Date   

Re: TEK514 needs new 5V4G tube

Steve Hendrix
 

At 2020-01-26 09:01 PM, Dennis Tillman W7PF wrote:


Is there any reason you can't buy a 5V4G? There are 123 of them on eBay at
the moment. Prices start at $12 for them and go up.
I can test it for you to confirm its good if want to send it to me.
Odd, I already looked. Out of the first hundred or so hits, I found only two, and both were way more expensive than that. I'll have another look, and try some different search terms so i don't get 4WD nuts etc. Thanks for the pointer.

Steve Hendrix


Re: Where have all the Schematics Gone?

Leo Bodnar
 

I am sure that 11800 series was COCOM / export controlled product and so was its technical documentation.

Maybe still is... When things get onto export control list they tend to stay there for a very long time: pulse generators with 500ps (or shorter) risetime and amplitude of 6V or more are still considered a strategic export and dual use technology and need export licence.
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/856510/UK_strategic_export_control_lists_20191231.pdf

Leo


Re: Where have all the Schematics Gone?

G Hopper
 

Quite possibly my best typo ever :-)

On Sun, Jan 26, 2020 at 10:01 PM Carsten Bormann <cabocabo@gmail.com> wrote:

On 2020-01-27, at 05:24, G Hopper <kb7wsd@gmail.com> wrote:

I think if you were to tell this story to a Boeing engineer, he might
call
it the McDonald Douglas disease.
This.

(Although they probably will call it McDonnell Douglas disease.
Somehow, McDonald’s does figure in, though :-)

Grüße, Carsten





Re: Where have all the Schematics Gone?

Brian Cockburn
 

Tam,

I'm sure that the US government put subtle or un-subtle pressure on US carriers to buy US made aircraft, just as happened in the EU. It is natural. And as a European it always delights me when the EU does similar things to the US and the US whines about it. (Not that I'm saying that you are whining.)

Cheers, Brian.


Re: Where have all the Schematics Gone?

Tam Hanna
 

Hello,

now, I will lean myself out of the window a bit and go OT. My ex-wife is a Mosaic, and was in Government in Austria at the time. So I know a bit, plus I am an aircraft buff.


What really did McDonnell in was the EU. SAS, Austrian Airlines, etc all were strong users of the DC9 and MD8x aircraft.

When the EU came in and the Airbus, governments were very motivated to push the countries national airlines to use these aircraft. In the case of Austria, the company really did not want the new A320 (pilots hated them, called them Atari Aeroplane initially) and wanted to stick with McDonnel. But at the time, most airlines were government owned - and who pays the piper decides which tune is to be farted out.


Tam

--
With best regards
Tam HANNA

Enjoy electronics? Join 15k7 other followers by visiting the Crazy Electronics Lab at https://www.instagram.com/tam.hanna/


Re: Where have all the Schematics Gone?

Carsten Bormann
 

On 2020-01-27, at 05:24, G Hopper <kb7wsd@gmail.com> wrote:

I think if you were to tell this story to a Boeing engineer, he might call
it the McDonald Douglas disease.
This.

(Although they probably will call it McDonnell Douglas disease.
Somehow, McDonald’s does figure in, though :-)

Grüße, Carsten


Re: 2430a carrying handle and face cover

Terry Gains
 

Thanks Craig, Will do.

On Mon, 27 Jan 2020 at 17:08, Craig Cramb <electronixtoolbox@gmail.com>
wrote:

I also need to buy a 2430a carrying handle and face cover.

I have lots of the 2430/2430A scope parts. contact me offline if
interested.
electronixtoolbox at gmail dot com

Craig
On Jan 26, 2020, at 8:04 PM, Terry Gains <terry.waihi@gmail.com> wrote:

I also need to buy a 2430a carrying handle and face cover.


--
Kind regards,
Terry


Re: TEK514 needs new 5V4G tube

Chuck Harris <cfharris@...>
 

Electrolytic caps get into a condition where they
become lower voltage versions of themselves.

An ohmmeter tests at 1.5V in most cases, and 9V in
VOM's. Using one to test a 400V capacitor is less
than worthless.

-Chuck Harris

Steve Hendrix wrote:

Okay, it's a "valve" for our limey friends!

Today I was able to do some more troubleshooting with my dad and my sons, on Dad's TEK514. I took along my thermal camera to help track down the short that was blowing the inlet fuse. Turned out i didn't need it, but it helped confirm. One rectifier tube right next to that monster power transformer started getting extra hot within seconds of power-on, and then started arcing and making a nice arc lamp. I've done a bit of searching and it seems the audiophiles like these tubes; the best I could find was AU$55 for a pair on eBay. Dunno how much shipping would be from down under. Fairly simple fix, to swap out a tube - if that's the only problem. But we checked all the electrolytic caps with an ohmmeter and none seemed to be shorted nor open. Looking for any thoughts on a good source for the tube, and/or whether it's a worthwhile fix.

Steve Hendrix




Re: Guernsey Island 2445

Chuck Harris <cfharris@...>
 

More than crazy, it is insane. But if that is what they did, that
is what they did.

-Chuck Harris

Mlynch001 wrote:


There have been a few times when Håkan looked up the cross references
in the modification summaries, and the last 5 digits were not synced,
I just bought a Guernsey manufactured 465 s/n 103496. I will need to crack it open and see what I have. Hope it is a "Late" series (but probably not). Seems crazy that they would not sync their serial numbers across all the production sites, since so many parts of these instruments are Serial number sensitive?


Re: Where have all the Schematics Gone?

G Hopper
 

A great analysis. Succinct and well written.

Sadly, it seems to me that a lot of companies are run by the MBAs and CPAs
that missed that day in business classes. I really enjoyed reading Dennis'
analysis and it prompted my thought that we've seen examples in several
different industries that it doesn't stop there.

It gets even worse for them at the end:
"This creates more competition at the low end of the marketplace where the
profit margin has eroded so deeply that Tek is no longer competitive"

More or less rehashing what Dennis said in order to frame up my
observation: When a buyer no longer sees an instrument as a very safe long
term investment (that continues to have value either being sold as surplus
(or given to employees) or in secondary or tertiary uses as one decides to
buy more or newer equipment) then those buyers start looking carefully at
life-cycle return (which I think is more than simply TCO) and buy gear that
is just good enough for the job and can be rapidly depreciated and
discarded (the true consumption model), so spending a premium for the
higher end gear (even for a lower end use) is a poor choice.

This creates the niche for the entrants at that low end who can produce a
'good enough' product to survive. And once they survive long enough and
become a reasonable choice for the 'cheap' products, they also gain enough
experience to start moving up little by little. Because they can operate
on such tight margins so effectively, they have enough 'agility' to grow
their product line and sophistication. For this to work, their products
don't even need to be great, they just need to be good enough and meet a
value expectation.

Soon they're taking away little bits of market share (in higher, more
sophisticated market segments) from the well known manufacturers, and
because their operation(s) can do this and remain lean, they can afford to
deeply undercut the competition in order to get people to try out their
products (because they're so much less expensive, the risk is close to zero
for the buyer), and many discover that they don't need Tek level products
even for more rigorous uses because the 'Chinese competition's' products
are good enough at that higher level and Tek, HP, etc. loose another sale.
And this happens over and over again. Truly death by a thousand invoice
paper cuts.

I think if you were to tell this story to a Boeing engineer, he might call
it the McDonald Douglas disease. The same shortsightedness has destroyed a
lot of businesses and all for the sake of propping up share prices and
pleasing stock analysts. As Dennis' explanation pointed out, blind pursuit
of revenue is the road to doom. Hopefully some day more business leaders
will learn that.

Thanks again for sharing your thoughts Dennis!

Grant
KB7WSD

On Sun, Jan 26, 2020 at 6:21 PM Mlynch001 <mlynch002@gmail.com> wrote:

Dennis,

You hit the nail on the head!

--
Michael Lynch
Dardanelle, AR




Re: 2430a carrying handle and face cover

Craig Cramb
 

I also need to buy a 2430a carrying handle and face cover.

I have lots of the 2430/2430A scope parts. contact me offline if interested.
electronixtoolbox at gmail dot com

Craig

On Jan 26, 2020, at 8:04 PM, Terry Gains <terry.waihi@gmail.com> wrote:

I also need to buy a 2430a carrying handle and face cover.


A piece of gear I would like to move on

Eric
 

Does anyone have an interest in a Tektronix CMD80? It is not a scope but it is tek branded. Mine came broken but mostly optioned up. I think it has 75% of the options installed. I can take pictures if anyone would like? It has been repaired.


Re: Guernsey Island 2445

Mlynch001
 

There have been a few times when Håkan looked up the cross references
in the modification summaries, and the last 5 digits were not synced,
I just bought a Guernsey manufactured 465 s/n 103496. I will need to crack it open and see what I have. Hope it is a "Late" series (but probably not). Seems crazy that they would not sync their serial numbers across all the production sites, since so many parts of these instruments are Serial number sensitive?

--
Michael Lynch
Dardanelle, AR


Re: Where have all the Schematics Gone?

Mlynch001
 

Dennis,

You hit the nail on the head!

--
Michael Lynch
Dardanelle, AR


Re: Type O plugin with Power Supply

Glenn Little
 

Link to picture.
Can take more if interested.

https://groups.io/g/TekScopes/photo/239601/0?p=Created,,,20,2,0,0

Glenn

On 1/26/2020 9:03 PM, Dennis Tillman W7PF wrote:
Groups.io strips out anything that isn't simple text. The photo didn't make it in your message.
Easiest thing to do is put your picture in the photos section of TekScopes, copy the link and send your post again including the URL for the photo.
Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Glenn Little
Sent: Sunday, January 26, 2020 4:39 PM
To: TekScopes@groups.io
Subject: [TekScopes] Type O plugin with Power Supply

Many years ago I bought this from Deane Kidd.
It has been in my back room since.
The plugin is serial 000096.
Serial 000098 sold for $100.00 as a parts unit.
The power supply has no type number on it.
I suspect that is may be a prototype.
The power supply is missing at least two tubes and one transistor and has no cover.
A picture is attached.
I would like to get $100.00 plus shipping for the plugin and power supply.
Is anyone interested?

Glenn

--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@arrl.net AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class of the Amateur that holds the license"





--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@arrl.net AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"


Re: 2430a carrying handle and face cover

Terry Gains
 

I also need to buy a 2430a carrying handle and face cover.

This for a 2430a with Tekmate restoration. The carrying handle and face cover are needed for portability and completion.

Kind regards,
Terry G


Re: Type O plugin with Power Supply

 

Groups.io strips out anything that isn't simple text. The photo didn't make it in your message.
Easiest thing to do is put your picture in the photos section of TekScopes, copy the link and send your post again including the URL for the photo.
Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Glenn Little
Sent: Sunday, January 26, 2020 4:39 PM
To: TekScopes@groups.io
Subject: [TekScopes] Type O plugin with Power Supply

Many years ago I bought this from Deane Kidd.
It has been in my back room since.
The plugin is serial 000096.
Serial 000098 sold for $100.00 as a parts unit.
The power supply has no type number on it.
I suspect that is may be a prototype.
The power supply is missing at least two tubes and one transistor and has no cover.
A picture is attached.
I would like to get $100.00 plus shipping for the plugin and power supply.
Is anyone interested?

Glenn

--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@arrl.net AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class of the Amateur that holds the license"






--
Dennis Tillman W7PF
TekScopes Moderator


Re: TEK514 needs new 5V4G tube

 

Hi Steve,
Is there any reason you can't buy a 5V4G? There are 123 of them on eBay at the moment. Prices start at $12 for them and go up.
I can test it for you to confirm its good if want to send it to me.
Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Richard Solomon
Sent: Sunday, January 26, 2020 4:33 PM
To: TekScopes <TekScopes@groups.io>
Subject: Re: [TekScopes] TEK514 needs new 5V4G tube

This may be blasphemy, but you
could replace the rectifier tube with
a couple of diodes.

You may need a small resistance to
adjust for the lower voltage drop in
the diodes.

73, Dick, W1KSZ

On Sun, Jan 26, 2020 at 4:34 PM Roy Morgan <k1lky68@gmail.com> wrote:

Steve,

I would strongly suspect a shorted filter cap in that supply.

If you have an external variable B+ supply, bring the voltage up VERY
SLOWLY at the tube cathode while monitoring the current. (Scope power
off)

Roy Morgan
K1LKY Western Mass

On Jan 26, 2020, at 6:10 PM, Steve Hendrix
<SteveHx@hxengineering.com>
wrote:

Okay, it's a "valve" for our limey friends!

... One rectifier tube right next to that monster power transformer
started getting extra hot within seconds of power-on, and then started
arcing and making a nice arc lamp. ...







--
Dennis Tillman W7PF
TekScopes Moderator


Re: TEK514 needs new 5V4G tube

Harvey White
 

Considering the cost for a 5V, which IIRC is a rectifier with an indrectly heated cathode (*many* years ago).  You might want to take some silicon rectifiers and put them in, substituting for the 5V4.  You may get a bit hotter B+ out of the combo, and I've heard that some people put some fairly large wattage resistors in series to limit the surge, but I'd certainly consider that fix for AU $45.00.  (which even at the last rate I remember is USD22.00 and that's a big bunch).  I suspect that 1N4006 might be a good candidate.

If you had an octal tube base you could build it into that.

Harvey

On 1/26/2020 6:10 PM, Steve Hendrix wrote:
Okay, it's a "valve" for our limey friends!

Today I was able to do some more troubleshooting with my dad and my sons, on Dad's TEK514. I took along my thermal camera to help track down the short that was blowing the inlet fuse. Turned out i didn't need it, but it helped confirm. One rectifier tube right next to that monster power transformer started getting extra hot within seconds of power-on, and then started arcing and making a nice arc lamp. I've done a bit of searching and it seems the audiophiles like these tubes; the best I could find was AU$55 for a pair on eBay. Dunno how much shipping would be from down under. Fairly simple fix, to swap out a tube - if that's the only problem. But we checked all the electrolytic caps with an ohmmeter and none seemed to be shorted nor open. Looking for any thoughts on a good source for the tube, and/or whether it's a worthwhile fix.

Steve Hendrix



Type O plugin with Power Supply

Glenn Little
 

Many years ago I bought this from Deane Kidd.
It has been in my back room since.
The plugin is serial 000096.
Serial 000098 sold for $100.00 as a parts unit.
The power supply has no type number on it.
I suspect that is may be a prototype.
The power supply is missing at least two tubes and one transistor and has no cover.
A picture is attached.
I would like to get $100.00 plus shipping for the plugin and power supply.
Is anyone interested?

Glenn

--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@arrl.net AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"

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