HP8350B Sweep Oscillator with 83522A RF Plug-in - callibration procedure - UK Vintage Radio Repair and Restoration Discussion Forum

Ti Pwun · 26th Aug 2015, 11:52 pm

Not sure if it's feasible to calibrate this gear myself or not but I won't know unless I can look at the procedure. Does anyone have a pdf?

I did try to align a radio with it but it's too far off to be usable. 10.7, for example, is lower on the scope trace than the 10MHz crystal marker! When I setup a sweep between 9.7 and 11.7MHz, I need to move the 'centre' marker to 4.5MHz for it to show up between the start and stop frequencies.

I'm presuming it's just a calibration issue; everything seems to work - it just isn't where it should be.

I may need to have it calibrated by someone but that is something I can't afford at the minute! :/

PETERg0rsq · 27th Aug 2015, 12:16 am

Service manuals, containing calibration information are available from the Keysight website

http://literature.cdn.keysight.com/litweb/pdf/08350-90092.pdf?id=813133

http://literature.cdn.keysight.com/litweb/pdf/83522-90003.pdf?id=1900255

You effectively have two instruments to calibrate!

I have not read the calibration procedure, but guess it will require some pretty good equipment, operating into the GHZ frequencies.

However you are using this at one extreme of its usable range

This instrument covers 10MHz to 2.4GHz, so anything down in the 10MHz range will be marginal for accuracy or stability, depending on how well the instrument is set up.

It is not really the best instrument for sweeping a 10.7MHz IF.

Peter

Ti Pwun · 27th Aug 2015, 2:48 am

Thanks - I did look there but didn't see them. Very tired so that didn't help.

I have something more suitable for down at the lower end for radio work but it requires parts so I'm just hoping to get this thing close enough at around 10MHz that I can use it for the radios I am working on. For the higher frequencies I definitely need to send it somewhere but I'll see what the manuals have to say.

Thanks again - appreciate the links.

Radio Wrangler · 27th Aug 2015, 6:52 am

I'm afraid calibration won't help you.

These are open-loop sweepers where an analogue voltage tunes a free-running oscillator. The 83522 manual gives the specs. Accuracy +/-5MHz in 'CW' mode (= not sweeping) and +/-15MHz in sweep modes.

With this spec, the output frequency couldn't just have been on the wrong side of 10MHz, it could have been negative ! It's a machine designed for testing and aligning broadband microwave stuff.

For moderate precision, they were used with an external frequency counter counting the frequency at one of the markers. Smart users mixed in the output of an accurate stable sig gen (synthesised) to put a blip marker on the trace of the display or plot at an accurate frequency.

Note also that its spec includes drift of up to 100kHz per 10 minutes.

Sorry, but at least I can save you from blowing a lot of money on calibration.

David

Ti Pwun · 27th Aug 2015, 11:59 am

Thanks - your expertise is very much appreciated. I didn't have time last night to study the manuals anyway.

Can I ask that this thread please now be closed - the unit is being returned and no further discussion is required. Much appreciated for the responses.

26th Aug 2015, 11:52 pm	#1
Ti Pwun Heptode Join Date: Aug 2013 Location: Bradford, West Yorkshire, UK. Posts: 888	HP8350B Sweep Oscillator with 83522A RF Plug-in - callibration procedure Not sure if it's feasible to calibrate this gear myself or not but I won't know unless I can look at the procedure. Does anyone have a pdf? I did try to align a radio with it but it's too far off to be usable. 10.7, for example, is lower on the scope trace than the 10MHz crystal marker! When I setup a sweep between 9.7 and 11.7MHz, I need to move the 'centre' marker to 4.5MHz for it to show up between the start and stop frequencies. I'm presuming it's just a calibration issue; everything seems to work - it just isn't where it should be. I may need to have it calibrated by someone but that is something I can't afford at the minute! :/ Last edited by Ti Pwun; 27th Aug 2015 at 12:04 am.

27th Aug 2015, 12:16 am	#2
PETERg0rsq Heptode Join Date: Jun 2009 Location: St Helens, Lancashire, UK. Posts: 641	Re: HP8350B Sweep Oscillator with 83522A RF Plug-in - callibration procedure Service manuals, containing calibration information are available from the Keysight website http://literature.cdn.keysight.com/litweb/pdf/08350-90092.pdf?id=813133 http://literature.cdn.keysight.com/litweb/pdf/83522-90003.pdf?id=1900255 You effectively have two instruments to calibrate! I have not read the calibration procedure, but guess it will require some pretty good equipment, operating into the GHZ frequencies. However you are using this at one extreme of its usable range This instrument covers 10MHz to 2.4GHz, so anything down in the 10MHz range will be marginal for accuracy or stability, depending on how well the instrument is set up. It is not really the best instrument for sweeping a 10.7MHz IF. Peter __________________ SPECIALIST.....Knows everything about nothing EXPERT..........Knows nothing about everything

27th Aug 2015, 2:48 am	#3
Ti Pwun Heptode Join Date: Aug 2013 Location: Bradford, West Yorkshire, UK. Posts: 888	Re: HP8350B Sweep Oscillator with 83522A RF Plug-in - callibration procedure Thanks - I did look there but didn't see them. Very tired so that didn't help. I have something more suitable for down at the lower end for radio work but it requires parts so I'm just hoping to get this thing close enough at around 10MHz that I can use it for the radios I am working on. For the higher frequencies I definitely need to send it somewhere but I'll see what the manuals have to say. Thanks again - appreciate the links.

27th Aug 2015, 6:52 am	#4
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,858	Re: HP8350B Sweep Oscillator with 83522A RF Plug-in - callibration procedure I'm afraid calibration won't help you. These are open-loop sweepers where an analogue voltage tunes a free-running oscillator. The 83522 manual gives the specs. Accuracy +/-5MHz in 'CW' mode (= not sweeping) and +/-15MHz in sweep modes. With this spec, the output frequency couldn't just have been on the wrong side of 10MHz, it could have been negative ! It's a machine designed for testing and aligning broadband microwave stuff. For moderate precision, they were used with an external frequency counter counting the frequency at one of the markers. Smart users mixed in the output of an accurate stable sig gen (synthesised) to put a blip marker on the trace of the display or plot at an accurate frequency. Note also that its spec includes drift of up to 100kHz per 10 minutes. Sorry, but at least I can save you from blowing a lot of money on calibration. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

27th Aug 2015, 11:59 am	#5
Ti Pwun Heptode Join Date: Aug 2013 Location: Bradford, West Yorkshire, UK. Posts: 888	Re: HP8350B Sweep Oscillator with 83522A RF Plug-in - callibration procedure Thanks - your expertise is very much appreciated. I didn't have time last night to study the manuals anyway. Can I ask that this thread please now be closed - the unit is being returned and no further discussion is required. Much appreciated for the responses. Last edited by Ti Pwun; 27th Aug 2015 at 12:06 pm.