QRZ! Ham Radio 13/QRZ Ham Radio Callsign Database - Volume 13.iso/modfiles/ft290.txt

Text File | 1999-04-07 | 15KB | 383 lines

Subject: FT-690RII info wanted
From:  Sergei Korotonozhkin <[e-mail]>


--------------------
FT290

 FROM: M. P. ("JUG") JOGOLEFF, WA6MBZ
       @ K6TZ BBS

 RE:   YAESU MICRO-PHONE NUMBER MH-15 C8.

        MOD.: HOW TO PREVENT THE TOUCH-TONE PAD FROM
AUTOMATICALLY KEYING UP YOUR RIG.

 RIGS INVOLVED: THIS MIC. COMES WITH THE YAESU FT 290 MK
II (2 METER RIG), THE FT 690 MK II (6 METER RIG), OR THE FT 490
MK II (UHF RIG),  AND POSSIBLY OTHERS.

 1) TAKE THE THREE (3) BACK SCREWS OFF.
 2) TAKE THE TWO (2) SCREWS OFF THE CIRCUIT BOARD TO FREE
IT FROM THE CASE.
 3) FIND THE RED WIRE GOING TO THE MICRO-SWITCH, IE, THE
PTT LINE.
 4) FOLLOW THAT RED WIRE TO THE CIRCUIT BOARD.  AT THAT
PLACE ON THE CIRCUIT BOARD ANOTHER RED WIRE WILL JOIN THE FIRST
ONE.
 5) UN-SOLDER BOTH RED WIRES FROM THE CIRCUIT BOARD AND
CLEAN UP THE SOLDER MESS, OTHERWISE HUM WILL OCCUR.
 6) SOLDER THE TWO RED WIRES TOGETHER AND COVER WITH TAPE
OR SHRINK TUBING.
 7) PUT THE CIRCUIT BOARD IN PLACE AND SCREW IT DOWN.
 8) PUT THE "LOCK" SLIDE SWITCH BACK IN PLACE.
 9) PUT THE REST OF THE CASE ON.
 10) PUT THE OUTSIDE SCREWS IN.
 11) YOU ARE NOW READY TO TRY IT OUT, SO GO AHEAD AND RE-
ATTACH IT TO YOUR RIG!
 12) ALL SHOULD WORK:
     PTT WORKS AND RELEASES,
     MIC PASSES AUDIO,
     TOUCH TONES WORK WHEN PTT BUTTON HELD,
     TOUCH-TONE RED "LED" STILL LIGHTS UP WHEN TOUCH-TONE
PAD KEYS ARE DEPRESSED, EVEN IF PTT BUTTON IS NOT HELD DOWN,
     NO HUM NOTICED.

-----
 Sorry I never seen FT's and can't say more.  And may be U can help me
converting (reprogramming) some Motorola radios for other frequencies.
I have Radius M110,P210,MX2000,HTX-I and HTX-II for 170 MHz band and
I'm looking for a way to program them to other bands. I have no
programmer and software to access internal code-plug eeprom and there
is no information also on signal description to make programmer and
write a software by myself. Please help me if U can.


   Sincerely yours, Sergei

---
From: "Nick G7COC" <[e-mail]>
To: <[e-mail]>
Subject: Yaesu FT290 MK I mods :-
Date: Mon, 9 Nov 1998 23:19:33 -0000


Please note, I am not the author of any of these suggestions.  I can
not take any responsibly of the consequences of any of your actions
upon using any of these hints.  The information below I have collected
from various sources via packet.

Good luck anyway, have fun in the hobby.


AUDIO DECOUPLING

It seems important to fit a 0.1uF cap into the receive audio line to
the TNC.  Fit it inside the five pin plug. The FT290R has no decoupling
capacitor in the audio output (See wiring Diag. IC No.Q1027 (uPC575C2)
off pin 7.

CAP CRUNCH

Many people have problems getting the Mk1 working on packet. This is
due to the receiver filtering attenuating frequencies above 2kHz, thus
the 2.2kHz tone is attenuated by 10-15dB.  The standard capacitor
crunch mod, originally designed to give more +ACI-sparkle+ACI- to the
audio cures this.  To do the mod, remove the case and turn the rig so
the control knobs face away and the SO239 antenna socket is nearest
you. At the back of the PCB is a relay (a box shaped component made of
semi-clear plastic). Just above the relay are two green capacitors.
Using small pliers, grip the capacitor nearest the relay (C110) and
crush it, removing all the debris.

DE-EMPHASIS - 1

There is a very +ACI-hard+ACI- de-emphasis in FT290R. This can cause
serious problems copying packet signals with some demodulator chips,
e.g. like the XR2211.  This modification increases the intelligibility
in noisy environments, and is also useful in FM voice  communications.
Add a serial RC unit, R +AD0- 4.7k, C +AD0- 1uF tantalum capacitor
between pin 9 of IC Q1019 and the collector of transistor Q1021. The
positive leg of the capacitor goes to the transistor collector. These
can be found as test points near to IC Q1019. Solder the components
together, insulate them, then solder to the test points mentioned.
With this modification, FM reception will sound somewhat noisy, but
louder.

DE-EMPHASIS - 2

Yaesu seem to have goofed on both the FM de-emphasis and the audio
filter.  A computer analysis of the audio circuit suggests:  1.  Reduce
C125 from 10n to 4.7n in filter   2.  Reduce C124 from 2.2n to 1.5n
(near Q1026)  This isn't perfect but it a lot better - the tones now
seem nearly equal.  There appears to be plain FM (cf phase) with no
pre-emphasis on Tx+ACE-

RESET TO 145MHz

This mod resets the CPU to 145MHz and sounds a bleep to tell you it's
been done.  Remove top and bottom covers, locate the hole in the case
near the SO239 socket covered by a stick-on aluminium label. Make a
hole in the label and install a push to make, non-latching switch.
Connect one side of the switch to ground and the other to pin 4 of
J5003 which connects the keyboard and control units. A 1nF capacitor
should also be connected from pin 4 to ground for decoupling. Replace
the covers, dial up any frequency, press the button and the set should
reset to 145MHz and bleep.

LISTEN ON INPUT

Place the set with controls towards you, remove the bottom cover and
locate the black/white wire on SK1. It's the tenth one from the left.
Cut this wire at the socket and insulate the free end. Locate the
green/white wire on SK1 and solder the anode of a 1N4148 diode to it.
Connect the cathode of the diode to the red/white wire on the PCB
adjacent to the mic. socket. Insulate the diode leads to prevent
shorts. When the call button is pressed, it allows listen on input on
both +-shift and -shift. When you want the rig to transmit a tone burst
you must close the PTT at the same time as pressing the call button.

CURING SYNTHESISER WHINE

Early 290s suffered from a high level of whine. Try moving the wiring
harnesses around inside the rig whilst monitoring the whine on another
rig.  The real cure, if you have a delicate hand for soldering, is
locate LO6 in the synthesiser and solder a 15pF capacitor in parallel
with it. This can usually be soldered between the hot ends of C24 +ACY-
C25 which are at the rear of the IC in the synthesiser unit.

MODIFIED SQUELCH

This mod reduces the difference in level between the opening and
closing points and speeds up the operation of the squelch enabling the
scanner to work better.  Reduce C94 from 4.7uF to 1uF, increase R79
from 270K to 330K and add a 10uF tantalum or subminiature electrolytic
between the leg of R78 (4.7K) and the body of the transistor T1007.

OPENING UP TO 148MHz

Remove the battery compartment and slide out the power board to allow
access to the microprocessor board. Two tinned copper wire jumpers are
visible on this board, next to the microprocessor. One is easy to see
and the other is not because it is next to the main board. Cut the
jumper which is difficult to see.  If the wrong jumper is cut then the
frequency display will not be correct when the unit is powered up.

73 Jim, G1HUL

FT290R Mk1 - mod for 1kc and 100hz steps on FM for satellite working

I asked around for details of this Mod but no-one had attempted it.
I decided to take the bit between my teeth and sort it out. Here goes.

1. Remove the covers of the rig and locate the mode select switch on the front
   panel. (you only need remove the covers...nothing else)
2. Locate the wafer of the switch nearest to the front of the rig and identify
   the green and yellow wires. Arrange a suitable method of switching
   the wires around. With the wires transposed the rig will now step
   1kc and 100hz on FM.  Note though that SSB will be 25/12kc, simply
   flick the switch to tune SSB normally. (I used an external switch,
   but I am sure that the noise blanker switch could be used or
   replaced with a suitable DPDT switch).  You will find that the rig
   will tune on TX making it much more suitable for satellite working.

If you want any more info please give me a call.

Joe.    G4XRZ +AEA- GB7WRC.+ACM-16.GBR.EU

FT-290R, modification of tuning range

There are 4 possible jumpers in the FT-290R close to the CPU on the
second small board from the rear.  Numbers are 1 - 4 from the bottom
(the most hidden one).  The indicated combination is perhaps the most
usable in Europe because the repeater shift is +-/- 600 kHz, the steps
on FM tunes to X00, X25, X50 and X75 standard frequencies and at the
same time it gives a larger tuning range.  But please note that it is
not legal to transmit on frequencies outside the amateur bands, Even by
mistake.  In some countries it is not legal to have a receiver that can
be tuned outside the amateur bands. Please check local regulations.

Frequency  Repeater  Step       1 2 3 4
Not usable                         0 0 0 0
144   - 148  600  25 +- 12.5    0 0 0 1
140   - 150  1.600  100 +- 25   0 0 1 0
144   - 146  600  10 +- 10      0 0 1 1
Not usable                      0 1 0 0
144   - 148  600  10 +- 5       0 1 0 1
140   - 150  8.000  100 +- 10   0 1 1 0
144   - 148  600  10 +- 5       0 1 1 1
Not usable                      1 0 0 0
144   - 146  600  25 +- 12.5    1 0 0 1   Standard in Europe
140   - 150  5.000  100 +- 25   1 0 1 0
143.5 - 148.5  600  10 +- 5     1 0 1 1
140   - 150  7.600  100 +- 25   1 1 0 0
140   - 150  600  20 +- 10      1 1 0 1
140   - 144  1.000  20 +- 10    1 1 1 1

COMMON FAULTS FOUND ON THE FT290R

NO RF O/P : PA

If it is not PA (the most likely cause) then check diode D24 in aerial
switching, check for L2012 physically shorting to copper screen, and
check driver Q2021 and R69.

OFF FREQUENCY RX +- TX

If this is just a couple of KHz then realign PLL local osc. If it is
several KHz (possibly 10-12) off frequency then suspect PLL local osc
xtal X02 (18.7414MHz).

OFF FREQUENCY FM TX

Realign L1002 (FM TX osc coil). If frequency error is significant then
suspect xtal X1001.

ERRATIC FREQUENCY JUMPS

Check X02 as above.

DRIFTING

Check -6.8v. rail, and check Q05 on REG unit if this is missing.

POOR SQUELCH OPERATION

Check Q1019 (MC3357P) and D32 in squelch circuitry.

POOR QUALITY FM RX

Xtal X1003 (11.265MHz).

ERRATIC TUNING

The tuning step switch.

TUNING JUMPS

The tuning step switch.

INTERMITTENT TX+-RX

Check TX/RX relay. Check alignment of VCO in PLL.

NO AUDIO O/P

Check audio IC Q1027. Also check to see if the reverse polarity diode
is blown, as reverse polarity causes failure of this IC.

CONTINUOUS CW OR NO CW TX

Check Q2010 (MC14001B). Also check the wire to the key socket is not
s/c or broken, as this can happen when the battery  compartment is
taken in and out.

LOW SENSITIVITY RX

Check T1001 Ae. i/p coil, D25 in aerial switching and RF amp.

LOW SENSITIVITY ON A UNIT WITH A MUTEK BOARD

Check for loose strands from the braid of the Mutek board's coax
shorting out the connecting pins on the Mutek board. Then check BF980
in Mutek board.

FADING LCD DISPLAY

Dismantle LCD display unit and clean the rubber connecting strip and
the PCB it makes contact to.

CRACKLING NOISE ON TX AUDIO (FM ONLY)

Q2004 mic amp IC.

CRACKLING NOISE ON TX+-RX

Check X3001 (5.76MHz) in PLL.

MELTED NICADS

Replace DC i/p socket (and nicads). This fault can also occur as a
result of using a DC input plug which is not quite the correct diameter
or length, because the batteries are then not disconnected when DC is
plugged in.

POOR SSB TX (NON-LINEAR)

If the PA has gone non-linear, then replace the PA and change R70 from
390R to 270R.

The pin connections for the FT290 Mk1 are:-

Pin 1 +AD0- Ground +ACY- Mike screen
Pin 2 +AD0- Audio from mike
Pin 3 +AD0- PTT
Pin 4 +AD0- 5 Volts, this is only good for a few milliamps+ACEAIQ-
Pin 5 +AD0- Speaker
Pin 6 +AD0- Up scan
Pin 7 +AD0- Down scan

You'll find the pin numbers on the inside of the line socket.

This is a circuit I was given to substitute for the relay in Yeasu's FT
series.

I have never fitted one, though I am assured it does work.

I have also managed to fit it onto a piece of Vero board, 6 holes X 4 strips +ACE-
That's close to the size of the relay.

+AF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8-  6.8 volts
      +AHw-                    +AHw-        +AHw-        +AHw-        +AHw-
     10K                 100K       +AHw-      100K       +AHw-
      +AHw-                    +AHw-        +AHw-        +AHw-        +AHw- E
PTT---o--------------------+AHw---------+AHw--1K5----o---B-(Q1)
      +AHw-                    +AHw-        +AHw-               C +AHwAXwBfAF8AXwBfAF8AXwBfAF8AXw- TX
    100K                   +AHw-        +AHw- E
      +AHw-      +AHw----10K-------o---B-(Q2)
      +AHw-      +AHw- C                  C +AHwAXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXwBfAF8AXw- RX
      ----(Q3)
             +AHw- E
-------------+AHw----------------------------------------------------- 0 Volts

Please excuse the basic graphics, I'm only using Baycom, and this is the only
way I can think of to draw it+ACE-

Q1 +AD0- BC178, a PNP general purpose transistor
Q2 +AD0- BC179, a PNP general purpose transistor
Q3 +AD0- BC107, a NPN general purpose transistor

All the transistor pinouts are the same, looking from the bottom,
next to the tag is E, B and C follow clockwise.

PTT+AF8AXwBf-o+AF8AXwBfAF8AXw-o+AF8AXwBfAF8AXw-o1+AF8AfA-K+AHwAXw-5o+AF8AXwBfAF8AXw-oB+AF8AXwB8AHwAXwBf-Co     +AHwAfA- +AD0- CUT TRACK HERE
     10K    +AHw-     / 100K /          Q1
+-  ---o-----+AHw------o-------oE----o-------Eo
          100K                100K       +AHw-        o +AD0- hole in board
   ---o-----o-----oB--+AHwAfA---o-----o-------Bo  Q2
               Q3        10K             +AHw-
    0vo+AF8AXwBfAF8AXw-oE+AF8AfAB8AF8-oC+AF8AXwBfAF8AXwBf-o+AF8AXwB8AHwAXw-oRX+AF8AXwBfAF8AXw-Co

If you can't understand the schematic diagram, I'm now going to try to
describe how it's done.

Take the piece of board, turn it over so that the tracks are facing
you, on the top track, cut between holes 1+ACY-2, and 3+ACY-4, leave
the 2nd track uncut, cut track 3 between holes 3+ACY-4, and cut track 4
between holes 2+ACY-3 and 4+ACY-5.

Turn the board over, length ways, then insert components as follows,
I shall number the holes from top left to bottom right. A1-A6, to D1-D6.

A1-B1, 10K.  A2-C2, 100K.   A3-A4, 1K5.   Insert the BC178, A5,B  A6,C
+ACY- B4,E put one end of the 100K in B3, and solder the other end to
the top bend of the 1K5.   B5-C5, 100K.  BC179, B6,E  C6,B   D6,C.
C4-D4, 10K.  And finally, the BC107, C3,B  D2,E   D3,C When complete,
turn it over, and solder wires to A1, A6, B2, D1, +ACY- D5.

According to a few replies I've had, it works a treat.


Hope these are of some interest?