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Homemade Squelched Triggered Repeater System COR

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ABOUT ME:

Know how I came to be a journalist, photographer,
and artist...

SITE LINKS:

GRENDEL DE RAMOS
Marikina City, Philippines

My Singer/ Fashion Model

DESTINY PILKEY
Vancouver, Canada

My Canadian Singer Friend

AIRA MARIE DE RAMOS

Marikina City,Philippines

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Antipolo City,Philippines

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This page contains news and schedules of events in the Art Circle, Entertainment, and any activites I am participating into.

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My Novelas and Short Stories

1. Binhi ng ...Katutubong .....Lahi
"Seed of the Primitive Race" (unfinished Novel)
Note: This article is copyrighted.

This is a story of four friends who braved the dangers of a mysterious woods somewhere South of the

Philippines for a college research project. They were expecting a bunch of ghosts, unearthly creatures and paranormal activites. But what they faced instead is a vicious tribe. Three of them would narrowly escape, one will be kept captive. Eight years of painstaking rescue, they would soon discover that their captive friend became the leader of the tribe, and has somehow civilized the once nomads nature of 'Pulong-Pulong' tribe. But Dentor a.k.a. 'Apo Serang' has lost all his previous memory, and this poses great danger to the rescuers. The real twist has yet to come as a war triggered by greed for power and revenge will claim the life of our hero. In the end, justice will prevail. The throne will be succeded by a baby boy, Apo Serang's son, the seed of the primitive race... 'Binhi ng Katutubong Lahi'.
Read preview in tagalog)

2. The Flight to
.......187th Floor

(Short Story, Copyrighted)

Old Mr. Dodgie is new to the big city. And entering a tall and strange building proved to be a
gigantic step for him. Not just a huge step though, but rather a flight to heaven... Or down through the gate of darkness?

The 187th Floor poses some great mystery. Nobody seemed to know whether it exist in the Moon Tower building, as it was only a supposed 150 storey structure. Crazy? But old and innocent Mr. Dodgie soon discover it's existence and takes him to one-of-a-kind travel in different time dimensions. To his amazement, everything that he is yearning for is there - his childhood memories and his dreams. Could it only be his imagination driving him nuts, or is this a solution to all his longings for a good life? Is the 187th Floor for real or a dead end entrapping and engulfing him nearer to his doom? A spell binding mystery with a touch of humor, caters to most young adults.... The Flight to 187th Floor.
Read Preview.

3. Deadlock

Drive

(Soon to be reviewed, short story)

Published Work:

*Reagan Times
Community Newspaper

As the Editorial Consultant and Lay-out Artist of this newspaper, I am presenting this to my website. Please view the pages. I have two articles in Up Close and Personal column and has written an editorial at the Editorial Page.

Reagan Times is a community newspaper of Reagan Street, Cuesta Verde Village, Antipolo City.

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MY HOMEPAGE

Email: mannydeguzmanjrartist.@yahoo.com

Telephone No: (Philippines): (02) 660-1869

MY HOMEMADE SQUELCH TRIGGERED

REPEATER SYSTEM (COR)

By: Manny De Guzman,Jr.

Squelched Triggered COR - Radio Shack PRO-2052

(Update: a more elaborate project is available.in this site.This time, I used Bendix King LMH-3142 VHF Base/ Mobile for the transmitter and receiver. To view this project, click the thumbnail on the left, or click here...)

This project is a response to the our Homeowners Association's need

for a reliable and low-cost means of communication.

Despite the rise of cellular phones.latest communication gadgetry, and other

recent communication modes, Radio Repeater Systems remain to be at high cost and out of reach for most small businesses and institutions. I designed this homebrewed repeater controller to answer this need, with a few handfull of parts. An Icom V68 is used for transmit, and a Radio Shack PRO-2052 scanner for receive purposes. The beauty of using a scanner radio in a repeater system is that you can do crossband (up or downlink) at any frequency band, from 29 Mhz up to 1.3 Ghz!.

The heart of this project is a squelched triggered electronic relay switch. Two

transistors were used to amplify the 3 volt squelch voltage of the PRO-2052 to drive a small electronic relay. The relay isolates the 3 volt DC Squelch voltage to it's output to the transmitter (Icom V68's mic input) in which the Baseband Audio out of the scanner were also routed. The relay and associating parts were biased and powered with the same12 volt Supply (Check the transistor's data sheet for the correct voltage input bias)..

FINDING THE RIGHT SQUELCH TAP

Refer to the photo below. The Squelch IC is IC8 and marked JRC-3403X. The

squelch voltage tap is at Pin 7.

With the squelch closed (receiver busy), connect the negative test prod of a digital

multimeter to any metal part or shield of the scanner which serves as common ground. Then carefully tap the positive tip to IC8's Pin 7. The multimeter should read about 3 volts. Rotate the squelch control clockwise until the hiss disappears. The tester should read 0 volts. This is the right squelch tap. Remove power and solder a piece of stranded wire to this terminal (avoid shorting the pins!). Connect this to the input of the relay trigger switch.

FINDING THE BASEBAND AUDIO OUT

You can use the headphone out of the scanner for the audio out and vary the

volume control to level the transmitter's mic input. But you cannot monitor the signals that were coming through or being received with this procedure. Fortunately with the PRO 2052 scanner, there is a better option: Baseband Audio tap provision. This would enable you to harness a good unfiltered audio out of the AF section before it is amplifed. You can therefore monitor the signals through the same scanner radio's speaker while routing the Baseband audio out and triggering your transceiver.

Refer to the photo below. The Baseband Audio is marked TP DS at the main

board.

THE RELAY SWITCHING DEVICE

Below is my prototype of a 2 stage relay switching device. The relay is located and

soldered on the foil side of the board.

Parts list:

TRANSISTORS: 2N3904, 2N3907

DIODE: 1N4148

RESISTOR: 100 ohm 1/2 watt

Homemade Repeater using Radio Shack PRO-2052 and Icom V68

ERRATA: (Last updated - April 16, 2009

This modification works only via squelch circuitry, and not not applicable for
CTCSS purposes. CTCSS is activated via audio line circuit. Initial test of this project shows that a squelched modified CTCSS equipped receiver will only trigger a dead carrier via the Transmitter (Icom IC-V68), and no audio will come out if the CTCSS encode is activated.

This article is also available at this forum site

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mannydeguzmanartist	Latest page update: made by mannydeguzmanartist , Oct 25 2009, 3:00 PM EDT (about this update About This Update Edited by mannydeguzmanartist view changes - complete history)
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