Cool. Got a postal address/PO box I can send them to? Do you have a private email address, rather than do all this on public forum? Cheers Craig
|
Re: Weird serial number on 7L14
Bruce
Serial number indicates it was Pilot build/ engineering unit there was a thread about these serial numbers but it was years ago.
One of the Tek veterans can probably provide a little? more info.
Interesting piece of history
-DC
manuals@...
toggle quoted message
Show quoted text
On 7/25/2018 2:11 AM, Bruce Lane wrote: (Facedesk!)
Right, I forgot.
OK -- I've posted the two photos in question to the 'kc7gr' album in
the group's photo storage area.
Thanks, Dave.
On 24-Jul-18 00:04, Artekmedia wrote:
Bruce
The list doesn't accept attachments. You will have to upload it to the
photos section or host it somewhere and then post a link
Dave
manuals@...
On 7/24/2018 1:44 AM, Bruce Lane wrote:
Fellow Tekkies,
????I picked up a 7L14 from an estate sale this last weekend. One of the
things which struck me is the bizarre serial number the thing has -- See
the attached photo.
????My best guess is -- Prototype? Something which was never
officially in
production? I've never seen the middle symbol (small circle with a
vertical slash through it) used on any Tek instrument I've ever owned.
????The other oddity with it is it seems to be missing its red filter
window over the LED display on the input module side (see other photo).
Is this something which can be replaced easily? Perhaps scavenged from,
say, a dead 7A13? They look like they're about the same dimensions.
????Thanks much!
--
Dave
Manuals@...
www.ArtekManuals.com
|
Cool. Got a postal address/PO box I can send them to?
I can probably scrounge up a few HV diodes too, as they suck for the intended use but would be fine to replace annoying vacuum rectifiers made of finest unobtainium.Vmax 24KV 10mA IIRC
www.cwgsy.net/private/mandoline "Error 008472. Horrible bug encountered. $Deity knows what happened."
toggle quoted message
Show quoted text
On Tuesday, 24 July 2018, 11:58:46 GMT+1, Craig Sawyers <c.sawyers@...> wrote: Hi Andre I'm near Oxford UK and would be very pleased to have these. Regards Craig -----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Andre de guerin via
Groups.Io
Sent: 24 July 2018 10:57
To: [email protected]
Subject: Re: [TekScopes] Tek bits
Tiny island near France, called Guernsey.
www.cwgsy.net/private/mandoline "Error 008472. Horrible bug encountered. $Deity knows what
happened."
? ? On Monday, 23 July 2018, 09:04:47 GMT+1, Craig Sawyers <c.sawyers@...> wrote:
? > Hi, in my shed I have a lot of Tek bits including very hard-to-find long pots.have a few flybacks
but not
sure what state they are in.
Anyone have a use and want to pay postage only?
_A Where on planet earth are you?
Craig
|
Re: Homemade tunnel diodes
1N4007's have been used in high voltage discrete NLTLs.
Anritsu use NLTLs in theire VNA samplers:
Even Ceramic capacitors have been tried:
Bruce
toggle quoted message
Show quoted text
On 25 July 2018 at 13:56 Mark Kahrs <mark.kahrs@...> wrote:
I hate to disagree with Jose, but there have been a fair number of papers
on constructing NLTLs --- some even using discrete diodes.
If you'd like to read a review of the patents, may I refer you to this
short paper? I know the author personally.
Patents and Microwave Measurements-Nonlinear Transmission Lines [TCC
Tidbits] <>
<>IEEE Microwave Magazine
<>
Year: 2016, Volume: 17, Issue: 7
<>
Pages: 78 - 81
On Tue, Jul 24, 2018 at 1:00 PM, Craig Sawyers <
c.sawyers@...> wrote:
FWIW non-linear optical methods are used to compress the length of laser
light pulses. Somewhat
analogous to NLTL's, but at 10^14Hz.
Craig
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Ed Breya via Groups.Io
Sent: 24 July 2018 17:32
To: [email protected]
Subject: Re: [TekScopes] Homemade tunnel diodes
Jose said:
"Not many people seem to have made DIY NLTL, let alone samplers based on it."
This is probably true, because NLTLs usually have lots of stages, so can
get very big and
complicated
before you get remarkable compression. For simplicity and effectiveness, a single SRD/varactor of
the
right type, in the right circuit environment, is pretty hard to beat for straight up impulse
generation or
frequency multiplication. A whole bunch of them cascaded can form a NLTL, with its edge-
enhancement and wide BW. As always, it depends on the particulars of the application.
I don't think there's a need for a "modern" replacement for the
SRD/varactor. It's a common RF
part -
not at all an obsolete technology. Nowadays there are alternatives for many applications, by using
fast
active devices capable of appropriate edge speeds.
Ed
|
Hi all,
Quick check of the FET's learned this:
the recommended IRF730 has a input capacity of 620pF
The ordered replacement IPA60R280E6 has a typical input capacity of 950pF.
Time will tell if the transistor driving the FET is able to drive this larger capacity.
For what it's worth: the broken FET I found in my scope when I got is was a IRF710 (400V 200pF...)
To be continued,
Un saludo,
Leo
|
Hi Bert & Vincent,
I'll check capacity specs on the FET's as well -although already ordered :-) - but the good news in relation to the secondary power supply:
The scope has been running fine for several hours now on an external 43VDC :-)
I needed it to run, because it turned out there was a problem with CH1 as well. (trace yes, but no signal showing)
I cleaned the switches using IPA, but it looked like it was one of the small trimpots in the attenuator having a dodgy contact.
As soon as I touched that one the signal came back on CH1.
After all repairs are done I will calibrate it.
I updated the album to show the progress.
Thanks for the feedback, un saludo,
Leo
|
Re: Weird serial number on 7L14
(Facedesk!)
Right, I forgot.
OK -- I've posted the two photos in question to the 'kc7gr' album in
the group's photo storage area.
Thanks, Dave.
toggle quoted message
Show quoted text
On 24-Jul-18 00:04, Artekmedia wrote: Bruce
The list doesn't accept attachments. You will have to upload it to the
photos section or host it somewhere and then post a link
Dave
manuals@...
On 7/24/2018 1:44 AM, Bruce Lane wrote:
Fellow Tekkies,
????I picked up a 7L14 from an estate sale this last weekend. One of the
things which struck me is the bizarre serial number the thing has -- See
the attached photo.
????My best guess is -- Prototype? Something which was never
officially in
production? I've never seen the middle symbol (small circle with a
vertical slash through it) used on any Tek instrument I've ever owned.
????The other oddity with it is it seems to be missing its red filter
window over the LED display on the input module side (see other photo).
Is this something which can be replaced easily? Perhaps scavenged from,
say, a dead 7A13? They look like they're about the same dimensions.
????Thanks much!
--
---
Bruce Lane, ARS KC7GR
kyrrin (at) bluefeathertech dot com
"Quando Omni Flunkus Moritati" (Red Green)
|
Re: Looking for Power Cord for 400-series Scope
Okay - I'll take a look again at that. Perhaps it isn't as much trouble as I was thinking it was.
Thanks,
Barry - N4BUQ
toggle quoted message
Show quoted text
----- Original Message ----- From: "Jim Olson" <v_12eng@...>
To: [email protected]
Sent: Tuesday, July 24, 2018 10:51:07 PM
Subject: Re: [TekScopes] Looking for Power Cord for 400-series Scope
The panel is easy to get off it is held on just two flat head phillips screws
and the fuse cover box it lifts off with the cord attached you just need to
take off the wires the ground is bolted to the frame right at the cord in
and the white neutral wire is soldered to the fuse box and the power is
attached to a blue piece on the main board soldered too.
Jim
|
Re: Replacing Electrolytics in a 465/465B
Here is what I found on digikey after some searching.
5600uf 50v Nichicons same class as yours.
330uf 160v Nichicon
1500uf 100v Nichicon
560uf 63v Nichicon
A couple of them are different class but all are 105 degree 20%. can't find 10% anywhere so 20 will have to do not sure what effect they will have on performance?
Jim
|
Re: Looking for Power Cord for 400-series Scope
The panel is easy to get off it is held on just two flat head phillips screws and the fuse cover box it lifts off with the cord attached you just need to take off the wires the ground is bolted to the frame right at the cord in and the white neutral wire is soldered to the fuse box and the power is attached to a blue piece on the main board soldered too.
Jim
|
Re: Looking for Power Cord for 400-series Scope
Hmmm. I'm not sure if that would work with the existing panel and not sure how much effort it is to replace the entire back panel. Also, shipping would start to climb with the panel and we're virtually on opposite sides of the country. If nothing else turns up, then I might take you up on it.
Truthfully, I wouldn't be terribly concerned about it except that I notice that at a certain, rather slow, sweep speed, there's an AC part that the signals are riding on. If I ground the chassis, that disappears so I'd really like to have that ground connection in the plug.
Thanks,
Barry - N4BUQ
toggle quoted message
Show quoted text
----- Original Message ----- From: "Jim Olson" <v_12eng@...>
To: [email protected]
Sent: Tuesday, July 24, 2018 10:29:11 PM
Subject: Re: [TekScopes] Looking for Power Cord for 400-series Scope
I actually have one that is at an angle but it is only a small plastic knob
it that helps but all the rest are in the large rubber style boot. I can
leave it in the panel if you like that way you don't have to mess around
with the lock.
Jim
|
Re: Looking for Power Cord for 400-series Scope
I actually have one that is at an angle but it is only a small plastic knob it that helps but all the rest are in the large rubber style boot. I can leave it in the panel if you like that way you don't have to mess around with the lock.
Jim
|
Re: Looking for Power Cord for 400-series Scope
That would probably work but I'd have to cut off the boot and I kind of hate to do that as those are hard to find. Perhaps I'll find one of the "plain" style cords.
Thanks,
Barry - N4BUQ
toggle quoted message
Show quoted text
----- Original Message ----- From: "Jim Olson" <v_12eng@...>
To: [email protected]
Sent: Tuesday, July 24, 2018 9:49:19 PM
Subject: Re: [TekScopes] Looking for Power Cord for 400-series Scope
I have some but they are the ones that come out in the 90 degree rubber boot.
Jim
|
Re: Looking for Power Cord for 400-series Scope
I have some but they are the ones that come out in the 90 degree rubber boot.
Jim
|
Looking for Power Cord for 400-series Scope
Anyone know where a replacement power cord can be obtained that matches the original for a 400-series scope (for U.S. power outlets)? Someone cut the ground pin off of my 465B and I'd like to replace it with a cord like the original (the kind that has the "keeper" clip). Mine is the style that comes out of a plain strain relief (not the larger rubber boot like I've seen on some 465B models).
Thanks,
Barry - N4BUQ
|
Re: Tek 495P A54 Memory Board Repair
Sorry on behalf of the group for the "helpless" comment. That was uncalled-for when you don't know who's at the other end of the conversation, or what their abilities/handicaps might be.
That being said... I'm surprised that the problem isn't your DIP switch. Those are very common failure items on these units. If you haven't gone back and double/triple-checked that switch, I'd definitely do so before going any further. Unlike the IC, I do believe it's a good idea to reflexively replace those DIP switches whenever you're working on the boards that include them. Same with the one on the back, if you think you will ever want to use the GPIB port for anything. Although Sergey's tip about cutting the leads on the IC won't be as effective for removing the DIP switches, it's still a valid strategy if you crush the plastic body with pliers and pull it off first. A Dremel tool is also a good way to go.
Working without extenders, it's sometimes helpful to tack-solder a few 'probe wires' onto various device pins to bring the signals out for monitoring. The extenders are nice to have -- and almost mandatory for some procedures -- but unfortunately they're not always available.
-- john, KE5FX
toggle quoted message
Show quoted text
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of
Rick Boswell
Sent: Tuesday, July 24, 2018 4:06 PM
To: [email protected]
Subject: Re: [TekScopes] Tek 495P A54 Memory Board Repair
Now sorry I posted here after the responses received so far. I didn't ask for
advice on how to repair the board, or comments on my helplessness, but
rather, a pointer to someone (knowledgeable) who could troubleshoot and
repair, or supply a replacement board.
|
Re: Replacing Electrolytics in a 465/465B
Hi Jim,
Thanks for the kind remarks. Unfortunately, I don't think there's any room for another snap-in cap on that board.
Here's the list I used. I'm pasting this in with tabs but I have a feeling those will be replaced with spaces so the columns may not align with their headers.
Note that there are two entries for C4429. I chose the taller one (45mm) as its tolerance kept it in the range of the original.
Mouser P/N Capacitance Voltage Diameter Length Temp
C4419 5000uF 25V 647-LGU1V682MELZ 6800uF 35V 22mm 40mm 105C
C4429 1200uF 100V 647-LGU2A122MELZ 1200uF 100V 22mm 40mm 105C
C4429 1200uF 100V 647-LGU2A152MELZ 1500uF 100V 22mm 45mm 105C 5mm taller but higher capacitance that will meet original tolerance
C4439 550uF 100V 647-LGU2C681MELZ 680uF 160V 22mm 40mm 105C
C4521 5500uF 30V 647-LGU1V682MELZ 6800uF 35V 22mm 40mm 105C
C4531 5000uF 25V 647-LGU1V682MELZ 6800uF 35V 22mm 40mm 105C
As you can see, I used 6800uF, 35V for a 5500uF, 30V cap.
I was thinking around $8 shipped in the U.S. for just the board. I'd have to look into the rest of the hardware. I could also supply the caps if there's enough interest. I ordered the #8-32 x 1.5" aluminum standoffs from Mouser as well. Also, I used stainless screws and stainless internal-toothed lock washers on both sides of both boards.
Note the solder lug that's sitting on top of one of the standoffs. I actually made a mistake on the board design. Without looking closely at the schematic, I thought the -8V supply's positive side was grounded but that's not the case (that's the side that's regulated to maintain -8V) and, thus, if you look closely, you can see where I had to remove part of a trace. I hose to run the positive lead soldered to the main board and then directly up against the pad on the small board. I could have done that a bit neater but that would have depended on the post and screws being part of the circuit and I didn't care for that as much. If I make another set of boards there will be solder pads for both sides of the cap for the -8V supply. I plan to also make a cutout to clear the thermal switch which will make it possible to use much shorter standoffs which might look neater.
Thanks,
Barry - N4BUQ
toggle quoted message
Show quoted text
----- Original Message ----- From: "Jim Olson" <v_12eng@...>
To: [email protected]
Sent: Tuesday, July 24, 2018 6:33:03 PM
Subject: Re: [TekScopes] Replacing Electrolytics in a 465/465B
Really neat practical fix very tidy I am doing a 466 which uses six caps so
how would that board work there would have to mount one closest to the
transformer to the main board?
What are you asking for the board and hardware I am in the US in CA.
Where did you get the new electrolytics from having a hard time finding the
correct ratings for the 466 the 5500uf 30v are scarce.
Jim
|
I was moving things around today, and happened to turn the tuning knob on my 190A, and the frequency display didn't rotate.? Turns out the rubber donut was cracked/broken in five places (but still soft!) and had fallen off.? This must be a common failure- is a there a simple, common replacement? If not, I'll have to drag out my box of o-ring and bushing catalogs.
-Dave
|
Re: Homemade tunnel diodes
I hate to disagree with Jose, but there have been a fair number of papers on constructing NLTLs --- some even using discrete diodes. If you'd like to read a review of the patents, may I refer you to this short paper? I know the author personally. Patents and Microwave Measurements-Nonlinear Transmission Lines [TCC Tidbits] <> <>IEEE Microwave Magazine <> Year: 2016, Volume: 17, Issue: 7 <> Pages: 78 - 81 On Tue, Jul 24, 2018 at 1:00 PM, Craig Sawyers < c.sawyers@...> wrote: FWIW non-linear optical methods are used to compress the length of laser
light pulses. Somewhat
analogous to NLTL's, but at 10^14Hz.
Craig
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Ed Breya via Groups.Io
Sent: 24 July 2018 17:32
To: [email protected]
Subject: Re: [TekScopes] Homemade tunnel diodes
Jose said:
"Not many people seem to have made DIY NLTL, let alone samplers based on it."
This is probably true, because NLTLs usually have lots of stages, so can
get very big and
complicated
before you get remarkable compression. For simplicity and effectiveness, a single SRD/varactor of
the
right type, in the right circuit environment, is pretty hard to beat for straight up impulse
generation or
frequency multiplication. A whole bunch of them cascaded can form a NLTL, with its edge-
enhancement and wide BW. As always, it depends on the particulars of the application.
I don't think there's a need for a "modern" replacement for the
SRD/varactor. It's a common RF
part -
not at all an obsolete technology. Nowadays there are alternatives for many applications, by using
fast
active devices capable of appropriate edge speeds.
Ed
|
On Tue, 24 Jul 2018 15:00:00 -0700, you wrote: Here is a pondering question for you all to think on. How many of you have considered replacing (upgrade) the ceramic disc caps to a higher class 2 grade like X5R or X7R to replace all the Z5U ones used as they are the worst of the class 2 and as they deteriorate with age plus are susceptible to temp and frequency changes to capacitance so they might be responsible for the little niggling problems with the scopes over time or after repairs but it is just not right? I haven't seen a problem where I can pin it down to one of them failing. I'm probably not as critical as others might be, though. Harvey I tend to use x5R and X7R for new designs, though.
After all they are old and older technology and in most cases much used. Just a thought to consider.
Jim
|
satbeginner
Bruce Lane