Post by 2600 on May 24, 2017 23:35:04 GMT -5
I thought I had posted this back in the day. Maybe, maybe not. Got a request for this procedure. Had to port it from the "fossil" DOS/Win3.1 computer, so maybe I didn't after all.
But here it is, minus the formatting nonsense from Wordstar Pro 4.0
I hope.
Clarifier/vfo modification for Tram D-201a 40-channel base radio.
C.R. 4-23-91; 3-4-98
ANSI text version 8-25-10 CR
Copyright 1991-2010 nomadradio.com
1:Cut violet wire (goes through hole below chassis) from s4-3,
insulate loose end.
2: On the early D-201A (has unshielded coil T100 on receiver
board the same as the 23-channel radio) ther are 3 blue/white
wires on s4-2. On the later D-201A (has 2 toroid coils and 2
trimmer capacitors under the main receiver board) there are four
of these blue/white wires. Remove these wires as a bundle from
s4-2, move all of them to s4-3.
3: Remove bare wire (clear tubing-covered lead to CW end of
clarifier pot) from S4-1, move to S4-2. ON LATE
PRODUCTION UNITS, THE YELLOW-WHITE WIRE FOUND ON S4-1
THAT LEADS BELOW THE CHASSIS ALSO GETS MOVED TO S4-2 ALONG WITH
THE CLEAR LEAD TO THE CLARIFIER POT.
4: ADD wire from S4-6 ( two or three white-orange wires) to S4-1.
5: Add a ground wire to S4-10 (Orange lead). No need to disturb
the YELLOW wire at all.
6: ---> BELOW CHASSIS: refer to foldout underside photo in Tram
owner's manual between pages 22 and 23.
--> Cut one lead of D125, bend lead away. This one is toward
the speaker on the tie strip directly behind the squelch
control. The diode at the opppsite end of this tie strip is
D124, which should be left in place.
--> MAKE SURE THAT D126 (strung across rear deck of S3 MODE
switch, S3d #9 on Cathode, S3d #1 on Anode) IS CONNECTED,
--> AND THAT D128 (Cathode on rear deck on S3d #9,same as
Cathode of D126, Anode on Main Receiver board foil pad 34) IS
ALSO PROPERLY IN PLACE, AND HAS NOT BEEN DISTURBED IN ANY PRIOR
MODIFICATION ATTEMPT.
7: SET R145 IN XTAL MODE (THE SECOND TRIMMER AWAY FROM THE
CHANNEL SWITCH) for desired clarifier range. SET all crystal
trimmers, or at least check for reasonable channel center at 12
0'clock clarifier position.
8: SELECT MANUAL MODE, connect counter to Synthesizer Board
output at J100, note synthesizer output frequency in LSB receive,
clarifier at 12 O'clock.
-> Key transmitter with mike gain down, set R143 (THE
TRIMMER JUST TO REAR OF THE CHANNEL SWITCH) so that transmit
frequency is as close as possible to receive frequency at 12
O'clock clarifier position when in receive. NOTE that the
clarifier position should have negligible effect on transmit
frequency, and clarifier should be active on receive only when in
MANUAL mode.
1
9: SELECT XTAL MODE, make sure that clarifier is active on both
transmit and receive, and that synthesizer frequency does not
change more than about 10 HZ between transmit and receive.
This version doesn't include the commentary about what each step accomplishes in the circuit.
Should be correct.
I hope.
73
But here it is, minus the formatting nonsense from Wordstar Pro 4.0
I hope.
Clarifier/vfo modification for Tram D-201a 40-channel base radio.
C.R. 4-23-91; 3-4-98
ANSI text version 8-25-10 CR
Copyright 1991-2010 nomadradio.com
1:Cut violet wire (goes through hole below chassis) from s4-3,
insulate loose end.
2: On the early D-201A (has unshielded coil T100 on receiver
board the same as the 23-channel radio) ther are 3 blue/white
wires on s4-2. On the later D-201A (has 2 toroid coils and 2
trimmer capacitors under the main receiver board) there are four
of these blue/white wires. Remove these wires as a bundle from
s4-2, move all of them to s4-3.
3: Remove bare wire (clear tubing-covered lead to CW end of
clarifier pot) from S4-1, move to S4-2. ON LATE
PRODUCTION UNITS, THE YELLOW-WHITE WIRE FOUND ON S4-1
THAT LEADS BELOW THE CHASSIS ALSO GETS MOVED TO S4-2 ALONG WITH
THE CLEAR LEAD TO THE CLARIFIER POT.
4: ADD wire from S4-6 ( two or three white-orange wires) to S4-1.
5: Add a ground wire to S4-10 (Orange lead). No need to disturb
the YELLOW wire at all.
6: ---> BELOW CHASSIS: refer to foldout underside photo in Tram
owner's manual between pages 22 and 23.
--> Cut one lead of D125, bend lead away. This one is toward
the speaker on the tie strip directly behind the squelch
control. The diode at the opppsite end of this tie strip is
D124, which should be left in place.
--> MAKE SURE THAT D126 (strung across rear deck of S3 MODE
switch, S3d #9 on Cathode, S3d #1 on Anode) IS CONNECTED,
--> AND THAT D128 (Cathode on rear deck on S3d #9,same as
Cathode of D126, Anode on Main Receiver board foil pad 34) IS
ALSO PROPERLY IN PLACE, AND HAS NOT BEEN DISTURBED IN ANY PRIOR
MODIFICATION ATTEMPT.
7: SET R145 IN XTAL MODE (THE SECOND TRIMMER AWAY FROM THE
CHANNEL SWITCH) for desired clarifier range. SET all crystal
trimmers, or at least check for reasonable channel center at 12
0'clock clarifier position.
8: SELECT MANUAL MODE, connect counter to Synthesizer Board
output at J100, note synthesizer output frequency in LSB receive,
clarifier at 12 O'clock.
-> Key transmitter with mike gain down, set R143 (THE
TRIMMER JUST TO REAR OF THE CHANNEL SWITCH) so that transmit
frequency is as close as possible to receive frequency at 12
O'clock clarifier position when in receive. NOTE that the
clarifier position should have negligible effect on transmit
frequency, and clarifier should be active on receive only when in
MANUAL mode.
1
9: SELECT XTAL MODE, make sure that clarifier is active on both
transmit and receive, and that synthesizer frequency does not
change more than about 10 HZ between transmit and receive.
This version doesn't include the commentary about what each step accomplishes in the circuit.
Should be correct.
I hope.
73
