开云体育

I have a sleepy-eye assembly, switch attached to cable, if interested. I got it from the Tek Country Store (Tek salvage and surplus). It appears to be unused.
Photographs at

/g/TekScopes/album?id=301673

Clark

Raymond! YES I mewant CRT expansion mesh, the SC504 have it bad, due to CRT geom, the SC501/2/3 do NOT

Cheers


Jon

I've had a couple of enquiries from US members here, requesting clarity on the new Customs Duties - which may or may not be applicable on my 24xx series Tekscope kits, which are shipped from here in Jerusalem, Israel.

For PERSONAL imports, which is EXACTLY what these are, when you buy the kits from me, there is what's called in Government language, a "De Minimus" level of US$800.

That means that any PERSONAL import (in this case, up to 3 kits) from Israel to the USA is EXEMPT from US Customs Duties, when the value is less than US$800, and 17% when the value is more than US$800.

Commercial imports (which these kits are not, unless you buy a number of kits for a commercial enterprise) from Israel are taxed at 17% from the first Dollar, irrespective of the value.

So, the bottom line is that if you (a US Resident) buy 1 or 2 kits from me, valued at about $70 each, then you are exempt from the new US Customs Duties.

I hope this helps to clarify the issue!

Regards

Menahem Yachad
www.condoraudio.com

According to Findchips.com, Quest Components has VN1316

Thanks to all that have posted - it looks like I'm just going to find the time to open it up and start diagnosing. My feeling, and that that seems to be the opinion here as well, is that the fault should be fairly easy to narrow down as all is working *except* for the display. Of course, finding the time is where the *real* work lies...

These parts are being operated in their linear region, so Rds(on) isn't relevant. As long as they can take the heat, what we need is agility, that is, minimal Ciss/Coss/Crss.
________________________________
From: [email protected] <[email protected]> on behalf of Chris Elmquist via groups.io <chrise@...>
Sent: Wednesday, April 2, 2025 11:18 AM
To: [email protected] <[email protected]>
Subject: Re: [TekScopes] horz output FETs in 2245?

On Wednesday (04/02/2025 at 05:47PM +0000), Dave Wise via groups.io wrote:

If I had a 2245 with your problem I'd be looking for... Hmm. Your parts are running naked, right - no heat sink? That's maybe 1W.

Yes-- they have no heatsinks and are spec'd at 3W max in the TO-39 can.

The left plate pair gets so hot I can't touch it but I realize that's not a
calibrated measurement.

An eBay seller has TO-92 VP0116 $15 for 10, glue on a copper fin. But nobody is selling VN1316 AFAICT.

There are also VP0120 and VN1320 which are similar devices with a higher
Vdgs (200V). These would likely work just fine too if they could be found.

Look at Mouser.com . They don't have any 160V P-channel RF MOSFETs so how about the regular ones? In 150V-300V select the lowest Ciss proxied as gate charge, that's Diodes Inc ZVP2545 in the SOT26-6 package. Put a copper fin on the drain pins and you should be okay.
For N-channel try Vishay SI3440 in TSOP-6. Second lowest gate charge and lowest Ciss.

Right. OK. Thanks. Ciss is the critical parameter then for performance
here? Was also wondering how critical the Rds (on resistance) would be
in this type of circuit? Modern FETs measure that in tenths of ohms
while these golden oldies measure it in 10s of ohms... eg, VN1316 is
at 40 ohm and VP0116 is at 25 ohm.

There's not a lot of clearance between the tops of these TO-39 and the
scope's enclosure though so some challenges with fitting new/different
stuff.

Could envision a little PCB that carries the SMT parts but has "leads"
coming out the bottom to mate up to the scope's PCB.

Chris

________________________________
From: [email protected] <[email protected]> on behalf of Chris Elmquist via groups.io <chrise@...>
Sent: Wednesday, April 2, 2025 9:28 AM
To: [email protected] <[email protected]>
Subject: [TekScopes] horz output FETs in 2245?


I was given a 2245 recently which of course doesn't work too well.

Investigation reveals that Q805 and Q806, in the horizontal right plate
output stage, are cold to the touch.

The service manual, section 6.2 (page 6-19) says,

The MOSFET output transistors (Q801 and Q802 left plate-- Q805 and
Q806 right plate) run hot. If either side is cold, it is defective.

So, that's me and now I need to find a couple of these VDMOS FETs, which
seem to have become quite rare.

They are Tek P/N,

151-1211 VN1316N2 N-Channel VDMOS FET, 160V, 250mA, 40 ohm
151-1212 VP0116N2 P-Channel VDMOS FET, 160V, 250mA, 25 ohm

Has anyone solved this problem with a modern replacement pair? and have
suggested substitutes? These are in TO-39 package which adds additional
challenge but I suppose TO-220 or equiv could be made to fit. Of course,
the real thing would be great too if there is a source.

Thanks for any leads!

Chris
--
Chris Elmquist

--
Chris Elmquist

internal CRT phosphor beam reflection ?

My money’s on scan expansion mesh (to increase deflection sensitivity) artefacts.

Raymond

On Wed, Apr 2, 2025 at 10:53?AM Harold Foster via groups.io <halfoster=
[email protected]> wrote:

How do you know which manual is appropriate to the SN? Am I missing the
obvious? I have manuals with the PN of 070-6863-00 and 070-6863-01

I'm not sure, and I'm not sure that it's going to matter until you're at
least elbows deep, at which point you'll know which SM you need. Note that
this scope may not correspond to a singular serial number, as individual
boards may have been moved from other scopes.

Also, something that nobody mentioned yet is whether the horizontal
connector to the CRT might have fallen off. I don't think that's likely, as
I think you'd have a trace and OSD on half the CRT, but again it's
something quick and easy to check.

Jean-Paul, David,

Thanks for your responses!

OK, straight up. I have 5ct SC502's, 4ct SC503s and 2ct SC504s. This problem is unique to the SC504s. Yes, if I turn up the intensity the ghosting gets worse. If I turn down the intensity the ghosting get better, but the range that is satisfactory is very, very, very small and hard to stay in that range. There is something wrong.

David, I am in the US.

Barry

Ghost is normal at higher intensity, internal CRT phosphor beam reflection ?

One scope is missing a knob, on focus, inten, suggest you fix that it may be set too high

J

On Wednesday (04/02/2025 at 05:47PM +0000), Dave Wise via groups.io wrote:

If I had a 2245 with your problem I'd be looking for... Hmm. Your parts are running naked, right - no heat sink? That's maybe 1W.

Yes-- they have no heatsinks and are spec'd at 3W max in the TO-39 can.

The left plate pair gets so hot I can't touch it but I realize that's not a
calibrated measurement.

An eBay seller has TO-92 VP0116 $15 for 10, glue on a copper fin. But nobody is selling VN1316 AFAICT.

There are also VP0120 and VN1320 which are similar devices with a higher
Vdgs (200V). These would likely work just fine too if they could be found.

Look at Mouser.com . They don't have any 160V P-channel RF MOSFETs so how about the regular ones? In 150V-300V select the lowest Ciss proxied as gate charge, that's Diodes Inc ZVP2545 in the SOT26-6 package. Put a copper fin on the drain pins and you should be okay.
For N-channel try Vishay SI3440 in TSOP-6. Second lowest gate charge and lowest Ciss.

Right. OK. Thanks. Ciss is the critical parameter then for performance
here? Was also wondering how critical the Rds (on resistance) would be
in this type of circuit? Modern FETs measure that in tenths of ohms
while these golden oldies measure it in 10s of ohms... eg, VN1316 is
at 40 ohm and VP0116 is at 25 ohm.

There's not a lot of clearance between the tops of these TO-39 and the
scope's enclosure though so some challenges with fitting new/different
stuff.

Could envision a little PCB that carries the SMT parts but has "leads"
coming out the bottom to mate up to the scope's PCB.

Chris

________________________________
From: [email protected] <[email protected]> on behalf of Chris Elmquist via groups.io <chrise@...>
Sent: Wednesday, April 2, 2025 9:28 AM
To: [email protected] <[email protected]>
Subject: [TekScopes] horz output FETs in 2245?


I was given a 2245 recently which of course doesn't work too well.

Investigation reveals that Q805 and Q806, in the horizontal right plate
output stage, are cold to the touch.

The service manual, section 6.2 (page 6-19) says,

The MOSFET output transistors (Q801 and Q802 left plate-- Q805 and
Q806 right plate) run hot. If either side is cold, it is defective.

So, that's me and now I need to find a couple of these VDMOS FETs, which
seem to have become quite rare.

They are Tek P/N,

151-1211 VN1316N2 N-Channel VDMOS FET, 160V, 250mA, 40 ohm
151-1212 VP0116N2 P-Channel VDMOS FET, 160V, 250mA, 25 ohm

Has anyone solved this problem with a modern replacement pair? and have
suggested substitutes? These are in TO-39 package which adds additional
challenge but I suppose TO-220 or equiv could be made to fit. Of course,
the real thing would be great too if there is a source.

Thanks for any leads!

Chris
--
Chris Elmquist

--
Chris Elmquist

If I had a 2245 with your problem I'd be looking for... Hmm. Your parts are running naked, right - no heat sink? That's maybe 1W.
An eBay seller has TO-92 VP0116 $15 for 10, glue on a copper fin. But nobody is selling VN1316 AFAICT.

Look at Mouser.com . They don't have any 160V P-channel RF MOSFETs so how about the regular ones? In 150V-300V select the lowest Ciss proxied as gate charge, that's Diodes Inc ZVP2545 in the SOT26-6 package. Put a copper fin on the drain pins and you should be okay.
For N-channel try Vishay SI3440 in TSOP-6. Second lowest gate charge and lowest Ciss.

HTH,
Dave Wise
________________________________
From: [email protected] <[email protected]> on behalf of Chris Elmquist via groups.io <chrise@...>
Sent: Wednesday, April 2, 2025 9:28 AM
To: [email protected] <[email protected]>
Subject: [TekScopes] horz output FETs in 2245?


I was given a 2245 recently which of course doesn't work too well.

Investigation reveals that Q805 and Q806, in the horizontal right plate
output stage, are cold to the touch.

The service manual, section 6.2 (page 6-19) says,

The MOSFET output transistors (Q801 and Q802 left plate-- Q805 and
Q806 right plate) run hot. If either side is cold, it is defective.

So, that's me and now I need to find a couple of these VDMOS FETs, which
seem to have become quite rare.

They are Tek P/N,

151-1211 VN1316N2 N-Channel VDMOS FET, 160V, 250mA, 40 ohm
151-1212 VP0116N2 P-Channel VDMOS FET, 160V, 250mA, 25 ohm

Has anyone solved this problem with a modern replacement pair? and have
suggested substitutes? These are in TO-39 package which adds additional
challenge but I suppose TO-220 or equiv could be made to fit. Of course,
the real thing would be great too if there is a source.

Thanks for any leads!

Chris
--
Chris Elmquist

On Wed, Apr 2, 2025 at 12:41?PM Raymond Domp Frank via groups.io <hewpatek=
[email protected]> wrote:

'm no expert on U800 failures, but the two videos I found show different
symptoms

I was triggered by the frequent symptom of the complete screen info
pulling to one side - and beyond. I hope it’s not that serious though.

Yeah, you may well be right. Aside from the power supplies and U800, I
can't think of much that's common to the OSD and traces in the horizontal.
Personally I like to look for simple, inexpensive and fixable problems
first, I guess it's a case of streetlight effect (
).

'm no expert on U800 failures, but the two videos I found show different
symptoms

I was triggered by the frequent symptom of the complete screen info pulling to one side - and beyond. I hope it’s not that serious though.
Raymond

I was given a 2245 recently which of course doesn't work too well.

Investigation reveals that Q805 and Q806, in the horizontal right plate
output stage, are cold to the touch.

The service manual, section 6.2 (page 6-19) says,

The MOSFET output transistors (Q801 and Q802 left plate-- Q805 and
Q806 right plate) run hot. If either side is cold, it is defective.

So, that's me and now I need to find a couple of these VDMOS FETs, which
seem to have become quite rare.

They are Tek P/N,

151-1211 VN1316N2 N-Channel VDMOS FET, 160V, 250mA, 40 ohm
151-1212 VP0116N2 P-Channel VDMOS FET, 160V, 250mA, 25 ohm

Has anyone solved this problem with a modern replacement pair? and have
suggested substitutes? These are in TO-39 package which adds additional
challenge but I suppose TO-220 or equiv could be made to fit. Of course,
the real thing would be great too if there is a source.

Thanks for any leads!

Chris
--
Chris Elmquist

Intensity is way too high IMHO, which is why you get that problem.

If OTOH you don't want your SC504s and are in the UK ...

D.

How do you know which manual is appropriate to the SN? Am I missing the obvious? I have manuals with the PN of 070-6863-00 and 070-6863-01

SN is B058926. it powers up normally and passes all self tests. It will complete (assumedly from the light sequences) the boot sequence and power on tests even when the display is wonky. It seems to be the focus is lost and the display position is just past the right edge of the screen. At first it appeared to possibly be temperature related but now not so much... it does it from a cold (well, at least cool) boot now and it started working *after* warmup one time prior. When the screen is not correct it seems to respond to all button presses - the fuzzy blobs move in concert with the presses although it is only what could be described as the left quarter of a fuzzy blob that shows on the right side of the CRT. Running the self test while also seems to complete it's entire sequence.

Hal

Greetings,

I have 2 SC504 scopes. I have done a lot of restoration work on both these units. They are both working now, but I am not satisfied with the trace having ghost. Please take a look at the photo I posted some days ago. At that time I had 1 SC504, since then I have bought another one. BOTH of these scopes display EXACTLY the same ghost trace.

When I bought the second SC504 I thought I would have the chance to swap out the CRTs.

/g/TekScopes/photo/300558/3883505?p=Created%2C%2C%2C20%2C2%2C0%2C0

Thanks for the responses.

Barrr

Hey Harold,

I'm no expert on U800 failures, but the two videos I found show different
symptoms: . While the trace is
affected, the on-screen-display is not in both of those cases. Of course we
don't know whether you've turned the OSD off on your scope, and there is
likely more than one failure mode for U800, so YMMV.
Does the scope successfully complete power up? If it's failing
power-on-self-tests, it'll stop at some point with a single front-panel LED
lit, and when you press A/B TRIG, it'll continue to operating mode, which
will click some relays.
After that, the first thing to look at is the power supplies at J119.
There's a table in the service manual that specifies limits on voltage and
ripple. The next thing to look at IMHO are the -1.25V and +1.36V references
on the A5 board. If any of those are out, there's no point in looking at
anything else.

From there it's a process of elimination, I'd say, and if you haven't read
this document: , maybe
that's a good start. It's a fun read, if nothing else.
Some things to try:
- Does the beamfinder do anything?
- Does the OSD show?
- Does X/Y mode work?
- Does the B-sweep work?
- Does the 10X horizontal magnify do anything?

Since the symptom is so severe, you should be able to quickly figure out
what is bad in the horizontal or the HV.

Good luck,
Siggi

On Wed, Apr 2, 2025 at 9:18?AM Harold Foster via groups.io <halfoster=
[email protected]> wrote:

That was the kind of thing that I was worried about. I do have a parts
unit so maybe that could be used if needed. I'm not sure when I will get
the chance to dig into it but I very much appreciate the ideas. I've not
worked on these before so at least knowing where to start reading up is
extremely helpful.

Thanks!