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Re: 8594E input attenuator issue?

 

Yes, good idea. However, I still have a broken plunger right now. Doing some 3D printing test...
Re: 8594E input attenuator issue?

 

¿ªÔÆÌåÓý

Since you have the long cover off, f you look closely you¡¯ll see the mechanical mechanism which moves the contacts. You should be able to gently push those to toggle between open and closed, as they actually latch mechanically. These are typically pulse driven, not DC. Manually moving them you will see what I mean. Much easier to test and no damage risk to coils or any on-board electronics.

?

From: [email protected] <[email protected]> On Behalf Of nicolas.mailloux@...
Sent: Wednesday, January 19, 2022 8:31 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] 8594E input attenuator issue?

?

Ho Ozan,
I have a signal generator, the lower I can go is 14Mhz.
I would like to know where I can find the pinout of the connector. I will manually feed the solenoids.
All I have on hand is my 100Mhz oscilloscope, which should be enough to measure the attenuation by using the Vpp measurement at 14Mhz.
I will of course terminate the connection from the ATT to the DSO with a 50ohm.

I regret not trying it on the bench first before opening it up. Now I do have a broken plunger (trying to fix it with glue...).

E5071C the program can't working

[email protected]
 

hi all
i have 1ea E5071c 2 port 8.5Ghz
The program can't working in picture.
help me! thanks all

z3123975221107_e0223357d4afa57cb1cd08c185317563.jpg

Re: 8594E input attenuator issue?

 

On Wed, Jan 19, 2022 at 05:30 PM, <nicolas.mailloux@...> wrote:
Ho Ozan,
I have a signal generator, the lower I can go is 14Mhz.
I would like to know where I can find the pinout of the connector. I will manually feed the solenoids.
All I have on hand is my 100Mhz oscilloscope, which should be enough to measure the attenuation by using the Vpp measurement at 14Mhz.
I will of course terminate the connection from the ATT to the DSO with a 50ohm.

I regret not trying it on the bench first before opening it up. Now I do have a broken plunger (trying to fix it with glue...).
------
Higher frequency is fine, the attenuator should work 300kHz-2.9GHz in AC coupling and pretty much down to DC without AC coupling.?

8590A CLIP manual is in the files section, pinout could be the same. I will dig up 8594E attenuator pinout and send in a few hours unless someone else have it handy.

Ozan
8566 5.2V supply

 

¿ªÔÆÌåÓý

All,

?

I have an 8566 with a problematic 5.2V supply.

?

Its schematic shows? a couple of transistors that seem not have commercial replacements. The xref I have here doesn¡¯t show those PNs.

?

These are:

1854-0404

and

1854-0441

?

Can anybody help me out?

?

Best, Francesco K5URG
Re: 8594E input attenuator issue?

 

Ho Ozan,
I have a signal generator, the lower I can go is 14Mhz.
I would like to know where I can find the pinout of the connector. I will manually feed the solenoids.
All I have on hand is my 100Mhz oscilloscope, which should be enough to measure the attenuation by using the Vpp measurement at 14Mhz.
I will of course terminate the connection from the ATT to the DSO with a 50ohm.

I regret not trying it on the bench first before opening it up. Now I do have a broken plunger (trying to fix it with glue...).
Re: 8594E input attenuator issue?

 

On Wed, Jan 19, 2022 at 03:35 PM, <nicolas.mailloux@...> wrote:
Do you happen to know the value of said capacitor ? Just for checking it.
Also, do you find anything suspicious in the pictured I posted ?
------
According to SM cap is 0.047uF/25V

Could be a late suggestion but did you try the attenuator on the bench? You can feed in a 1MHz signal (50-ohm output) and observe the attenuation at the other end ?(50-ohm terminated) without opening the box. You can activate relay contacts one by one on the bench with a power supply and check for steps. A bad relay driver can give similar symptoms.

When you observe your signal to be off, is it exactly off by an attenuator step? More than expected or less than expected?

Attenuator sections look like pi-attenuators. There are many online calculators that will tell you the expected resistances.?

Ozan
Re: 8594E input attenuator issue?

 

Do you happen to know the value of said capacitor ? Just for checking it.
Also, do you find anything suspicious in the pictured I posted ?
Re: 8594E input attenuator issue?

 

Nicolas,
That is a capacitor which can be switched in for AC coupling.? Low frequency response is reduced in AC mode.? (I have seen a cal lab reject an 8594E due to poor low frequency response because they did not realize it was in AC coupled mode.)
Note that the attenuator can be installed reversed.? If that happens, the AC cap is at the wrong end and the input connector does not read as a DC open in AC coupled mode.
--John Gord


On Wed, Jan 19, 2022 at 02:54 PM, <nicolas.mailloux@...> wrote:
I figured this guy looks like a simple resistor placed in-line and not connected to chassis.
Re: 8594E input attenuator issue?

 

I figured this guy looks like a simple resistor placed in-line and not connected to chassis.
Re: 8594E input attenuator issue?

 

I took some measurements and I think I found something interesting.
Probing resistance from the contact pads to the aluminum block, where the pads are bolted to, I get these readings :
--> Infinite ohm
--> Measure 51.11 ohm
--> Measure 49.9 ohm
--> Measure 61,2 ohm
Re: 8594E input attenuator issue?

 

Thank you for the suggestion. I do not see anything burned or blemished.
Please have a look at the pictures :
Re: 8594E input attenuator issue?

 

Nicolas,
While you have it open, examine the attenuator elements under magnification.? You may find that the 10dB element has been damaged by excess power.? If so, you might want to look for a spare attenuator that has a good 10dB element as well as good plungers.
--John Gord


On Wed, Jan 19, 2022 at 02:01 PM, <nicolas.mailloux@...> wrote:
While disassembly the ATT, I broke the very tip of a plunger. Anyone here have a spare defective ATT then can part with ?
Also, all o-rings look good, so it seems I've broke it for nothing.

Today is not a good day.
Re: 8594E input attenuator issue?

 

While disassembly the ATT, I broke the very tip of a plunger. Anyone here have a spare defective ATT then can part with ?
Also, all o-rings look good, so it seems I've broke it for nothing.

Today is not a good day.
Re: HP 8566B repair: -10V rail went down

 

"Bruce" <bruce@...> writes:

Before you ear things apart do some more measurements.

Note that L5 supplies VF1 which is only used in the sampler driver (Blokk A).

I would measure the voltage drop across the following resistors on A28
- R3,R7,R8,R6 (R7, R6 are very unlikely to be the problem but mesure
just for completeness).

I would measure the drop across R3 and R8 with the sampler removed and
with it in the circuit to see if it is the culpert (there is no other
easy way to estimate the sampler current).

This should give you an estimate of the total current drawn from VF1
by active components (including the sampler). Then measure the
current on the VF1 line at the feed through cap. If it is greater than
the computed values, the active components are likely ok and you are
probably looking at C9 particularly since L6 does not seem to be fried.

ESR is unlikely to be important as that is an AC measurement and
unless the -10v has high ripple ESR is less significant.
Thanks for the advice Bruce. I'll take a look in detail at these things
when I reopen the unit.

However, stepping back a bit. How likely is it that the sampler is at
fault here? The instrument started working again after the incident (0
dBm input tones at 5, 10 and 15 GHz all appeared exactly as expected on
on the SA, and no error indicators appeared). If the sampler had been
fried, wouldn't I see basically no signal on the CRT?

Matt
Need help with induction soldering

 

I was impressed with the induction soldering photos supplied by Sandra and purchased one of the 12V max voltage ones like the one she used.? I CANNOT get the connnector hot enough to melt sodere.? The induction device will heat a small screw driver hot enough to burn fingers (do NOT ask how I know this).

So my QUESTION IS: Has anybody else tried this and been able to get her results?? If so, I'd like to know the "secret" or what I'm doing incorrectly.?

I've tried to message Sandra with no results, if anyone else has a handle on her, I'd appreciate you pinging her and asking her for some help.

Cheers!? Bruce
Re: HP 8566B repair: -10V rail went down

 

Matt -
Before you ear things apart do some more measurements.

Note that L5 supplies VF1 which is only used in the sampler driver (Blokk A).

I would measure the voltage drop across the following resistors on A28 - R3,R7,R8,R6 (R7, R6 are very unlikely to be the problem but mesure just for completeness).

I would measure the drop across R3 and R8 with the sampler removed and with it in the circuit to see if it is the culpert (there is no other easy way to estimate the sampler current).

This should give you an estimate of the total current drawn from VF1 by active components (including the sampler). Then measure the current on the VF1 line at the feed through cap. If it is greater than the computed values, the active components are likely ok and you are probably looking at C9 particularly since L6 does not seem to be fried.

ESR is unlikely to be important as that is an AC measurement and unless the -10v has high ripple ESR is less significant.

Cheers!

Bruce


Quoting Matt Huszagh <huszaghmatt@...>:

I believe I located the source of the burn smell. A11A5 L5 and C9 were both charred (see attached image). C9 is a 2.2u 20V axial tantalum. These form a lowpass filter on the -10 V rail for the YTO sampler assembly. I could also clearly make out the smell I'd noticed when I opened this assembly. And, the capacitor in particular smelled really bad. I measured both on my low impedance meter. The cap got a reading of 1.93u (should be 2.2u) and 1.544ohm ESR at 100kHz. The capacitance is pretty close but the ESR seems high to me. Still, surprisingly close for something that looks as bad as it does. I didn't attempt a leakage test, though maybe that would be informative.

The inductor measured 0.267u (should be 1.2u) at 100kHz. My best guess for this drop in value is that the high current fused and thus shorted consecutive loops. Does that seem plausible?

I also pulled A11A4C3, which is the same part as A11A5C9, but on the YTO loop phase detector. I measured it to have about 1.5ohm ESR at 100 kHz out of circuit, which seems a bit high to me. Also, C28 is the same exact cap on that assembly and measured a fraction of an ohm in ESR.

Matt
Re: HP 8496H Attenuator cable

 

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Right, the H model means SMA female connectors and programmable through the Viking connector rather than with the knob.? Those 11713A boxes are dirt cheap on eBay, about $40 last I checked.? I pencil in the attenuation values over the lighted buttons for Attenuator X and Attenuator Y for convenience.? ?Good luck!? ? ? ? Jim Ford?



Sent from my T-Mobile 4G LTE Device


-------- Original message --------
From: Steve - Home <steve-krull@...>
Date: 1/19/22 10:24 AM (GMT-08:00)
Subject: Re: [HP-Agilent-Keysight-equipment] HP 8496H Attenuator cable

Henry,
Look on eBay for an 11713A attenuator driver. You¡¯ll need that to drive the attenuator, or you¡¯ll have to build something equivalent. Often they are offered with the necessary cable included and for about the same as what some sellers ask for just the cable.


Steve
WB0DBS



On Jan 19, 2022, at 12:09 PM, Henry Newton <EequalsIR@...> wrote:

?I recently bought a 8496H at a ham tailgate for $4.? There is no manual control knob, however there is a 12 pin connector.
I've look on ebay and cables run between $50 to $75 or more plus shipping from off shore.
Does anyone have a spare cable w/connector that I could purchase?? Or another source?
Thanks from a newbie

Re: HP 8496H Attenuator cable

 

¿ªÔÆÌåÓý

Henry,
Look on eBay for an 11713A attenuator driver. You¡¯ll need that to drive the attenuator, or you¡¯ll have to build something equivalent. Often they are offered with the necessary cable included and for about the same as what some sellers ask for just the cable.


Steve
WB0DBS



On Jan 19, 2022, at 12:09 PM, Henry Newton <EequalsIR@...> wrote:

?I recently bought a 8496H at a ham tailgate for $4.? There is no manual control knob, however there is a 12 pin connector.
I've look on ebay and cables run between $50 to $75 or more plus shipping from off shore.
Does anyone have a spare cable w/connector that I could purchase?? Or another source?
Thanks from a newbie

Re: New to the group, troubleshooting HP4261A

GeoVE3GZB
 

I sent it to Toronto Surplus and Scientific, they are actually the ones who I bought it from in the first place.
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