?

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.
>
>
>
>
>

?

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.

?

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.

If the analyzer shows the correct level from the calibrator - it's probably fine.? If your instrument requires you to connect a jumper between the calibrator output and the RF input - that is an even higher confidence.

For a more comprehensive verification, connect your signal generator to the spectrum analyzer and measure various frequencies and amplitudes.

When measuring signals in a high RF environment, if you suspect mixer overload, increase the input attenuation.? If the suspect signals decrease by more that the extra attenuation, they were bogus.

Also, most analyzers won't reduce attenuation below 10 dB without extra steps.? That protects the instrument because attenuators aren't as easy to damage (or as expensive) as mixers are.? Zero dB attenuation can give you the most sensitivity for viewing weak signals - but - don't go there unless you are sure it is safe.

?

Hi All,
I have been puzzling for a while but I'm not sure that I have got to the truth yet.
I have a H-P 334A Distortion Analyzer which I put away a while ago and now I find that something is not right. When I turn the instrument on, the meter-needle swings to the right and then comes back to zero fairly quickly. Unfortunately, there is still a little movement on the meter-needle but this settles down eventually. Since it looks as though the current isn't passing completely down the A2R44, A2Q8 and A2Q9 components completely, I have ascertained that transistor A2Q9 has probably died on me. This transistor was originally a Motorola SM4713 PNP silicon type. Research tell me that while this transistor is discontinued, an equivalent is probably a 2N3251. However, this is a bit pricey just to check out and I suspect that a?2N3906 will probably suffice just to check. Has anyone else any better ideas? I really want to get this Distortion Analyser working satisfactorily. Thanks is anticipation,
Colin.

On Mar 2, 2022, at 11:23, DW via groups.io <wilson2115@...> wrote:

?There might be cases where a spectrum analyzer is used to measure a particular signal that is surrounded by many adjacent strong signals. Perhaps the signal measured isn't as strong as the adjacent signals and requires and increase in level but unfortunately the adjacent signals are raised as well.

Although none of the strong adjacent signals are overpowering of the analyzer, perhaps they are all somewhere around -30dBm but there are about 10 of them or more, is it possible that although the input levels look fine on screen when in reality the analyzer is actually seeing higher than -30dB at it's input thus staying below the input level limits might not always be so obvious.

Thoughts on this, thanks

?

Hello George, from 12,000 miles away.

?

If only I had met you when I lived and worked in the UK.

?

I have a couple of 8640Bs that I’ve managed to keep going – the odd capacitor failing, and those dreaded gears going U/S.

?

A member of the radio club asked me to look at an 8640B that wasn’t working. There was no RF output and gears were so badly cracked you couldn’t turn the knobs. Someone must have tried because one of the wings on the band-change knob is missing. Now that I’ve replaced gears and lubricated bearings, the band change is fine. Unfortunately, even Walter of Sphere Research in Canada can’t help with that knob; can you?

?

I now have reliable RF output, but no frequency readout. I purchased another frequency readout module from a person scrapping an 8640B, who claimed his counter had been working. But, in fact, neither counter works. Can you help?

?

73 de Brian, VK2GCE

?

?

Hi

I have repaired a number of HP8640B signal generators with similar faults, the TO3 sockets for the power supply pass transistors go faulty with time resulting in poor Base and Emitter connections.

G Edmonds G6HIG

On Mar 2, 2022, at 12:01 AM, Lothar baier <Lothar@...> wrote:

? Not surprised at all ! Virtually all “NI”

GPIB/USB adapters sold by Chinese vendors on ebay are Fake , unfortunately this also starts to spill over on US sellers as people who bought them from china and couldn’t get them to work are selling them again on ebay !

The best thing you can do is buy from a US seller a unit that is new in box , you can also check the unit to see if it has the little white barcode serial number label on it and run the serial number by NI?

On Mar 2, 2022, at 00:00, Lou Blasco via groups.io <vk3alb@...> wrote:

?

Interesting Dave,

You must have installed NI drivers to get it to work. What version are you using?

Regards

Lou
VK3ALB

On 2/03/2022 16:47, Dave Miller wrote:

I purchased recently from EBL2018 on a NI USB HS and it seemed to recognize fine on time labs.
I can’t say 100% that I did anything else other than plugging it in and seeing software found it   FWIW. It looks exactly like the one I purchased from NI a few years ago. 

Dave
VE7HR 

On Mar 1, 2022, at 9:43 PM, Lou Blasco <vk3alb@...> wrote:

?Thanks All,

It probably won't surprise you as much as it disappointed me to learn that I bought a fake adapter from eBay. The seller gave me all my money back in a heartbeat as soon as I lodged a complaint so I guess he had an idea of what he was doing. 

-- 
Regards

Lou
VK3ALB

On Mar 2, 2022, at 00:42, Matt Huszagh via groups.io <huszaghmatt@...> wrote:

?What’s the test set and does it provide any reason why it requires a newer serial number source? I had a compatibility issue with my 8341 and 8510C but it was firmware related and simply fixed by flashing newer firmware (I believe it needed the April ‘92 though I can check to be sure if you’d like to know). I have a copy of this firmware but you can also download it from ko4bb (FYI I found the 8340 and 8341 firmware to be identical). If there are actual hardware changes needed I’d be curious to hear this too.

?Matt

On Mar 2, 2022, at 00:00, Lou Blasco via groups.io <vk3alb@...> wrote:

?

Interesting Dave,

You must have installed NI drivers to get it to work. What version are you using?

Regards

Lou
VK3ALB

On 2/03/2022 16:47, Dave Miller wrote:

I purchased recently from EBL2018 on a NI USB HS and it seemed to recognize fine on time labs.
I can’t say 100% that I did anything else other than plugging it in and seeing software found it   FWIW. It looks exactly like the one I purchased from NI a few years ago. 

Dave
VE7HR 

On Mar 1, 2022, at 9:43 PM, Lou Blasco <vk3alb@...> wrote:

?Thanks All,

It probably won't surprise you as much as it disappointed me to learn that I bought a fake adapter from eBay. The seller gave me all my money back in a heartbeat as soon as I lodged a complaint so I guess he had an idea of what he was doing. 

-- 
Regards

Lou
VK3ALB