Date   
Re: Restoring 3 (well, actually 2) tek 2225

Craig Sawyers <c.sawyers@...>
 

Huh? Do you mean the TL594 switching regulator controller of which the 2225 has two? It is
readily
available from both TI and On and at a low cost.
Oops. I was thinking of the 2215 switching regulator! Apologies for the confusion.

Craig

Re: Restoring 3 (well, actually 2) tek 2225

Colin Herbert
 

Dave,
You might want to know that Elektrotanya also have your 2225 manual at:

https://elektrotanya.com/tektronix_2225_oscilloscope_sm.pdf/download.html

It actually has your info on it too! Cheeky blighters.
Colin.

-----Original Message-----
From: TekScopes@... [mailto:TekScopes@...]
Sent: 21 September 2017 05:17
To: TekScopes@...
Subject: Re: [TekScopes] Re: Restoring 3 (well, actually 2) tek 2225

I note with displeasure that the copy of the manual listed below is an
illegal posting of one of our scans .

Let your conscience be your guide when downloading it from this pirate.
We are seeking to have it removed

:-(
Dave

 Artekmanuals / ArtekMedia

On 9/20/2017 11:39 PM, nicolas.sog@... [TekScopes] wrote:

Thanks for the answers.

Since the problem with the scope that is in worse cosmetic/circuit
condition is a little more complicated than expected, I´m going to
leave it there for a while and concentrate in the scope that is in
best condition... the one that doesn´t power up.

I checked the power supply DC levels at the different nodes indicated
in the manual, and they read as follow:


w984 -> 32.9 vdc
w972 -> 26.7 vdc
w987 -> 0.4 vdc
w989 -> 0.4 vdc
w991 -> 0.86 vdc


The voltage at the emiter of Q913 is 54.4VDC The voltage at R934 and
C914 is -5.27 Voltage at C900 + lead is 52VDC and at the negative lead
is -5.2VDC


I´m not sure if this data will allow you to guess what the heck is
going on, but it certainly seems weird.


If you want to check the manual with the schematics you can download
it here:


http://www.schematicsunlimited.com/t/tektronix/tektronix-2225-oscillos
cope-service-manual
http://www.schematicsunlimited.com/t/tektronix/tektronix-2225-oscillos
cope-service-manual




Thanks a bunch.
















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

Re: Restoring 3 (well, actually 2) tek 2225

Craig Sawyers <c.sawyers@...>
 

I`m sorry Dave... I wasn?t aware that this was a "copyrighted"?scan. Though I have to tell you, it
doesn?t look too good to resell a copy?of?someone else?s work either, in this case a?manual edited
and published by Tektronix...?I?m not sure if they?re copyrighted,?or?you have a licence?or maybe
you pay a fee to Tektronix for each copy you sell??If not?It?s like scanning some?book by "X" author
that I know people need/like to read?to make some money at his expense. Not sure if that?s good
practice.
Let me know?where can I get a free copy please.
Regards.
I think you need to do a bit more reading around before shooting from the hip like that, Mr Olmos.

Tek copyrights for manuals (WAS Re: Re: Restoring 3 (well, actually 2) tek 2225)

ArtekManuals
 

Tektronix released the copy rights to duplicating there manuals back in
1999. We scan from an original Tektronix manual at 600 dpi for the
schematics, add text searching and the book marks...all very legal.
Comes under the heading of "derivative copyrights"

Text searching is a bit of hit and miss proposition for several
reasons...which I am happy to discuss off list.
I really don't want to tie up the list further on the topic, but will
entertain questions directly to manuals@...

Dave manuals@...


On 9/21/2017 8:50 AM, Nicolas Olmos nicolas.sog@... [TekScopes] wrote:

I`m sorry Dave... I wasnt aware that this was a "copyrighted"scan.
Though I have to tell you, it doesnt look too good to resell a
copyofsomeone elses work either, in this case amanual edited and
published by Tektronix...Im not sure if theyre copyrighted,oryou
have a licenceor maybe you pay a fee to Tektronix for each copy you
sell?If notIts like scanning somebook by "X" author that I know
people need/like to readto make some money at his expense. Not sure
if thats good practice.
Let me knowwhere can I get a free copy please.
Regards.

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

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

Re: Restoring 3 (well, actually 2) tek 2225

 

On Wed, 20 Sep 2017 15:12:39 +0100, you wrote:

Hi all, i just scored 3 tek 2225 for cheap that i am going to restore, well, one will be the donor
so that
make 2 scopes restored ...eventually.
The favourite thing to be dead is the (switched mode) power supply. But it is an easy supply as
compared with the 7000-series monsters.

All the devices are still available other than the controller chip - but you can still get them cheap
on eBay. I just replaced the pass transistor and controller chip in each, and that was all that was
needed.

Craig
Huh? Do you mean the TL594 switching regulator controller of which
the 2225 has two? It is readily available from both TI and On and at
a low cost.

Re: Restoring 3 (well, actually 2) tek 2225

The Guy
 

I`m sorry Dave... I wasn´t aware that this was a "copyrighted" scan. Though I have to tell you, it doesn´t look too good to resell a copy of someone else´s work either, in this case a manual edited and published by Tektronix... I´m not sure if they´re copyrighted, or you have a licence or maybe you pay a fee to Tektronix for each copy you sell? If not It´s like scanning some book by "X" author that I know people need/like to read to make some money at his expense. Not sure if that´s good practice.
Let me know where can I get a free copy please.
Regards.

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

Re: 575 Mod122C with keys. SN005100 - disposal update

Christopher Hilton-Johnson
 

Dave

ah, but surely that is the point of it all!

It's not what you need, it's what you want.

We're talkng lust here, heart not brain.

also once you have it you will find all sorts of reasons to use it - at
it's most basic, as a really good room warmer!

Actually the ability to display curves and characteristic matching with
the flick of a switch is really useful & Tek used lots of matched pairs
- many as duals in the same outer case, very often unobtanium either at
all or at a half reasonable price. Much easier to use matched singles
bonded together for temperature matching characteristics - but you knew
all this already.

go on treat yourself!

Christopher


On 21/09/2017 11:25, Dave Voorhis voorhis@... [TekScopes] wrote:

I’m watching it.

I'm tempted, and I’d like it, but I’m having a hard time justifying
buying it because I don’t really need it.

On 21 Sep 2017, at 11:07, Christopher Hilton-Johnson
chj@... [TekScopes] <TekScopes@...> wrote:

Although the item 'sold' on ebay, they rejected the buyer.

managed to get my fees back from them, so not a total loss

So the 575 is back up on the UK site.

So who wants an early Christmas present to 'self'?

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



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

Re: OT : Bird 43 RF wattmeter upgrade

Brian <brianclarke01@...>
 

Hello Ancel,

Thanks you for keeping me in the loop.

I do like your address-book look-up table approach to calibration. For most amateur radio operation, getting within 10% is probably close enough, although as you note, the Bird slugs and possible reading errors of the Bird meter’s non-linear markings, may possibly allow one to get within 5%. Your example of 6.3 W true power when reading 5 W is 26% out – not wonderful. In Australia, the Foundation Licensee is allowed 10 W maximum power on HF. But we all know that, unless you really mess things up and cause interference to your neighbours, the licencing authority is unlikely to attempt to police this requirement.

However, for people like me who design stuff, knowing what power is being developed / delivered can be a useful diagnostic for tweaking the design. I did find a lovely-looking Sifam meter with a broader, more easily readable scale than the Weston 50 uA, and although its linear scale was in better agreement with the actual current flowing, the FSD is 997 uA. Could your design deliver that much current?

I look forward to further advice about your design progress.

73 de Brian, VK2GCE.

On Thursday, September 21, 2017 1:34 PM, you said:

Hi Brian:
I have done some design changes to accommodate the 50uA meter with the 75mV FS deflection.
There will be 2 levels of calibration to handle 3rd party meters.

1)A stepped (6 point) - 20,40,50,60,80,100% of the meter scale where the uC 'learns' the mV required to match the scale graduations. This means you can linear-ize the meter movement and use a non-Bird meter..

2) A two point 10% deflection and 100% deflection cal based upon supplying a calibrated CW ref signal to match the slug's range. Provides for a custom precision cal. based on user instrumentation.

This enables compensation for meter range irregularities via Cal#1 and compensation for significant slug low range error which is intrinsic to the BIRD43 via CAL#2.

Cal#2 isn't necessary unless you wish to do your own cal as I will input the BIRD slug cal. data I develop as a default. Notably I have found that 5W on the 50W scale is actually 6.3W true power. This improves to 49.7W =50W display on the FSD. This is well within the BIRD spec, but I will improve on that substantially with the uC corrections. Perhaps by an order of magnitude. Also the 0.4%/C temp comp will be active.

I have selected a 20 pin SOIC PIC16LF1828 as the core uC and TLC27L7 instrumentation op amps for the DC signal path.

I've also done away with DPDT switches in favour of a telecom 5V DPDT TX2SA SMT relay to switch the Bird 43 to OEM behaviour. This allows uC control of the relay and the capability to throttle the relay current down to 7mA to keep it latched to activate all the non-OEM performance improvements after the initial 28mA switching current pulse.

I figure on perhaps a 20mA draw from the supply all told. So a stock, cheap ($8), 12000mA pocket USB Powerbank (EBAY # 322183500350) should be good for 600 hours before needing a charge..

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

.



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

Re: 575 Mod122C with keys. SN005100 - disposal update

Dave Voorhis
 

I’m watching it.

I'm tempted, and I’d like it, but I’m having a hard time justifying buying it because I don’t really need it.

On 21 Sep 2017, at 11:07, Christopher Hilton-Johnson chj@... [TekScopes] <TekScopes@...> wrote:

Although the item 'sold' on ebay, they rejected the buyer.

managed to get my fees back from them, so not a total loss

So the 575 is back up on the UK site.

So who wants an early Christmas present to 'self'?

Christopher

575 Mod122C with keys. SN005100 - disposal update

Christopher Hilton-Johnson
 

Although the item 'sold' on ebay, they rejected the buyer.

managed to get my fees back from them, so not a total loss

So the 575 is back up on the UK site.

So who wants an early Christmas present to 'self'?

Christopher

Re: Restoring 3 (well, actually 2) tek 2225

Craig Sawyers <c.sawyers@...>
 

I note with displeasure that the copy of the manual listed below is an illegal posting of one of
our scans
.

Let your conscience be your guide when downloading it from this pirate.
We are seeking to have it removed

:-(
Dave

�Artekmanuals / ArtekMedia
Well that is shocking Dave. Especially since a kosher copy from your site is only $11.50

Makes you wonder how many of the Tek/HP manuals from that site are likewise ripped off. Worth
checking, if laborious.

Did you notice that they have the cheek to have a button that says "Donate"?

Craig

Re: Restoring 3 (well, actually 2) tek 2225

ArtekManuals
 

I note with displeasure that the copy of the manual listed below is an
illegal posting of one of our scans .

Let your conscience be your guide when downloading it from this pirate.
We are seeking to have it removed

:-(
Dave

Artekmanuals / ArtekMedia

On 9/20/2017 11:39 PM, nicolas.sog@... [TekScopes] wrote:

Thanks for the answers.

Since the problem with the scope that is in worse cosmetic/circuit
condition is a little more complicated than expected, Im going to
leave it there for a while and concentrate in the scope that is in
best condition... the one that doesnt power up.

I checked the power supply DC levels at the different nodes indicated
in the manual, and they read as follow:


w984 -> 32.9 vdc
w972 -> 26.7 vdc
w987 -> 0.4 vdc
w989 -> 0.4 vdc
w991 -> 0.86 vdc


The voltage at the emiter of Q913 is 54.4VDC
The voltage at R934 and C914 is -5.27
Voltage at C900 + lead is 52VDC and at the negative lead is -5.2VDC


Im not sure if this data will allow you to guess what the heck is
going on, but it certainly seems weird.


If you want to check the manual with the schematics you can download
it here:


http://www.schematicsunlimited.com/t/tektronix/tektronix-2225-oscilloscope-service-manual
http://www.schematicsunlimited.com/t/tektronix/tektronix-2225-oscilloscope-service-manual




Thanks a bunch.
















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

Re: Restoring 3 (well, actually 2) tek 2225

The Guy
 

Thanks for the answers.

Since the problem with the scope that is in worse cosmetic/circuit condition is a little more complicated than expected, I´m going to leave it there for a while and concentrate in the scope that is in best condition... the one that doesn´t power up.

I checked the power supply DC levels at the different nodes indicated in the manual, and they read as follow:


w984 -> 32.9 vdc
w972 -> 26.7 vdc
w987 -> 0.4 vdc
w989 -> 0.4 vdc
w991 -> 0.86 vdc


The voltage at the emiter of Q913 is 54.4VDC
The voltage at R934 and C914 is -5.27
Voltage at C900 + lead is 52VDC and at the negative lead is -5.2VDC


I´m not sure if this data will allow you to guess what the heck is going on, but it certainly seems weird.


If you want to check the manual with the schematics you can download it here:


http://www.schematicsunlimited.com/t/tektronix/tektronix-2225-oscilloscope-service-manual http://www.schematicsunlimited.com/t/tektronix/tektronix-2225-oscilloscope-service-manual



Thanks a bunch.

Re: OT : Bird 43 RF wattmeter upgrade

mosaicmerc
 

Hi Brian:
I have done some design changes to accommodate the 50uA meter with the 75mV FS deflection.
There will be 2 levels of calibration to handle 3rd party meters.

1)A stepped (6 point) - 20,40,50,60,80,100% of the meter scale where the uC 'learns' the mV required to match the scale graduations. This means you can linear-ize the meter movement and use a non-Bird meter..

2) A two point 10% deflection and 100% deflection cal based upon supplying a calibrated CW ref signal to match the slug's range. Provides for a custom precision cal. based on user instrumentation.

This enables compensation for meter range irregularities via Cal#1 and compensation for significant slug low range error which is intrinsic to the BIRD43 via CAL#2.

Cal#2 isn't necessary unless you wish to do your own cal as I will input the BIRD slug cal. data I develop as a default. Notably I have found that 5W on the 50W scale is actually 6.3W true power. This improves to 49.7W =50W display on the FSD. This is well within the BIRD spec, but I will improve on that substantially with the uC corrections. Perhaps by an order of magnitude. Also the 0.4%/C temp comp will be active.

I have selected a 20 pin SOIC PIC16LF1828 as the core uC and TLC27L7 instrumentation op amps for the DC signal path.

I've also done away with DPDT switches in favour of a telecom 5V DPDT TX2SA SMT relay to switch the Bird 43 to OEM behaviour. This allows uC control of the relay and the capability to throttle the relay current down to 7mA to keep it latched to activate all the non-OEM performance improvements after the initial 28mA switching current pulse.

I figure on perhaps a 20mA draw from the supply all told. So a stock, cheap ($8), 12000mA pocket USB Powerbank (EBAY # 322183500350) should be good for 600 hours before needing a charge..

Re: 7L13 from 1.8Ghz to 2.5Ghz

Ed Breya
 

I recall there was some discussion about that here maybe a couple of years ago. You may want to search back to see if there's anything. It had to do with removing the LPF in the front end. But, there are performance tradeoffs in doing so.

Re: Restoring 3 (well, actually 2) tek 2225

Tom Jobe <tomjobe@...>
 

Hi Nicolas,
Obviously you start with the power supplies, until all of their low
voltages and ripple readings are within spec it is a waste of time to
look elsewhere for solutions to any of your problems.
On the one with the focus difficulty, look at the chain of focus
resistors R888 to R891. Those resistors often go bad on other small 22xx
scopes because they each have to drop about as much voltage as each
resistor is rated for. There are several ways to improve the focus
string if you are interested, my favorite is to put two resistors in
series for each one of them, so each individual resistor only has to
drop half as much voltage.
tom jobe...

On 9/20/2017 1:53 PM, Nicolas Olmos nicolas.sog@... [TekScopes] wrote:

Alright.... as I said I just scored THREE Tek scopes 2225 for cheap
that I want to fully restore, hopefully you might want to help me a
little along the way... I´m just a newbie regarding scope stuff.
Anyway... for easier understanding I´m gonna call´em Charlie, Mr. Dean
and Ben.

(I might sacrifice good ole Ben as a parts donor if necessary, sorry
Ben... so don´t get too attached to Ben)

Alright, I´m obviously going to read the service manual that I already
got but If you have any suggestion regarding the failures they are
showing please let me know... I´m just a newbie.
Anyway, let´s get started:
Charlie... Charlie, also known as "one eyed scope", he has only one
channel working... channel B. Channel A is as dead as a channel A can be.

Ben.... Ben is mostly alright but he lost his glasses who knows
when... maybe in a fight. He doesn´t focus. This guy doesn´t care
about nuthin´ he´s the careless-lest Mofo of the whole world. Ben has
his face, knobs and shafts all broken, twisted and scratched up... He
works perfectly though it seems, besides the focus that is non
existent. Instead of a dot there is a blob, like a squear-ish big
spot.... but the blob moves and sweeps just fine.

(I already looked it up and it has the wires that go from the board
to the focus adjustment pot unsoldered. So, Hopefully that`s all that
needs to be fixed. But as I said I might use it as a parts donor for
Mr. Dean cuz Mr. Dean is the classiest looking scope of all three).

Mr. Dean... Poor Mr. Dean.... he is F**ked up, though he´s handsome
and classy, he doesn´t even have a scratch. But yea... he´s probably
already dead. He doesn´t even power up.

Aaight... that´s how thing are lookin so far.

Let me know if you have any ideas.


On Wednesday, September 20, 2017 12:05 PM, "hahi@...
[TekScopes]" <TekScopes@...> wrote:


>I've read that these scopes were made in china or something like that?

Not China, they were designed and manufactured by Tek UK in Hoddesdon.
Good or bad ?

/Håkan

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

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Re: Restoring 3 (well, actually 2) tek 2225

Siggi
 

Hey Nicolas,

In your shoes, I'd start by checking the low voltage supplies for ripple,
as well as value. Ripple in the LV supplies will grow your spot size, but
it's also a fool's errand to diagnose other problems with bad supplies.
If the LV supplies are blameless, I'd look at R888-R894, my bet is you'll
find the string open. You can measure the resistors in-circuit, after
waiting for a repectful amount of time for the cathode supply to bleed it's
charge.

Siggi

On Wed, Sep 20, 2017 at 19:59 nicolas.sog@... [TekScopes] <
TekScopes@...> wrote:



...sorry, here´s the video:



https://youtu.be/5e5Y0Ppiv7E https://youtu.be/5e5Y0Ppiv7E








Re: Restoring 3 (well, actually 2) tek 2225

Stan Corbett
 

Hi Nicolas--look at the wires on the deflection pins--I had a 2235 where these had fallen off.
cheers Stan
________________________________
From: TekScopes@... <TekScopes@...> on behalf of nicolas.sog@... [TekScopes] <TekScopes@...>
Sent: September 20, 2017 5:59 PM
To: TekScopes@...
Subject: Re: [TekScopes] Re: Restoring 3 (well, actually 2) tek 2225



...sorry, heres the video:



https://youtu.be/5e5Y0Ppiv7E https://youtu.be/5e5Y0Ppiv7E




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Re: Restoring 3 (well, actually 2) tek 2225

The Guy
 

Re: Restoring 3 (well, actually 2) tek 2225

The Guy
 

Alright, tried to fix Ben´s CRT and nothing happened (soldered back the loose wires, blah blah blah). Here´s a video showing the problem. Does it mean we have a broken CRT?

Thanks. Cheers...