Archive of Material from VU2JN - Prof. R. Jayaraman

Here is a collection of material from VU2JN - Prof. R. Jayaraman.

Please click on the images to view a high resolution version in a new window.

"Faded Dream"


"Faded Dream" - by Prof. Jayaraman VU2JN - November 2005 !

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Faded-dream


Toroid Characteristics


This article on using Ferrite and Powdered Iron toroidal cores was completed by Prof. Jayaraman VU2JN on 10 March 2013 for Ham Radio News, the online magazine of Amateur Radio Society of India (ARSI).

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Cockroft-Walton Voltage Multiplier


This article on a technique for generating high voltage DC from low voltage AC was completed by Prof. Jayaraman VU2JN on 10 March 2013 for Ham Radio News, the online magazine of Amateur Radio Society of India (ARSI).

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ATU with Reflectometer


This article on an Antenna Tuning Unit with reflectometer was completed by Prof. Jayaraman VU2JN on 25 April 2011.

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VU2JN-ATU-SWR

A compact ATU handles 100 watts


This article on a simple to build Antenna Tuning Unit was completed by Prof. Jayaraman VU2JN on 26 March 2011.

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VU2JN-Frimatch-ATU

College of Engineering Trivandrum, Amateur Radio Club, VU2TEC - Transmitter


This 150W HF Amateur Bands Transmitter/Amplifier was designed by Prof. Jayaraman VU2JN for the club around 1983. A solidstate FET - VFO (Variable Frequency Oscillator) and a multiplier tube tranmitter with 807 final tubes. Operates on AM (Solidstate modulator with TBA810 AF power amplifier) and CW, with provision to use the transmitter as an SSB linear amplifier. May be more details and story later ...

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150W-TX


College of Engineering Trivandrum, Amateur Radio Club, VU2TEC - Variable Frequency Oscillator (VFO)


This VFO was used along with the transmitter given above. The slow motion drive used for the tuning capacitor came from a WWII transmitter tuning unit. Please note that the unit is competely sealed - DC power to the VFO is supplied through the RF output connector !

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7MHz-VFO


40673 Dual Gate MOSFET Receiving Converter for HF


This article on the Dual-gate FET Converter appeared in the February 1970 issue of CQ magazine. Probably, that was the first article by a ham on a converter using dual-gate FETs.

There is an interesting background to the construction of my 40673 Converter. RCA released 40673 in Aug. 1969. A U.S. ham, who owned a small electronics firm and who had earlier read the QST article on my 500 mW Transistor Transmitter, sent me 2 Nos. of 40673 (along with the data sheets) which he had received from RCA as "Experimenter's Sample" in Sept. 1969. In Oct. 1969, I started building the converter and finished it in Nov. Surprised by the good performance of the converter, I sent an article on it to CQ magazine. They acted quickly to publish my article in the Feb. 1970 issue of CQ. Quite a few U.S. hams expressed their appreciation for my article. - VU2JN

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40673_1

40673_2

40673_3


DELUXE Receiver Gain Control


This article on HF receiver gain control appeared in the September 1970 issue of 73 magazine.

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HF_RX_gain_cont_1

HF_RX_gain_cont_2

HF_RX_gain_cont_3


A Transistor Transmitter From India


This article on a low power transmitter using transistors easily availabe in India appeared in the November 1967 issue of QST magazine.

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TranTx_1

TranTx_2


The Transistor Giant


This article on a high power transmitter appeared in the October 1969 issue of QST magazine.

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TranGt_1

TranGt_2

TranGt_3

TranGt_4

TranGt_5

TranGt_6

TranGt_7

TranGt_8

TranGt_9


I. C. Keyer


The article "I.C. Keyer", appeared in the Feb. 1970 issue of The Indian Radio Amateur.

The month of Feb. 1970 turned out to be memorable for me because of the publication of two of my better-appreciated ham-radio articles. The keyer described in the above article was the first I.C. keyer to be built by a VU ham. - VU2JN

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IC-Keyer_1

IC-Keyer_2

IC-Keyer_3

IC-Keyer_4

IC-Keyer_5

IC-Keyer_6


IRA 7 Mcs VFO


The article "A 7 Mcs V.F.O.", appeared in the February 1967 issue of The Indian Radio Amateur.

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IRA_7-mcs-VFO_1

IRA_7-mcs-VFO_2

IRA_7-mcs-VFO_3

IRA_7-mcs-VFO_4

IRA_7-mcs-VFO_5


IRA Mighty Midget


The article "THE MIGHTY MIDGET", appeared in the October 1967 issue of The Indian Radio Amateur.

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IRA_Mighty-Midget_1

IRA_Mighty-Midget_2

IRA_Mighty-Midget_3

IRA_Mighty-Midget_4

More details later !


Salim    Thu Jan 26 20:38:00 2006.