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Re: HP5335A fan replacement
Many now have integral sensors. They run slow until they sense increased temperature then increase to maintain temperature of the airflow. Peter
By Peter Gottlieb · #95423 ·
Re: HP5335A fan replacement
Usually the temp sensing fans have additional wiring to the sensing element (which is often located elsewhere in the equipment), so it may not be that¡­ Regards Nigel Sent: 25 March 2019 14:56 To:
By nigel adams · #95422 ·
Re: on using Logic Analyzers to understand and reverse engineer systems
An additional comment about telling clocks from serial buses. The spectrum analyzer display will tell you if the signal is modulated. I was just getting started reverse engineering an Instek GDS-2072E
By Reginald Beardsley · #95421 ·
Re: HP8664A with issues
Harke, if that ROM is U32, that's the attenuator assembly cal constants ROM. Definitely make a backup of that & tag it with the serial number of your attenuator assembly if you ever end up with
By Colby Burkett · #95420 ·
Re: HP5335A fan replacement
I didn¡¯t mean to suggest that but it¡¯s an intriguing possibility. Peter
By Peter Gottlieb · #95419 ·
Re: HP5335A fan replacement
PeterG are you suggesting that the fan I used was a temperature sensing fan and this is what I was seeing where it began to roar at full speed after about 30 minutes? This would explain a lot. It was
By peter bunge · #95418 ·
Re: on using Logic Analyzers to understand and reverse engineer systems
Ouch. This is when you shoot the programmer, and all of his managment that allowed any of this to happen.
By Harvey White · #95417 ·
Re: on using Logic Analyzers to understand and reverse engineer systems
Now this can be nasty.... Well, there are only so many formats to consider. In terms of parallel, you look for lines changing, then some sort of control strobe. In terms of serial, you look for known
By Harvey White · #95416 ·
Re: HP5335A fan replacement
In this case, the power supply is for a 500W 2M amplifier. Maximum draw is about 20 amps @ 50 volts, and that's never more than 50% duty cycle for <5 minute periods, so the 50A continuous supply is
By John Ackermann N8UR · #95415 ·
Re: HP5335A fan replacement
I have used temperature sensing fans as some are available with remote sensors which can be mounted on a hot item like a heat sink. You can¡¯t always do this, for example the Tek 2465 scope with
By Peter Gottlieb · #95414 ·
HP8664A with issues
Hello Group, I have obtained a very cheap HP8664A, but, of course, with issues. Ser no starts with 3744 but internal date codes show well into 2000. It has options 010, 004 and an oven. It has a
By Harke Smits · #95413 ·
Re: HP5335A fan replacement
Very interesting! An only slightly related learning: A few months ago I wanted to replace the very noisy and over-rated fan on a power supply with something quieter. I got a nice unit that was a
By John Ackermann N8UR · #95412 ·
Re: HP5335A fan replacement
*A lesson to be learned about fans.* *HP8753B Fan Repair* *Problem* The analyzer is not working *Symptoms* The fan is not running. The analyzer will not work if the fan is not running. *Repair* Fan
By peter bunge · #95411 ·
Re: 431B Power Meter
At 2019-03-24 12:53 PM, [email protected] wrote: Does anyone know where I can find a line cord to fit it? I found the operating and service manual, and I'd like to get it back to operating condition. I'll
By Steve Hendrix · #95410 ·
Re: on using Logic Analyzers to understand and reverse engineer systems
BTW For finding clocks, a spectrum analyzer and a small H field probe is much better than a scope. Less risk of disturbing the circuit operation and it's easy to locate the clock lines even if they
By Reginald Beardsley · #95409 ·
Re: on using Logic Analyzers to understand and reverse engineer systems
I can't speak to doing this in HW, but I spent many years fixing large (>50KLOC) programs which had *no* comments other than the author's name. In the aggregate about 2 million lines. I relied on my
By Reginald Beardsley · #95408 ·
Re: 8753ES YTO freq vs. Main Coil mA
Hi Peter I don't know this instrument, but here a couple of things I would check.. I cant remember if you already checked this, but can you connect a coupler to the 3.8GHz oscillator, to tap of a
By Askild · #95407 ·
on using Logic Analyzers to understand and reverse engineer systems
In addition to debugging my own designs, one of my common use cases for using logic analyzers is to peer into designs of existing hardware systems. These systems are sometimes poorly documented with
By Keith Monahan · #95406 ·
Re: 16900A cleanup and modernization experience including installation notes!
Not a problem. I sometimes wonder what I'd do with all the channels. Most
By Harvey White · #95405 ·
Re: 16900A cleanup and modernization experience including installation notes!
Responses in-line Heh. I was mostly bragging because I'm excited about the possibilities! :) So forgive me! I've got a fully-loaded 16700 too. Yeah scrolling through those is a bit painful. I've done
By Keith Monahan · #95404 ·