WM490 mixer: can someone identify this component? (Pix)
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Re: Tek 475A 5V PS filter cap removal?
If you have a wide tip, depending on what you are desoldering, that works well.? You do have to be rather quick once the solder wicks into the braid.
Definitely second the saturate it with braid, especially if it's the cheap stuff.
Harvey
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On 5/15/2024 3:39 PM, Greg Muir via groups.io wrote: I have found solder wick poorly lacking in rosin content. When using I will saturate it with liquid rosin making the ability to draw out solder significantly better.
Greg
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Re: Tek 475A 5V PS filter cap removal?
An upvote for Paul Amaranth's mention of Chip Qwik.
This is a low temperature alloy that can be added to existing solder joints.
It melts at 136 degrees F. Yes, below the boiling point of water.
The new combination alloy has a melting point between normal solder and
the low temp alloy. Add some to each of the 4 joints. It is then easy to get
all 4 joints melted/liquid and at a temp well below damaging the PCB.
After you have removed the cap, remove all of the remaining solder/alloy
with flux and solder braid. You do not want any of the allow to remain,
as it is not a soldering alloy, and the alloy is somewhat brittle.
When I do SMT parts on PCBs, I follow the above cleanup with adding
normal solder to all the pads, and then remove with wick. Sort of a
rinse process. If you have never used this stuff, spend 10 minutes playing
with it on a scrap PCB, to get used to how it works. I usually add liquid
flux during the initial adding of the alloy. Also, wipe all solder of your
iron when done, and re-tin it.
The Digikey link above is to a surface mount kit, but it has more than enough
low temp alloy for your task, and is the cheapest item that includes this alloy
I've been using it successfully for repairs for 25 years to get high pin count
connectors off boards, and many other board rework challenges.
Philip
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Re: Tek 475A 5V PS filter cap removal?
I have found solder wick poorly lacking in rosin content. When using I will saturate it with liquid rosin making the ability to draw out solder significantly better.
Greg
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Re: Is this the BSM Connector?
You might try this:
Back in the 70’s I received an Ampex 24 channel instrumentation recorder in a 7 foot rack from NASA where all of the channel modules had the same jacks. If I can recall they were termed “MB” connectors by Amphenol RF. Along with the recorder came a big box of cables terminated in the plugs as well a box full of new plugs. Unfortunately the recorder was transferred to another concern along with all of the accessories.
I don’t believe that mini BNC connectors will mate. In addition mini BNC connectors were primarily designed for the 75 ohm market and are used in video applications.
Greg
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Re: Is this the BSM Connector?
The ones I purchased from Fair Radio were "cut offs", but were easily be reworked to whatever was required: For example converting the S-52 pre-trigger output to BNC or SMA. I originally bought them to replace missing or damaged connectors on the R390A receiver.
Shaun M.
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Re: Tek 475A 5V PS filter cap removal?
Very clever Gordon.
I wouldn't have had the presence of mind to reason through to that solution after discovering said assembly error.
Kudos.
Mike
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Re: Is this the BSM Connector?
Those are on the front of the 7D14 for the Reference Frequency connection and, yes, the MB connector from an R390A will fit it.
Barry - N4BUQ
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Richard, I just checked my? TG501 trigger and it is an MB 2 lug
connector( FYI there are 2 and 3 lug versions). This is the same
connector that is used on R390A Radio.
搁别苍é别
On 5/15/24 4:19 AM, Richard Steedman via groups.io wrote:
A 'real' BSM plug looks like this:
Back in 2020 I posted some photos of a hack BSM plug I'd made using BNC
connectors:
/g/TekScopes/album?id=256572
I'd be very interested if someone could confirm that a mini-BNC connector is
compatible with a BSM socket.
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Re: Is this the BSM Connector?
Richard, I just checked my? TG501 trigger and it is an MB 2 lug connector( FYI there are 2 and 3 lug versions). This is the same connector that is used on R390A Radio.
搁别苍é别
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On 5/15/24 4:19 AM, Richard Steedman via groups.io wrote: A 'real' BSM plug looks like this:
Back in 2020 I posted some photos of a hack BSM plug I'd made using BNC connectors:
/g/TekScopes/album?id=256572
I'd be very interested if someone could confirm that a mini-BNC connector is compatible with a BSM socket.
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Re: Tek 475A 5V PS filter cap removal?
On Wed, May 15, 2024 at 05:56 AM, Raymond wrote:
I find the following technique (from youtube) useful:
4. Either use sucker to clean up solder pin by pin (for manual sucker, use the
one with soft silicone tip which can withstand direct contact with soldering
iron)
OR built a jig with 16 gauge pure copper wire (e.g. copper core wire from
power cable) that will cover all pins, use a high power iron (60w+) to heat up
all pins at the same time, you'll need a lot of solder so that they are molten at
all time.
The trick here is to provide a large amount of heat to a very small area in a short amount of time so that the heat does not have time to spread. Way back in the day I bought a wonderful Nixie tube clock kit. I proceeded to solder in all of the Nixie tubes on the WRONG side of the PCB board (was working fast and did not check my work. Lesson learned). I did not have access to desoldering equipment so I was faced with getting all 12 pins of the Qty 6 Nixie Tubes desoldered quickly and at the same time so that I could pull said tube out. I covered the face of the PCB board with aluminum foil and pushed the Nixie Tube Pins out of the foil so that they were exposed. I then took a propane torch and very quickly heated up the tube pins (taking care to heat up the pins evenly by moving the flame over the pins in a circular motion) while gently pulling on the tube with my hand. The procedure worked great and I was able to quickly remove all 6 nixie tubes without damage to them or the board. Just an idea for you to consider. 73, Gordon KJ6IKT
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Thank you Jaap and Jon,
Excellent troubleshooting advice! Looking at suspect parts the one I think maybe a bit difficult to source is the CR130, which is a Tek manufactured Schottky diode quad p/n 152-1063-00. I looked through the Tek Semi cross reference: tek_xref_free.pdf, but I think that doc is pre-1990 so no diodes above 152-0800-00 were listed. Anyone have a newer Tek semi cross reference/databook?
If it does turn out to be a failed part I may try some 2 ns SOT-23 Schottky diodes in its place.
I will report back after the next bit of troubleshooting.
Cheers,
Howard Hoyt
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Re: 5B44 Dual Timebase parts - knobs wanted!
Hi,
maybe this link is helpful for identifying the knobs based on images.
Best regards
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Re: Tek 475A 5V PS filter cap removal?
I find the following technique (from youtube) useful:
1. First add new solder to old joint and straighten all curve pins
2. Clean up (use sucker or desoldering gun) to clean up old solder as much as you can, keep the temperature just high enough to melt the solder
3. Add in low-melt solder
4. Either use sucker to clean up solder pin by pin (for manual sucker, use the one with soft silicone tip which can withstand direct contact with soldering iron)
OR built a jig with 16 gauge pure copper wire (e.g. copper core wire from power cable) that will cover all pins, use a high power iron (60w+) to heat up all pins
at the same time, you'll need a lot of solder so that they are molten at all time.
You should be able to pull the cap out without pulling out all the trace with it.
The common problem are likely related to the 'tab' from the can.
Good luck.
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Re: Is this the BSM Connector?
A 'real' BSM plug looks like this:
Back in 2020 I posted some photos of a hack BSM plug I'd made using BNC connectors:
/g/TekScopes/album?id=256572
I'd be very interested if someone could confirm that a mini-BNC connector is compatible with a BSM socket.
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Re: FS: Need help finding a home for these 500 series scopes
Bumping this, I need the space back soon. I will probably list them on Craigslist for $100 each?
I'm located in Southern Arizona. If anyone is interested in them, or has any ideas on how to better re-home them, please chime in. I'd really like to avoid scrapping them.
Thanks in advance!
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Re: Tek 475A 5V PS filter cap removal?
Thanks all. I found this message: /g/TekScopes/topic/465_electrolytic_capacitor/82404041?p=,,,20,0,0,0::recentpostdate%2Fsticky,,posterid_91206,20,2,0,82404041 I was using a manual solder sucker and solder wik, looks like I didn't get all of the solder out.
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Re: Tek 475A 5V PS filter cap removal?
The can is a big ol' heat sink. If you can carefully cut it away from the top of the board (or, at least, remove as much of it as close as you can), it should help. There may be limited room and that's not possible but if so, it's something you could try.
Good luck,
Barry - N4BUQ
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Working on a Tek 475A/DM44. The 5V filter cap C1452 (5000uF 25V) is
intermittantly open. A strange one.
I'm struggling with removing it, desoldered the 4 terminals, tried heating all 4
of them quickly while wiggling the cap but it will not budge.
Any tips? I'd rather not pull boards if I don't have to.
Thanks!
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Re: Tek 475A 5V PS filter cap removal?
Ugh, those are a pain. If you put too much heat in the board the trace will delaminate.
You need a good desoldering tool. At the least a vacuum tool, maybe some chip quick, solder braid as a last resort. Get all of the solder out without overheating.
Use a small pcb as an adapter to fit a 105c snap cap into that footprint. You need to tie all of the ground pins together
Paul
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On May 14, 2024 2:22:26 PM EDT, Charlie <chubba@...> wrote: Working on a Tek 475A/DM44. The 5V filter cap C1452 (5000uF 25V) is
intermittantly open. A strange one.
I'm struggling with removing it, desoldered the 4 terminals, tried
heating all 4 of them quickly while wiggling the cap but it will not
budge.
Any tips? I'd rather not pull boards if I don't have to.
Thanks!
!DSPAM:6643abea73067705836704!
--
Sent from Open Mail on Android.
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Tek 475A 5V PS filter cap removal?
Working on a Tek 475A/DM44. The 5V filter cap C1452 (5000uF 25V) is intermittantly open. A strange one.
I'm struggling with removing it, desoldered the 4 terminals, tried heating all 4 of them quickly while wiggling the cap but it will not budge.
Any tips? I'd rather not pull boards if I don't have to.
Thanks!
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Re: WTB Tek 475A & DM44 Service Manuals
Thanks, that's what I thought, just wanted to confirm that.
Still could use both SMs.
Thanks
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Philip Freidin
Shaun M