Keysight 3000T scope 1 GHz(or more) hardware upgrade mod

[Netroman]

I've just completed my mod (MSOX3024T now 1GHz) and it works great - many thanks to all envolved users from this Forum; especially Steve for additional hints and support.

If someone needs contacts, i got plenty of offers for the teledyne relays. Most where between ~40-59 US (i bought mine much too expensive and they are not very hard to get  ).

For the really tiny parts i used a JBC NASE nano rework station - not cheap, but definitive worth the money. I did not believe that, but i'll never buy another brand anymore.

I had some problems with the user calibration, but the reasons were just wrong ordered parts. Especially the Driver "74ACT04" - MUST be an "ACT", because it is driven by Levels about 2.4 Volts and Needs to be able to work with TTL-Levels. So the "ACT" is absolute must (i had a "HCT" which has much too low power, whilst the ACT delivers up to 25 mA).

And i made absolute equal length cables for the calibration with 250mm (important: not longer than 300mm per cable), also bought hight quality tee-connectors bnc.

Though i was successful in reusing the desoldered cheaper relays, i would also suggest to buy new ones, because these should work for years without Troubles. I replaced the two ones in channel 1 whilst finding out my calibration problems.

Best regards from Austria, Josef

[EE-digger]

Thanks for your report !  Now I'm stoked again to perform the mod.  I had a thought on clean shield removal.  What do you guys think about heating a single corner, sliding a piece of Kapton film under it, then on to the next 'til done?  Re-soldering should be a piece of cake but I might use NC paste to keep it neat.

Also, 74ACT is almost twice as fast as 74HCT.  Is this the cal signal?  The 74HCT rise time may have been inadequate.

[TheSteve]

Thanks for your report !  Now I'm stoked again to perform the mod.  I had a thought on clean shield removal.  What do you guys think about heating a single corner, sliding a piece of Kapton film under it, then on to the next 'til done?  Re-soldering should be a piece of cake but I might use NC paste to keep it neat.

Also, 74ACT is almost twice as fast as 74HCT.  Is this the cal signal?  The 74HCT rise time may have been inadequate.

Removing the shields isn't actually too bad. You can just lift them up corner by corner. The 74ACT04 drives the FET's that turn the Teledyne attenuator relays on and off.

[EE-digger]

There must be some other loading on the '04 output then, that does not permit the HC04 to satisfy the Vgs.

[Netroman]

@EE-digger: I broke a small piece of GND-route, because the shields do not really bend well. I suggest to spend some solder wick to remove as much as possible before you lift the corners. IMHO the corners do not lift (bend) more then 1/2 to 1 mm - that was not enough (too much solder on it and at first i did not use wick) in one case, so i ripped the route :-(

Josef

[adranp]

As I said previously, lifting the shields works best with pre-heater and hot-air gun. This way you won't have problems. Solder wick requires good skills.

[EE-digger]

adranp: That's why I thought that a hot iron, slide some high temp, thin film under that corner.  Clean up after all four have been lifted.  I may give it a shot.  I have bottom heat but would rather not involve that side.  I know it would work great though 

Did you ever finish your mods?

Josef:  Sorry about your lifted copper.  That can be heartbreaking but glad that your scope works well 

[Samogon]

Got 4024A and being inspired by TheSteve will try to mod it to 1G or 1.5G with his and hopefully community help.

here are some pictures of areas we interested.

[Samogon]

In ideal if someone can open little expensive 4104A or 4154A scope remove backside shield and make hirez pictures that would be fantastic.

[Pinkus]

The "back" picture shows a lot of flux as if somebody already reworked this. Did they (Agilent) really deliver such a board?

The front end looks (almost) identical to the 3000 series, thus it should be not a big deal. Though the mod for 1.5 Ghz has afaik not been made yet.

[sibeen]

You are all mad, and my DSOX3024T is sitting on my bench and madly agreeing with me.

As I work in the power area I sometimes go as high as the 60th harmonic, so 3 kHz. I think I'll leave mine well alone, but respect to those who did this mod.

[Samogon]

in contrast to 3000T series we have already populated inverter U1507 74ACT04  on 3000T corresponds to U1613 on 4000x
This is how CPU manages front attenuator relays. It uses serial data going to Serial to parallel converter U502 74AHCT594 and then finally transistors drive relays.

[Samogon]

The "back" picture shows a lot of flux as if somebody already reworked this. Did they (Agilent) really deliver such a board?

The front end looks (almost) identical to the 3000 series, thus it should be not a big deal. Though the mod for 1.5 Ghz has afaik not been made yet.

Well board has flux all over it especially where through hole components are, looks to me nobody cared to clean it. But board looks intact

[Samogon]

You are all mad, and my DSOX3024T is sitting on my bench and madly agreeing with me.

As I work in the power area I sometimes go as high as the 60th harmonic, so 3 kHz. I think I'll leave mine well alone, but respect to those who did this mod.

Well it depends what tasks you are aiming. For you probably 50Mhz scope would be enough.
For me just as example i needed 500MHz scope minimum to measure Pulse Edge Time of Agilent 33250A when calibrating it.

[TheSteve]

Had another look at the input SWR to my modded scope tonight with a newer VNA. I am quite pleased with what I see. Generally scopes seem to be specified as having an input SWR of 1.5:1 or less over the rated bandwidth with the 50 ohm input enabled. The scope beats this spec with and without the Teledyne attenuator switched in to 1.5 GHz. With that in mind I'll have another look at the low pass filter components and see if we can't finally mod the 3000t series to a full 1.5 GHz.

100 mV range(Teledyne switched in):


200 mV range:

[Samogon]

Monster TheSteve!

[2N3055]

I apologize if somebody already asked this. I was reading 3000T X-series User manual and found this mentioned in few places:
"With the 3000T X-Series 1 GHz and 1.5 GHz bandwidth models"
Is that just remnant from when they rewrote (reused,recycled) manual from 4000 series or there ever was mention of 1.5 GHz version of 3000T ?
Regards,
Sinisa

[TheSteve]

I apologize if somebody already asked this. I was reading 3000T X-series User manual and found this mentioned in few places:
"With the 3000T X-Series 1 GHz and 1.5 GHz bandwidth models"
Is that just remnant from when they rewrote (reused,recycled) manual from 4000 series or there ever was mention of 1.5 GHz version of 3000T ?
Regards,
Sinisa

There is no factory released 1.5 GHz 3000 series model.

[badbiki]

Ok I'm keen. Ordered all parts bar the relays.

I've PMd someone on here about them.. if anyone has four cheap?

I have a MSOX3024T and assume I need them, even tho the comment;

K1   A150-20-12    - 3104T only - This is the money part. I bought mine from a trusted vendor in China and verified they were 100% legit before install.

says only for 3104T.. bit weird.

Description	Manufacturer	Manufacturer Part Number	Digi-Key Part Number	Designator	Reference Designator	Qty	Unit Price
FERRITE  BEAD 600 OHM 0805 1LN	Wurth Electronics Inc.	742792040	732-1620-1-ND	BD1	Per Channel	1	$0.25
CAP CER  2PF 100V C0G/NP0 0603	Murata Electronics North America	GQM1885C2A2R0CB01D	490-3555-1-ND	C1 C2	Per Channel	2	$0.59
CAP CER  4PF 100V C0G/NP0 0603	Murata Electronics North America	GQM1885C2A4R0CB01D	490-3557-1-ND	C3 C4	Per Channel	2	$0.59
CAP CER  10PF 50V C0G/NP0 0603	Murata Electronics North America	GQM1885C1H100GB01D	490-6087-1-ND	C5	Per Channel	1	$0.76
CAP CER  10000PF 50V X7R 0603	Murata Electronics North America	GCM188R71H103KA37D	490-4778-1-ND	C6 C7	Per Channel	2	$0.10
CAP CER  0.1UF 50V X7R 0603	Murata Electronics North America	GCM188R71H104KA57J	490-8020-1-ND	C8 C9 C10 C11 C12 C14 C15	Per Channel	7	$0.17
CAP CER  10000PF 50V X7R 0402	Murata Electronics North America	GCM155R71H103KA55J	490-13295-1-ND	C13	Per Channel	1	$0.10
HIGH  RELIABILITY AND SMALL MOLD	Rohm Semiconductor	BAV99HMFHT116	BAV99HMFHT116CT-ND	CR1	Per Channel	1	$0.25
DIODE  PIN 100V 250MW SOT-23	Skyworks Solutions Inc.	SMP1321-005LF	863-1097-1-ND	D1	Per Channel	1	$0.78
RELAY  TELECOM DPDT 2A 125V	Panasonic Electric Works	AGQ210S4HZ	255-2096-1-ND	K2	Per Channel	1	$2.17
MOSFET  N-CH 20V 300MA SOT-23	ON Semiconductor	MMBF0201NLT1G	MMBF0201NLT1GOSCT-ND	Q1	Per Channel	1	$0.57
RES SMD  110 OHM 1% 1/4W 1206	Vishay Dale	CRCW1206110RFKEA	541-110FCT-ND	R1	Per Channel	1	$0.10
RES SMD  162 OHM 1% 1/10W 0603	Panasonic Electronic Components	ERJ-3EKF1620V	P162HCT-ND	R2	Per Channel	1	$0.10
RES SMD  100K OHM 1% 1/8W 0805	Panasonic Electronic Components	ERJ-6ENF1003V	P100KCCT-ND	R3	Per Channel	1	$0.10
RES SMD  23.7 OHM 1% 1/10W 0603	Vishay Dale	CRCW060323R7FKEA	541-23.7HCT-ND	R4 R5	Per Channel	2	$0.10
RES SMD  68.1 OHM 1% 1/8W 0805	Vishay Dale	CRCW080568R1FKEA	541-68.1CCT-ND	R8	Per Channel	1	$0.10
RES SMD  51.1K OHM 1% 1/10W 0603	Vishay Dale	CRCW060351K1FKEA	541-51.1KHCT-ND	R9 R10 R11	Per Channel	3	$0.10
RES SMD  10 OHM 1% 1/10W 0603	Yageo	AC0603FR-0710RL	311-10LDCT-ND	R12	Per Channel	1	$0.10
RES SMD  64.9K OHM 1% 1/10W 0603	Panasonic Electronic Components	ERJ-3EKF6492V	P64.9KHCT-ND	R13-L1	Per Device	1	$0.10
RES SMD 100K OHM 0.5% 1/10W 0603	Vishay Dale	CRCW0603100KDHEAP	541-100KAYCT-ND	R14-H1	Per Device	1	$0.32
IC INVERTER 6CH 6-INP 14SOIC	Texas Instruments	SN74ACT04DR	296-1065-1-ND	U1507	Per Device	1	$0.48

This is my BOM. I've used GCM over GRM cap parts due to availability and better specs being automotive. I could be wrong tho.

[TheSteve]

You absolutely need the Teledyne attenuator relays to perform the bandwidth upgrade(they are used in the 3104T only which is why you need them as that is what hardware you're upgrading to).

[badbiki]

Ye I reread the upgrade and the comment about the upgraded relays makes it clear. I have four on order so I’ll see how it goes.

Is anagilent 1130A probe sufficient for testing and general scoping? Can eBay one for around 1k

Ill take some photos of my unit pre and post. Will use my ESD room and straps on all irons for sure!

[badbiki]

My relays arrived from https://www masterelectronics com/teledyne-relays/a1502012-12686042.html

Their documentation seems legit and they came well packaged. Gold pins and underbelly with a nickel played top and markings.

Getting the shields off was a pain. Ended up wiking most of the solder off each corner and then using a heat gun and flux to lift a side at a time. I would t recommend prying corners. The sheils have tabs mid way forcing a vertical lift. They really could have used 1/5 the solder to put these on IMHO.

A lot of residue marks on the board before dissassemby and I even found a stray solder ball!

Perhaps I should X-ray the board before final assembly:)

It really is a work of art inside. My pre mod user cal ran through to success so here goes.

I’m removing, desoldering, cleaning (Kim wipes and IPA) then fluxing and reapplying or installing new parts. Am I missing anything?

I’ll photo check with my SLR pre/post mods.

ESd Mat and strap in use.

Using lead free solder. I’m assuming this is RHOS mostly?

[TheSteve]

The shields can be a pain, with experience they get much easier. Add a little leaded solder to each joint, then use good quality wick to remove the solder. I am generally able to then lift each corner .5mm or so one at a time working my way around. If they don't want to move then just add heat while lifting, they should stay raised when you remove the heat as there should be next to no solder left holding them in place.

The scope is certainly assembled with lead free solder. I always use leaded during rework.

More then anything I'd say just take your time with the mod, don't rush it. To me the biggest challenge was removing the existing relays as I didn't want to damage anything else. With some board preheating(which I didn't do) they will come off very nicely though. The pads are very tiny on the signal path so inspect your connections very carefully. It is too much of a pain to be disassembling and reassembling too many times.

[badbiki]

I agree with taking time and not rushing. Lifting tracks is my worst fear.

Touch wood, I’ve only lifted 1980s era traces thus far.

I too added a little leaded to help it flow, with tacky flux and good quality wick. CHIPQUIK 291 flux and chemtronics no clean desoldering braid, multiple sizes with hoof tip

I was trying not to mix types of solder during rework. I find it comes out dull and doesn’t wet well otherwise. Even thought I hate reworking lead free.

I was thinking of using kapton tape and some little insulators I have from my 3D printer to act as air barriers to remove the relays. I don’t have an IR or heated mat under my pcb holder at home. Perhaps I should borrow one for the weekend.

Also don’t yet have my active GHz probe (shipping atm) or a ghz source handy.

Any ideas of some cheap quick solutions for testing? My friend works at a lab with Calibrated rf gear, or I may call in a favour to use some equipment at my EDM.

Do you tack the shields down with a little less solder?

Also, one channel had a green sticker on it. I noticed some pictures have different colours or none at all. Are they a post check or marker for component values? As in they have a different set to pass?

Green dot, red dot, orange... what do they mean?

[TheSteve]

No idea on the dots, but it is normal. Ideally to determine performance you need a signal generator that goes to 1.5 GHz or so with a level output. You don't want to use a probe for testing, the signal generator should be directly connected to a channel input with 50 ohm mode enabled.

I would use kapton tape to protect the areas around the relays, or metal shields if you have them. You can always at least warm the board a little with a heat gun - just don't go crazy.