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Old November 13th 15, 12:52 AM posted to rec.radio.amateur.antenna
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Default MFJ-269 repair (I win)

On Thu, 12 Nov 2015 12:20:53 -0600, "Robert L Wilson Jr."
wrote:

I was afraid that my rant was going to turn into a discussion on MFJ
quality or lack thereof. I was more interested in giving owners of
the various MFJ antenna analyzers a clue as to what might be wrong
with theirs, than attempting to fix the problem at the source. I'm
sure MFJ knows that they have a problem by now.

Wave soldering is a marginal thing, I think it is amazing how many times
it does work. Think about how it goes: Basically the PC board is
suspended just above a vat of molten solder, and a wave is caused to run
across the vat. The wave, we hope, just reaches up to the connections on
the board and solders them.


Nope. PCB's with surface mount devices are not wave soldered. I
worked for several companies that had wave solder machinery during the
1970's, before SMT parts were common. Keeping the production line
machinery going was one my side projects. These daze, components are
attached with solder paste and soldered using infrared or vapor phase
reflow ovens.

Please note that the MFJ-269 PCB's have all the components on the
component side and have no leaded components on the board (except for
some flex wires to the meter and battery and several ribbon cables).

Too high and it makes solder bridges.


Nope. Too low a temperature and you get bridging. The wave has to
touch the pads on the bottom of the PCB or the pads don't get
soldered. Too low a wave is a bigger problem, where the pads don't
get any solder.

Too
low and it either misses connections or at least does not stay on them
long enough.


Soldering time is controlled by the speed of the chain drive moving
the PAB across the wave, not by the height of the wave. There might
be a tiny variation in timing with height, but with the nearly
vertical sides of the wave caused by the weight of the solder, the
soldering time is about the same for all wave heights.

And it is not long on a connection at best, so does it get
it hot enough?


We had thermocouples stuck into the wave to control the temperature.
At worst, were off a few degrees one way or the other.

It is not just fairly inexpensive things like my MFJ analyzer that have
had problems. I did the "resolder the whole board" thing on my Phase
Linear preamp many years ago also, and that was by no means low end!

Bob Wilson


I'm still slightly mystified how the components looked like they were
properly soldered, while the solder didn't stick to the PCB pad. The
best I can offer is some grease on the pads. Also, it was only in one
part of the PCB (around the RF connector). The other half of the RF
board was just fine.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Old November 14th 15, 09:11 PM posted to rec.radio.amateur.antenna
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Posts: 63
Default MFJ-269 repair (I win)

On 12/11/15 18:20, Robert L Wilson Jr. wrote:
On 11/7/2015 8:25 PM, Jeff Liebermann wrote:
I just repaired an old MFJ-269 antenna analyzer. This time, the 4
diodes around the RF connector were NOT blown. Instead, it was crappy
SMT soldering for the components surrounding the diodes. The solder
joints looked ok before I resoldered them, but were obviously a bad
connection because several resistors just fell off the board when I
touched one end with the soldering iron, indicating the other end was
not properly soldered. With the resistor removed, the PCB pad looked
like it had never been soldered. If you don't have good soldering
tools, a steady hand, and a good microscope, DON'T try this as you'll
probably make a mess, as I did before I realized what was happening.

Because the various parts on the RF board were not originally making
good contact to the PCB pads, the calibration is off. The display
reads about 12% too high for impedance and dead on for reactance. I'm
debating if it's worth calibrating.
http://www.w8ji.com/mfj-259b_calibration.htm

Now working on an MFJ-259A, which looks like the usual blown diode
problem:
http://802.11junk.com/jeffl/MFJ-269-repair/

I've generally found MFJ stuff has decent design and rather good
components, but terrible wave soldering on the PC boards (and sometimes
hand soldering on components off the board like chassis mounted
connectors). On my 259B, it worked well for almost a year, and then
became erratic. When I saw how many soldered joints weren't, I decided
not to try to figure out which ones were bad: I just went around and
resoldered everything on the board. Since then it has worked perfectly.

Wave soldering is a marginal thing, I think it is amazing how many times
it does work. Think about how it goes: Basically the PC board is
suspended just above a vat of molten solder, and a wave is caused to run
across the vat. The wave, we hope, just reaches up to the connections on
the board and solders them. Too high and it makes solder bridges. Too
low and it either misses connections or at least does not stay on them
long enough. And it is not long on a connection at best, so does it get
it hot enough?

It is not just fairly inexpensive things like my MFJ analyzer that have
had problems. I did the "resolder the whole board" thing on my Phase
Linear preamp many years ago also, and that was by no means low end!

Bob Wilson

=======
What strikes me in this newsgroup thread , time and again, is that MFJ´s
quality control people (if they exist) pass badly soldered PCBs and
other imperfections which affect their products´ reliability . But for
some reason they get away with it. To me this seems to be an attitude
brought about by management.........Martin F. Jue ?

Frank , GM0CSZ / KN6WH










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Old November 16th 15, 12:27 AM posted to rec.radio.amateur.antenna
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Posts: 3
Default MFJ-269 repair (I win)

On 11/14/2015 2:11 PM, highlandham wrote:
On 12/11/15 18:20, Robert L Wilson Jr. wrote:
On 11/7/2015 8:25 PM, Jeff Liebermann wrote:
I just repaired an old MFJ-269 antenna analyzer. This time, the 4
diodes around the RF connector were NOT blown. Instead, it was crappy
SMT soldering for the components surrounding the diodes. The solder
joints looked ok before I resoldered them, but were obviously a bad
connection because several resistors just fell off the board when I
touched one end with the soldering iron, indicating the other end was
not properly soldered. With the resistor removed, the PCB pad looked
like it had never been soldered. If you don't have good soldering
tools, a steady hand, and a good microscope, DON'T try this as you'll
probably make a mess, as I did before I realized what was happening.

Because the various parts on the RF board were not originally making
good contact to the PCB pads, the calibration is off. The display
reads about 12% too high for impedance and dead on for reactance. I'm
debating if it's worth calibrating.
http://www.w8ji.com/mfj-259b_calibration.htm

Now working on an MFJ-259A, which looks like the usual blown diode
problem:
http://802.11junk.com/jeffl/MFJ-269-repair/

I've generally found MFJ stuff has decent design and rather good
components, but terrible wave soldering on the PC boards (and sometimes
hand soldering on components off the board like chassis mounted
connectors). On my 259B, it worked well for almost a year, and then
became erratic. When I saw how many soldered joints weren't, I decided
not to try to figure out which ones were bad: I just went around and
resoldered everything on the board. Since then it has worked perfectly.

Wave soldering is a marginal thing, I think it is amazing how many times
it does work. Think about how it goes: Basically the PC board is
suspended just above a vat of molten solder, and a wave is caused to run
across the vat. The wave, we hope, just reaches up to the connections on
the board and solders them. Too high and it makes solder bridges. Too
low and it either misses connections or at least does not stay on them
long enough. And it is not long on a connection at best, so does it get
it hot enough?

It is not just fairly inexpensive things like my MFJ analyzer that have
had problems. I did the "resolder the whole board" thing on my Phase
Linear preamp many years ago also, and that was by no means low end!

Bob Wilson

=======
What strikes me in this newsgroup thread , time and again, is that MFJ´s
quality control people (if they exist) pass badly soldered PCBs and
other imperfections which affect their products´ reliability . But for
some reason they get away with it. To me this seems to be an attitude
brought about by management.........Martin F. Jue ?

Frank , GM0CSZ / KN6WH





It is too often that some of these things get past QC. The good news is
that some of their products, like their linear amplifiers have allowed
the ordinary ham to run power. Other amplifiers always cost more and
seem to be no more reliable than an Ameritron model. I have two, the
ALS-600 and the 1300. Both have been excellent products for me. I did
have an AL-80B, but sold it.

Most of us hams do not have the money to go out and buy an Alpha amp.
From my own experience, I can tell not difference in the signal from an
Alpha or Tokyo from an Ameritron.

I am guessing that Martin is pushing those products through QC very
quickly to keep margins up. It is a balance between QC and profit margin
that is probably hard to find. My own guess is that if he put more
emphasis on QC and charged a bit more for each product, that his
business would do better just from the reputation he would gain.

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Old November 16th 15, 12:51 AM posted to rec.radio.amateur.antenna
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Posts: 702
Default MFJ-269 repair (I win)


"Tom" wrote in message
...
Most of us hams do not have the money to go out and buy an Alpha amp. From
my own experience, I can tell not difference in the signal from an Alpha
or Tokyo from an Ameritron.

I am guessing that Martin is pushing those products through QC very
quickly to keep margins up. It is a balance between QC and profit margin
that is probably hard to find. My own guess is that if he put more
emphasis on QC and charged a bit more for each product, that his business
would do better just from the reputation he would gain.


I think Ameritron was bought by MFJ as they have bought a few other
companies.
I have only bought 2 items made by MFJ. One was a packet tnc years ago. It
was defective and I sent it back. They sent me a new one and I had it in
about 3 days. No problem on that as I know it is easy for a new item to be
defective out of the box and they did ship a new one just as fast as
possiable. About 5 years later I bought a new antenna tuner from a dealer at
a hamfest. It had loose screws and after I tightened them and recalibrated
the wattmeter that was way off with a Bird meter, it seemed to work fine.
The schematic in the manual did not match the tuner either. I try not to
even look at the MFJ items due to the poor reputation of the quality
control.

From what I am hearing, when MFJ buys a company, the quality goes down hill.


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Old November 16th 15, 01:47 AM posted to rec.radio.amateur.antenna
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Posts: 409
Default MFJ-269 repair (I win)



"Tom" wrote in message ...

On 11/14/2015 2:11 PM, highlandham wrote:
On 12/11/15 18:20, Robert L Wilson Jr. wrote:
On 11/7/2015 8:25 PM, Jeff Liebermann wrote:
I just repaired an old MFJ-269 antenna analyzer. This time, the 4
diodes around the RF connector were NOT blown. Instead, it was crappy
SMT soldering for the components surrounding the diodes. The solder
joints looked ok before I resoldered them, but were obviously a bad
connection because several resistors just fell off the board when I
touched one end with the soldering iron, indicating the other end was
not properly soldered. With the resistor removed, the PCB pad looked
like it had never been soldered. If you don't have good soldering
tools, a steady hand, and a good microscope, DON'T try this as you'll
probably make a mess, as I did before I realized what was happening.

Because the various parts on the RF board were not originally making
good contact to the PCB pads, the calibration is off. The display
reads about 12% too high for impedance and dead on for reactance. I'm
debating if it's worth calibrating.
http://www.w8ji.com/mfj-259b_calibration.htm

Now working on an MFJ-259A, which looks like the usual blown diode
problem:
http://802.11junk.com/jeffl/MFJ-269-repair/

I've generally found MFJ stuff has decent design and rather good
components, but terrible wave soldering on the PC boards (and sometimes
hand soldering on components off the board like chassis mounted
connectors). On my 259B, it worked well for almost a year, and then
became erratic. When I saw how many soldered joints weren't, I decided
not to try to figure out which ones were bad: I just went around and
resoldered everything on the board. Since then it has worked perfectly.

Wave soldering is a marginal thing, I think it is amazing how many times
it does work. Think about how it goes: Basically the PC board is
suspended just above a vat of molten solder, and a wave is caused to run
across the vat. The wave, we hope, just reaches up to the connections on
the board and solders them. Too high and it makes solder bridges. Too
low and it either misses connections or at least does not stay on them
long enough. And it is not long on a connection at best, so does it get
it hot enough?

It is not just fairly inexpensive things like my MFJ analyzer that have
had problems. I did the "resolder the whole board" thing on my Phase
Linear preamp many years ago also, and that was by no means low end!

Bob Wilson

=======
What strikes me in this newsgroup thread , time and again, is that MFJ´s
quality control people (if they exist) pass badly soldered PCBs and
other imperfections which affect their products´ reliability . But for
some reason they get away with it. To me this seems to be an attitude
brought about by management.........Martin F. Jue ?

Frank , GM0CSZ / KN6WH





# It is too often that some of these things get past QC. The good news is
# that some of their products, like their linear amplifiers have allowed
# the ordinary ham to run power. .

MFJ seems to have gotten a bit better as the years go by.
Once I bought something (a cw filter perhaps) that had the PC board mounted
by wedging it at an angle and using a bead of epoxy to hold it in place.

I haven't seen that kind of sloppy work from them in a while.



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Old January 22nd 16, 05:15 AM posted to rec.radio.amateur.antenna
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Default MFJ-269 repair (I win)



"Robert L Wilson Jr." wrote in message
...

snip

It is not just fairly inexpensive things like my MFJ analyzer that have
had problems. I did the "resolder the whole board" thing on my Phase
Linear preamp many years ago also, and that was by no means low end!

Bob Wilson

++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++

In 1970, I bought a new Chevy Impala, drove it for a couple of years,
including cross-country. One day the radio quit. One dashboard-thump
later, the radio was back.

After another YEAR, the radio quit again and no amount of thumping had any
effect. On the weekend, I pulled it and opened it. Inside, a single wire
ran from the DC plug on the back to the ON/OFF switch. The front end of
that wire was looped through a lug on the switch but it had never been
soldered. Not a trace of solder on the lug or the wire. After a minute's
work and a centimeter of solder, I had my radio back. No more problems.

How/why did it work all those years ... then abruptly quit, work again, then
quit again? Unexplained.

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Old January 22nd 16, 05:26 AM posted to rec.radio.amateur.antenna
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Default MFJ-269 repair (I win)



"Jeff Liebermann" wrote in message
...


I'm still slightly mystified how the components looked like they were
properly soldered, while the solder didn't stick to the PCB pad. The
best I can offer is some grease on the pads. Also, it was only in one
part of the PCB (around the RF connector). The other half of the RF
board was just fine.

================================================== =========

Showing my age, I worked on a tube TV which had a red hum bar floating up
through an essentially normal color picture. The ground on the R-Y amp tube
heater needed to be resoldered. It was a quick fix after hours of fruitless
troubleshooting. (A high resistance joint caused the 60 Hz A/C voltage to
be coupled onto the cathode, modulating the R-Y signal. Oddly, the tube was
lit, keeping us from looking where the trouble lay.)

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Old January 22nd 16, 05:32 AM posted to rec.radio.amateur.antenna
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Default MFJ-269 repair (I win)



"highlandham" wrote in message ...

snip

What strikes me in this newsgroup thread , time and again, is that MFJ´s
quality control people (if they exist) pass badly soldered PCBs and
other imperfections which affect their products´ reliability . But for
some reason they get away with it. To me this seems to be an attitude
brought about by management.........Martin F. Jue ?

Frank , GM0CSZ / KN6WH

================================================== =======

I picked up an MFJ "Deluxe Versatuner" at a ham swap meet. I opened it at
home to give it some poking and prodding. I quickly discovered that most of
the hardware need to be tightened or retightened -- if it was ever tight.
This reminds me to open it again. It's been a few years. :-)

"Sal" (really KD6VKW)









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Old January 23rd 16, 01:03 AM posted to rec.radio.amateur.antenna
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Posts: 37
Default MFJ-269 repair (I win)

On 1/21/2016 10:32 PM, Sal M. O'Nella wrote:


"highlandham" wrote in message ...

snip

What strikes me in this newsgroup thread , time and again, is that MFJ´s
quality control people (if they exist) pass badly soldered PCBs and
other imperfections which affect their products´ reliability . But for
some reason they get away with it. To me this seems to be an attitude
brought about by management.........Martin F. Jue ?

Frank , GM0CSZ / KN6WH

================================================== =======

I picked up an MFJ "Deluxe Versatuner" at a ham swap meet. I opened it
at home to give it some poking and prodding. I quickly discovered that
most of the hardware need to be tightened or retightened -- if it was
ever tight. This reminds me to open it again. It's been a few years. :-)

"Sal" (really KD6VKW)









It's not just what we first think of as electronics: I have a Chevrolet
pickup truck, and the windshield wipers quit working. (Of course it
happened during an intense storm while I was far from home.)

Online I found that (a) it was a common problem among many models from
General Motors (not just Chevy) for quite a few years, and (b) if you
went to the dealer they would install a new wiper motor for about $200.

I took the motor out and disassembled it. There was a surprisingly
complicated PC board governing the several different speeds of
operation. And, of course, at least half the soldered connections needed
to be redone.

It has now worked fine for another decade, but I feel badly about the
(hundreds of?) thousands of people who wasted all that money, and all
the wasted (probably trashed rather than recycled) motors and gear
trains and electronics, etc.

Maybe I should be amazed at how well so much of our electronics does
work, if it is this hard (read expensive to the manufacturer, not really
difficult!) to do mass production PC board soldering right!
Bob Wilson
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Old August 26th 16, 10:40 PM posted to rec.radio.amateur.antenna
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Posts: 1
Default MFJ-269 repair (I win)

On Saturday, November 7, 2015 at 8:25:39 PM UTC-6, Jeff Liebermann wrote:
I just repaired an old MFJ-269 antenna analyzer. This time, the 4
diodes around the RF connector were NOT blown. Instead, it was crappy
SMT soldering for the components surrounding the diodes. The solder
joints looked ok before I resoldered them, but were obviously a bad
connection because several resistors just fell off the board when I
touched one end with the soldering iron, indicating the other end was
not properly soldered. With the resistor removed, the PCB pad looked
like it had never been soldered. If you don't have good soldering
tools, a steady hand, and a good microscope, DON'T try this as you'll
probably make a mess, as I did before I realized what was happening.

Because the various parts on the RF board were not originally making
good contact to the PCB pads, the calibration is off. The display
reads about 12% too high for impedance and dead on for reactance. I'm
debating if it's worth calibrating.
http://www.w8ji.com/mfj-259b_calibration.htm

Now working on an MFJ-259A, which looks like the usual blown diode
problem:
http://802.11junk.com/jeffl/MFJ-269-repair/

--

snip..

Hi Jeff & the list,
I found your post while looking for potential solutions to the problem I'm having with my MFJ-269. It seems to work fine below UHF. Activating the UHF portion, I see "Increase Frequency" in the display, which is usually followed by "Voltage Low .2Volts". I wonder if you've seen this problem before and if you might share any insight as to the usual cause of it.

Thank you,
Robin K4IDC
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