Modifications for the Yaesu
FT-290
19-07-1998 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 ham band. Even by misstake.
In some
countries it is not legal to have a reciever that can be tuned outside the ham
bands. Plese check local regulatins.
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 Probably most usable
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
19-07-1998 Yaesu
FT290R for TXV use
Once in a while I see questions about the use
of an FT290R for transverter use.
I have an Yaesu FT-290R, about 12 years
old. The look-alike rig for 70 cm is the FT-790R. If I'm correct, the PLL-system
was exactly the same (exept for the X-tal for mixing up).
It could well be
that the mark II versions still use the same processor type.
The
information was printed in the VERON DX-press/VHF-bulletin abt 11 yaers ago. I
don't know the author or the exact year. The primary intention of the
publication was using an FT-290 as transverter for 70 cm.
The
information concerns the microprocessor chip 'HMCS45C' probably noted as Q01. On
the pins 38, 39, 40 and 41 jumpers to ground specify the freqency-range, preset
and step. With 4 pins there should be 16 different combinations. The factory set
position determins the version for European or US-market.
In the table
below you find the known combinations for the FT-290R. 'X' means jumper to
ground.
My guess is that removing the jumper at pin 39, the PLL is
transformed to a wider frequency range used in the FT-790R. Once you are able to
reach the print-board, you could try to (de)solder the jumpers and determin the
results.
These modifications are best made with power and battery backup
switched off.
--------------------------------------------------------------------
band ¦ 144-146 ¦144-148 ¦143.5-148.5¦ 144-148 ¦145-146 ¦144-148
preset¦ 145 ¦145 ¦146 ¦ 147 ¦145 ¦145
step ¦ 12.5/25 ¦12.5/25 ¦5/10 ¦ 5/10 ¦10/20 ¦5/10
41 ¦ X ¦ ¦X ¦ ¦ ¦
40 ¦ ¦ ¦X ¦ X ¦ ¦X
39 ¦ ¦ ¦ ¦ X ¦X ¦
38 ¦ X ¦ X ¦X ¦ X ¦X ¦X
--------------------------------------------------------------------
I hope this information is of some use.
Best 73, good DX and
perhaps we meet in an direct QSO.
Tom PA3DXV @ PI8JOP
QTH: Sittard,
JO21WA
19-07-1998 FT-290
Bulb-Replacement
FT 290 MK1. Bulb replacement instructions.
- Remove speaker wires (white + & black -)
- Remove aerial to tag.
- Remove yellow wire to meter, left hand side (viewed from rear)
- Remove black wire to meter, right hand side (viewed from rear)
- Remove earth connection to pc board on front end of unit (thin braid
approximately 1/2 inch, 12MM in length)
- Remove 2 screws from pc board.
- Remove both support pillars.
- Take off front.
- Remove screw (second front panel)
- Remove meter.
- Remove led display screws.
- Remove post.
- Remove black and red wires.
- Now test new bulb.
- Remove unit & fit new bulb, solder bulb wires.
- Replace items in reverse order.
- Grab a bottle of your favourite tipple and poor a glass or two from it.
You have just saved over 30.00 pounds sterling. Mine has today gone for the
second time, that's why i made these notes first time round.
Good
luck. now will i get a new bulb quickly?
73. IAN. G0JRE @ GB7GFD.
GUILDFORD.
19-07-1998 Appendix by DG3UAP (with
acknowledgements to Ian, G0JRE)
Following a few hints about
problems which I had during the work and which might save somebodies
time.
(Because of that I had to disassemble my rig three times,
hi!)
ALL INFO IS GIVEN WITHOUT WARRANTY BUT WITH VY 55
There might be
minor changes during the series of which I am not aware !
- REMEMBER THAT STATIC ELECTRICITY IS POISON FOR YOUR RIG ! YOUR CONTROLLER
IS CMOS-TECHNOLOGY !!!
- Ground-connections to front pcb-block has to be unsoldered (at my rig on
TWO places: to antenne-ground-tube and to metal box in the center (top view !)
- Unsolder black ground wire to antenne-ground-tube
- Hot wire and ground to antenna coax-cable at the antenna-filter (to get
space for handling)
- The bulb size is about 3mm diameter and 6..7 mm long (without wires, hi) I
added a resistor of 100 ohms/0.15 watts in series, so the 12 V-bulb can
withstand up to 15 volts without trouble, a car battery has about 14 volts
which means conntinuous overload without resistor. This killed my bulb.
- (If your rig's bulb is still ok it might be advisable to add such a
resistor on a suitable place of the rear switch-board BEFORE the bulb burns
out. This board is much better accessible (remove the battery-case....) This
saves a lot of time for your hobbies ! For the lamp change your should
calculate half a day if you do it for the first time !)
- The frequency display is only CLAMPED onto the display-pcb which carries
the bulb to replaceby means of the mounting frame (under which is the bulb).
Removing the frame causes the display to fall down or at least result in its
displacement.
- Change bulb as mentioned by Ian, add 100 ohms-resistor if desired (If you
want to use an extra bright LED 3mm use a 680 ohms-resitor with 0.33 watts for
20 mA current. I have not tested the illumination effect of such a LED.
Problem also: The light is not going to both sides for the illumination, meter
and LCD.) The resistor should be in series to the red wire, isolation with
insulating tape or equivalent.
- Fix the above mentioned frame together with the metal support by means of
the two srews. If you want you can remount it to the front plate.
- Now THE IMPORTANT STEP which saves a lot of time in case of
display-displacement. **Make sure that you have connected all bords together
and that none of the unsoldered wires come to ground !!! REMIND YOU MAKE THIS
TEST ON YOUR OWN RISK AND RESPONSIBILITY !!! *** Switch off your FT 290.
Connect a dummy-load (because of the unsoldered antenna) to the rear antenna-
connector or a frequency counter via a 20 dB-attenuator. Connect the
microphone as usual. Switch your FT 290R to LOW power and apply 10..12 V to
the DC extern from a current LIMITED supply (Limit 1 A, NO Car-Battery !
Center to MINUS!) Switch the Lamp-Switch to ON. Last chance: No short-circuits
? Switch on your FT 290. The new lamp should be on and the display show a
frequency. If not: Check current consumption (Be careful, to make no
short-circuits in this test-setup !) Try to transmit and check if you can
change the transmit-frequency at counter. (With dummy use a second receiver
and see if receive-frequency changes Check if the measured transmitted
frequency corresponds with the displayed one in the range of tolerances. If
all is ok, goto step a10. If you don't have a display on the LCD but can
change the frequencywith the knob, you might have the same problem like me:
'Display-Displacement' or bad contact of the LCD. (Try to press slightly
against the display, if now figures are announced, it' a big progress.) Switch
off the power . Just disassemble the frontpanel with the display again and
re-assemble it more accurate. Start again at a8. vy 55 for the second time !
(I had the complete rig together, when I had this fault !)
- Now re-assemble your rig and before resoldering all meter-cables and the
antenna you can repeat this test, if you want.
- Check that you didn't forget any srews for fixing the boards together !
(My third partly disassembly !)
- Resolder all wires.
For other details see Ian's instruction
which I don't want to repeat.
Comments, additional infos and questions
welcome. But please understand that.
I'm not a YAESU-technician. (Otherwise I
wouldn't have recommended this serial resistor for the bulb, as I could earn
money with this constructive bug and save my job ,hi !
19-07-1998 FT790RI und FT290RI für
9k9
FROM: DG3OO @ DB0CEL
FT790RI und FT290RI
- NF Rx 1k2, 2k4 Auskopplung über 10 µF C und 25 Kohm Trimmpotentiometer
(Schleifer nach außen) am Collektor von Q1021;
- PTT seitlich über Zusatzbuchse, Einkopplung via Schutzdiode;
- NF Rx 9k6 ebenfalls an Pin 9 des Q1019 MC3357 auskoppeln;
- NF Tx 9k6 (1k2, 2k4): Umbau des Hubreglers VR02, sodaß Schleifer und
"heißes" Ende vertauscht sind (rechts vom Q2004); Einkopplung des Signales an
dem Schleifer über Zusatzverstärker:
+------3,9K-------< + 5 Volt bis 6,8 Volt
|
+-----+-----22nF---------+
| | |
9k6 220K | 22K
NF in | C |
>-----+ +--0,47µF---+-----B 2SC945 +--------> NF out
| TrPo| | E (BC109) o.ä. |
10K +--+ | | |
| 100K 330 Ohm 330K
Masse | | |
Masse Masse Masse
TrPo = Trimmpoti
Auskopplung auch via 25 K Trimmpoti möglich; Schleifer dann gegen
Verstärker; "heiße" Ende nach außen;
- Verstärker auch für 1k2, 2k4 Tx-Signal nutzbar;
- bei Verwendung eines XR2211 - siehe oben
Bastlerisch
Unerfahrene sollten u.U. die Finger von den Änderungen gerade bei FT290RI
lassen!
73 de dg3oo @ db0cel-7.#nds.deu.eu *** manfred ***
19-07-1998 FT-290R (first version)
Extensions
I hve nothing about the second version. Perhaps
later...
73's of Ludovic.
------------------------------------------------------------------------
The pins no 38,39,40,41 near HMCS45C are used for extensions.
PIN No BAND STEP FM/SSB SHIFT
38 39 40 41 MHz KHz Hz
----------------------------------------------------------------------
* * 140-150 25 1000 7.6MHz
100 100
-----------------------------------------------------------------------
* * * 140-144 10 1000 1MHz
20 100
-----------------------------------------------------------------------
* * * * 140-150 5 1000 no shift possible
10 100
-----------------------------------------------------------------------
* * 144-146 12.5 1000 600KHz
25 100 (European version)
-------------------------------------------------------------------------
* * * 144-149 10 1000 600KHz
20 100
------------------------------------------------------------------------
* * 140-150 25 1000 5MHz
100 100
------------------------------------------------------------------------
* * 140-150 25 1000 5MHz
100 100
------------------------------------------------------------------------
* * * 144-148 5 1000 600KHz
10 100
-------------------------------------------------------------------------
* * 144-148 5 1000 600KHz
10 100
-------------------------------------------------------------------------
* 140-150 25 1000 1.6MHz
100 100 (FB for 70 cm transverter)
--------------------------------------------------------------------------
* * 144-146 10 1000 600KHz
20 100
---------------------------------------------------------------------------
* 144-148 12.5 1000 600KHz
25 100
---------------------------------------------------------------------------
* * * 143.5-148.5 5 1000 600KHz
10 100
---------------------------------------------------------------------------
Thanks to F1GAN for this info.
19-07-1998 Problem width
packet
There is a very "hard" de-emphasis in FT-290R. This can
cause serious problems copying packet signals with some demodulator chips, eg.
like the XR2211. By a common request, here is a modification of this popular
TCVR for packet radio. It was made after a RADIO-REF article in several copies,
by HA5OB, HA5DI, HA3MA and others. Increasing the intelligibility in noisy
environment, this modification is also useful in FM voice
communications.
You'll have to add only a serial RC unit, the R being 4.7
kOhm, and C being a 1uF tantalum capacitor. Put them between the pin 9 of IC
Q1019 and the collector of transistor Q1021, with the positive leg of the
tantalum capacitor to the collector of the transistor. These points can be found
as test points, near to IC Q1019. Solder the components together, wrap some
insulation around them, then solder to the test points mentioned. That's all you
have to do! With this modification, FM reception will sound somewhat noisy, but
much louder.
19-07-1998 FT-290RII
12,5KHz-Raster!
From: DD2TJ @ HB9EAS.CHE.EU
(Josef)
Liebe OM's!
Ich habe bis jetzt schon mehrere
Umbauanleitungen gelesen u. auch mein Geraet dementsprechend umgerüstet. Aber im
Grunde brauchen wir doch den 12,5KHz-Raster nur für unsere Zwischenkanaele,
oder?
Das heißt, wenn ich mich mit dem Abspeichern der Frequenz begnuege,
geht's auch ohne Umbau!
- Die Taste -MR- betaetigen u. einen freien Speicherplatz suchen.
- Auf irgendeinen VFO umschalten und die gewuenschte Frequenz bis auf 5KHz
genau einstellen.
- Umschalten der Modulationsart mit der Taste -MODE- auf CW.
- Nun die gewuenschte Frequenz genau einstellen. (richtig, auf CW!)
- Jetzt die obrige Frequenz uebernehmen auf den vorher eingestellten freien
Speicherplatz durch druecken der Taste -M-. (rechts unten)
- Nun schalten wir wieder zurueck mit der Taste -MR- in unsere
Speicherablage, wo jetzt unsere Frequenz mit dem CW-Mode erscheint.
- Als letztes aendern wir jetzt den CW-Mode auf z.B. FM und legen noch die
Ruftonablage (- od. +) fest.
- Zum Abschluss des Ganzen nochmal's die Taste -M- druecken!
Das
war's!
Ich hoffe dem einen oder andern einen Umbau wegen nur einer od. zwei
Frequenzen erspart zu haben. Wer natuerlich den 12,5KHz-Raster grundsaetzlich
benoetigt, kommt um den Umbau nicht herum.
Etwahige Schreibfehler bitte
ich zu entschuldigen!
Für Bedien- oder Programmierfehler kann ich leider
keine Haftung uebernehmen. Also viel Spass beim ausprobieren!
vy 73 de
DD2TJ (Josef)
28-03-1999 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.
- Take the three (3) back screws off.
- Take the two (2) screws off the circuit board to free it from the case.
- Find the red wire going to the micro-switch, ie, the ptt line.
- Follow that red wire to the circuit board. At that place on the circuit
board another red wire will join the first one.
- Un-solder both red wires from the circuit board and clean up the solder
mess, otherwise hum will occur.
- Solder the two red wires together and cover with tape or shrink tubing.
- Put the circuit board in place and screw it down.
- Put the "lock" slide switch back in place.
- Put the rest of the case on.
- Put the outside screws in.
- You are now ready to try it out, so go ahead and re-attach it to your rig!
- 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.
28-03-1999 Some small mods for FT-290 MK
I
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:
- Reduce C125 from 10n to 4.7n in filter
- 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.
28-03-1999 FT-290R 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.
- Remove the covers of the rig and locate the mode select switch on the
front panel. (you only need remove the covers...nothing else)
- 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
28-03-1999 Common faults found on the
FT-290R
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
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
ERRATIC TUNING
TUNING JUMPS
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)
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.
Have you any tips, trick or modifications you can't find
here, please E-mail them to me, or use
the mail form.
Can't you
find a mods, please don't e-mail to me. All mods i have is listed on this
site. Back to start
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