Date   
Re: OT: Win 8.1 and 10?

ArtekManuals
 

Depends on what software you run... I upgraded ONE machine and was plagued with lockups... I reverted back to WIN-7 ... I will wait till Service pack 1 comes out even if I have to pay for WIN-10 by then...why do you think they are giving away WIN-10 upgrades?

Dave
ArtekManuals

On 2/8/2016 4:00 PM, @Raymond [TekScopes] wrote:
Simple. Upgrade. A few disadvantages (notably the push-updates and lack
of privacy if you choose default settings) but better user experience
overall.
I have upgraded 4 machines so far. All positive experiences.

Raymond
--
Dave
Manuals@...
www.ArtekManuals.com

Re: OT: Win 8.1 and 10?

Geoffrey Thomas
 

On 08/02/2016 20:53, mechanic_2@... [TekScopes] wrote:
Hello all,
I am posing this question in this group because of the high level of experience and knowledge. I have just built a dream computer and I installed Win 8.1 on it. MS is offering Win 10 as an upgrade. Could I please get thoughts on this.
Thanks,
rich!

Re: OT: Win 8.1 and 10?

 

Simple. Upgrade. A few disadvantages (notably the push-updates and lack of privacy if you choose default settings) but better user experience overall.
I have upgraded 4 machines so far. All positive experiences.

Raymond

Re: OT: Win 8.1 and 10?

ArtekManuals
 

Uninstall WIN-8 and instal WIN-7
WIN-8 was an Alpha test and WIN-10 is the worlds largest BETA test
Wait another year till WIN-10 has an update

Dave
ArtekManuals.com

On 2/8/2016 3:53 PM, mechanic_2@... [TekScopes] wrote:
Hello all,
I am posing this question in this group because of the high level of
experience and knowledge. I have just built a dream computer and I
installed Win 8.1 on it. MS is offering Win 10 as an upgrade. Could I
please get thoughts on this.
Thanks,
rich!
--
Dave
Manuals@...
www.ArtekManuals.com

OT: Win 8.1 and 10?

Richard R. Pope
 

Hello all,
I am posing this question in this group because of the high level of experience and knowledge. I have just built a dream computer and I installed Win 8.1 on it. MS is offering Win 10 as an upgrade. Could I please get thoughts on this.
Thanks,
rich!

Re: TDS 380 calibration and vertical scale problem

Ed Breya
 

I think there may be some confusion because of the "50" number - now I'm confused a bit. I thought that the repair in that link was about the 50 ohm termination feature, namely a resistor on the input and grounded at the other end. I also thought the 380 does not have this feature.

In AC/GND/DC coupling circuits, a small resistance may be included in series with the cap, to limit discharge current and protect the switch or relay contacts - that could also be 50 ohms, but it is very unlikely that it would be burned out since it's normally in series with the high-Z attenuators. If the topology is such that there's a "precharge" of the cap to the signal's DC level when the input is set to GND, then I suppose it could be damaged by a high enough voltage at a high enough frequency applied directly on the input. Usually precharge resistance is quite a bit higher than 50 ohms though.

On the other hand, 50 ohm input termination resistors are exposed directly to the outside world, and easily burned out by too much input - a common occurrence.

Regarding measuring "50 ohms" on one channel versus "nothing" on the other, what does that mean? 50 ohms to ground? Is nothing an open circuit or zero resistance? I assume it's the measurement from the input node to something on the hybrid after the relays, and it looks like the continuity is 50 ohms through the coupling circuit on one, and open-circuit on the other.

Before pulling the hybrid, I'd recommend thoroughly studying the relays and try to figure out the topology by making measurements right on the pins, and then sketch out what it seems to be. If you haven't already, you should be able to find a data sheet with pinout, which is probably standard. BTW be sure to see if they are regular type relays - it's possible they could be latching type, which could really get confusing. Presuming it's opened up and on the operating table, and the hybrids are accessible while running, it should be possible to measure the coil voltage on each relay for each state, and the contact states.

From the recent discussions, unless I missed something again, I think there are two problems - the original missing signal ranges, and now also CH2 coupling. Again, my guess is still that it's a relay-not-doing-the-right-thing problem, for whatever reason, causing both.

Ed

Re: 2465B Power Supply Problem

 

I have had off-line bridge rectifiers fail before and the bulk storage
capacitors were not damaged that I could tell. I assume that the fuse
blowing was enough to protect them.

On Mon, 8 Feb 2016 09:29:25 -0500, you wrote:

David,

I can see the failure taking out the bridge. When something like that fails,
pretty much everything connected to it can fail because you never know exactly
what might happen during the failure or the exact timing which can make a big
difference. Since it didn't fail instantly, probably the blown C1016 partially
damaged the bridge, which then failed over the next few seconds.

Since I am now aware of that issue, I will replace the bridge as soon as
Mouser gets my parts here (supposedly shipping today).

My concern is that my "smoke" test may have also damaged the bulk storage
capacitors. I just replaced those and I hope not to need to replace them
again, so quickly! The bridge circuit that failed is the connection between
(-) and (~). That is connected to the bottom (-) of C1021. So when a positive
cycle is happening the negative side of C1021 would be lifted up. I am not
sure that it would cross the positive side, but since the input would be
unfiltered it might. But, it would also be discharging the capacitor which
might protect it.

Do you think that it's likely to be damaged? My DMM is not terribly good at
testing capacitance and removing C1021 is real pain with the "extended" legs,
so I don't really want to do that. However, I aslo don't want to "spread" the
failure any further.

Mike

Re: Tektronix (7854 e.a.) Fan Controller revisited

 

On 08 Feb 2016 11:53:09 -0800, you wrote:

David,

It has a modern "Panaflo" tubeaxial box fan like you would find in a PC.

The change notice that I have says the fan was changed starting with
B090000 which is before the RAM and ROM cards were combined starting
with serial number B100000.
My paper SM (070-2874-01, April 1980, revised April 1987) contains:

1. A change notice, dated 2/28/86, stating the replacement of the older style 147-0035-00 fan and associated components by a tubeaxial 12 V, 4.8W, 35 CFM fan, effective S/N B090000. Change ref. M56709.

2. A change notice, dated 1/30/87, stating the replacement of the two separate ROM/RAM boards by a single one, effective S/N B100000, Change ref. M59032, size 31 pages....

Both comply with your info.

It also contains a sheet, referring to M56709, stating that Guernsey 7854's with S/N from 100082 are equipped with the new fan. This is consistent with my 1000158, which does, and my 1000078, which doesn't have the mod.

Raymond
We are looking at the same change notices.

I ended up compiling 13 difference change notices for the 7854 from
difference sources because no one source had all of them.

Re: Tektronix (7854 e.a.) Fan Controller revisited

 

David,

It has a modern "Panaflo" tubeaxial box fan like you would find in a PC.
>
The change notice that I have says the fan was changed starting with
> B090000 which is before the RAM and ROM cards were combined starting
> with serial number B100000.
My paper SM (070-2874-01, April 1980, revised April 1987) contains:

1. A change notice, dated 2/28/86, stating the replacement of the older style 147-0035-00 fan and associated components by a tubeaxial 12 V, 4.8W, 35 CFM fan, effective S/N B090000. Change ref. M56709.

2. A change notice, dated 1/30/87, stating the replacement of the two separate ROM/RAM boards by a single one, effective S/N B100000, Change ref. M59032, size 31 pages....

Both comply with your info.

It also contains a sheet, referring to M56709, stating that Guernsey 7854's with S/N from 100082 are equipped with the new fan. This is consistent with my 1000158, which does, and my 1000078, which doesn't have the mod.

Raymond

Re: TDS 380 calibration and vertical scale problem

Siggi
 

Hey David,

I see - you've found where there is a missing connection in the DC path of
the CH2 attenuator, and this path has 50Ohm resistance. That's great to
hear. I hope you'll keep sharing your findings with the group as you go
along, as this will - hopefully - help others in the future :).

Note that the TDS420 attenuator looks very different from yours, and as the
420 has 50Ohm termination, I'd assumed that's what had blown.

Hopefully once you pop the attenuator, you'll also see where the other
blown resistors are, and hopefully this is repairable.

Good luck,
Siggi

On Mon, 8 Feb 2016 at 13:57 david.wilson92@... [TekScopes] <
TekScopes@...> wrote:



Siggi, sorry that I wrote my previous reply a little unclear


Recently you presented me with a link from another site
http://www.antiqueradios.com/forums/viewtopic.php?p=1816411 where someone
had a blown input on their hybrids so they pulled it. On the back side of
their hybrid revealed a blown thick film resister going from the bnc input
to what looks like the first nearest relay. They mentioned that this
resistor was 50 ohms and that got me wondering. On ch1 I measure with dc
coupling and I also get 50 ohms and when I measure on channel 2 with dc
coupling I get nothing. I was wonder where this 50 ohm resister was as I
couldn't find it anywhere on top measuring with the volt meter. So visiting
the link it occurred to me that this 50 ohm resister I am trying to find is
on the underside and I can't get to it without taking the hybrid off. So I
think why I am not getting any dc coupling on channel 2 is a blown
resister. If I fix that I can at least get ch2 to measure dc again though
it won't fix the decade problem I am having as you said. I think I have an
idea here and ordered that resister.


I also ordered capacitors to replace on the main board, and low impedance
capacitors for the monitor board and power supply along with that resister.
When those parts come in I will pull ch2 hybrid first and see what is
really going on under there.


Does this clear up some confusion? I feel certain that I found the dc
coupling problem for ch2 why it won't measure dc voltage though it will
measure ac and that missing 50 ohms that I can't get that I measure on ch1.
I feel certain here but then again I could be wrong. We will find out when
I pull ch2 hybrid, I will include pictures of course.


And thanks again for your help, and others who helped me as well. It could
be possible to have a functional scope again if the damage is only minor,
hopefully not in the hybrid IC but she shall find out soon.










[Non-text portions of this message have been removed]



[Non-text portions of this message have been removed]

Re: TDS 380 calibration and vertical scale problem

David Wilson
 

Siggi, sorry that I wrote my previous reply a little unclear


Recently you presented me with a link from another site http://www.antiqueradios.com/forums/viewtopic.php?p=1816411 where someone had a blown input on their hybrids so they pulled it. On the back side of their hybrid revealed a blown thick film resister going from the bnc input to what looks like the first nearest relay. They mentioned that this resistor was 50 ohms and that got me wondering. On ch1 I measure with dc coupling and I also get 50 ohms and when I measure on channel 2 with dc coupling I get nothing. I was wonder where this 50 ohm resister was as I couldn't find it anywhere on top measuring with the volt meter. So visiting the link it occurred to me that this 50 ohm resister I am trying to find is on the underside and I can't get to it without taking the hybrid off. So I think why I am not getting any dc coupling on channel 2 is a blown resister. If I fix that I can at least get ch2 to measure dc again though it won't fix the decade problem I am having as you said. I think I have an idea here and ordered that resister.


I also ordered capacitors to replace on the main board, and low impedance capacitors for the monitor board and power supply along with that resister. When those parts come in I will pull ch2 hybrid first and see what is really going on under there.


Does this clear up some confusion? I feel certain that I found the dc coupling problem for ch2 why it won't measure dc voltage though it will measure ac and that missing 50 ohms that I can't get that I measure on ch1. I feel certain here but then again I could be wrong. We will find out when I pull ch2 hybrid, I will include pictures of course.


And thanks again for your help, and others who helped me as well. It could be possible to have a functional scope again if the damage is only minor, hopefully not in the hybrid IC but she shall find out soon.

Re: 7904 - Very Dim Trace

 

It has to be more than a z-axis amplifier problem because Jim measured
the 2950 volt cathode voltage at 3250 volts. I wonder if that by
itself would be enough to cause the problem.

Alternatively, could the measurement be wrong? Jim, can you verify
proper operation of the probe you used to make that measurement?

On Mon, 8 Feb 2016 10:24:59 +0100, you wrote:

*If* the X / Y deflection works as before, so calibrated time base steps
are still correct and calibrated vert amp steps, too, then you are
likely looking at a Z axis issue.

I'd recommend to check if the Z axis amplifier output is as expected. If
it is not, check the amplifier, if the amp is okay, check the Z axis logic.
If the amp output is okay, replace all HV caps and all diodes in the Z
axis DC restorer circuit.

Cheers, Marian

Re: HP 1722

ArtekManuals
 

Bill

It would be useful and more appropriate to offer this item over on the HP-Agilent group rather than here on the Tektronix forum

have fun in Orlando
Dave
NR1DX&#92;4
Riverview , FL

On 2/8/2016 12:27 PM, ws1c_4@... [TekScopes] wrote:
I have a HP 1722 for sale. All analog seems to be working fine.
Digital not repaired. Asking $75.00
Can bring to Hamcation in Orlando.
Bill WS1C , ws1c@...




--
Dave
Manuals@...
www.ArtekManuals.com

HP 1722

William Schwartz
 

I have a HP 1722 for sale. All analog seems to be working fine.
Digital not repaired. Asking $75.00
Can bring to Hamcation in Orlando.
Bill WS1C , ws1c@...

Tek 485

William Schwartz
 

I have a Tek 485 in excellent condition for sale.
Everything seems to be working.
I can bring to Hamcation. Asking $150.00


Bill WS1C, WS1C@....

Re: Ebay Rip-off ? - "Global Shipping Program"

David DiGiacomo
 

On Mon, Feb 8, 2016 at 9:02 AM, Sergey Kubushyn <@KSI> wrote:
Note, you no longer get any discount when you buy postage from USPS
(Click-n-Ship). It's better to use PayPal shipping.
Nope, I would not pay a single cent over that constantly growing fee they
already charged me.
Even though it would save you money?
I don't believe it would. Exactly like their GSP that claimes to save you a
million but in reality is something that is better to be avoided at all
costs like a plague.
It's not a matter of belief... price out a USPS shipment on paypal.com
and usps.com and you'll see the difference.

As of discounts -- I shipped my last box something like 2 weeks ago and
still got a discount. When did this change?
January 17th. I was surprised too.
Don't know, I think I shipped after that date but would have to check. And
anyways that discount is not that big anyways so hardly a deciding factor.
I was mistaken, it changed on January 27th:

http://shippingeasy.com/click-n-ship-price-increase-2016-3-alternatives/

(Yes, that's an advertorial, but it has the information about the change.)

Re: Tektronix 160A Transformer--Mostly Off-Topic, and really old

Ed Breya
 

You are probably correct that the current rating on the HV windings is for DC out, assuming full wave push-pull rectification with the tubes. In terms of VA rating and total power dissipation in the transformer, increasing the current in one set of windings is OK while the others are lower than normal - up to a point. I don't think you should go that far though - from 175 to 300 mA is a pretty big jump. It will be wire-limited, and you won't be able to tell just how much more it can take before a hot spot develops that can damage the winding. I could picture getting to 200-225 mA with no problem, but 300 may be a bit much.

It also depends on the output voltage needed. If you use silicon rectifiers instead of the originally designed tube rectifier circuit, you'll get more peak voltage available anyway, but also the charging current waveform will be sharper and bigger, depending on the load, so the RMS value can get pretty high. If the peak voltage can be lower, and tolerate more ripple, you can add resistance to soften up the rectifier current and increase the conduction angle, which will ease the burden on the winding, trading off output voltage for higher current.

The duty factor also plays here - I'm assuming continuous. If the duty is short, then the windings have a chance to cool between cycles, so more can be taken when needed. At the extreme, most transformers can easily take many times their VA rating - and so can the windings - for very short times like in clearing the fuse when a fault occurs.

Ed

Re: Ebay Rip-off ? - "Global Shipping Program"

Sergey Kubushyn
 

On Mon, 8 Feb 2016, David DiGiacomo telists@... [TekScopes] wrote:

On Sun, Feb 7, 2016 at 10:12 PM, Sergey Kubushyn <@KSI> wrote:
Note, you no longer get any discount when you buy postage from USPS
(Click-n-Ship). It's better to use PayPal shipping.
Nope, I would not pay a single cent over that constantly growing fee they
already charged me.
Even though it would save you money?
I don't believe it would. Exactly like their GSP that claimes to save you a
million but in reality is something that is better to be avoided at all
costs like a plague.

Then, last time I checked (long ago but I seriously doubt they fixed it and
100% sure they added a ton of stupid bells and whistles since then) it did
_NOT_ work with Linux Firefox and did not offer USPS pickups.
PayPal shipping does work in current Firefox. I don't see why it
would be different on Linux.
Because the entire thing is totally taken by script kiddies putting more and
more Java[,script] crap onto it with new bangwhiz frameworks and so on. And
all this is being constantly put on production servers without any testing
so nobody already gets surprised that some part of it is not working, some
of personal stuff comes and goes, search is totally unusable and so on.

And please don't tell they are separate now with Ebay.

You would have to request the USPS pickup on the USPS site.
Yup.

As of discounts -- I shipped my last box something like 2 weeks ago and
still got a discount. When did this change?
January 17th. I was surprised too.
Don't know, I think I shipped after that date but would have to check. And
anyways that discount is not that big anyways so hardly a deciding factor.

---
******************************************************************
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
******************************************************************

Re: Ebay Rip-off ? - "Global Shipping Program"

Colin Herbert
 

I do buy a fair amount of stuff off eBay which comes from the USA. The last item that I got (a front-cover for a 400-series ‘scope) needed a Customs charge paying. Now, even though I didn’t have this in my possession until I paid the charge, the shipping info that eBay sent indicated that the item had been “delivered”. Clearly being economic with the truth, but at least it protected the seller from a similar fraud. Perhaps they have just tightened up recently…. Would Pitney-Bowes could employ some more diligent label-stickers, though.

Colin.



I personally have had some close calls where instruments I sold on Ebay appeared not to arrive at their destination. In one case it was because the buyer refused to pay the customs duties so the package sat in Customs but I had no way to know that. Then the buyer contacted Ebay to say I never sent it and demanded his money back. I imagine that once he got his money refunded he would be happy to pay the customs duty and keep the instrument. I would be out the money and the instrument. With experiences like that I cannot blame sellers here not wanting to deal with overseas shipping.



[Non-text portions of this message have been removed]

Re: Ebay Rip-off ? - "Global Shipping Program"

Colin Herbert
 

Fat chance, I think, Patrick. That would be far too much bother for them. I
daresay that both my complaint and the possible one from the original
purchaser of the watch were filed away in the waste-paper basket. Bigger
stick needed!

Colin.



From: TekScopes@... [mailto:TekScopes@...]
Sent: 08 February 2016 01:25
To: TekScopes@...
Subject: [TekScopes] Re: Ebay Rip-off ? - "Global Shipping Program"





Hi Colin,

I would have expected that the recipient of the 7B92A, expecting a blingy
watch instead, also would have complained to eBay. I'm wondering whether
eBay would then be smart enough to match the two complaints to recognize
your concern was honest and accurately stated?


Patrick Wong AK6C