Working on an old FT301 Yaesu Transceiver and now...that my FT301 is working fine and is my
'main rig' for the past year or so. NOTE: a problem has developed. 40 meter receive signal strength
way down. I have traced the problem to either T1, T2 or T3 the peaking coils/preselector. I will
publish my trouble shooting and repair results as I work on the problem (Sept 09). In the mean time,
I use my FT101 or my Ten Tec Argonaut 515 to make qsos. Argo 515 for cw qrp contesting.
'main rig' for the past year or so. NOTE: a problem has developed. 40 meter receive signal strength
way down. I have traced the problem to either T1, T2 or T3 the peaking coils/preselector. I will
publish my trouble shooting and repair results as I work on the problem (Sept 09). In the mean time,
I use my FT101 or my Ten Tec Argonaut 515 to make qsos. Argo 515 for cw qrp contesting.
Type: Amateur HF transceiver
Frequency range: 10-160 m
Mode: AM/SSB/CW
RF Power output: SSB/CW: 100 W
AM: 25 W
Sensitivity: N/A
Selectivity: N/A
Image rejection: N/A
Voltage: 13.5 VDC
Current drain: RX: Max 1.1 A
TX: Max 21 A
Impedance: 50 ohms, SO-239
Dimensions (W*H*D): 280*125*370 mm
Weight: 9 Kg
Manufactured: 197x-19xx
Other: Digital readout
Related documents: User manual (3.95 MB)
Frequency range: 10-160 m
Mode: AM/SSB/CW
RF Power output: SSB/CW: 100 W
AM: 25 W
Sensitivity: N/A
Selectivity: N/A
Image rejection: N/A
Voltage: 13.5 VDC
Current drain: RX: Max 1.1 A
TX: Max 21 A
Impedance: 50 ohms, SO-239
Dimensions (W*H*D): 280*125*370 mm
Weight: 9 Kg
Manufactured: 197x-19xx
Other: Digital readout
Related documents: User manual (3.95 MB)
The picture above is from rigpix.com
and so is the general specifications
to the left.
RigPix is a good resource for general
information about radios. Good
reviews about ham radio equipment
can be gleaned from eham.net
I got the FT301D used. It had a few
problems. I have now got the unit
operational but the 100watt amplifier
section does not seem to be working.
Iam going to do a repair on that and
at the same time, I am going to
modifiy the Power Suppy for my
specific purposes.
and so is the general specifications
to the left.
RigPix is a good resource for general
information about radios. Good
reviews about ham radio equipment
can be gleaned from eham.net
I got the FT301D used. It had a few
problems. I have now got the unit
operational but the 100watt amplifier
section does not seem to be working.
Iam going to do a repair on that and
at the same time, I am going to
modifiy the Power Suppy for my
specific purposes.
I bought the power supply for $50 used. It has a nice husky transformer that looks like it can last
forever. This is the matching power supply for the FT301D. NOW..it did power the rig but there were
a few issues. The main situation seemed to be the low power output of the rig. At first I thought it
might have been out of alignment.
I never suspected the power supply to be the problem!! IMPORTANT LESSON-- never assume the
obvious!
What one of the previous owners had done was he or she moved the tap of the primary on the
transformer and bridged the center windings so that the transformer would run on 220 volts
properly not 117 volts. Perhaps the modification was abandoned part way through the process..but
anyways..I discovered the problem. I took out the jumper and rewired the transformer to run on 117
vac and then adjusted the voltage regulator potentiometer so that the output was closer to 13.5
volts. Before it had been more like 11 volts at the most.
Anyways..now she plays! The rig now puts out full power whereas before fixing the power supply, I
could only get about 3 watts out of the driver stages and that was not sufficient to get any output
from the two power transistors in the heatsink assembly. (The FT301D has a bolt on heatsink
assembly with that contains two RF amplifier Transistors and takes the nominal 8 watts or so and
amplifies it up to 100watts).
forever. This is the matching power supply for the FT301D. NOW..it did power the rig but there were
a few issues. The main situation seemed to be the low power output of the rig. At first I thought it
might have been out of alignment.
I never suspected the power supply to be the problem!! IMPORTANT LESSON-- never assume the
obvious!
What one of the previous owners had done was he or she moved the tap of the primary on the
transformer and bridged the center windings so that the transformer would run on 220 volts
properly not 117 volts. Perhaps the modification was abandoned part way through the process..but
anyways..I discovered the problem. I took out the jumper and rewired the transformer to run on 117
vac and then adjusted the voltage regulator potentiometer so that the output was closer to 13.5
volts. Before it had been more like 11 volts at the most.
Anyways..now she plays! The rig now puts out full power whereas before fixing the power supply, I
could only get about 3 watts out of the driver stages and that was not sufficient to get any output
from the two power transistors in the heatsink assembly. (The FT301D has a bolt on heatsink
assembly with that contains two RF amplifier Transistors and takes the nominal 8 watts or so and
amplifies it up to 100watts).
| the center loop of wire (yellow/white) was removed and the primary was wired properly for 117 vac. Now the transformer and power supply works as it should. It is still a little puzzling to me..why would someone do something like this!!?? Perhaps just experimenting! |
At first I thought the Power
Amplifier stage was at fault. I did a
test on it and found that it needed
significantly more drive than it
should to produce a decent power
output. I thought to myself that one
of the 2 transistors was damaged.
It never occurred to me that the
power supply had been rewired to
give lower voltage output to these
stages.
Live and learn. Never assume
anything I guess. I made the
assumption that the power supply
was OK because the radio did
work for the most part!
My next project may well be
building myself a large dunce hat!
Amplifier stage was at fault. I did a
test on it and found that it needed
significantly more drive than it
should to produce a decent power
output. I thought to myself that one
of the 2 transistors was damaged.
It never occurred to me that the
power supply had been rewired to
give lower voltage output to these
stages.
Live and learn. Never assume
anything I guess. I made the
assumption that the power supply
was OK because the radio did
work for the most part!
My next project may well be
building myself a large dunce hat!
| Y |
| X |
The thick white
wire was moved
from position X
to position Y.
The jumper in
the center was
also removed.
This resulted in
the transformer
primary being
properly wired
for 117 vac
operation.
The secondary
voltage about
doubled and
was adjusted to
13.5 vdc.
wire was moved
from position X
to position Y.
The jumper in
the center was
also removed.
This resulted in
the transformer
primary being
properly wired
for 117 vac
operation.
The secondary
voltage about
doubled and
was adjusted to
13.5 vdc.
I have some parts radios and radios that I have
bought to fix up. Some of these are: Atlas 210x,
ts820, various older Ten Tec Argonauts, varous
power supplies, dx160 swl rx, hw7s,SWAN 700,
ts780 vhf/uhf transciever (problem with the logic and
digital readout), and a 440 mhz multimode that needs
a PLL circuit fix that I bought from Larry Kaiser VE3Qy
before he became a silent key.
I take donations of busted rigs and I purchase rigs
that are not quite right and I can fix them up.
The rigs that are real goners..like this old Kenwood
TS820s, are used for parts. I can pull parts and test
parts in some cases.
bought to fix up. Some of these are: Atlas 210x,
ts820, various older Ten Tec Argonauts, varous
power supplies, dx160 swl rx, hw7s,SWAN 700,
ts780 vhf/uhf transciever (problem with the logic and
digital readout), and a 440 mhz multimode that needs
a PLL circuit fix that I bought from Larry Kaiser VE3Qy
before he became a silent key.
I take donations of busted rigs and I purchase rigs
that are not quite right and I can fix them up.
The rigs that are real goners..like this old Kenwood
TS820s, are used for parts. I can pull parts and test
parts in some cases.
These kinds of repairs are my
bread and butter. I enjoy doing
them and the older larger
equipment is easier to work on.
I have parts for this older stuff
too. This particular fix to the
power supply did not require
any parts at all! All the better!
I do the odd repair for other
people. Mostly word of mouth
and sometimes they find my
web site and contact me. I dont
heavily promote my services.
For a relatively simple repair
like the repair I just did on this
power supply..I would only
charge a person $20.00
If a person were to email me
some detailed photos and
outline the situation I could
probably solve the problem at a
distance.
I have done this for free when it
comes to young potential hams
who have corresponded with
me. Other times I just ask for a
small donation. I have a fairly
good pension and I do this as a
hobby mainly (at least at this
point).
Some of this old stuff is not
worth all that much
nowadays..so I have to charge
less than the shop rate that the
big boys charge.
Also..I am up in Northern
Ontario and do not get much
business up here.
I do travel down to Ottawa
several times a year and go
through Sudbury North Bay and
Pembrooke.
I have been travelling to
several Southern Ontario flea
markets as well. A good number
of them this year.
bread and butter. I enjoy doing
them and the older larger
equipment is easier to work on.
I have parts for this older stuff
too. This particular fix to the
power supply did not require
any parts at all! All the better!
I do the odd repair for other
people. Mostly word of mouth
and sometimes they find my
web site and contact me. I dont
heavily promote my services.
For a relatively simple repair
like the repair I just did on this
power supply..I would only
charge a person $20.00
If a person were to email me
some detailed photos and
outline the situation I could
probably solve the problem at a
distance.
I have done this for free when it
comes to young potential hams
who have corresponded with
me. Other times I just ask for a
small donation. I have a fairly
good pension and I do this as a
hobby mainly (at least at this
point).
Some of this old stuff is not
worth all that much
nowadays..so I have to charge
less than the shop rate that the
big boys charge.
Also..I am up in Northern
Ontario and do not get much
business up here.
I do travel down to Ottawa
several times a year and go
through Sudbury North Bay and
Pembrooke.
I have been travelling to
several Southern Ontario flea
markets as well. A good number
of them this year.
I mostly work on the older gear with transistors and
tubes. I have the parts and experience with these
types of equipment.
I buy stuff and fix it up too!
tubes. I have the parts and experience with these
types of equipment.
I buy stuff and fix it up too!
also some notes pertinent to other
used ham gear.
Note: hams are often technical
people and tinkerers. Sometimes
we haven't the time to build things
from scratch anymore.
For those who are technically
inclined; sometimes fixing up old
gear and getting it to work better
is rewarding.
used ham gear.
Note: hams are often technical
people and tinkerers. Sometimes
we haven't the time to build things
from scratch anymore.
For those who are technically
inclined; sometimes fixing up old
gear and getting it to work better
is rewarding.
The bolt on power amplifier stage for the FT301D. There are 4
spring loaded bolts (2 visible in the picture).
spring loaded bolts (2 visible in the picture).
Visible on my main work
bench: the smokers fan
(to suck up solder
smoke), spectrum
analyser, sweep
generator, various power
supplies, 100 mhz Leader
Scope
bench: the smokers fan
(to suck up solder
smoke), spectrum
analyser, sweep
generator, various power
supplies, 100 mhz Leader
Scope
click here to go to the NEXT PAGE of my
FT301 REPAIR
FT301 REPAIR
or.....
CLICK HERE TO GO TO MY MAIN HOME PAGE
OF www.earlandrews.com
OF www.earlandrews.com
With these old rigs from around the late 70s and the 80s, problems
crop up from time to time. The other day..I fired up my ATLAS 210X
for the first time in many months. It has developed a problem of low
transmitter output on 75 meters. As I go up in frequency towards 4
mhz the power goes up! I suspect a problem with the low pass filter
or some filter. Perhaps a capacitor has gone and the bandpass
characteristics have changed!
Good thing I now have the time to work on these problems and I'm
developing skills at troubleshooting and analysis.
Im making lots of notes as well. I keep a lab notebook of my findings.
crop up from time to time. The other day..I fired up my ATLAS 210X
for the first time in many months. It has developed a problem of low
transmitter output on 75 meters. As I go up in frequency towards 4
mhz the power goes up! I suspect a problem with the low pass filter
or some filter. Perhaps a capacitor has gone and the bandpass
characteristics have changed!
Good thing I now have the time to work on these problems and I'm
developing skills at troubleshooting and analysis.
Im making lots of notes as well. I keep a lab notebook of my findings.