Date   

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

Richard in Edenton NC
 

Thanks Matthew

73 Richard W4MCD


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

David Kuhn
 

I have 11 of them (if not more) in my library. I am looking at "103
Projects for the Electronics Experimenters", by TAB BOOKS Inc, Blue Ridge
Summit, PA 17212, first edition June 1981.

Other include the "Power Supply Handbook" by the editors of 73 Magazine,
TAB Books, first edition, January 1979.

Dave

On Sat, Mar 28, 2020 at 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: 2782 electrical schematics

Mark Wendt
 

https://w140.com/tekwiki/wiki/2782

You'll find the service manual there.

Mark

On Mon, Mar 30, 2020 at 3:47 PM evdsp39 <evdsp39@...> wrote:

Hi all,I am new in this forum and I hope that I can find a solution to my problem.I have a 2782 spectrum analyzer whom the focus, astigmatism and intensity are not operating at all.I have the 2782 user manual but without any electrical schematics, just a block diagram.So if somebody has these schematics I will be happy to buy a copy !Thank you so much.Etienne.





2782 electrical schematics

evdsp39
 

Hi all,I am new in this forum and I hope that I can find a solution to my problem.I have a 2782  spectrum analyzer whom the focus, astigmatism and intensity are not operating at all.I have the 2782 user manual  but without any electrical schematics, just a block diagram.So if somebody has these schematics I will be happy to buy a copy !Thank you so much.Etienne.


2430A Fails Repet

Rich Frahm
 

I recently picked up a Tektronix 2430A for next to nothing because it had failures on the self test. Most of these failures were caused by a dead backup battery. I found a suitable replacement and installed it and that got me past most of the failures. It still failed 9000 Trigs on the extended diagnostics. I did the ext cal on the atten, triggers, and repet...atten and triggers passed, but repet failed. I opened it up and looked it over carefully and found an electrolytic cap on the low voltage power supply board that was bulged on top, so I removed it and tested it. It was a 2200uF cap that read 15uF, so I ordered and replaced all electrolytics on the low voltage power supply board but it made no difference. It still has these failures:

9113 Slope
9123 Slope
9300 Trigs/Repet

And I don't have a nice straight trace...this is what I have:

display_006_r.jpg

The displays changes as it should when the time base is changed but not when the volts/div is changed, even though the readout showing the setting it's on does change as it should.

Can someone point me in the right direction on this? I do have a pdf of the service manual.  If this requires special test equipment to troubleshoot I'm probably out of luck.  I'm just a hobbyist and my test equipment consists of a Tektronix 2215 (which I bought new when they first came out in the mid to late 80s), a Fluke 77 (also purchased new in the early to mid 80s), a couple more meters, a couple of signal generators, a couple of power supplies...that's about it.

Thanks,
Rich


Re: Tektronix 2235A

barry.ballenger@...
 

i own 4 2235A and the military version as well and they are a great analog
scope. Mine came off Ebay after negotiating each one. i won't go above
$200 on them myself. I did pay 400 for a brand new still in the sealed
packing material with probes, cover, accessory set and pouch with the
manuals.

On Mon, Mar 30, 2020 at 12:06 PM Bill via Groups.Io <ko4nrbs=
yahoo.com@groups.io> wrote:

In my search for an Oscilloscope I ran across a local 2235A in excellent
cosmetic condition and it produces a signal on both channels. Looks like
it had a very easy life. Doesn't even have scratches on it. No probes
just a power cord.

I don't know what it is worth so came here to ask how much is a fair offer.

Thanks,
Bill




WTB: Parts for P6131 Probe

Phil Wong
 

Hello:

I received 3 P6131 probes for the cost of shipping. The problem is the
probes came with the collar but no ground lead.

I need:
1) 3 Ground leads that connects to the collar.
2) 3 probe tips with retractable hooks

Please email offers.
Shipping to New York City, 11373.


Re: Tektronix 2235A

Bert Haskins
 

On 3/30/2020 1:06 PM, Bill via Groups.Io wrote:
In my search for an Oscilloscope I ran across a local 2235A in excellent cosmetic condition and it produces a signal on both channels. Looks like it had a very easy life. Doesn't even have scratches on it. No probes just a power cord.

I don't know what it is worth so came here to ask how much is a fair offer.

Thanks,
Bill
I would guess $100 to $150 but for myself, I would hold out for a 2232.

The 2232 does a lot more for about the same space and cost.

 Bert


Re: Tek 222/224 Battery Replacement

Jeff Davis
 

All,

Update on the group purchase. As of this morning, we have deposits for 7 kits, plus I'm planning to order 2 for my own use, making 9 total.

To avoid spamming the list with daily status updates, I've created a web page where I'll keep the current order status<https://www.n0dy.com/2020/03/29/tek-222-224-charger-order-status/> updated. The URL is https://www.n0dy.com/2020/03/29/tek-222-224-charger-order-status/.

For those of you not familiar with the project, here's a brief summary:

The kit allows the use of readily available 18650 rechargeable lithium batteries to replace the now unavailable sealed lead acid battery originally sold with the Tektronix 222/224 oscilloscope. No modifications to the scope are required other than removal of the original sealed lead acid battery. Charging and protection circuitry is provided, allowing the use of unprotected 18650 cells. The kit will consist of one assembled and tested battery charger circuit board, one 3D printed case, and at my option some miscellaneous parts such as light pipes to bring the LED indicators to the front of the case and a jumper cable to attach to the scope’s battery connector. Kit does not include rechargeable 18650 lithium batteries (required for operation).

Circuit board design based upon the work of Kitsune-Denshi<http://kitsune-denshi.net/projects:tek222bat>. licensed under the Creative Commons Attribution-ShareAlike License.

Case design based upon the work of NearFarMedia on Thingiverse<https://www.thingiverse.com/thing:3623622> licensed under the Creative Commons Attribution License.

Thanks,
Jeff / N0DY

________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Jeff Davis <n0dyjeff@...>
Sent: Saturday, March 28, 2020 5:51 PM
To: TekScopes <TekScopes@groups.io>
Cc: Dave Voorhis <voorhis@...>; Miguel Work <harrimansat@...>; benx618(g) <benx618@...>; rubbrdux@... <rubbrdux@...>; g m <saphill7@...>; Dave Holigan <dave@...>; Byron Hayes, Jr. <bhayes@...>; SuddenLink <bob.ripley@...>; satbeginner <castellcorunas@...>; garp66 <hrgerson@...>
Subject: Re: [TekScopes] Tek 222/224 Battery Replacement

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://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.n0dy.com%2Fproduct%2Ftek-222-224-battery-charger-deposit%2F&;data=02%7C01%7C%7C9ddf3c8d9e9e4bcff63a08d7d37b624d%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637210399184673953&amp;sdata=3HOf5aZem%2FQ5BeQFzLbq36xJ0uORMH4PVjQeOLFVMU0%3D&amp;reserved=0. 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


Tektronix 2235A

Bill
 

In my search for an Oscilloscope I ran across a local 2235A in excellent cosmetic condition and it produces a signal on both channels. Looks like it had a very easy life. Doesn't even have scratches on it. No probes just a power cord.

I don't know what it is worth so came here to ask how much is a fair offer.

Thanks,
Bill


Re: 485 Z axis

Tom Gardner
 

On 30/03/20 15:43, sittners wrote:
I powered up a 485 that had been sitting on the shelf for awhile, finding it completely dead. It was working nicely prior to that. After replacing a pair of famous tantalum caps it powered up but no trace resulted. Further research found that it has sweep at the deflection plates and high voltage. I suspect issues with the Z-axis, possibly with the DC restore diodes. The -3000 volt test point reads correctly but I don't know what I should see at the cathode regulator TP1614 or TP1653 or TP1665. Regarding the restore diodes is there a way to test them and what is a recommended replacement? Thanks in advance for your responses.
First question: are all the CRT voltages about right?

Second question: are the "low voltage" z-modulation waveforms correct?

It is simpler to inspect grid waveforms if you have a suitable probe, e.g. a P6013/5, but you can make inferences without that.

When I was faultfinding a 465, I had to learn about this topic. I eventually traced the problem to the grid connection being broken inside the CRT.

The principal is that the "low voltage" z-modulation circuit has an output waveform as seen at TP1781/2 will have an AC component that depends on sweep speed, holdoff time, autotrigger delay, intensified beam and I sure a couple of other things.

That waveform is simply translated up to be the grid-kathode waveform at ~3kV by the DC restoration circuit. The AC component should be identical.

Hence you can measure the AC voltage at TP1781/2 and Vgk with a multimeter, and they should change in sympathy with each other. Obviously measuring Vgk means there is 3kV on each lead, and you need to be very careful it doesn't leap elsewhere!


485 Z axis

sittners <sittners@...>
 

I powered up a 485 that had been sitting on the shelf for awhile, finding it completely dead. It was working nicely prior to that. After replacing a pair of famous tantalum caps it powered up but no trace resulted. Further research found that it has sweep at the deflection plates and high voltage. I suspect issues with the Z-axis, possibly with the DC restore diodes. The -3000 volt test point reads correctly but I don't know what I should see at the cathode regulator TP1614 or TP1653 or TP1665. Regarding the restore diodes is there a way to test them and what is a recommended replacement? Thanks in advance for your responses.

Phil


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

Richard in Edenton NC
 

Roy, thank you for the information

I appreciate it

73 Richard W4MCD


Re: Tektronix 2445A slow startup

victor.silva
 

I've seen bad capacitors in the Low Voltage Power Supply cause a slow startup. I would say that's usually the main cause especially in this model since it will not have the surface mount capacitor leak problem in the A5 assembly (CPU controller on the left side). This unit will have the through-hole A5 controller.

--Victor


Re: TDS 420 Oscilloscope

Tam Hanna
 

Hello,

on my bench: LeCroy 9354AM as main scope, Danaher TDS754D as second.


IMHO, the TDS754_D_ is the best of the old TDS gaggle. Unlike the A / B / C, it has intensity grading in the DPO view. This is the only feature I really use it for, for everything else digital scope related, I prefer the LeCroy due to the much stronger maths suite. Oh, and an Iwatsu DS6612A for Roll Mode...


Tam

--
With best regards
Tam HANNA

Enjoy electronics? Join 15k7 other followers by visiting the Crazy Electronics Lab at https://www.instagram.com/tam.hanna/


Tektronix 2445A slow startup

Steve
 

I’m getting ready to purchase this scope from eBay. The add says it’s slow to startup and assumes it has problems. I won’t know until I get it tomorrow or in a few days if it’s the delayed startup circuit or errors are the fault or normal operation. Has anyone experienced this? Please enlighten Me as to what’s most likely the cause and a solution to the error problems if it’s not the delayed start circuit. Thanks everyone and nice to meet you all. I have the service manual.
--
Kind Regards,

steve


Re: Shorting strap for Tektronix 515A

Harvey White
 

I'd say 1/4 to 1/2 watt with the provisions that the original (given the date) would be 1/2 watt.  Considering that you're shorting plate leads together (or the equivalent in a later scope of collector leads together), if you're worried about the wattage, and if you need to be, you're shorting the wrong two points together.  IMHO, look at the points to be shorted together.  then look at the plate resistors (or grid resistors), then ask "how much current could flow even if one is on and the other is off".

Bet that 1/2 watt will do nicely.

Harvey

On 3/29/2020 10:00 PM, Brenda via Groups.Io wrote:
Hello everyone! I hope that everyone is being safe with this virus going around. Now to the topic on hand, I have a Tektronix 515A that I have the bug to attempt to fix, and that is I believe that there is an imbalance in the vertical amplifier. I cannot center the trace to the center line. The closest that I can get is 2 major divisions with the vertical control turned all the way CCW. I have gone through all the tubes, reseated and reseated them and tried different ones with no avail. I got this scope with all the audiophool tubes pulled from it. There was only 1 6DJ8 in the scope that was left in, and whoever harvested the tubes missed this one. Anyways, I digress, I wanted to make a shorting strap that is shown in the manual for the Tektronix 535A, and there is a 100ohm resistor in the middle. What wattage would suffice as the manual didn't mention the wattage?

Brenda



Re: TDS694C 50 Ohm Overload

Jerry
 

I have a TDS694C that works perfectly in every way as far as I can tell,
however under calibration, the signal path check reads fail.
Is there anything to do for that?
Jerry

On Sat, Jan 4, 2020 at 3:15 AM Jay Walling via Groups.Io <jayw_comark=
yahoo.com@groups.io> wrote:

Hi George,

I believe that is the input preamp, not the ADC. There's a good
possibility that someone overloaded and killed it. They are BGA devices so
they're not very repairable without a donor board and re-balling.




Shorting strap for Tektronix 515A

Brenda
 

Hello everyone! I hope that everyone is being safe with this virus going around. Now to the topic on hand, I have a Tektronix 515A that I have the bug to attempt to fix, and that is I believe that there is an imbalance in the vertical amplifier. I cannot center the trace to the center line. The closest that I can get is 2 major divisions with the vertical control turned all the way CCW. I have gone through all the tubes, reseated and reseated them and tried different ones with no avail. I got this scope with all the audiophool tubes pulled from it. There was only 1 6DJ8 in the scope that was left in, and whoever harvested the tubes missed this one. Anyways, I digress, I wanted to make a shorting strap that is shown in the manual for the Tektronix 535A, and there is a 100ohm resistor in the middle. What wattage would suffice as the manual didn't mention the wattage?

Brenda


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

Roy Morgan <k1lky68@...>
 

See also
Youroldtimebookstore.com

Has many Lindsay book reprints. Many about radio.

Roy Morgan
K1LKY Western Mass

On Mar 29, 2020, at 3:14 PM, aldue <garydirkse@...> wrote:

Electronics book club
P.O. Box 182600
Columbus, OH 43272-3027 .......ask about 5 books for 4.97
electronic engineers book club
P.O. Box 182601
Columbus, OH 43272-3028

paperbacks from
Electronic Technology Today
P.O. Box240
Massapequa Park, NY
11762-0240



On Sat, Mar 28, 2020 at 11:20 PM aldue via Groups.Io <garydirkse=
gmail.com@groups.io> 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:
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

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