Date   
Re: Anyone have a 5.5 to 18PF variable ceramic trimmer they would like to sell

 

On Thu, Oct 25, 2018 at 03:14 AM, lop pol wrote:
Hi Lop Pol,

Re: Anyone have a 5.5 to 18PF variable ceramic trimmer they would like to sell



I added a photo of the capacitor. Just in case.

https://groups.io/g/TekScopes/photo/76822/0?p=Name,,,20,1,0,0
Quite likely I have one NOS, possibly original. Cost is shipping from Netherlands. To be certain, please tell me which cap (C...) on which board.

Raymond

Re: Anyone have a 5.5 to 18PF variable ceramic trimmer they would like to sell

Brendan
 

On Thu, Oct 25, 2018 at 12:59 PM, Raymond Domp Frank wrote:


On Thu, Oct 25, 2018 at 03:14 AM, lop pol wrote:
Hi Lop Pol,

Re: Anyone have a 5.5 to 18PF variable ceramic trimmer they would like to
sell



I added a photo of the capacitor. Just in case.

https://groups.io/g/TekScopes/photo/76822/0?p=Name,,,20,1,0,0
Quite likely I have one NOS, possibly original. Cost is shipping from
Netherlands. To be certain, please tell me which cap (C...) on which board.

Raymond
The cap is C120 on the A13 board so its A13C120. Thanks for looking.

Re: Anyone have a 5.5 to 18PF variable ceramic trimmer they would like to sell

 

On Thu, Oct 25, 2018 at 10:05 PM, lop pol wrote:


The cap is C120 on the A13 board so its A13C120. Thanks for looking.
Just realized yours is a 468. It's probably the same as the equivalent cap in a 465(B). I'll be in the lab coming Tuesday and have a look, possibly take a few pictures. I can't imagine the "rotated-by-90 degrees same-function cap" in both models being different. The physical location definitely is but they both are the lying-down variety.
Please send me a PM on Tuesday as a reminder and we'll take our communication off-group.

Raymond

Re: Type G plugin versions

cmjones01
 

On Thu, Oct 25, 2018 at 12:44 PM, Albert Otten wrote:
According to the later manual Type G switched from UHF (131-012) to BNC
(131-277) at S/N 9480. No idea in which year that was.
My 535A and G are Guernsey-built. The 535A is s/n 101936, and the G is s/n 101127. They both have BNCs which look like they were factory-fitted, though they are of the special Tek type with enlarged flanges to fit the UHF connector hole.

Chris

Re: Type G plugin versions

Dave Wise
 

I was partly wrong. Tek retooled the front panel for BNC, but not until 1967. From 1963 through 1966, they used the UHF front panel with a square-flange BNC jack and plastic trim covering the annular gap. The letter-series plugins built this way are CA, D, G, and L. Others like the K were retooled immediately, if the catalogs are right.

I have plugins of each construction. One of my scopes, a 545, was definitely field-modded, since it was built in the 1950's. It doesn't have the trim and it looks a bit awkward without it.

Beaverton 535A switched to BNC at 31260, but that doesn't tell us anything about Guernsey.

Dave Wise
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of cmjones01 <chris@...>
Sent: Thursday, October 25, 2018 1:27 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Type G plugin versions

On Thu, Oct 25, 2018 at 12:44 PM, Albert Otten wrote:
According to the later manual Type G switched from UHF (131-012) to BNC
(131-277) at S/N 9480. No idea in which year that was.
My 535A and G are Guernsey-built. The 535A is s/n 101936, and the G is s/n 101127. They both have BNCs which look like they were factory-fitted, though they are of the special Tek type with enlarged flanges to fit the UHF connector hole.

Chris

Re: Anyone have a 5.5 to 18PF variable ceramic trimmer they would like to sell

Michael A. Terrell
 

I recently bought one of these assortments to get several different values for a project. I haven't used any of them, so far:

https://www.ebay.com/itm/112638729469?epid=5003063441

Honbay-30pcs-6mm-Plastic-Cover-Trimmer-Variable-Capacitance-5PF-10PF-20PF-30PF/

Michael A. Terrell

-----Original Message-----
From: Raymond Domp Frank <@Raymond>
Sent: Oct 25, 2018 3:59 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Anyone have a 5.5 to 18PF variable ceramic trimmer they would like to sell

On Thu, Oct 25, 2018 at 03:14 AM, lop pol wrote:
Hi Lop Pol,

Re: Anyone have a 5.5 to 18PF variable ceramic trimmer they would like to sell



I added a photo of the capacitor. Just in case.

https://groups.io/g/TekScopes/photo/76822/0?p=Name,,,20,1,0,0
Quite likely I have one NOS, possibly original. Cost is shipping from Netherlands. To be certain, please tell me which cap (C...) on which board.

Raymond


Re: Anyone have a 5.5 to 18PF variable ceramic trimmer they would like to sell

Brendan
 

On Thu, Oct 25, 2018 at 02:45 PM, Michael A. Terrell wrote:


I recently bought one of these assortments to get several different values for
a project. I haven't used any of them, so far:

https://www.ebay.com/itm/112638729469?epid=5003063441

Honbay-30pcs-6mm-Plastic-Cover-Trimmer-Variable-Capacitance-5PF-10PF-20PF-30PF/

Michael A. Terrell


-----Original Message-----
From: Raymond Domp Frank <@Raymond>
Sent: Oct 25, 2018 3:59 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Anyone have a 5.5 to 18PF variable ceramic trimmer
they would like to sell

On Thu, Oct 25, 2018 at 03:14 AM, lop pol wrote:
Hi Lop Pol,

Re: Anyone have a 5.5 to 18PF variable ceramic trimmer they would like to
sell



I added a photo of the capacitor. Just in case.

https://groups.io/g/TekScopes/photo/76822/0?p=Name,,,20,1,0,0
Quite likely I have one NOS, possibly original. Cost is shipping from
Netherlands. To be certain, please tell me which cap (C...) on which board.

Raymond


Looking at the part number it looks like its an air dielectric trimmer. Its the trimmer for the A ramp 10us timing :/ am I going to run into issues trying to use a ceramic trimmer there compared to air? The one I have coming from Tedss is a Vishay film dielectric . I just hope someone here has a NOS or used OS. One of the ones on they way will at least work until I can get a better suited replacement.. I hope. One member here is going to look at what he has on Tuesday.

Re: Anyone have a 5.5 to 18PF variable ceramic trimmer they would like to sell

Gary Appel
 

-----Original Message-----
From: Raymond Domp Frank
Sent: Thursday, October 25, 2018 9:59 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Anyone have a 5.5 to 18PF variable ceramic trimmer they would like to sell

On Thu, Oct 25, 2018 at 03:14 AM, lop pol wrote:
Hi Lop Pol,

Re: Anyone have a 5.5 to 18PF variable ceramic trimmer they would like to sell



I added a photo of the capacitor. Just in case.

https://groups.io/g/TekScopes/photo/76822/0?p=Name,,,20,1,0,0

Re: Anyone have a 5.5 to 18PF variable ceramic trimmer they would like to sell

 

On Thu, Oct 25, 2018 at 11:59 PM, lop pol wrote:


Its the trimmer for the A ramp 10us timing :/ am I going to run into issues
trying to use a ceramic trimmer there compared to air?
No issues to be expected at the frequencies involved. Any good-quality trimmer should do but you may prefer the looks and fit of an original...... As promised, I'll have a look on Tuesday but please, send me a PM if you haven't heard until 20.00 GMT.
If I'd have to send one from NL, shipment may be expensive, although it may be sent as a letter. Where would I have to send it to?

Raymond

Re: Anyone have a 5.5 to 18PF variable ceramic trimmer they would like to sell

Brendan
 

On Thu, Oct 25, 2018 at 03:53 PM, Raymond Domp Frank wrote:


On Thu, Oct 25, 2018 at 11:59 PM, lop pol wrote:


Its the trimmer for the A ramp 10us timing :/ am I going to run into issues
trying to use a ceramic trimmer there compared to air?
No issues to be expected at the frequencies involved. Any good-quality trimmer
should do but you may prefer the looks and fit of an original...... As
promised, I'll have a look on Tuesday but please, send me a PM if you haven't
heard until 20.00 GMT.
If I'd have to send one from NL, shipment may be expensive, although it may be
sent as a letter. Where would I have to send it to?

Raymond
Thanks for all the replies. The one in this link https://www.surplussales.com/Variables/Ceramic/CerCap3.html posted by Gary looks amazingly close. I'm going to see what else they have and make an order from them. Looks like an awesome site. Thank you for that. What I'm going to do it get the scope up and running with the trimmers that will be here tomorrow and then when the one from surplussales gets here I will put it in and calibrate the monster. Thanks guys.

Tektronix 067-0625-00 Peak to Peak Detector Battery

Craig Cramb
 

Anyone had to locate replacement batteries for this unit. Only marking on the battery is 1A.
Original Tektronix description is: 1.5V, 650MAH, Alkaline-Manganese Dioxide
Tektronix 067-0625-00 Peak to Peak Detector Battery
Pictures on link with dimensions required.

https://groups.io/g/TekScopes/album?id=76872

My 2465B has arrived + A5 Board leaky caps cleanup

tekscopegroup@...
 

This is a 2465B Sn 55K purchased off ebay, very good external cosmetics, almost pristine interior with only very few traces of dust and so far have not seen any signs of having been disturbed or repaired in the past. Seller was stating that a Test 05 Fail 40 error was coming up upon power up, and that the traces where showing a lot of vertical jitter and eventually would move off screen towards the bottom. I figured that price and shipping cost numbers where decent for a B version, with the front cover and storage pouch (<$250), given the description, which I figured could be related to the well known leaky caps problem, so went for it and won. Oh and somehow the blue filter was loose and almost fell out when I took off the front cover. Have to check the manual, but I figure the filter just needs to snapped back into the groves that seem to hold it in place? If it is so easy to fall off, no wonder so many scopes are being offered without the blue filter, gone missing.

But today upon arrival when I powered up the scope it does not show a trace at all, or even a readout, nothing at all on screen, so not sure how long ago it still had a live screen. The power up self test does stop at the "ADD" label, so as I understand this seems to match the reported Test 05 scenario error. In any case pulled out the A5 board and got started on the leaky cap mess cleanup following some very good suggestions from Chuck not to try to desolder the caps in one piece, but rather carefully chop them up to get to the pads. Well, I kind of cheated and very carefully lifted the single cap in the corner by desoldering it bit by bit by extremely gently rocking it side by side very little at a time while heating the (cleaned up) pads, as it looked easy to do it on that location. It came out fine. But then decided to heed the recommendations as the other remaining 3 caps looked more difficult to get at due to less space around them. I think in the end all went quite well, there was not too much corrosion damage on the pads, and I could not see any traces that where eaten away.

Off course still quite a few other affected parts with dull/greenish pads that will need to be cleaned or replaced (see pictures liked bellow), and I am guessing that in the case of the IC legs that show corrosion they will have to be cleaned thoroughly. Also once I am done removing the rest of the affected SMD resistors and caps, will wash both the affected areas of the board with dish soap and water with a soft toothbrush. Then its into the oven at 375 deg for 45 minutes. Just kidding... its really only 40 minutes that are needed.

Some A5 pictures here:
https://groups.io/g/TekScopes/album?id=76874

BTW the scope has a TEK U800 (not the less desirable Maxim part), and most ICs show a 1990 date code. The NVRam has a 9020 date code. Once I can sort out the most pressing issues with the inoperative display I'm thinking of going the FM16W08 route, to do away with the need of a backup battery for good. I only hope getting the A5 board back in shape will bring back the screen to life. If not once I'm done with it will start checking voltage rails at J119 as well.

Comments and suggestions very welcomed about any follow up tests to make sure I have possibly not missed anything on the A5 cleanup, any know suspect VIAs to check, or hidden traces to verify they have continuity to another part, etc. Any other obvious possibilities besides the A5 mess on why the screen is non-op?

BTW, noticed that one of the 3 caps had two very fine traces between the pads to which the cap is mounted. I see these traces on one side go to what looks like two test points, but on the other side they seem to end nowhere, and don't seem to be connected to the capacitor pads either. Out of curiosity, anyone know what they are meant for? Thanks for any input.

Alex

Re: My 2465B has arrived + A5 Board leaky caps cleanup

 

Alex,
Very nice cleanup job.

I'd just like to jump in here about removing SMD caps with minimal chance of pad damage.

Every technician has his own favorite method of removing SMD capacitors.

My favorite method is to grip the capacitor from above with a pair of pliers, push DOWN, and simultaneously firmly twist the capacitor in the horizontal plane, about 120-180°.

NEVER pull the capacitor in an upwards direction.

The correct horizontal twisting action will break the capacitor leads at their weak point, and the capacitor will separate from the PCB.

If this method is done correctly, it will never cause damage to the solder pads on the PCB.

Re: Tektronix 067-0625-00 Peak to Peak Detector Battery

Craig Sawyers <c.sawyers@...>
 

I have two of these. The batteries are used for is to provide a DC offset "bucking voltage" of 0.3V
via a resistor network and adjustable resistors R8/R9 that sets zero output at 1.2V p-p.

If R10/R11, which are usually 120k at 1.5V are increased to 348k then the common 3V tagged cells could
be used with the same sensitivity of adjustment of R8/R9.

Having just worked that out, I've just worked out how to resurrect my own!

Just need to find a suitable tagged 3V battery that can take 7.5uA draw 24/7.

Craig

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Craig Cramb
Sent: 26 October 2018 03:52
To: TekScopes@groups.io
Subject: [TekScopes] Tektronix 067-0625-00 Peak to Peak Detector Battery

Anyone had to locate replacement batteries for this unit. Only marking on the battery is 1A.
Original Tektronix description is: 1.5V, 650MAH, Alkaline-Manganese Dioxide Tektronix 067-0625-00
Peak to Peak Detector Battery Pictures on link with dimensions required.

https://groups.io/g/TekScopes/album?id=76872

Re: Type G plugin versions

Dave Seiter
 

Wow- my G is s/s 9934, so it's just after the change.  Strange that they didn't change the sheet metal right away.
-Dave

From: Albert Otten <aodiversen@...>
To: TekScopes@groups.io
Sent: Thursday, October 25, 2018 12:44 PM
Subject: Re: [TekScopes] Type G plugin versions

According to the later manual Type G switched from UHF (131-012) to BNC (131-277) at S/N 9480. No idea in which year that was.
Albert

On Thu, Oct 25, 2018 at 08:17 PM, Dave Wise wrote:


I don't know the G serial number at which Tek switched from UHF to BNC*, but
the 1962 catalog shows UHF while 1963 is BNC**.  I think I have a newer manual
at home, I'll try to remember to look.

There was a mod kit for converting instruments in the field.  I have at least
one modded scope and plugin.  Yours too, most likely, as Tek would not have
sold instruments with such an obvious bodge.

Dave Wise

* For what it's worth, the 535A mainframe switched at 31260.
** Some old models were not updated.

Re: Tektronix 067-0625-00 Peak to Peak Detector Battery

Kerry Burns
 

Hello Craig

I've recently had to replace the original 1.35v mercury batteries in my 067-0625-00. I used 1.5v alkaline A1PX-BP1 batteries. Readily available and they are an exact fit - but you do need to have the battery supplier spot weld tags on to them for soldering. I got mine from my local 'Battery World' store, but you can get them from various online suppliers, such as 'Battery Direct' (https://www.batteriesdirect.com.au/shop/product/12224/a1px-bp1.html).

I've put two photos of my device with the new batteries ( both wrapped in black tape to reduce the chance of shorting) in the album 'Tektronix 067-0625-00 Peak to Peak Detector Battery'. I also had to replace the 50ohm input resistor in mine as a previous owner had broken this trying to remove the RF input section (contrary to the instructions in the manual).

Mine seems to work OK now, but I haven't yet checked it right out to 500 MHz.

Kerry

Re: Tektronix 067-0625-00 Peak to Peak Detector Battery

Craig Sawyers <c.sawyers@...>
 

That is really neat! Apparently available in Australia and NZ. But so far no luck finding in the UK or
Europe.

I'll try out my solution and report back what the result is.

Craig

Hello Craig

I've recently had to replace the original 1.35v mercury batteries in my 067-0625-00. I used 1.5v
alkaline
A1PX-BP1 batteries. Readily available and they are an exact fit - but you do need to have the
battery
supplier spot weld tags on to them for soldering. I got mine from my local 'Battery World' store,
but
you can get them from various online suppliers, such as 'Battery Direct'
(https://www.batteriesdirect.com.au/shop/product/12224/a1px-bp1.html).

I've put two photos of my device with the new batteries ( both wrapped in black tape to reduce the
chance of shorting) in the album 'Tektronix 067-0625-00 Peak to Peak Detector Battery'. I also
had to
replace the 50ohm input resistor in mine as a previous owner had broken this trying to remove the RF
input section (contrary to the instructions in the manual).

Mine seems to work OK now, but I haven't yet checked it right out to 500 MHz.

Kerry

Re: Tektronix 067-0625-00 Peak to Peak Detector Battery

Craig Sawyers <c.sawyers@...>
 

OK - the correct physical size is 1/3 AA. Although tagged batteries of that size are available, they
all seem to be rechargeable 1.2V.

But, the physically smaller 1/3 N (11.6mm dia, 10.8mm long) at 3V and solder tags is Varta
https://uk.farnell.com/varta/6131201501/battery-lithium-cr1-3n-170mah/dp/1781983

At 170mAh that should give about three years life at 7.5uA drawn. That is about half that of the
original battery, which should have given 7-8 years' service (although Tek suggested that they be
replaced yearly).

Craig

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Craig Cramb
Sent: 26 October 2018 03:52
To: TekScopes@groups.io
Subject: [TekScopes] Tektronix 067-0625-00 Peak to Peak Detector Battery

Anyone had to locate replacement batteries for this unit. Only marking on the battery is 1A.
Original Tektronix description is: 1.5V, 650MAH, Alkaline-Manganese Dioxide Tektronix 067-0625-00
Peak to Peak Detector Battery Pictures on link with dimensions required.

https://groups.io/g/TekScopes/album?id=76872

Re: My 2465B has arrived + A5 Board leaky caps cleanup

BryanByTheSea
 

That's a excellent tip for removing SMD caps, thanks for sharing.

Re: My 2465B has arrived + A5 Board leaky caps cleanup

Roger Evans
 

Alex,
There is a vast amount of information around about the A5 corrosion problem. The corrosion usually causes two 10k precision resistors to change their value. These set the voltage reference for the DAC that controls most of the operating points for the scope, including trigger levels (that causes the Test 5 failre) and also the brightness levels of trace and readout. There is a high probability that the screen will be OK after you replace the damaged components. Before I did my A5 repair I also had nothing visible on screen, I adjusted the Grid Bias pot before repairing the A5 board as a confidece measure to see that the rest of the scope was OK.
Roger