?

Note that the problem could also be in the 85102 IF unit.? Do you have?
either the test set simulator or a second test set of some kind?

The test set simulator is a plug that fits the IF RF outputs and has a?
connector for the 20.4MHz signal from the IF to provide a signal?
approximating the outputs from the test set.

It would be bet to confirm the 85102 before digging nto the 8516.

Cheers!

Bruce

Quoting Lothar baier <Lothar@...>:

> Ok so the 8510 test-sets have 4 samplers , 2 of them are connected?
> to the couplers , the other 2 are reference samplers , those are?
> connected to the switch/splitter , the RF coming in from the source?
> is split inside of this assembly in 3 paths , 2 reference paths that?
> are connected to the reference samplers the third one is routed to a?
> switch which switches the RF either to coupler 1 or 2 while?
> terminating the unused coupler in 50ohm !
> NO IF FOUND usually indicates that either one or both reference?
> samplers does not receive a signal or that the signal level is to?
> low .
> This can have multiple reasons :
>
>?? 1.? The Source output level is to low , cable from source to the?
> testset might be broke
>?? 2.? Doubler amplifier assembly is bad
>?? 3.? Switch /Splitter bad
>?? 4.? Bad sampler or sampler driver
> Note that for 2 or 3 defective can also mean issues with the control?
> circuits !
> You can also get this error if you have power holes in the source
>
> First thing to do is to set the start and stop frequency to a small?
> range like 2-4GHz or 1-2GHz and see if the error goes away, if it?
> does then increase the sweep range to see where the error starts to?
> appear !
> Next check the source level at the end of the cable you use to?
> connect the source to the test-set , make sure the level is within?
> the range the test-set can process
> If this doesn’t resolve things take the lid of the test-set and?
> check your DC Voltages to ensure they are all correct , next?
> disconnect the output of the doubler amplifier block and check if?
> you have RF coming out ,? you can also connect the source directly?
> to the cable that connects the doubler to the switch splitter set?
> your sweep from 2-10GHz if the error goes away you have a problem?
> with the doubler or doubler control if its still present you have to?
> check the signal at your samplers if the signal is there your?
> sampler is bad or the sampler driver
>
> Sent from Mail<> for Windows
>
> From: ratn9ne via groups.io<mailto:ratn9ne@...>
> Sent: Wednesday, March 2, 2022 2:37 PM
> To:?
> [email protected]<mailto:[email protected]>
> Subject: Re: [HP-Agilent-Keysight-equipment] 8516A cable question
>
> I have a complete 8516 VNA setup and it was intermittently working?
> with a standard DB25 Thru cable. Right now I am stuck on "NO IF?
> FOUND" error and out of ideas.
>
>
>
>
>

?