a)       M0DAD – For whole circuit idea.

            (b)       YC3LVX – For biasing method.

            (c)        VU3INJ – For making of 4:1 transformer.

3.         The MOSFET IRF530 is biased as Class ‘C’ amplifier (1K resistor between GATE and SOURCE). Since it’s biased as Class ‘C’, I have eliminated the use of variable resistor at the GATE (though variable resistor and resistors are shown in the picture, they are not connected in the circuit) thus making the circuit even simpler.

4.         The linear amplifier takes 1 – 2 watts of RF power input and delivers about 9 – 10 watts output.

5.         The RF voltage at the DRAIN should be about 70V (without DUMMY LOAD) and with 50 OHM DUMMY LOAD, the RF voltage should measure between 30 to 35 volts.

6.         T1 – 6 to 8 turns bifilar on two stacked binocular cores or pig nose cores (OR) 8 turns on FT50 – 43 ferrite core.          

7.         Equivalents for MOSFET used in the circuit:

            (a)       Q1 (IRF530) -  IRF510, IRF830

8.         Appropriate HEATSINK need to be used on Q1.

9.         LPF – Low Pass Filter used is for 20m. L1 is 15 turns on (T68 – 6) yellow toroid (OR) 11 turns on ½ inch diameter air core.

73 !!

(V KISHORE)

VU3INK