Date   

Re: Hakko FR-301 alternatives?

Paul Amaranth
 

I use Metcal equipment and have the DS1 desoldering gun. Some people
don't like the venturi vacuum generator, but it never bothered me.
The handpiece is small, light and easily positioned. It's great
for, say, removing NVRAMs.

Once I got a Metcal I never looked at another iron. None of my other
gear has been touched since.

Pricey, but they're all over the used market and you can get something
for reasonable money. Probably not a good fit for you if you like your
current stations.

Paul

On Tue, Jan 07, 2020 at 04:49:05AM -0800, Jean-Paul wrote:
Hello all, this old EE has used solder wick and various spring loaded solder suckers, all are slow, and damage delicate PCBs. Due to maintenance, cost and bench space, I never got a rework station like the Pace. Now am restoring a number of TEK 2465/7B and 7000 plugins, so easily unsoldering components and ICs without board damage is a must.

Seems the Hakko FR-301 is highly regarded and gun style, needs no separate power supply/vacuum. (USA 120V model) But rather costly $250-350.

I have several other Hakko 926 (ancient analog control) irons quality and longevity is super.
I ask the Forums feedback on the Hakko, as well as lower cost alternatives.

Most of my work is thru hole, not SMD, perhaps 3-10 jobs in a year.

MANY THANKS

Jon





!DSPAM:5e147e4b293962061714628!
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Unix & Windows


Re: Hakko FR-301 alternatives?

Harold Foster
 

I've had a Hakko 808 for about 8 years or so and it ranks as one of the best investments I've made in electronic tools - ties with my soldering iron, also Hakko. The FR-301 improves on a few things from the 808 and I would imagine it would be every bit as good and durable. I realize that I sound like a fanboy but it's an opinion that I have come to through a *lot* of use and abuse and the Hakko's just keep delivering.

In short they are expensive but, IMHO, very much worth it.

Hal


Re: 'Solder Rot'

Jean-Paul
 

Besides this problem you have "tin disease" in very cold climates and "tin whiskers" for very close spaced solder connections and at higher voltages.

Jon


Re: tek 7xx4 series brightness dimming after power on

Jean-Paul
 

Hello Alberto: Wonderful to have these vintage scopes, in perfect operation and on the bench!

Just checked, my 7904 (NOT A) has no variation in intensity after turn on, and the 7104 microchannel intensifier has a ferocious beam intensity timeout/limiter, I believe the 7104 time out is inversely proportioned to beam current. The more modern 2467/B also have the timeout but in a more advanced implimentation.

Chuck and Dennis, any comments?

Jon


Hakko FR-301 alternatives?

Jean-Paul
 

Hello all, this old EE has used solder wick and various spring loaded solder suckers, all are slow, and damage delicate PCBs. Due to maintenance, cost and bench space, I never got a rework station like the Pace. Now am restoring a number of TEK 2465/7B and 7000 plugins, so easily unsoldering components and ICs without board damage is a must.

Seems the Hakko FR-301 is highly regarded and gun style, needs no separate power supply/vacuum. (USA 120V model) But rather costly $250-350.

I have several other Hakko 926 (ancient analog control) irons quality and longevity is super.
I ask the Forums feedback on the Hakko, as well as lower cost alternatives.

Most of my work is thru hole, not SMD, perhaps 3-10 jobs in a year.

MANY THANKS

Jon


Re: 454 screen brightness issues?

Albert Otten
 

Hi Jack,

The grid appears to be at
-150 to -190 volts depending on the brightness setting, and the grid bias
trimmer does essentially nothing, moving the grid bias by around 8 volts
only (not sure if this is a fault or just the design).
So far this finding has has been overlooked I think. I suppose for this you attached a DMM between grid and cathode leads. Even measured with a 10M meter there will be some reduction in voltage, so in reality the grid voltage would be still more negative. The tube T4540 is missing from tek_crt_data.pdf but the cut-off voltage of similar tubes is above -100 V. For instance -80 V for the 453 tube T4530. Your trace should be complete dark, unless there is a broken connection to the grid somewhere. (Are you sure about the sign of the voltage difference?)

Update:
Upon resistance testing the cathode and grid, it seems to want to conduct
one way (in negative resistance, according to my meter), and not conduct at
all the other...
So perhaps the grid is not broken after all? Although this was with the
whole socket connected, so for all I know I could just be reading a diode
in the circuit, although the -10Mohm resistance would be odd for that.
I'm not sure what you mean with negative resistance. Are there still some capacitor voltages present that disturb your resistance measurement? Or does you meter pick up rectified "hum" or so? You can't check for a broken connection to the grid this way; you might discover a short between grid and cathode.

Albert


Re: 'Solder Rot'

Roy Thistle
 

On Mon, Jan 6, 2020 at 08:19 PM, EricJ wrote:


National Physical Laboratory's "Good Practice Guide #136.
Hi Tam, Hi Eric .et al.:
Just a caveat... this N.P.L. article is referring to mostly low volume automated soldering (using expensive soldering machines, such as laser soldering)… for instruments (and their associated components) meant to operate at high temperatures (that is instruments operating at 180 to 300 centigrade.)… according to the article's introduction, at least.
How much traction the information presented there bears upon the stuff we deal with in this forum... well, would we still be in Kansas?
Despite the above restriction... there are some really cool pictures.
Best regards and wishes.
Roy
P.S. Eric thanks for sharing this great link, and this information...always appreciated. Best regards.


Re: Sony/Tek 318 Logic Analyser - parts needed

Gala Dragos
 

My email address is

gala underline dragos at yahoo dot com

I've sent some of you emails, hopefully I will get a reply. This groups.io this is not as convenient as the old mail list.


Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

Greg Muir
 

The legacy USAF SAGE system AN/FSQ-7 computers each (2 computers per SAGE center operating alternately for reduced possibility of failure) used approximately 50,000 vacuum tubes each. The techs replaced on the average of 300 tubes per week. As these systems continued to be used into the 1980’s the supply of US made tubes dwindled so the military had to resort to purchasing them from Russian manufacturers. Quite an irony given that the SAGE system was developed to protect us from the Russians during the cold war.

During the development of the FSQ-7 predecessor computer – the “Whirlwind” at MIT Lincoln Labs it was calculated that a computer containing 5000 vacuum tubes could be expected to fail around every 1/2 hour. They came up with a simple testing technique to determine in advance if a tube was going to fail by lowering tube electrode voltages to see where the failure point would occur. Using this method on the FSQ-7 standby computer during maintenance allowed the operation of the overall system to only experience total downtime for unscheduled maintenance for only 3 to 4 hours per year. Downtime from other factors (air conditioning, power outages or other situations) resulted to up to 24 hours a year. For mission reliability each SAGE center did not use local utility power. Instead AC power was derived from 5 - 650 kW 480 VAC 12-cylinder generators running 24/7/365 and consuming 1,800,000 gallons of diesel oil per year (thanks to our taxes). Even this form of power was not totally reliable. At one center failure of the generation system in 1979 forced the replacement of 400 vacuum tubes.

Greg


Re: 'Solder Rot'

EricJ
 

Hi Tam,

It is National Physical Laboratory's "Good Practice Guide #136."

--Eric

On Jan 6, 2020 10:04 AM, Tam Hanna <tamhan@...> wrote:




Hello Eric,
May I ask for you to provide me a link or reference to the paper?

Tam
---
With best regards
Tam HANNA (emailing on a BlackBerry PRIV)

Enjoy electronics? Join 14k other followers by visiting the Crazy
Electronics Lab at https://www.instagram.com/tam.hanna/






Re: 454 screen brightness issues?

 

Jack:

In my previous email, I unsuccessfully tried to transcribe the procedure
for CRT grid bias adjustment described on page 6-11 of the manual.  Grid
bias adjustment control R1447 does not directly affect the voltage at
TP1349. Refer to the manual (page 6-11) for the exact process; my
apologies for my error.  I suggest the following:

1.  Setup the scope's controls as described on page 6-8 and 6-9
"Preliminary Procedure".
2.  Try to adjust the INTENSITY control  to get +12V at TP1349, as per
page 6-11 "Adjust CRT Grid Bias."  If this cannot be done, there might
be a Z-axis problem. If you can get +12 volts, then go to step 3 below:
3.  Adjust CRT Grid Bias potentiometer R1447 per paragraph 6.d on page 6-11.
4.  Let us know what the results are. Although at this point I might be
at a loss as to further ideas.

It's also possible that there might be an issue with the grid bias
resistors/potentiometer (R1442 thru R1449) as others have suggested.  If
you have access to a ohmmeter (such as a VTVM) that can detect
variations of about 1.8 megohms in a total resistance of about 52
megohms, then you can check this by measuring the resistance (with power
down) from the CRT pin 3 to TP1349 while varying grid bias potentiometer
R1447 from fully CCW to fully CW.  You might get one measured value with
the ohm meter's leads in one position, and another with the meter leads
"reversed"; if so then go with the higher set of measurements, as the
lower set of measurements would be due to forward bias of D1440.

Mike D N4MWP

On 1/6/20 7:37 PM, Jack Ohme wrote:
Mike,

I have a copy of the manual in PDF and on paper. The intensity dial
correctly changes the voltage (although the screen brightness shows no
change), but the grid biasing potentiometer does not change the voltage at
TP1349, which stays at around 6.8v. I'm not sure whats happening here, if
this is the grid biasing pot that is broken or something nearby on the Z
axis board, but I will inspect the schematics. Let me know if you think of
anything to look for.

-Jack

On Mon, Jan 6, 2020 at 2:15 PM Albert Otten <aodiversen@...> wrote:

Hi Jack,
Where should I be looking for those DC restorers, in the -1920v?
The 454 has no DC restorers. The HV transformer has separate windings for
the grid and the cathode circuit. The rectified voltage for the grid can be
reduced somewhat by the grid bias pot R1447 (in the divider chain with
R1442-R1446) and is stacked on the voltage supplied by the Z-axis
amplifier.
When you follow Mike's suggestion and use a pdf of the manual, you will
note that the waveform at TP1349 is almost invisible. The blue picture in
the paper manual is also very faint. The voltage switches between the 2
written values 17.7 V and 6.75 V.

Albert




Re: Trying to bring back a AA501

Eric
 

Seems the 5V is leaking from the next chip up stream the MC14490E when removed the 5V goes away sence it has 5V coming out and input it is most likely bad as well

On 1/6/2020 9:21 PM, Chuck Harris wrote:
CMOS of that era can drive essentially nothing.

Therefore, I would think that the 5V on the empty
socket is muscling the output to 5V.

-Chuck Harris

Eric wrote:
OK so trouble shooting of the night. Voltage on pin 9 of U1410 is about 7.5 V, CR1412
tests as a diode. However, on the socket with the chip removed I do see the 4.95V
present. Also on pin 13 it looks like everything is behaving I think . The voltage
goes down as the frequency goes up so I think the op Amp U1610D is working as
expected. Or is at least changing it output. So I am still at a bad stage in U1410
specifically D. I have NOS ones on order about 10 of them so we will see what happens.


On 1/6/2020 12:01 PM, Eric via Groups.Io wrote:
I'll check tonight when I get back to the bench if there is voltage in the
socket with the ic removed. When I curve traced the outputs with the chip
out on a bread board referenced to ic ground point 1 2 and 4 showed a
diode. 3 showed nothing fully open circuit.

On Mon, Jan 6, 2020, 11:41 AM Dave Wise <david_wise@...> wrote:

That happened here a few weeks ago. Fluke 8000A DMM. After a transient,
it would only display even digits. Turned out the 7447 display driver
developed an internal short on its 1's input. The MOS A/D chip was fine.
Whew!

Dave Wise
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Chuck Harris
via Groups.Io <cfharris=erols.com@groups.io>
Sent: Sunday, January 05, 2020 10:36 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Trying to bring back a AA501

I am having trouble imagining how a 15V CMOS device could spontaneously
generate 5V on one of its outputs.... I can see ~0V, or ~15V, or even 7.5V,
but 5V is an odd value for a device that has no resistors in it.

Are you sure that it isn't being bullied around by whatever it is driving?
old style CMOS has very little drive capability.

-Chuck Harris









Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

Leon Robinson
 

We had receivers on the Navy ship I was on, WW2 vintage that had RF amps to prevent the
local oscillator radiation from leaking out the antenna and giving the ships position away.

Leon Robinson    K5JLR

Political Correctness is a Political Disease.

Politicians and Diapers should be changed
often and for the same reasons.

On Monday, January 6, 2020, 8:19:06 AM CST, Geoffrey Thomas <geoffreythomas@...> wrote:

I recall reading somewhere (years ago) that some military receivers were
running a few amps in the front end to protect against emp.
Anybody verify or was it an apocryphal tale/April fool article?

Geoff.

On 06/01/2020 01:59, Roy Thistle wrote:
On Sun, Jan  5, 2020 at 11:25 AM, Greg Muir wrote:


the vacuum tube equipment still possessed by the military for use when EMP
from a nuclear blast renders a portion of the solid-state hardware useless.
Hi Greg:
Although obviously I am privy to very little information about what the "military" has, or does not have... I am doubtful, if the military keeps any vacuum tube type equipment because of "transistorized" = solid state equipment failing due to NEMP. The reason I say this is that... at least the high EMF generated by the Type 1 pulse of a NEMP event requires relatively long conductors to couple energy. Small conducting paths; small inductor values, fully metallically shielded, and enclosed cases... besides other common EMP hardening measures... significantly null out NEMP effects.
That said... militaries are working on... and due claim to have... EMP weapons that act to produce extremely large local EMP pulse that can disable/destroy EMP hardened gear very locally... or so they say.
Cheers. Best regards and wishes.
Roy


Re: Trying to bring back a AA501

Chuck Harris
 

CMOS of that era can drive essentially nothing.

Therefore, I would think that the 5V on the empty
socket is muscling the output to 5V.

-Chuck Harris

Eric wrote:

OK so trouble shooting of the night. Voltage on pin 9 of U1410 is about 7.5 V, CR1412
tests as a diode. However, on the socket with the chip removed I do see the 4.95V
present. Also on pin 13 it looks like everything is behaving I think . The voltage
goes down as the frequency goes up so I think the op Amp U1610D is working as
expected. Or is at least changing it output. So I am still at a bad stage in U1410
specifically D. I have NOS ones on order about 10 of them so we will see what happens.


On 1/6/2020 12:01 PM, Eric via Groups.Io wrote:
I'll check tonight when I get back to the bench if there is voltage in the
socket with the ic removed. When I curve traced the outputs with the chip
out on a bread board referenced to ic ground point 1 2 and 4 showed a
diode. 3 showed nothing fully open circuit.

On Mon, Jan 6, 2020, 11:41 AM Dave Wise <david_wise@...> wrote:

That happened here a few weeks ago. Fluke 8000A DMM. After a transient,
it would only display even digits. Turned out the 7447 display driver
developed an internal short on its 1's input. The MOS A/D chip was fine.
Whew!

Dave Wise
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Chuck Harris
via Groups.Io <cfharris=erols.com@groups.io>
Sent: Sunday, January 05, 2020 10:36 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Trying to bring back a AA501

I am having trouble imagining how a 15V CMOS device could spontaneously
generate 5V on one of its outputs.... I can see ~0V, or ~15V, or even 7.5V,
but 5V is an odd value for a device that has no resistors in it.

Are you sure that it isn't being bullied around by whatever it is driving?
old style CMOS has very little drive capability.

-Chuck Harris










Re: Trying to bring back a AA501

Chuck Harris
 

7447 is now a CMOS part?

CMOS is free of dissipation elements, like resistors, and
analog region transistors.

How would it find 5V from a 15V supply? To get 7.5V, it would
have to get really, really hot, as two transistors in a totem
pole pair were both turned on at the same time...

5V would be pretty much the same thing, with the lower of the
two transistors (N type) being slightly stronger than the upper.

Point is, it would be very hot.

-Chuck Harris

Dave Wise wrote:

That happened here a few weeks ago. Fluke 8000A DMM. After a transient, it would only display even digits. Turned out the 7447 display driver developed an internal short on its 1's input. The MOS A/D chip was fine. Whew!

Dave Wise
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Chuck Harris via Groups.Io <cfharris=erols.com@groups.io>
Sent: Sunday, January 05, 2020 10:36 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Trying to bring back a AA501

I am having trouble imagining how a 15V CMOS device could spontaneously
generate 5V on one of its outputs.... I can see ~0V, or ~15V, or even 7.5V,
but 5V is an odd value for a device that has no resistors in it.

Are you sure that it isn't being bullied around by whatever it is driving?
old style CMOS has very little drive capability.

-Chuck Harris







Re: Tek 576 Curve Tracer USB port to a cpu ... ?

Eric
 

Arduino has potential Pi is too much like a computer... well is a computer. I have had this rolling around in my head for a while as to how to do this, I was even thinking of omitting all the HV stuff tapping off the CRT driver pins digitizing the inputs and driving a VGA port with them. Some challenges I have come across already. computer monitors are raster driven. Not X-Y driven so we would need to time the raster. Not TOO huge a deal with a curve tracer but a scope the sweeps are WAY to fast for a computer monitor. Color not really an issue due to the curve tracers being monochrome. You can just set some values and make it a color. The 576 has a sweep rate of 60Hz so it would lend its self to a conversion however the BIG one is how to get the grid lines on the image. These would have to be driven digitally given they are etched in to the glass. So not sure how to do that part yet but I think an Arduino has 1024 value ADC full scale. Then of course can we get it through a calibration process to aline everything. We would need about 60FPS at a res of 1024x768 monochrome with and adjustable persistence as a possible feature upgrade to aid in the matching of transistors. By REALLY being able to over lay the traces. But I really like the idea of a 576 with a 19 inch screen.

On 1/6/2020 6:40 PM, Mlynch001 wrote:
Seems like they are getting a premium for their interface. But they are also the only game in town. If you want to play, I suppose one should prepare to pay dearly? I wish some of the brilliant minds in the group would come up with something reasonable. Arduino or Raspberry Pi seem to have potential, I am not at all familiar with either.


Re: Trying to bring back a AA501

Eric
 

OK so trouble shooting of the night. Voltage on pin 9 of U1410 is about 7.5 V, CR1412 tests as a diode. However, on the socket with the chip removed I do see the 4.95V present. Also on pin 13 it looks like everything is behaving I think . The voltage goes down as the frequency goes up so I think the op Amp U1610D is working as expected. Or is at least changing it output. So I am still at a bad stage in U1410 specifically D. I have NOS ones on order about 10 of them so we will see what happens.

On 1/6/2020 12:01 PM, Eric via Groups.Io wrote:
I'll check tonight when I get back to the bench if there is voltage in the
socket with the ic removed. When I curve traced the outputs with the chip
out on a bread board referenced to ic ground point 1 2 and 4 showed a
diode. 3 showed nothing fully open circuit.

On Mon, Jan 6, 2020, 11:41 AM Dave Wise <david_wise@...> wrote:

That happened here a few weeks ago. Fluke 8000A DMM. After a transient,
it would only display even digits. Turned out the 7447 display driver
developed an internal short on its 1's input. The MOS A/D chip was fine.
Whew!

Dave Wise
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Chuck Harris
via Groups.Io <cfharris=erols.com@groups.io>
Sent: Sunday, January 05, 2020 10:36 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Trying to bring back a AA501

I am having trouble imagining how a 15V CMOS device could spontaneously
generate 5V on one of its outputs.... I can see ~0V, or ~15V, or even 7.5V,
but 5V is an odd value for a device that has no resistors in it.

Are you sure that it isn't being bullied around by whatever it is driving?
old style CMOS has very little drive capability.

-Chuck Harris







Re: Tek 576 Curve Tracer solid state replacement for relays ?

Brad Thompson
 

garp66 wrote on 1/6/2020 6:03 PM:

hi

Still I wonder if *any* of the Tek 576 relays could be replaced with power Mosfets.
I am curious if some Hexfet / Mosfet relay replacement(s) might then be more reliable ?

Brad:
Are all of the relays in the Tek 576 that you are referring to susceptible to the issue you have brought up ?

I have used a number of different power Hexfets , Mosfets made by IR ( IRF.com ) , having very low "On" resistances ( 0.0001 Ohms ) at various voltages. These Fets are capable of being turned 'on' via the output of a single TTL gate, without issue. I have also placed these in series or parallel (D-S) to achieve a wider ranges of specification with good results.
Hello, Rick--

Thank you for your comments. I have an ailing 577 awaiting attention, but I haven't studied its
schematic with an eye toward replacing relays with MOSFETs nor have I done the same with a 576.
Thus I'd be guessing about the feasibility of making *any* replacements.

It would be interesting to hear from someone who was involved with design of Tek's more-recent
curve tracers. Are there reliability issues that would justify the time spent in reverse-engineering the relays
followed by forward-engineering the MOSFET replacements?

73--

Brad  AA1IP


Re: 454 screen brightness issues?

Jack Ohme
 

Mike,

I have a copy of the manual in PDF and on paper. The intensity dial
correctly changes the voltage (although the screen brightness shows no
change), but the grid biasing potentiometer does not change the voltage at
TP1349, which stays at around 6.8v. I'm not sure whats happening here, if
this is the grid biasing pot that is broken or something nearby on the Z
axis board, but I will inspect the schematics. Let me know if you think of
anything to look for.

-Jack

On Mon, Jan 6, 2020 at 2:15 PM Albert Otten <aodiversen@...> wrote:

Hi Jack,

Where should I be looking for those DC restorers, in the -1920v?
The 454 has no DC restorers. The HV transformer has separate windings for
the grid and the cathode circuit. The rectified voltage for the grid can be
reduced somewhat by the grid bias pot R1447 (in the divider chain with
R1442-R1446) and is stacked on the voltage supplied by the Z-axis
amplifier.
When you follow Mike's suggestion and use a pdf of the manual, you will
note that the waveform at TP1349 is almost invisible. The blue picture in
the paper manual is also very faint. The voltage switches between the 2
written values 17.7 V and 6.75 V.

Albert




Re: Tektronix 532 LV rail shorted

John Williams
 

It has been a while since I had to fix a 503-series power supply. But when C640 blows it shorts and blows the 10 ohm fuse resistor. If there are solid state rectifiers one or more of them could also be blown. If there is a tube rectifier you can pull the tube and see if it will power up. There is also an electrolytic on the top by the hv supply which filters the -150. It could also be somewhere else that is shorting the -150. There is a lot of interconnection.