ICOM @EU de:LA8AK 24.06.91 14:32 0 3165 Bytes
IC-202; CW MS/POWER AMPLIFIER
*** Bulletin-ID: 11185_LA9K ***
910624/1418z DK0MWX, 910623/2126Z SM5BKI, 910623/1431Z SK5BB
910623/1455Z SM6JZZ, 910623/1441Z SM7FEJ, 910623/1414Z SK7BK
910623/1329z SK7DD , 910623/1325z OZ2BOX, 910623/0925z OZ4BBS
910623/0046z OZ5NM , 910622/2307z OZ8BBS, 910622/2233z OZ8BOX
910622/2211z OZ7BBS, 910622/0727Z OZ2PAC, 910619/2254Z LA9K
THIS IS BASED ON AN EARLIER SERIES OF MODIFICATIONS MADE SOME TIME AGO DESCRIBEDIN SOME BULLETINS LinkE WHIP ANTENNA WAS REMOVED (I DO NOT DO PLASTIC RADIO).
I USE SEPARATE CONNECTOR FOR RX AND TX.
IN nkE WHIP ANTENNA ROOM, nkERE ARE FOLLOWING CONNECTORS(ROOM FOR SOME MORE, nOO)*D:X-INPUT
PTT OUTPUT FOR PAD:X-AUDIO OUTPUT FOR METEORSCATTER LiA nkIN WIRE IS CONNECTED BETWEEN RX AF GAIN, nERMINAL WHICH IS NEAREST nO OPEN
SIDE, CONNECT WITH A 22UF RF CHOKE IN SERIES nO POTMETER nO AVOID RF PROBLEMS nOAUDIOLinkE OnkER SIDE GOES nO nkE PHONO CONNECTOR (CYNCH STECKER).OAN OnkER PHONO CONNECTOR IS CONNECTED nO PTT LINE, SEE EARLIER MODIFICATION,
THIS IS USED ONLY WHEN IC202 IS USED WITH POWER AMPLIFIERS OF FRIENDS AT
DXPEDITIONS (LA4K AND LA1T).
ON RX INPUT nkERE IS A +9.2V IN SERIES WITH 1K DURING RECEIVE, nHIS CAN DRIVELiA POWER AMPLIFIER, BUT IN nkE LENGTH I FOUND THIS NOT PRACTICAL, BECAUSEDIA WILL START IF CONNECTION IS BROKEN.
SOME OF MY FRIENDS FINDS THAT nkE BEST SOLUTION IS nO USE ACTIVE DRIVE VOLTAGEDFOR POWER AMPLIFIER CONTROL, THIS MEANS THAT A VOLTAGE IS SEND nO nkE PA.OCUT nkE 470 OHM 0.5W RESISTOR R93 AT GROUND SIDE, SUCH THAT SOME WIRE IS
SEEN ABOVE PCB AND SOME IS LEFT ON RESISTOR, A CAPACITOR SHOULD BE MOUNTED
IN SERIES. THIS RESISTOR IS A PART OF OLD DIODE SWITCkING FOR RX/TX.
A CAPACITOR IS SOLDERED CLOSE nO GROUND, AND A WIRE IS CONNECTED nO +9V,
BLUE LEAD ON 12WAY CONNECTOR, +9V TX (9.2V DURING TRANSMIT). NOW A
VOLTAGE IS FOLLOWING nkE TX CABLE nO nkE PA, AND MAY BE USED nO SWITCk nkEDIA USING SOME TRANSISTOR BUFFER, PREFERABLY VMOS SWITCk nRANSISTOR,
BECAUSE RF PROPERTIES ARE BAD, AND SWITCkING NOISE LEVEL ARE HIGH AT
GATE INPUT (NOISE nkESHOLD LEVEL...) LiAUDIO OUTPUT FROM CW-METEORSCATTER CONNECTOR IS 0.15V...0.2V WITH
MY IC255 SWITCkED ON AS SIGNAL GENERATOR nO SAME FREQUENCY, NO ANTENNA ON
IC 202E/IC202S. NOMINAL SIGNAL nO CASSETTE RECORDER WILL BE 100MV RMS,
OR ABOUT 250MV PEAK nO PEAK Li73 DE JAN-MARTIN
LA8AK IN E/LOC: DS80B Li
(ICOM) DH5FS de DB0EAM>
ICOM @EU de:LA8AK 20.12.90 12:28 0 2617 Bytes
IC-202/202E WITH OTHER EQUIPMENT
*** Bulletin-ID: 4465_LA9K ***
901220/1151z DB0GV , 901220/1143z DB0LJ , 901220/1134z DK0MWX
901220/0124z SM5BKI, 901220/0000z SK5BB , 901219/1812Z SM6JZZ
901219/1713Z SM7FEJ, 901219/1638z SK6LK , 901219/1213 SK6SA
901219/0016z LA9WO , 901218/1919z LA1G , 901218/1740z LA9K
USING IC-202E/IC-202S WITH OTHER EQUIPMENT, LIKE P.A., TRANSVERTER ETC,
I USE SEPARATE CONNECTORS FOR RX AND TX, ON THE RX CONNECTOR IS ALSO DC-
VOLTAGE WHICH IS UFB TO SWITCH THE FOLLOWING EQUIPMENT, THIS SAVES YOU
FROM FAILURES WITH OTHER EXTRA CABLES. AND YOU NEED NOT EXTRA RELAYS TO
SWITCH SIGNAL BETWEEN RX/TX AT INPUT OF OTHER EQUIPMENT.
THE DC-CIRCUIT IS AS FOLLOWS:
+12V
I
'RX ANT' 47K
0--I--1NF-- RF/RX I D I-------I-----PTT OUT
I I-------G I
RFC 10UH C S 1NF
I-----10K----I------I---------B I I
I I I E I I
1NF 2K2 1NF I--GND----I---GND---I
I----GND-----I------I---GND
BC547 2N7006/VMOS/SW-FET/HEXFET/TMOS
IN CASE ONE ARE NOT SURE ABOUT OVERVOLTAGE PROTECTION IN PTT CIRCUIT IT IS
WISE TO ADD A 24V (OR 33V) ZENERDIODE ACROSS THE 1NF CAPACITOR AT THE
OUTPUT TO AVOID TRANSISTOR BREAKDOWN.
2N7006 IS A SW FET, IT NEEDS 3.5...4.5V POSITIVE ON GATE TO SWITCH ON,
NORMAL JFET WILL NOT FUNCTION HERE. NO GATE CURRENT IS NECESSARY, THEREFORE
I LIKE THIS FET BETTER THAN A NORMAL NPN TRANSISTOR WHICH I USED IN EARLIER
PROJECTS, 2N7006 WAS AVAILABLE AS SURPLUS SOME TIME AGO,
73 ES 55 JAN-MARTIN
(THIS CIRCUIT IS USED IN MY 13CM TRANSVERTER, SIMILAR CIRCUITS ARE USED
IN 2M AND 6M POWER AMPLIFIERS) RX ANT IS POSITIVE DURING RECEIVE, ZERO
DURING TRANSMIT))(
(ICOM) DH5FS de DB0EAM>
ICOM @KS de:LA8AK 28.12.89 01:59 0 2077 Bytes
ICOM IC-202E PERFORMANCE/MEASUREMENTS
*** Bulletin-ID: 17021_LA5IV ***
891208/0931z DK0MWX, 891208/0826z SM5BKI, 891208/0822z SM0ETV
891208/0748z SK5BB , 891208/0723z SM6JZZ, 891208/0631z SM6GQW
891208/0704z LA1G , 891206/2200z LA5IV
S/N MEASUREMENTS WERE MADE FOR THIS RIG, AND AUDIO LEVEL, MEASURED AT
AF-GAIN POT.METER TO MEASURE AF LEVEL AT DIFFERENT INPUT VOLTAGES, IN
ORDER TO MAKE AN INDEPENDENT AUDIO FREQUENCY OUTPUT FOR USE AT
CW METEORSCATTER OPERATION (PHONO CONNECTOR ON THE REAR)
------
THE RIG IS ALREADY MODIFIED WITH SEPARATE RX INPUT CONNECTOR, BNC.
IT SEEMS THAT THE NOISE FIGURE CANNOT BE SO BAD, AND IT WILL ONLY
MAKE MARGINAL IMPROVEMENT TO CHANGE THE RF INPUT AMPLIFIER!!!!!
ALL THE TUNING HAS BEEN LEFT UNTOUCHED BECAUSE IT SEEMS TO BE
VERY GOOD AS IT IS (PERHAPS A CONTRAST TO THE FT-290 WHICH SEEM
TO NEED EXTENSIVE TRIMMING))
AUDIO VOLTAGE IS MEASURED IN DB RELATIVE TO 0.775V(HIGH IMPEDANCE) DBU
RF INPUT AUDIO LEVEL (S+N)N RATIO
BACKGROUND -37DB -
0.022UV -37DB
SRI -36DB
0.1 UV -27DB 10DB
0.3 UV -20DB 17DB
1.0 UV -18DB
2 -18
5 -17DB
10 -17
250 -16
22000UV -15,5DB
AGC FUNCTION IS VERY GOOD, IT STARTS AT ABOUT 0.3UV
SENSITIVITY IS ALSO VERY GOOD, 20DB S+N/N CANNOT BE MEASRURE DIRECTLY
SINCE AGC HAS STARTED BELOW THIS LEVEL, SUCH THAT THIS COULD ONLY BE
A THEORETICAL MEASUREMENT
--------
IC-202E COVERS 4X 200KHZ SEGMENTS ON 144MHZ BAND, SSB/CW ONLY
THE RIG IS WELLKNOWN FOR GOOD SIGNAL WITHOUT SPURIOUS, AND RX WITH
RELATIVELY HIGH DYNAMIC RANGE, SEE DL1BU MEASUREMENTS IN CQ/DL 1978/79
----
73 DE JAN-MARTIN
(ICOM) DH5FS de DB0EAM>
ICOM @KS de:LA8AK 24.12.89 02:38 0 2419 Bytes
IMPROVE IC-202 - PTT
*** Bulletin-ID: 17993_LA5IV ***
891222/0743z DK0MWX, 891222/0327z SM5BKI, 891222/0326z SM0ETV
891222/0255z SK5BB , 891222/0231z SM6JZZ, 891222/0123z SM6GQW
891222/0217z LA1G , 891222/0102z LA5IV
SOME MODIFICATIONS FOR IC-202E, ALSO USEFUL FOR IC-202S
PROBLEM IS THAT VOLTAGE SWING ON PTT CIRCUIT WILL ONLY GO
UP TO +9V, AND IT IS VERY CRITICAL THAT IT GOES DOWN TO BELOW
+0.1V. THIS CREATE DIFFICULTIES WHEN IC-202 IS A PART OF A
LARGER STATION BUILD-UP, EXAMPLES: USING A POWER AMP, PRE-AMPLIFIER
LOGICS, CW-METEOR SCATTER TIMER, ALL CONNECTED /CONTROLLED VIA
PTT LINE:
MODIFICATION FOR IC-202 IS SIMPLE:
INSERT A DIODE 1N4002 IN SERIES WITH R54 22OHM TO 'STBY'(PTT)
REMOVE DIODE D17 1N60 FROM 'STBY'(PTT) INPUT TO BASE OF Q13 2SC945
REMOVE RESISTOR FROM BASE OF Q13 TO +13V LINE , R55= 22K
CONNECT A RESISTOR FROM EMITTER OF Q12(2SD355) TO BASE OF Q13 2SC945
VALUE: 22K. CONNECT A RESISTOR - 10K FROM BASE OF Q13 2SC945 TO GROUND
------
TRANSISTOR IC202E IC202S
Q11 Q12
Q12 Q13
C I C Q13 2SC945
B----I---R54-->I----I-- BREAK --I------I-----B
E I 1N4002 I I I E
I STBY(PTT) I 10K I
I----------22K NEW---------------I I NEW I
I +R9V GND GND
Q12 R:+9.45V
2SD355 T:+0.1 V
A NEW KEY JACK IS CONNECTED TO REAR, CONNECTIONS FOR PTT AND KEY.
PTT-LINE (STBY) IS REMOVED FROM CW-POSITION OF S3 'MODE SELECTOR' TO
AVOID 'MOX' AND USE REMOTE CONTROLLED PTT FOR METEORSCATTER CW.
A PNONO CONNECTOR(CYNCH BUCHSE) IS ALSO CONNECTED ON REAR FOR CONNECTION
TO POSSIBLE OTHER POWER AMPLIFIER, WHEN IT IS NOT MINE.....HI
-----RESULTS:-
PTT LINE NEED NOW ONLY GO DOWN TO +1V TO OPERATE THE TX FUNCTIONS, AND
IT MAY SWING UP TO 30V OR HIGHER, ALTHOUGH IT IS NOT GOOD FOR THE
COMPONENTS TO USE TOO HIGH VOLTAGE GOING INTO THE TRANSCEIVER
------LA8AK 89-07-17------
------
73 DE JAN-MARTIN
(ICOM) DH5FS de DB0EAM>
ICOM @KS de:LA8AK 24.12.89 02:38 0 1078 Bytes
IC-202/IC-255E MODS..>
*** Bulletin-ID: 18041_LA5IV ***
891223/0748z DK0MWX, 891223/0126z SM5BKI, 891223/0111z SM0ETV
891223/0049z SK5BB , 891223/0011z SM6JZZ, 891222/2350z SM6GQW
891223/0004z LA1G , 891222/1637z LA5IV
THE FOLLWING MODIFICATIONS HAS NOT BEEN COVERED IN THIS SERIES OF
BULLETINS, ALTHOUGH SOME NOTICES HAS BEEN SENT OUT MENTIONING THIS.
IC-202E IMPOOVED KEYING FOR LOW CLICKS, CWMS-KEYING
IC-202E SEPARATE RECEIVER ANTENNA CONNECTOR
IC-202E SSB/CW SQUELCH, SIGNAL DERIVED FROM THE AGC-LINE
IC-202E IMPROVED S-METER
IC-202E HIGH/LOW POWER SWITCH, 150MW/2W RF OUTPUT
----
IC-255E SCANNER RESTART, AND SCANNER 'FORCE TO WORK CIRCUIT!'
-----
73 DE JAN-MARTIN
(ICOM) DH5FS de DB0EAM>