From: [email protected] [mailto:[email protected]] On Behalf Of Ken Goodhew
Sent: Thursday, February 20, 2020 18:04
To: [email protected]
Subject: [HP-Agilent-Keysight-equipment] hp 83592A problem

?

Hi Gang,
I have an 8350b fitted with an 83592A plug in.
The problem exhibits as no control over the output power,but the unleveled indicator is not illuminated and the output power indication responds to the power control knob as it should.
It sorta puts out full unleveled power, but the actual output power varies from + 5 dbm to +15dbm depending on the frequency.
I originally thought this was an ALC fault (A4) and after much trouble shooting i noticed that after looking at the output with a spectrum analyzer i? that the output starting at 10mhz up until about 1 ghz consisted of multiple signals which slowly disappear as you approach 1 ghz.
After 1 ghz there is only the one signal at about 15-18 dbm ( i can only go to 1.8ghz on the spectrum analyzer).
Now for the tricky part, this distortion only occurs when actually sweeping the band, if i manually vary the frequency from 1.8ghz right down to 10mhz the output consists of one signal only!
Any suggestions as where to look?
Ken VK2TKE.

?

What do you see when you slow the 8350 sweep rate down to be much slower than the sweep rate of the spec an?

DaveB, NZ

?

?

From: [email protected] [mailto:[email protected]] On Behalf Of Ken Goodhew
Sent: Thursday, February 20, 2020 18:04
To: [email protected]
Subject: [HP-Agilent-Keysight-equipment] hp 83592A problem

?

Hi Gang,
I have an 8350b fitted with an 83592A plug in.
The problem exhibits as no control over the output power,but the unleveled indicator is not illuminated and the output power indication responds to the power control knob as it should.
It sorta puts out full unleveled power, but the actual output power varies from + 5 dbm to +15dbm depending on the frequency.
I originally thought this was an ALC fault (A4) and after much trouble shooting i noticed that after looking at the output with a spectrum analyzer i? that the output starting at 10mhz up until about 1 ghz consisted of multiple signals which slowly disappear as you approach 1 ghz.
After 1 ghz there is only the one signal at about 15-18 dbm ( i can only go to 1.8ghz on the spectrum analyzer).
Now for the tricky part, this distortion only occurs when actually sweeping the band, if i manually vary the frequency from 1.8ghz right down to 10mhz the output consists of one signal only!
Any suggestions as where to look?
Ken VK2TKE.

?

Hi Dave,

??????????????? The sweep rate for the sweeper was 10 seconds for 10 mhz to 1.8ghz as depicted in the picture

?

?

What do you see when you slow the 8350 sweep rate down to be much slower than the sweep rate of the spec an?

DaveB, NZ

?

?

From: [email protected] [mailto:[email protected]] On Behalf Of Ken Goodhew
Sent: Thursday, February 20, 2020 18:04
To: [email protected]
Subject: [HP-Agilent-Keysight-equipment] hp 83592A problem

?

Hi Gang,
I have an 8350b fitted with an 83592A plug in.
The problem exhibits as no control over the output power,but the unleveled indicator is not illuminated and the output power indication responds to the power control knob as it should.
It sorta puts out full unleveled power, but the actual output power varies from + 5 dbm to +15dbm depending on the frequency.
I originally thought this was an ALC fault (A4) and after much trouble shooting i noticed that after looking at the output with a spectrum analyzer i? that the output starting at 10mhz up until about 1 ghz consisted of multiple signals which slowly disappear as you approach 1 ghz.
After 1 ghz there is only the one signal at about 15-18 dbm ( i can only go to 1.8ghz on the spectrum analyzer).
Now for the tricky part, this distortion only occurs when actually sweeping the band, if i manually vary the frequency from 1.8ghz right down to 10mhz the output consists of one signal only!
Any suggestions as where to look?
Ken VK2TKE.

?

set 8350b to 15 mhz cw and did a single sweep on the spectrum analyzer and it produced a similar waveform to the previous picture, just a bit more squashed up.

?

Thanks Jim will let you know, would be probably to measure signal levels as it appears that the problem is related to harmonics in band 0 so I have to measure a few signals to see if they are correct before proceeding further.

Ken.

?

?

set 8350b to 15 mhz cw and did a single sweep on the spectrum analyzer and it produced a similar waveform to the previous picture, just a bit more squashed up.

?

Been away all day Ken- just back. If that? CW signal is producing multiple sigs ?on the spec an then it should be easy enuff to check if they are harmonically related to the fundamental. I see you are using 3MHZ RBW so incidental FM etc on the sweeper output shouldn’t be causing any confusion. If you have multiple sigs, see if they reduce significantly with higher freq ?ones reducing the most when you drop the input to the spec an. They may not, but worth it to check. ?If they do reduce then its just? an overdriven spec an mixer causing much of the issue. ??If they are NOT harmonically related to the ?CW sig ex the sweeper then ?you probably need to dig further into the 8350/plugin. Do you get much the same result with the CW sig set much higher, say to around 600 MHz?

?Not sure all ?this addresses your original issue where the signals on the spec an were all a more or less constant 120 MHz or so apart up to 1.8 GHz- but sort this one first. ?

?DaveB, NZ

?

?

?

Thanks Jim will let you know, would be probably to measure signal levels as it appears that the problem is related to harmonics in band 0 so I have to measure a few signals to see if they are correct before proceeding further.

Ken.

?

?

set 8350b to 15 mhz cw and did a single sweep on the spectrum analyzer and it produced a similar waveform to the previous picture, just a bit more squashed up.

?

Hi Dave

?????????????? Checked the signals and they are all exactly harmonically related, dropping the input to the spec analyzer by 9db with fixed attenuators just lowers the signals by 9db so it is not overdriving the spec analyzer

Setting the generator to 600 mhz does lower the harmonics but they are then 600 mhz apart

By the time I get to 1ghz the harmonics are -40 db down from the fundamental which is not too bad

So whatever is causing the problem, which the service manual suggest could be low drive in to the internal mixer, is only mainly affecting the lower portion of band 0 below about 500 mhz to any great extent.

Time to measure the 3.9 ghz ?signal level into the mixer which I tried to do yesterday but with the cables I had I had to use a 2m length of rg58 to get the right connectors so the attenuation at that frequency would be pretty high.

Trying to find some figure was impossible so I took a wild guess at the figure and came up with about 5 db when added to the level of 5.4 db I measured means the signal is only about 10.4 db well below the 13.5 db specified.

So on the way home yesterday I brought a N to SMA adaptor so I ?can put the power sensor right at the end of the hard line to measure the input into the mixer.

If that signal is low then I need to chase back through the circuit to see where it is being lost.

I have had to mechanically dismantle some of the case to get to the hard line SMA connectors as it is tucked in under the side rails of the chassis

Hope it is not one of those modules down there in the RF section as the manual warns that they are not repairable and very expensive and by now probably unobtainium other than from a parts unit.

Will advise further

Ken

VK2TKE

Sent from for Windows 10

?

?

Been away all day Ken- just back. If that? CW signal is producing multiple sigs ?on the spec an then it should be easy enuff to check if they are harmonically related to the fundamental. I see you are using 3MHZ RBW so incidental FM etc on the sweeper output shouldn’t be causing any confusion. If you have multiple sigs, see if they reduce significantly with higher freq ?ones reducing the most when you drop the input to the spec an. They may not, but worth it to check. ?If they do reduce then its just? an overdriven spec an mixer causing much of the issue. ??If they are NOT harmonically related to the ?CW sig ex the sweeper then ?you probably need to dig further into the 8350/plugin. Do you get much the same result with the CW sig set much higher, say to around 600 MHz?

?Not sure all ?this addresses your original issue where the signals on the spec an were all a more or less constant 120 MHz or so apart up to 1.8 GHz- but sort this one first. ?

?DaveB, NZ

?

?

?

Thanks Jim will let you know, would be probably to measure signal levels as it appears that the problem is related to harmonics in band 0 so I have to measure a few signals to see if they are correct before proceeding further.

Ken.

?

?

set 8350b to 15 mhz cw and did a single sweep on the spectrum analyzer and it produced a similar waveform to the previous picture, just a bit more squashed up.

?

Seems like you are onto it now Ken. ??Yes, digging round in the guts of this “old but good” gear can be darned awkward sometimes-hope you can get things sorted. ?Lets know how you get on.

Cheers

DaveB, NZ

?

?

Hi Dave

?????????????? Checked the signals and they are all exactly harmonically related, dropping the input to the spec analyzer by 9db with fixed attenuators just lowers the signals by 9db so it is not overdriving the spec analyzer

Setting the generator to 600 mhz does lower the harmonics but they are then 600 mhz apart

By the time I get to 1ghz the harmonics are -40 db down from the fundamental which is not too bad

So whatever is causing the problem, which the service manual suggest could be low drive in to the internal mixer, is only mainly affecting the lower portion of band 0 below about 500 mhz to any great extent.

Time to measure the 3.9 ghz ?signal level into the mixer which I tried to do yesterday but with the cables I had I had to use a 2m length of rg58 to get the right connectors so the attenuation at that frequency would be pretty high.

Trying to find some figure was impossible so I took a wild guess at the figure and came up with about 5 db when added to the level of 5.4 db I measured means the signal is only about 10.4 db well below the 13.5 db specified.

So on the way home yesterday I brought a N to SMA adaptor so I ?can put the power sensor right at the end of the hard line to measure the input into the mixer.

If that signal is low then I need to chase back through the circuit to see where it is being lost.

I have had to mechanically dismantle some of the case to get to the hard line SMA connectors as it is tucked in under the side rails of the chassis

Hope it is not one of those modules down there in the RF section as the manual warns that they are not repairable and very expensive and by now probably unobtainium other than from a parts unit.

Will advise further

Ken

VK2TKE

Sent from for Windows 10

?

?

Been away all day Ken- just back. If that? CW signal is producing multiple sigs ?on the spec an then it should be easy enuff to check if they are harmonically related to the fundamental. I see you are using 3MHZ RBW so incidental FM etc on the sweeper output shouldn’t be causing any confusion. If you have multiple sigs, see if they reduce significantly with higher freq ?ones reducing the most when you drop the input to the spec an. They may not, but worth it to check. ?If they do reduce then its just? an overdriven spec an mixer causing much of the issue. ??If they are NOT harmonically related to the ?CW sig ex the sweeper then ?you probably need to dig further into the 8350/plugin. Do you get much the same result with the CW sig set much higher, say to around 600 MHz?

?Not sure all ?this addresses your original issue where the signals on the spec an were all a more or less constant 120 MHz or so apart up to 1.8 GHz- but sort this one first. ?

?DaveB, NZ

?

?

?

Thanks Jim will let you know, would be probably to measure signal levels as it appears that the problem is related to harmonics in band 0 so I have to measure a few signals to see if they are correct before proceeding further.

Ken.

?

?

set 8350b to 15 mhz cw and did a single sweep on the spectrum analyzer and it produced a similar waveform to the previous picture, just a bit more squashed up.

?

Hi Dan

?

Thank you for the line

?

* Blue Shift 92 and Blue Shift 93 will change some tuning constants for the YTM tracking

?

This is a new one for me

?

Ken:

Hi...A couple of things you can try:
* Put your spec an on the AUX connector on the rear. Make sure the levels there are as the manual suggests for the full sweep of the 7 - 13.5 GHz band. This signal is from a splitter of the signal from the power amp inside as it is applied to the balance of the RF stuff.
* Blue Shift 92 and Blue Shift 93 will change some tuning constants for the YTM tracking and such. The constants are changed from the rotary knob on the plug in. These are not saved, but you can check to see if it affects the RF.

Dan in Chandler, AZ

No virus found in this message.
Checked by AVG -
Version: 2016.0.8048 / Virus Database: 4793/15886 - Release Date: 08/14/18
Internal Virus Database is out of date.

?

Been away all day Ken- just back. If that? CW signal is producing multiple sigs ?on the spec an then it should be easy enuff to check if they are harmonically related to the fundamental. I see you are using 3MHZ RBW so incidental FM etc on the sweeper output shouldn’t be causing any confusion. If you have multiple sigs, see if they reduce significantly with higher freq ?ones reducing the most when you drop the input to the spec an. They may not, but worth it to check. ?If they do reduce then its just? an overdriven spec an mixer causing much of the issue. ??If they are NOT harmonically related to the ?CW sig ex the sweeper then ?you probably need to dig further into the 8350/plugin. Do you get much the same result with the CW sig set much higher, say to around 600 MHz?

?Not sure all ?this addresses your original issue where the signals on the spec an were all a more or less constant 120 MHz or so apart up to 1.8 GHz- but sort this one first. ?

?DaveB, NZ

?

?

?

Thanks Jim will let you know, would be probably to measure signal levels as it appears that the problem is related to harmonics in band 0 so I have to measure a few signals to see if they are correct before proceeding further.

Ken.

?

?

set 8350b to 15 mhz cw and did a single sweep on the spectrum analyzer and it produced a similar waveform to the previous picture, just a bit more squashed up.

No virus found in this message.
Checked by AVG -
Version: 2016.0.8048 / Virus Database: 4793/15886 - Release Date: 08/14/18
Internal Virus Database is out of date.

Hi Ken

?

You say (on the way home yesterday I brought a N to SMA adaptor )

?

You are lucky as in the uk that would be imposable from a high street store or amateur radio store ?

?

Radio spares would be the only retailer to pick up from but we do have Farnell & dige key by mail

?

We still have people in the UK that think the PL259 connector is good for UHF then complain when there SWR is out at 23 CM

?

Paul UK

?

---

From: HP-Agilent-Keysight-equipment@groups.io [mailto:HP-Agilent-Keysight-[email protected]] On Behalf Of Dave Brown
Sent: 22 February 2020 00:08
To: HP-Agilent-Keysight-equipment@groups.io
Subject: Re: [HP-Agilent-Keysight-equipment] hp 83592A problem

?

Seems like you are onto it now Ken. ??Yes, digging round in the guts of this “old but good” gear can be darned awkward sometimes-hope you can get things sorted.? Lets know how you get on.

Cheers

DaveB, NZ

?

From: HP-Agilent-Keysight-equipment@groups.io [mailto:HP-Agilent-Keysight-[email protected]] On Behalf Of Ken Goodhew
Sent: Saturday, February 22, 2020 12:36
To: HP-Agilent-Keysight-equipment@groups.io
Subject: Re: [HP-Agilent-Keysight-equipment] hp 83592A problem

?

Hi Dave

?????????????? Checked the signals and they are all exactly harmonically related, dropping the input to the spec analyzer by 9db with fixed attenuators just lowers the signals by 9db so it is not overdriving the spec analyzer

Setting the generator to 600 mhz does lower the harmonics but they are then 600 mhz apart

By the time I get to 1ghz the harmonics are -40 db down from the fundamental which is not too bad

So whatever is causing the problem, which the service manual suggest could be low drive in to the internal mixer, is only mainly affecting the lower portion of band 0 below about 500 mhz to any great extent.

Time to measure the 3.9 ghz ?signal level into the mixer which I tried to do yesterday but with the cables I had I had to use a 2m length of rg58 to get the right connectors so the attenuation at that frequency would be pretty high.

Trying to find some figure was impossible so I took a wild guess at the figure and came up with about 5 db when added to the level of 5.4 db I measured means the signal is only about 10.4 db well below the 13.5 db specified.

So on the way home yesterday I brought a N to SMA adaptor so I ?can put the power sensor right at the end of the hard line to measure the input into the mixer.

If that signal is low then I need to chase back through the circuit to see where it is being lost.

I have had to mechanically dismantle some of the case to get to the hard line SMA connectors as it is tucked in under the side rails of the chassis

Hope it is not one of those modules down there in the RF section as the manual warns that they are not repairable and very expensive and by now probably unobtainium other than from a parts unit.

Will advise further

Ken

VK2TKE

Sent from for Windows 10

?

From: Dave Brown
Sent: Friday, February 21, 2020 6:14 PM
To: HP-Agilent-Keysight-equipment@groups.io
Subject: Re: [HP-Agilent-Keysight-equipment] hp 83592A problem

?

Been away all day Ken- just back. If that? CW signal is producing multiple sigs ?on the spec an then it should be easy enuff to check if they are harmonically related to the fundamental. I see you are using 3MHZ RBW so incidental FM etc on the sweeper output shouldn’t be causing any confusion. If you have multiple sigs, see if they reduce significantly with higher freq ?ones reducing the most when you drop the input to the spec an. They may not, but worth it to check. ?If they do reduce then its just? an overdriven spec an mixer causing much of the issue. ??If they are NOT harmonically related to the ?CW sig ex the sweeper then ?you probably need to dig further into the 8350/plugin. Do you get much the same result with the CW sig set much higher, say to around 600 MHz?

?Not sure all ?this addresses your original issue where the signals on the spec an were all a more or less constant 120 MHz or so apart up to 1.8 GHz- but sort this one first. ?

?DaveB, NZ

?

?

From: HP-Agilent-Keysight-equipment@groups.io [mailto:HP-Agilent-Keysight-[email protected]] On Behalf Of Ken Goodhew
Sent: Friday, February 21, 2020 17:59
To: HP-Agilent-Keysight-equipment@groups.io
Subject: Re: [HP-Agilent-Keysight-equipment] hp 83592A problem

?

Thanks Jim will let you know, would be probably to measure signal levels as it appears that the problem is related to harmonics in band 0 so I have to measure a few signals to see if they are correct before proceeding further.

Ken.

?

From: HP-Agilent-Keysight-equipment@groups.io <HP-Agilent-Keysight-[email protected]> On Behalf Of Jim Ford
Sent: Friday, 21 February 2020 2:26 PM
To: HP-Agilent-Keysight-equipment@groups.io
Subject: Re: [HP-Agilent-Keysight-equipment] hp 83592A problem

?

Hi, Ken.

?

I have an 8350B and 83592B plug-in, both in perfect working order, as far as I know.? I don't mind ;) taking mine apart if there's something you want me to check vs your ailing beast.? Also 8566A spec an to check output purity etc.

?

Jim Ford?

?

?

?

?

?

Sent from my Verizon, Samsung Galaxy smartphone

?

-------- Original message --------

From: Ken Goodhew <kgoodhew@...>

Date: 2/20/20 3:19 AM (GMT-08:00)

To: HP-Agilent-Keysight-equipment@groups.io

Subject: Re: [HP-Agilent-Keysight-equipment] hp 83592A problem

?

set 8350b to 15 mhz cw and did a single sweep on the spectrum analyzer and it produced a similar waveform to the previous picture, just a bit more squashed up.

?

No virus found in this message.
Checked by AVG -
Version: 2016.0.8048 / Virus Database: 4793/15886 - Release Date: 08/14/18
Internal Virus Database is out of date.