Hello,?

as i saw, i nether see anyfing on the screen os the HP 182T.

Except!!!? Look at the vidéo...very strange

All is good connected.? The input N go to the block attenuator

some idéas??

cdt

开云体育

Paul,

thank's for your answer.
That’s the problem, I’ve never been able to display a signal with the RF plug.

In fact, my first question was whether this catch was smeared because you can’t see the silkscreens. There was supposed to be a BNC. It seems to be well connected to the attenuator input.

for display something:
That’s the problem, I’ve never been able to display a signal with the N RF plug.

In fact, my first question was whether this catch was smeared because you can’t see the silkscreens. There was supposed to be a BNC. It seems to be well connected to the attenuator input

My second question was also to know which positions should be the main buttons to display a 20MHZ AM signal with a voltage of 0.3V.
I’ve tested many combinations, we don’t show any signal. Some ideas?

Indeed, by chance when I connected the calibration output to the LO socket, I display something. I know that’s not the way it’s supposed to work, it’s really strange. It proves that some things work.

Normally input cable must be do like that (I thing)


on my analyzer it's like a small aluminium coaxial cable (2/3 mn diametral) from RF N input to the attenuator.
So the capacitor and other are directly on the plug and i don't see it? Capacitor burn???

I’m going to test this cable, even if it means injecting a signal directly into the attenuator input with a 0.1 ?f capacitor whith a small signal?

cdt

Re,

I just disconnected the cable to the attenuator inlet.
there is no short circuit between the shield and the core
On the other hand, the connection is direct (0 ohm) between the N socket input and the end of the core.
So in fact I have trouble understanding the role of the capacitor (no 4)

Also: If I plug an ohmeter on the input of the attenuator I have an infinite impedance. Idem by moving the switch boutton. I don’t know if that’s normal, too, because we’re still talking about 50 ohm impedance?

some ideas,

cdt

The purpose of the capacitor in the input assembly would be a DC block.
It appears that the input assembly was changed on your unit.
The attenuator input section appears to be damaged,

Hello,

NJ902, please?Can you be more specific
What’s a DC block?
For me a capacitor dont't indicate 0 ohm?
What is excatly the impedance of the attenuator?

If someone have a HP8558B analyzer and put un ohmeter on the N plug, what is the result: Infinite, 50 ohms, other????
Without specific cases of measurement I do not move forward

You said: ""The attenuator input section appears to be damaged,"
Why???

cdt

The capacitor in the original input assembly will block DC from reaching the attenuator.

Yours may have been damaged by having DC or excessive RF level applied to the input.

The attenuator should measure 50 ohms resistance because it is constructed of resistive divider elements.

This is a common problem.? There are numerous articles on-line that show how to check and repair these attenuators.

Such as:?

hello,

News from the internal attenuator of this 8558B HP
As this is a mechanical attenuator (Action of a rotary button only), I did this little test.
Disconnect in and out attenuator.?it is autonomous now
Sending a sinusoidal signal 10 MHZ with a generator via a resistor of 50 ohm
Oscilloscope measurement input and output.

As I turn the button, the signal drops out (constant input).
The method is not very academic and I am not amused to convert to DB.?I am allergic to all measures in DB (LOL)

I think it works, because it’s a constant decay, even if you only see a few millivolts 3 notches before the end of the rotation. (For only 0.3v input)
I did not want to force too much the signal to the enter?
I think it’s not burned, so I’m gonna look at something else

cdt

"I am allergic to all measures in DB"

Maybe this will help: