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Re: 8594E input attenuator issue?
This video? https://www.youtube.com/watch?v=eChxU90OgGk HP RF Attenuators: o-ring repair 'Failed o-rings' means stuck o-rings, that prevent some actuator plungers from moving. Hence wrong
By Guy Dunphy · #121805 ·
8594E input attenuator issue?
Hi! In my quest to repair my SA, I am now facing a potential failed input attenuator. The dbm readings are within specs as long as I use a multiple of 20 in the attenuator setting. For example,
By Nicolas Mailloux · #121804 ·
Re: New to the group, troubleshooting HP4261A
I tried cold spray and I did clean all of the edge connectors. I also went ahead and refreshed the solder joints on all edge connectors contact points where they are soldered in place. Nothing about
By GeoVE3GZB <guslikokle@...> · #121803 ·
Re: HP35660a service manual, the complete version ?
Still looking :) Even the adjustments section is missing!!!
By Richard Merifield · #121802 ·
Re: New to the group, troubleshooting HP4261A
?This unit is old enough that the card edge connectors may not be gold plated, they may be tinned connectors. If so, cleaning and a very thin coating of De-Oxit would be a very good idea on all of
By Don Bitters · #121801 ·
Re: HP Diode ID Help
Hi Tom: I expect that a sorting machine, like that shown on my web page: https://prc68.com/I/RASS_PP.html#ALG would be setup to bin the diodes where each bin would be matched to some spec and there
By Brooke Clarke · #121800 ·
Re: HP 8566B repair: -10V rail went down
Get a thermal camera. They are dirt cheap nowadays, considering what they can do for you. -- john, KE5FX
By John Miles · #121799 ·
Re: HP 8566B repair: -10V rail went down
"Harvey White" <madyn@...> writes: I did check these, however, I couldn't discern any smell coming from the RIFA or the input filter, so I think they're probably not the source. I'll
By Matt Huszagh · #121798 ·
Re: HP Diode ID Help
I came across an old HP price list from 1971 where HP was asking a whopping $8.55 for the 5082-2308 matched pair. The matched quad was $27.15. At that time HP was also offering the individual
By Greg Muir · #121797 ·
Re: New to the group, troubleshooting HP4261A
Here is a video of the malfunction. Typically on first start up in the morning it runs normally and then slowly drifts into this state you see. The capacitor being attached is a brand new mica 820pF.
By GeoVE3GZB <guslikokle@...> · #121796 ·
Re: HP 8566B repair: -10V rail went down
------ I think your question is if -10V is supplying 1.5A from your measurement why a 5A fuse. ?Fuse in -10V section carries current of -5.2V supply in addition to -10V. The fuses are there in case
By Ozan · #121795 ·
Re: HP 8566B repair: -10V rail went down
So many very good responses. The old smoking tantalum cap issue. How many pieces of HP test equipment have I picked up for little cost because of those. I think shorted tantalums are my friend. That
By paulswed · #121794 ·
Re: HP Diode ID Help
Yes, indeed, matching to that level in general requires not insignificant effort, hence the reference to cost. However, if the diodes aren't from a random collection, but rather from the same general
By Tom Lee · #121793 ·
Re: HP8563E A6 powers supply-What is the maximum current per voltage rail
---------- Easier to guess for the supplies with IC regulators but a back of the envelope guess: +28V -> 1.5A -12.6 -> 1A +15V -> 3.7A -15V -> 3.1A +5V -> 7.8A -5V -> 1.4A These estimates depend on
By Ozan · #121792 ·
Re: HP Diode ID Help
Craig >
By Craig Sawyers · #121791 ·
Re: Dead 54720D
The cmp file is compressed, if I remember correctly it's a scheme similar to LZ77 or LZSS. I ended up desoldering the eeprom used for the bootloader (there's a 17th one off to the side of the main
By Mike Walters · #121790 ·
Re: HP 8566B repair: -10V rail went down
I have seen the power rail pass transistors fail - they are actually socketed to the motherboard with copper rivets. Failure mode: sometimes corrosion (copper oxide) between the motherboard and the
By Don Bitters · #121789 ·
Re: Dead 54720D
Great job!?What is that cmp file format - uncompresed from firmware release for 54750 unit ? Is it some sort of disk image ? can't open it by Ghidra, code analysis doesn't show anything for mc68k my
By Arkadiusz Gibes · #121788 ·
Re: Dead 54720D
Basically just from spending lots of time staring at the disassembly in Ghidra and making educated guesses about what the code is doing. I've attached a screenshot of the relevant parts of the code.
By Mike Walters · #121787 ·
Re: HP Diode ID Help
"I'm not rich enough to use cheap tools" -Dave
By Dave McGuire · #121786 ·