开云体育

-----Original Message-----
From: David G., Sent: Friday, May 18, 2018 11:57 AM

Hello All,

As some of you will easily recall, back in 2010 I tried desperately to pull
this together via donations from the group. At first we were successful at
gathering the funds through email commitment however; not nearly as many
people actually donated compared to the number that committed through
email.

I am retired and could not foot the remainder of the bill and have felt
like an ABSOLUTE HEEL ever since!!!!!

I have now made a contribution in the sum total of ALL monies received back
then. 480.00USD

I am not at all interested in anything other than trying to help the
community and possibly save a little face for a project that was started in
earnest to benefit the masses.

I VERY MUCH APPRECIATE the understanding of those generous souls whom tried
to help initially and deeply regret the direction my effort turned when
things fell so desperately short.

Thank you for the bandwidth.

Cheers,

David

-----Original Message-----
From: David Berlind Sent: Friday, May 18, 2018 11:02 AM

I would like to donate $25. How do I do that?

On Fri, May 18, 2018 at 1:56 PM, Dennis Tillman W7PF <dennis@...>
wrote:

Hi Vincent,
As an original member of the museum I thank you for your donation and
for raising the importance of the museum and the work it will be
capable of doing when they start scanning all those fiche.

The museum needs just $785 to reach their goal. With 7,264 members
surely we can push the museum over the top.

IF JUST 1% OF OUR MEMBERS DONATE $10 I WILL BE HAPPY TO MAKE UP THE
REST TO REACH $6,000.

If you ever have a reason to come to Seattle you have a place to stay
here with us. You can take a train down to Portland (3 hours away) and
see the museum while you are here. You can also take the Boeing
Factory Tour and see them assembling the 747, 767, 777, and 787
planes. You can also take a ferry ride through the beautiful San Juan

Islands in Puget Sound.

Dennis Tillman W7PF

-----Original Message-----
From: Vincent Trouilliez, Sent: Friday, May 18, 2018 9:15 AM

Just made a little donation (35, not a US citizen so not tax
deductible...), every little helps.

Been a month and a half and I see only 90 people donated ? Despite
the important number of members on this forum ?

Must say I am little surprised/disappointed... :-/

Good news is that despite that, they have almost reached their 6,000
USD goal... still missing 840 bucks.

Hopefully this message will bump the topic and people who may have
missed/not heard of this donation campaign, now will be aware ! :-)

I am so very excited at the prospect of unlocking this mountain of
documents and see what's in it ! :-D

Wish I lived nearby the museum so I could give some of my time to
help

them

scan all these microfiche... gonna take while for sure... gonna be
an on- going effort. In the meantime, hopefully we can start by
pulling the

"most

wanted" instruments...

Vincent Trouilliez

--
Dennis Tillman W7PF
TekScopes Moderator

I went to the homepage and clicked on the box on top for how to donate.

where did you get to select paypal ?

On Fri, May 18, 2018 at 11:44 AM, Jack Reynolds <
jackandladyreynolds@...> wrote:

Unless Paypal is pulling my leg, they just took a donation!

Jack Reynolds


On 5/18/2018 2:16 PM, Adrian wrote:

I just donated - The easy way is go to Vintagetek home page and follow
the link to the YouCaring donations page. Takes any credit/debit card but
not PayPal as far as I could see..


On 5/18/2018 7:02 PM, David Berlind wrote:

I would like to donate $25. How do I do that?

Unless Paypal is pulling my leg, they just took a donation!

I just donated - The easy way is go to Vintagetek home page and follow the link to the YouCaring donations page. Takes any credit/debit card but not PayPal as far as I could see..


On 5/18/2018 7:02 PM, David Berlind wrote:

I would like to donate $25. How do I do that?

Thanks for your perseverance ;-) I get it now.

That's bad news then.. means they will never ever release any schematics.

I wonder though, why they were not "scared" or releasing their schematics up to the '80s, and decided it was suddenly too "risky" when they entered the "digital" age in the early '90's with the first TDS scopes and such.

Only hope would be (not a lawyer again) : if law states for example, that any patent on such devices, can only be valid up to 30 years no matter what... then it means Tek could release all the schematics with a 30 year (or whatever) delay, knowing that even if they did unwillingly infringe some patent, no matter what it was... they would be safe. Unless such a scenario exist, then yeah I guess there is nothing to hope for, even in 50 years time... :-(


Vincent Trouilliez

Fabio. There is no way a simple 33 ohm resistor could cause that... pshhh...
HAHA. Nice job!!
/g/TekScopes/photo/49370/7?p=Name,,,20,1,0,0
/g/TekScopes/photo/49370/6?p=Name,,,20,1,0,0
Now I can put the old blocks back in and.... Wait until the next problem rolls
around.
Thanks for everyones help again!!!
On Fri, May 18, 2018 at 08:55 am, Fabio Trevisan wrote:

Hello Lop Pol,

Well... Attenuator blocks are not really swapable "Plug-andPlay" as they are
usually adjusted to match each 7A26's input capacitance...
But, since the behavior is consistent and the performance is good on the

other

attentuator settings, I think you successfully ruled-out the attenuator

block

as a possible cause.

With all that in perspective, I can only see 3 possible causes for this
problem (if logic is sound and if Mr. Murphy is not fooling around your

7A26).

1. A poor leaf switch contact(s) of the X2 attenuation section (the B
contacts, as they're named on the schematics), either the one before the X2
attenuator block, or the one after the X2 attenuator block.
2. Or the R106 / LR106, whichever is the case on your particular 7A26.
3. Bad contact (or dry solder joint) at the X2 attenuator block contact

pins,

but that seems rather unlikely as those are gold plated "collet-type" socket
pins and seems very reliable to me.

From all 3, the most likely seems to be number 1, the leaf switch

contacts...

The problem is that those contacts are the ones on the back side of the
attenuator block PCB (the same side of the attenuator rotary cam which is a
lot of work to disassemble).
If the bad contact doesn't clear with contact cleaner (and be sure you use
only the ones that are safe to plastics), I`m afraid you have some tough

work

ahead because, to clean them as per the manual, with IPA and paper, you'll
have to dismantle the whole thing.

Rgrds,

Fabio



On Fri, May 18, 2018 at 06:51 am, lop pol wrote:

I changed the attenuators with a set of known good ones. Still the same

20mV

issue.

20mV /g/TekScopes/photo/49370/4?p=Name,,,20,1,0,0
10mV /g/TekScopes/photo/49370/3?p=Name,,,20,1,0,0
50mV is the same as the 10mV so you get the picture.
Pretty crazy bad.

I would like to donate $25. How do I do that?