Date   
Re: Off topic - Electronics Book Club from the 70s and 80s

Richard in Edenton NC
 

Hi John, Yes it is. I am in the ARRL. I am OK with reading publications as pdf documents online but being old school I prefer an actual book. It defeats the purpose but I often print out pdf books I find online, then read them. Depending on how thick they are, and if it is something i think I would want to keep for later reference.

73 Richard W4MCD

Re: Off topic - Electronics Book Club from the 70s and 80s

Richard in Edenton NC
 

Thank you Aldue

Re: Off topic - Electronics Book Club from the 70s and 80s

John
 

Hello Richard,

QST is online for ARRL members. Prowl around the net and you can probably find what you want for cheap!

Digging in the new stuff really not that hard to grasp. In fact, we old timers have a lot of experience that goes a long way.

de W8CCW John

On 3/28/2020 11:23 PM, aldue wrote:
Hi Richard, I shall dig around in the morning. 73 aldue

On Sat, Mar 28, 2020, 2:20 PM Richard in Edenton NC via Groups.Io <w4mcd=
yahoo.com@groups.io> wrote:
--
John Ferrell W8CCW
Julian NC 27283
It is better to walk alone,
than with a crowd going the wrong direction.
--Diane Grant
--
John Ferrell W8CCW

Re: Off topic - Electronics Book Club from the 70s and 80s

aldue
 

Hi Richard, I shall dig around in the morning. 73 aldue

On Sat, Mar 28, 2020, 2:20 PM Richard in Edenton NC via Groups.Io <w4mcd=
yahoo.com@groups.io> wrote:

Hi, I have been a ham radio operator since 1976 when I was a teenager. I
do have a Tektronix scope and a 492 spectrum analyzer and a bunch of other
electronic test equipment but it has been years since I was a component
level bench tech. I am hoping some on here might have a catalog from the
former Electronics Book Club that advertised in electronics magazines back
in the 70s and 80s. My goal is to find names of older pubs and order them
and give me something to do that I used to enjoy. I have a few of Harold
Kinleys books, some by John Link and some decent oscilloscope books. I am
wanting to get back to basics on theory and troubleshooting. Thanks
everyone.

73 Richard W4MCD



Re: New 2465 Seimens brushless motor

PAUL KOBY
 

Take a Dremmel with one of those abrasive discs and run it lightly  across the connectors and then try to solder them.
Works for me almost every time.
P.K.Ka5obi

Re: Tek 222/224 Battery Replacement

Jeff Davis
 

All,

Here's an update on the Tek 222/224 Battery Replacement project. After a few go rounds, I was able to create a BOM that the fab house could source. Unfortunately, the parts that had been pending turned out to be somewhat expensive. The cost in low quantities went from $60 each to about $93. Given the minimum order of 10 pieces is committing nearly $1,000 upfront, I need to ask for deposits from people who are interested in purchasing to reduce my financial exposure. If you're interested in participating in the group buy (and hopefully helping us get a better quantity discount), the link is https://www.n0dy.com/product/tek-222-224-battery-charger-deposit/. There you'll find not only details on the deposit and possible volume discounts, there are also links to technical sites for more information on the project.

While I'm not doing this project entirely out of the goodness of my heart, I'm making this first buy available at just slightly over my cost, plus shipping, both as a way of paying back the value I've gotten from the list over the years, and as an encouragement to get the quantities up so we can all get a volume discount. Any volume discounts would be passed along as explained on the deposit web page.

Thanks for the bandwidth.

Regards,
Jeff / N0DY

Re: 7104, fixing a few minor things

@0culus
 

On Thu, Mar 26, 2020 at 03:17 PM, David DiGiacomo wrote:


This is quite a common issue on the 7104 and 7103. There has been
discussion of it here in the past, but I don't think anyone ever
tracked down the exact cause and cure.

On one of my 7104s I was able to sort of fix it by putting 1.2K in
parallel with R1922 and 1.1K in parallel with R1925, but I was never
exactly happy with that.
Hmmm, interesting that no one has pinpointed a cause. Maybe it's that U1714 going flaky?

Sean

Re: Tek 222/224 Battery Replacement

Jeff Davis
 

Hi Rick,

Thanks for your inquiry. It's a little late in the game for this round, but in all likelihood there will be a second round in which I could accommodate some design changes.

Being unfamiliar with the Tek 422, can you tell me a little bit more about what would be needed? In the case of the 222/224, the battery is expected to supply 8V, and the scope disconnects if the battery voltage drops below 7.5V. That never happens with this design as the converter supplies 8V regardless of the battery discharge condition, over-discharge cutout is handled by the charge circuitry on board. When plugged it, the scope supplies charging current at 9.5V. The only interface to the scope is the battery power connector - +8V (nom) and ground.

Regards,
Jeff

________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of garp66 <@garp66>
Sent: Friday, March 27, 2020 9:33 AM
To: TekScopes@groups.io <TekScopes@groups.io>
Subject: Re: [TekScopes] Tek 222/224 Battery Replacement

hi Jeff,

Any chance you can include some *jumpers* so that this battery replacement PCB unit can also function in an AC/DC Tek 422 scope ?
(With or without a 3D printed plastic retrofit case ?)

thank you,
rick

Re: TDS420 Oscilloscope

 

On Sat, Mar 28, 2020 at 10:08 PM, Mlynch001 wrote:


The biggest downside to all of these later scopes is the total lack of service
information, including the SMPS. There are ZERO schematics available and no
"Component Level" parts list published. For repairs, you are pretty much on
your own as the factory service manuals instruct you to "replace XXX board" to
"Repair" a given fault.
Several years ago, I owned several TDS4XX 'scopes and had to repair their SMPS; at least models TDS420 and TDS420A.
It turned out that the exact same PS's were used in specific LeCroy 93XX-series 'scopes. I remember that in some PS's, one model provided a different combination of LV supplies (polarity and voltages) than others and again different in the Teks but the circuits and PCB layout were identical between some LeCroys and Teks.
Didier's site (KO4BB) has the detailed SM's, including SMPS schematics.

Raymond

Re: need a tunnel diode

Miguel Work
 

Re: TDS420 Oscilloscope

toby@...
 

On 2020-03-28 5:08 PM, Mlynch001 wrote:
Bill,

I have two TDS360's and two TDS460A scopes. The 460A's are powerful and capable units, much more so than my older 465/475/485 series analog scopes. I bought my first 460A dirt cheap, but it did work great when I unboxed it. Had that first one not worked, that would have likely been my first and last purchase of the series. For me, the weakness of my TDS series scopes has been the Switch Mode power supplies. After about a year, the SMPS failed, so I bought a "Parts only" unit, again dirt cheap. Turns out this unit was also 100% functional, so rather than parting that one out, I decided to attempt to repair the SMPS on the first unit. After much effort, I was able to fix them with the generous help and advice from members of this forum. I believe that there are three different versions of the power supplies used on the 420-460 and 420A-460A series, depending on serial number. Getting good replacement parts of the correct type to match your unit is darn near impossible. I have seen the SMPS for the 460A going for $100-$125 Dollars, plus shipping. This is twice what I paid for both of my 460A's, in working condition.

The biggest downside to all of these later scopes is the total lack of service information, including the SMPS. There are ZERO schematics available and no "Component Level" parts list published. For repairs, you are pretty much on your own as the factory service manuals instruct you to "replace XXX board" to "Repair" a given fault. I like the capabilities of my TDS Scopes, but they are over my head for any complex "component level" repairs, beyond board complete replacements. As far as replacement parts go, there are almost all surface mounted parts and a ton of custom IC's. Not repairs for the faint of heart. I have fixed many older TEKTRONIX Scopes, but these are in a totally different universe from the older TEK scopes. They reflect the "new" direction that TEKTRONIX took in the mid to late 80's, and a turn in the wrong direction for hobbyist such as myself. Such is the price of progress and improved capability.

Just my two cents and FWIW.

Thanks for posting!

I own a TDS460A and I love it. I hope, if the worst happens, the info
will be available to fix the supply :/

--Toby

Re: TDS420 Oscilloscope

Mlynch001
 

Bill,

I have two TDS360's and two TDS460A scopes. The 460A's are powerful and capable units, much more so than my older 465/475/485 series analog scopes. I bought my first 460A dirt cheap, but it did work great when I unboxed it. Had that first one not worked, that would have likely been my first and last purchase of the series. For me, the weakness of my TDS series scopes has been the Switch Mode power supplies. After about a year, the SMPS failed, so I bought a "Parts only" unit, again dirt cheap. Turns out this unit was also 100% functional, so rather than parting that one out, I decided to attempt to repair the SMPS on the first unit. After much effort, I was able to fix them with the generous help and advice from members of this forum. I believe that there are three different versions of the power supplies used on the 420-460 and 420A-460A series, depending on serial number. Getting good replacement parts of the correct type to match your unit is darn near impossible. I have seen the SMPS for the 460A going for $100-$125 Dollars, plus shipping. This is twice what I paid for both of my 460A's, in working condition.

The biggest downside to all of these later scopes is the total lack of service information, including the SMPS. There are ZERO schematics available and no "Component Level" parts list published. For repairs, you are pretty much on your own as the factory service manuals instruct you to "replace XXX board" to "Repair" a given fault. I like the capabilities of my TDS Scopes, but they are over my head for any complex "component level" repairs, beyond board complete replacements. As far as replacement parts go, there are almost all surface mounted parts and a ton of custom IC's. Not repairs for the faint of heart. I have fixed many older TEKTRONIX Scopes, but these are in a totally different universe from the older TEK scopes. They reflect the "new" direction that TEKTRONIX took in the mid to late 80's, and a turn in the wrong direction for hobbyist such as myself. Such is the price of progress and improved capability.

Just my two cents and FWIW.

--
Michael Lynch
Dardanelle, AR

Re: vintageTEK scanned transformer drawings for 120-0998-01 and up

Dave Brown
 

I have added a 3rd document on TekWiki with drawings for 120-1007-00 to 120-1349-00. That takes it up to 1984 where SMPS were common. After this all the specifications went to a 12+ page format which is too much time to make scanning worthwhile. Enjoy.

Dave

TDS 420 Oscilloscope

Bill
 

How reliable is the TDS 420 oscilloscope? Saw a video about it and thought it would be a nice upgrade from my 453. Looks to be easily service but have no knowledge about the reliability or availibility of the ICs if needed at some time.
Thanks,
Bill

TDS420 Oscilloscope

Bill
 

How reliable is the TDS 420. I've been thinking about buying ever since I saw a video about it. Looks to be easily serviced and would be handy in the shop. The only scope I have now is a 453 which I use quite a bit. Would like to upgrade from it.
Thanks,
Bill

Off topic - Electronics Book Club from the 70s and 80s

Richard in Edenton NC
 

Hi, I have been a ham radio operator since 1976 when I was a teenager. I do have a Tektronix scope and a 492 spectrum analyzer and a bunch of other electronic test equipment but it has been years since I was a component level bench tech. I am hoping some on here might have a catalog from the former Electronics Book Club that advertised in electronics magazines back in the 70s and 80s. My goal is to find names of older pubs and order them and give me something to do that I used to enjoy. I have a few of Harold Kinleys books, some by John Link and some decent oscilloscope books. I am wanting to get back to basics on theory and troubleshooting. Thanks everyone.

73 Richard W4MCD

Re: New 2465 Seimens brushless motor

victor.silva
 

Ok, I'll try both Zinc dissolved in some HCl and Zinc Chloride soldering paste and report back here on the results.

--Victor

Re: Any Tektronix magnetic shield for a CRT? A strange problem...

Roy Thistle
 

On Thu, Mar 26, 2020 at 08:27 PM, Ed Breya wrote:


The shielding effectiveness does degrade from deformation, but doesn't go to
zero. I wouldn't worry too much about minor dents and dings.
Hi:
I do recall that working mu-metal alloy, alters its crystal structure and so decreases its permeability (but by how much?... don't recall). I'm guessing cutting it with shears would substantially decrease it near the cut line. When they fabricate structures, like shields, they sometimes anneal the object in an oven to reform the crystal structure, and get back the rated permeability. Something to keep in mind, if you are retrofitting a CRT with a repurposed shield, and you have to cut or reshape it.
Best regards and wishes.
Roy

Re: TM500/TM5000 extender v0.8

Ke-Fong Lin
 

Hi everyone,

As for the sharp back corners, I'll fix that for v1.0, that's easy!

Regarding the high current consumption, this is about the plug-in modules themselves. The PCB extender is purely passive, except for the TM5000 "power ok" circuitry that I've not yet populated for my testing. It has no led in particular.
The FG501 (2MHz function generator) that I tested, eats up around 200mA on each of the +/- 26VDC rails, for a total of around 10W. Well within specification, but I expected a "simple" function generator to use much less.

Regarding the wiring, I'm using 22AWG 1551 "premium" from Alpha Wire, these are PVC and even "mil-spec". I have some 24AWG at hand but only in white, so I used 22AWG all along.
This is completely overkill, as they have a 1000V at 3A rating. Probably because of that, the PVC insulation is thick and stiff (silicon should be "softer" than PVC).
Perhaps, if I've used 24AWG or 26AWG, things would have been more convenient.

As for connectors, 56p connectors are both tough and easy to find. They're the same as jamma standard so aliexpress is full of them, but solder eyelets.
Right angled PCB mount connectors are available at manufacturers, but Mouser or Farnell don't have them in stock. Whereas they have the solder eyelet ones.
For probing, this can be done on the eyelets.

All in all, this is certainly not the perfect, but should do the job for some hobby repair/calibration of TM500/TM5000 plug-ins.

Best regards,

Re: Tektronix 2440 no channel 2 trace

Szabolcs Szigeti
 

Hi,

First see what the extended diagnostics says.
Then the usual suspects:
Power supply voltages and ripple.
Remove the hybrids from their socket, clean the contacts a reseat then.
If that does not help, then you can swap the hybrids between the channels.

Szabolcs

<andystewart211@...> ezt írta (időpont: 2020. márc. 27., Pén 18:20):

Channel 1 trace is fine but no channel 2 trace only noise . The cursers
move fine but the noise stays at the bottom of the screen . Any repair tips
would be helpful.