Date   
Re: vintageTEK museum releases Replaceable Parts Registry (RPR)

 

Would be very grateful if you could find the time to scan the RPR for Diodes (152).

PS it's not possible (AFAICT) to navigate to the RPR page from the home page.

Thanks
David

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of walter shawlee
Sent: 13 October 2018 17:05
To: TekScopes@groups.io
Subject: Re: [TekScopes] vintageTEK museum releases Replaceable Parts Registry (RPR)

Thanks so much for another great RPR scan, the 311 set is very handy to
have!
I can hardly wait for that 366 scan, it will answer a lot of questions.
the page link is here: http://w140.com/tekwiki/wiki/RPR

I notice it doesn't seem to tie to the general main page at all.

thank you for all the hard work!
-walter

--
Walter Shawlee 2
Sphere Research Corp. 3394 Sunnyside Rd.
West Kelowna, BC, V1Z 2V4 CANADA
Phone: +1 (250-769-1834 -:- http://www.sphere.bc.ca
We're all in one boat, no matter how it looks to you. (WS2)
All you need is love. (John Lennon)
But, that doesn't mean other things don't come in handy. (WS2)

Replacement for 152-0061-00 diode

 

The leads on one of these diodes in the inverter circuit of the 7854 I'm
working on have completely corroded away (copper covered iron I think).

The parts list says this is an FDH2161, and that it has a 175V PIV rated for
100mA so a 1N4148 won't hack it. I think it's a fast or ultra-fast diode.

Thanks
David

Re: Replacement for 152-0061-00 diode

Craig Sawyers
 

David - that supply has everything apart from dandruff!

Craig

====================
Replacement for 152-0061-00 diode

The leads on one of these diodes in the inverter circuit of the 7854 I'm
working on have completely corroded away (copper covered iron I think).

The parts list says this is an FDH2161, and that it has a 175V PIV rated for
100mA so a 1N4148 won't hack it. I think it's a fast or ultra-fast diode.

Thanks
David
===================

Re: Replacement for 152-0061-00 diode

Craig Sawyers
 

It isn't stupidly fast - 700ns for 20mA to -1mA transition


=======================================
The parts list says this is an FDH2161, and that it has a 175V PIV rated for
100mA so a 1N4148 won't hack it. I think it's a fast or ultra-fast diode.

Thanks
David

Re: No start 7854 Power supply

Harvey White
 

On Tue, 15 Jan 2019 04:46:55 -0000, you wrote:

Thanks Harvey,

I think I have probably located the problem with the PSU not starting - one
of the leads to T30 which is part of the oscillator base drive circuit had
corroded. A bit of current through was left of the copper soon finished it
off as the supply was running for the first minute or so.
That certainly won't help. Transistors seem to be rather picky about
turning on when there's no base drive.

Hope this fixes it.

Harvey


Dave

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Harvey
White
Sent: 14 January 2019 23:37
To: TekScopes@groups.io
Subject: Re: [TekScopes] No start 7854 Power supply

On Mon, 14 Jan 2019 21:08:36 -0000, you wrote:

Hi George, perhaps you could explain to me why the ohmmeter reads 180k when
its removed from the board, but megohms when in circuit?

It's not the only resistor I saw with this odd behaviour.
Is there any voltage across this resistor? I've seen that really bug
ohmmeters...




And darn it why can't I buy a 180k ceramic or carbon composition 1W
resistor - Ohmite OY 2W resistors are too large and not readily available in
UK - drat it.



If you can't find one, I think I could.

Harvey


I have some value flexibility I think as the 7104 supply used a 300k part!

Dave

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of george
edmonds via Groups.Io
Sent: 14 January 2019 17:49
To: TekScopes@groups.io
Subject: Re: [TekScopes] No start 7854 Power supply

Hi Dave
R10 is the AC start up series resistor, replace it, it is going voltage OC.
Better replace is wit two resistors in series to obtain a high working
voltage, or you can find on eBay 500 V working resistors .
73 George G6HIG

On Monday, January 14, 2019 5:34 PM, David C. Partridge
<@perdrix> wrote:


Hah! Not for long - it stopped running after about two or three minutes.

Both the new inverter transistors still check OK in circuit.

Interestingly the start circuit is *not* firing any more. The voltage
across C42 is around .45V so something is pulling it down or not feeding it
volts. Strangely when I measured the resistance of R10 in circuit to see
if
that had gone open it measured in megohms, but when I removed it, it read
180k which is spot-on. After reinstalling, it reads in the megohms
again?!?!?

Any ideas?

Thanks
David
-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of David
C.
Partridge
Sent: 14 January 2019 14:26
To: TekScopes@groups.io
Subject: Re: [TekScopes] No start 7854 Power supply

Good news! The inverter is now running OK, but the supply is ticking at
about 5Hz or so! I suspect over-voltage shutdown circuit.

Dave

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of David
C.
Partridge
Sent: 11 January 2019 16:26
To: TekScopes@groups.io
Subject: Re: [TekScopes] No start 7854 Power supply

Both Q34 and Q40 (151-0632-00) were totally deceased - one completely fell
apart once I unsoldered the leads, and the other lost a lead and the case
is
cracked! Clearly both suffered massive over-current and burnt out.

So, before I solder in some new MJE13007s to replace them what is likely to
have caused that to happen - I can see the replacements blowing up too
unless the root cause is fixed!

Thanks
David
















Re: Replacement for 152-0061-00 diode

george edmonds
 

Hi Dave
Try a uf4004.
George

On Tuesday, January 15, 2019 1:43 PM, Craig Sawyers <c.sawyers@...> wrote:


It isn't stupidly fast - 700ns for 20mA to -1mA transition


=======================================
The parts list says this is an FDH2161, and that it has a 175V PIV rated for
100mA  so a 1N4148 won't hack it.  I think it's a fast or ultra-fast diode.

Thanks
David

Re: Looking for replacements for primary buffer caps for 7854, 7104 etc. Power Supplies

 

I have insider contacts at Vishay, and can get anything anyone needs, direct, at well below distributor price.
Of course MOQ's and lead-times are required, but there is absolutely no obstacle to obtaining any of their current production components at all.

For any further details, contact me off-line

Menahem

Re: 2467B Trace flicker

thespin@...
 

DIA line is very noisy from the S/H circuit. Seems to be correlated with display brightness, but it's hard to see. I reckon the input to the opamp is similarly noisy, but it's hard to see with the gain of my scope. Guess I need a 1A7? Not sure if I should blame the mux, the sampling caps, the opamp, or the resistors. Any thoughts?

On Mon, Jan 14, 2019 at 01:00 PM, Raymond Domp Frank wrote:


On Mon, Jan 14, 2019 at 06:57 PM, Siggi wrote:



And yeah, this is my 7th Tek scope. I can stop whenever I want I tells ya!

Yeah, me too. Whenever I want.
I stop every single day!

Raymond

Re: No start 7854 Power supply

 

OK that was part of the problem and in fact both the diodes CR36 and CR37
were corroded away as well as the wire - I've temporarily stolen some from a
7904 supply. That is now fixed up.

However the start circuit still wasn't working which I found was because of
a low impedance path between collector and emitter of Q40 which shorted out
the start-up capacitor to ground via CR49. I removed Q40 at this point to
check (it was OK) and have left it out of circuit for now. I also
disconnected the primary winding of T110 at the "earthy end" (where it
connects to the single turn through T35 and then via the bottom winding of
T30 to the emitter of Q40).

I still have a short circuit between the collector pad for Q40 (connects to
TP34 labelled TANK) and the right hand end of C37 which is the main tank
capacitor (junction with CR38 diode and top of T110 primary). The
capacitor is *not* shorted! I'm totally puzzled what could cause this! I
even disconnected the winding screen of T110 in case of a short from that to
the primary.

Your thoughts are most welcome!

Thanks
David

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of David C.
Partridge
Sent: 15 January 2019 04:47
To: TekScopes@groups.io
Subject: Re: [TekScopes] No start 7854 Power supply

Thanks Harvey,

I think I have probably located the problem with the PSU not starting - one
of the leads to T30 which is part of the oscillator base drive circuit had
corroded. A bit of current through was left of the copper soon finished it
off as the supply was running for the first minute or so.

Dave

Re: Replacement for 152-0061-00 diode

 

<GRIN> It had that too! At least it looked like it when I opened it up.
Luckily most of that cleaned up pretty easily!

D.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Craig
Sawyers
Sent: 15 January 2019 13:09
To: TekScopes@groups.io
Subject: Re: [TekScopes] Replacement for 152-0061-00 diode

David - that supply has everything apart from dandruff!

Craig

Re: 2467B Trace flicker

 

The DIA line is the control processors "estimate" of the DI (Display Intensity) command from the front panel.  DI can be measured on either side of R2702.  If R2702 signal (DI) is not noisy and DIA is noisy then the problem is in the MUX/DEMUX circuitry or the sample and hold output.   If DI is noisy the problem is in the front panel pot or its power supply.  Its hard for the MUX/DEMUX to fail on just one signal, DIA unless it is a specific failure of a specific part (U2501, U2530, U2630, or the supporting passive components of these three devices). 
Its possible to observe the signal on pin 5 of U2630 if you have a high impedance test probe.  That signal should be 1/2 of DIA.

On ‎Tuesday‎, ‎January‎ ‎15‎, ‎2019‎ ‎10‎:‎51‎:‎35‎ ‎AM‎ ‎CST, thespin@... <thespin@...> wrote:

DIA line is very noisy from the S/H circuit. Seems to be correlated with display brightness, but it's hard to see. I reckon the input to the opamp is similarly noisy, but it's hard to see with the gain of my scope. Guess I need a 1A7? Not sure if I should blame the mux, the sampling caps, the opamp, or the resistors. Any thoughts?

On Mon, Jan 14, 2019 at 01:00 PM, Raymond Domp Frank wrote:


On Mon, Jan 14, 2019 at 06:57 PM, Siggi wrote:



And yeah, this is my 7th Tek scope. I can stop whenever I want I tells ya!

Yeah, me too. Whenever I want.
I stop every single day!

Raymond

Re: vintageTEK museum releases Replaceable Parts Registry (RPR)

Dave Brown
 

On Tekwiki it is on the Reference Material page so two clicks. On vintageTEK.org it is only in the news blog for the RPR.

Re: Some 2430A questions

Brendan
 

On Thu, Jan 10, 2019 at 01:15 PM, Szabolcs Szigeti wrote:


Hi,

If the capacitance value and voltage rating maches then electronically it
should be ok. The pin spacing should also match for the sake of ease of
replacement and nice result. And of course, it must be X2 type for safety.

Szabolcs

2019. jan. 10., Csü 17:23 dátummal lop pol via Groups.Io
<the_infinite_penguin=yahoo.com@groups.io> ezt írta:



After using the 2430A scope for a few weeks I decided I like it
quite a
bit.
I'm ordering the NVRAM and caps for the power supply today. There are
some
.068uf X2 caps on the power supply board. What is a good replacement for
those?

Brendan
I am looking at these on Mouser.
https://www.mouser.com/ProductDetail/Vishay-Roederstein/F1772SX236831KFIB0?qs=sGAEpiMZZMu3dWSqd4Tl0E8WHS8VB0qi%252bns5xWbnmgfGxT%2fNs1wefQ%3d%3d
Do they look like a good replacement?



Ok. I replaced all caps on both power supplies and the NVRAM in one scope re-calibrated and all is working correctly. The second scope has a Keeper II battery instead of Dallas NVRAM and amazingly the battery is 3.7V, I have no idea how that is even possible. At least my heart wont stop every time I turn on the scopes now. All the Nichicon PL series capacitors were in spec (changed anyway) but the silver all metal caps were all out of spec mostly high in capacitance most of them close to double. The RIFA X2 capacitors definitely needed replacement they were cracked and discolored. Now I'm on the lookout for a TDS320 main board.

Brendan

Re: Replacement for 152-0061-00 diode

Renée
 

you might also try a schottky diode....worked in my 422 pwr sply...do not remember which one it was what I had available
 1n493x  fast recovery may work too.
Renée

On 2019-01-15 7:12 a.m., george edmonds via Groups.Io wrote:
Hi Dave
Try a uf4004.
George

On Tuesday, January 15, 2019 1:43 PM, Craig Sawyers <c.sawyers@...> wrote:

It isn't stupidly fast - 700ns for 20mA to -1mA transition


=======================================
The parts list says this is an FDH2161, and that it has a 175V PIV rated for
100mA  so a 1N4148 won't hack it.  I think it's a fast or ultra-fast diode.

Thanks
David









Re: No start 7854 Power supply

 

Hi Dave,
Rolynn made a good suggestion. Incandescent photo light bulbs should still be available since they have unusual color temperature spectra that can't be easily duplicated by other high efficiency lamp technologies.

If you want, I can mail you a few incandescent bulbs from the US. We still have them but they're gradually being phased out.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of David
C. Partridge
Sent: Friday, January 11, 2019 2:17 PM

One problem I have is that while I'm well aware of the light bulb trick I
have no incandescent light bulbs (apart from one 200W one) that I could
use, and I have no clue where I can buy any these days (since they've
been banned by the EU).

Dave

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of
george edmonds via Groups.Io
Sent: 11 January 2019 20:50
To: TekScopes@groups.io
Subject: Re: [TekScopes] No start 7854 Power supply

Hi David
Not an unusual problem with probe slips, I have seen more SMPSU's blown
up/destroyed by the individuals trying to repair them than by component
failure.
I have a HP SA supply in my workshop to repair that was blown up by use
of a class one scope to look at the switcher waveforms.
73 George G6HIG

On Friday, January 11, 2019 8:33 PM, David C. Partridge
<@perdrix> wrote:


Hi George - I'm aware of the light bulb current limiter.

Oh yes! I'm well alive to the possibilities that can arise when working
on direct conversion SMPS! 400V+ DC backed by 400uF or so can ruin your
day!

Interestingly, when looking at the remains of Q40, I found evidence of a
serious probe slip (partly vaporised leads) causing a short from
Collector to Emitter. I suspect that this could well have wreaked havoc
and taken the other xistor with it.

Dave



--
Dennis Tillman W7PF
TekScopes Moderator

Re: No start 7854 Power supply

Ted Rook
 

In the USA ebay has incandescents, it seems ebay UK also can help out

https://www.ebay.co.uk/itm/100w-Watt-BC-B22-Bayonet-Cap-Push-In-Clear-Incandescent-Li
ght-Bulb-Lamp-x-4/231621469955?epid=909622304&hash=item35edb72703:g:DY8AAOxyz
GlQ7W4G:rk:13:pf:0

Ted

On 15 Jan 2019 at 15:58, Dennis Tillman W7PF wrote:

Hi Dave,
Rolynn made a good suggestion. Incandescent photo light bulbs should still be available
since they have unusual color temperature spectra that can't be easily duplicated by other
high efficiency lamp technologies.

If you want, I can mail you a few incandescent bulbs from the US. We still have them but
they're gradually being phased out.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of David
C. Partridge
Sent: Friday, January 11, 2019 2:17 PM

One problem I have is that while I'm well aware of the light bulb trick I
have no incandescent light bulbs (apart from one 200W one) that I could
use, and I have no clue where I can buy any these days (since they've
been banned by the EU).

Re: [Novice] Double checking safety, avoidinginjury/damage, best practices

Roy Thistle
 

Yup... always did... always do,,, but, that is a personal choice, to do so from my own shop. And, that's what I thought many of us do... and, what many of us have done. We do work alone, and we did work alone. Yet, if I was to hurt myself...you know, however... while working alone.. and then try to claim on my insurance...I'm pretty sure I'd never see any significant payment. It's tricky to generalize from that scenario; but, I think what it turns on is what the word reasonable means. For the folks and institutions that control the money, the employment, and the research, and repair facilities... they go with "it isn't reasonable to work alone..". I think that is because they can't get insurance, if they let people do it. For us who routinely work alone... is it reasonable for the people who depend on us, or love us, to accept that it was reasonable for us to work alone...if we are suddenly gone because of it. Finally, I know lots of us do it... and most of us are still here, despite learning the hard way about H.V.... but is it reasonable to think that someone new to H.V. should feel safe to do what we do, and in the manner which we sometimes do it. For my part, I always say...if any one asks... don't work alone.

Re: No start 7854 Power supply

 

Thanks Dennis,

I found some 100w "Traffic Light" bulbs (same as Rough Service but probably longer life).

Dave

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Dennis Tillman W7PF
Sent: 15 January 2019 23:59
To: TekScopes@groups.io
Subject: Re: [TekScopes] No start 7854 Power supply

Hi Dave,
Rolynn made a good suggestion. Incandescent photo light bulbs should still be available since they have unusual color temperature spectra that can't be easily duplicated by other high efficiency lamp technologies.

If you want, I can mail you a few incandescent bulbs from the US. We still have them but they're gradually being phased out.

Dennis Tillman W7PF

Re: 2467B Trace flicker

thespin@...
 

I’m not sure how I missed this earlier, but DI looks noisy. It has lots of fast spikes in comparison to the OSD brightness pot.

On Tue, Jan 15, 2019 at 12:52 PM, machineguy59 wrote:


The DIA line is the control processors "estimate" of the DI (Display
Intensity) command from the front panel.  DI can be measured on either side
of R2702.  If R2702 signal (DI) is not noisy and DIA is noisy then the
problem is in the MUX/DEMUX circuitry or the sample and hold output.   If DI
is noisy the problem is in the front panel pot or its power supply.  Its hard
for the MUX/DEMUX to fail on just one signal, DIA unless it is a specific
failure of a specific part (U2501, U2530, U2630, or the supporting passive
components of these three devices). 
Its possible to observe the signal on pin 5 of U2630 if you have a high
impedance test probe.  That signal should be 1/2 of DIA. 
On ‎Tuesday‎, ‎January‎ ‎15‎, ‎2019‎
‎10‎:‎51‎:‎35‎ ‎AM‎ ‎CST, thespin@...
<thespin@...> wrote:

DIA line is very noisy from the S/H circuit. Seems to be correlated with
display brightness, but it's hard to see. I reckon the input to the opamp is
similarly noisy, but it's hard to see with the gain of my scope. Guess I need
a 1A7? Not sure if I should blame the mux, the sampling caps, the opamp, or
the resistors. Any thoughts?

On Mon, Jan 14, 2019 at 01:00 PM, Raymond Domp Frank wrote:


On Mon, Jan 14, 2019 at 06:57 PM, Siggi wrote:



And yeah, this is my 7th Tek scope. I can stop whenever I want I tells
ya!

Yeah, me too. Whenever I want.
I stop every single day!

Raymond

Re: 2467B Trace flicker

 

Those fast spikes on DI are sampled by the control processor at about a 10 Hz rate and become aliased down to about a 10 Hz signal on DIA.  So it seems to me your culprit is the control pot itself or a power feed (not likely).

On ‎Wednesday‎, ‎January‎ ‎16‎, ‎2019‎ ‎07‎:‎24‎:‎46‎ ‎AM‎ ‎CST, <thespin@...> wrote:

I’m not sure how I missed this earlier, but DI looks noisy. It has lots of fast spikes in comparison to the OSD brightness pot.

On Tue, Jan 15, 2019 at 12:52 PM, machineguy59 wrote:


  The DIA line is the control processors "estimate" of the DI (Display
Intensity) command from the front panel.  DI can be measured on either side
of R2702.  If R2702 signal (DI) is not noisy and DIA is noisy then the
problem is in the MUX/DEMUX circuitry or the sample and hold output.   If DI
is noisy the problem is in the front panel pot or its power supply.  Its hard
for the MUX/DEMUX to fail on just one signal, DIA unless it is a specific
failure of a specific part (U2501, U2530, U2630, or the supporting passive
components of these three devices). 
Its possible to observe the signal on pin 5 of U2630 if you have a high
impedance test probe.  That signal should be 1/2 of DIA. 
    On ‎Tuesday‎, ‎January‎ ‎15‎, ‎2019‎
‎10‎:‎51‎:‎35‎ ‎AM‎ ‎CST, thespin@...
<thespin@...> wrote:

  DIA line is very noisy from the S/H circuit. Seems to be correlated with
display brightness, but it's hard to see. I reckon the input to the opamp is
similarly noisy, but it's hard to see with the gain of my scope. Guess I need
a 1A7? Not sure if I should blame the mux, the sampling caps, the opamp, or
the resistors. Any thoughts?

On Mon, Jan 14, 2019 at 01:00 PM, Raymond Domp Frank wrote:


On Mon, Jan 14, 2019 at 06:57 PM, Siggi wrote:



And yeah, this is my 7th Tek scope. I can stop whenever I want I tells
ya!

Yeah, me too. Whenever I want.
I stop every single day!

Raymond