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Re: Fail over input board for the HP-5087A distribution amplifier
Ed, Count me in, that would be a nice feature for my 5087A. Ron
By Ron · #151239 ·
Re: 8594E Cal Signal not Found ?
I had an edit failure resulting in the wrong draft being sent. (Wipes egg off face)
By Ed Marciniak · #151238 ·
Re: 8594E Cal Signal not Found ?
Ed, You are incorrect on the size.? The Intel HEX format provided at KO4BB is two bytes of ASCII to be converted to one byte of binary, plus the Intel format includes some overhead for each record
By Mark Litwack · #151237 ·
Re: 8594E Cal Signal not Found ?
The files in the folder referenced are 636KB each as hex. As binary, that should be around 512KBytes each, or 4 megabits. I guess you could do the math on whether your two chips hold 8 megabits
By Ed Marciniak · #151236 ·
Re: 8594E Cal Signal not Found ?
Mark, great thanks I actually found 4 AMD AM27C020’s I will use them they state they have HP 859XE 95-09-14 on them. I kind of remember picking them up at a hamfest a few years ago and some digging
By KB2LMN · #151235 ·
Re: 8594E Cal Signal not Found ?
That is the latest firmware on KO4BB. Look at the size of the four HEX files when loaded into your programmer. ?You will need (4) 27C020-150 2Mbit (256kbyte) EEPROMs to hold them all. The firmware
By Mark Litwack · #151234 ·
Re: 8594E Cal Signal not Found ?
Well I believe I found the newest software https://www.ko4bb.com/getsimple/index.php?id=manuals&dir=01_ROM_Images_and_Drivers/HP_8590/HP_-_8590-ROM-1998/98-06-15 My question is I only have 2 EPROMS
By KB2LMN · #151233 ·
Re: Intermittent REF UNLOCK error message on 8591A Spectrum Analyzer
Hi Anders, I'm glad to hear that you were able to fix your Spectrum's 600 MHz VCXO circuit and get it working. Yves
By Yves Tardif · #151231 ·
Re: Manuals for an HP3456B DMM?
The 3456A is a very nice meter, and I think the only of its sort HP ever certified as a transfer standard. There are a couple of failures you should watch for. First, the more desirable is the
By Chuck Harris · #151230 ·
Re: 8594E Cal Signal not Found ?
Yves thanks for sharing that info after I read the ENTIRE how to input constants section I found at the very end a work around so I’m good now. Now I’m just looking for the newest firmware version
By KB2LMN · #151229 ·
Re: 8594E Cal Signal not Found ?
Mark I did get everything working last night thank to your help I appreciate it! I ran it through some tests and it passed them all so the firmware was my next leap. Fortunately I have done some chip
By KB2LMN · #151228 ·
Re: Intermittent REF UNLOCK error message on 8591A Spectrum Analyzer
I am very impressed by your knowledge Yves! My spectrum analyzer is fixed now - at least sort of fixed. My fix was to replace C75, change from 3.3 pF to 2.2 pF. Conditions after the fix: 300 MHz
By Anders L??v · #151227 ·
Re: 8594E Cal Signal not Found ?
I repaired an 8591A for a friend two weeks ago, and he had the same problem. In his case, it had lost its calibration constants due to a low battery. What caused the signal not found or LOCK
By Yves Tardif · #151226 ·
Re: 8594E Cal Signal not Found ?
Hi Andrew, It's ok to have 2 or 4 EEPROMs for version G (94.03.15).? You can read about the various versions and EEPROM part numbers here (original doc
By Mark Litwack · #151225 ·
Re: 8594E Cal Signal not Found ?
Mark, my 8594E only has 2ea firmware chips U24 & U27, is this normal? Everything I seem to find about this unit says 4 chips? I was trying to see if I had the latest firmware installed.
By KB2LMN · #151224 ·
Fail over input board for the HP-5087A distribution amplifier
Recently saw a you tube video of an HP-5087A with an HP designed (I think) fail over amplifier board. I have never seen any documentation on the board before. The board takes a signal from two of the
By Ed (scskits) · #151223 ·
Re: Intermittent REF UNLOCK error message on 8591A Spectrum Analyzer
Anders, So, in green is the active bias stage, R66 serves as the current sense. In my case, I have 5.186V, which means that the collector current of Q13 is about 9.8mA. In blue is the
By Yves Tardif · #151222 ·
Re: 8594E Cal Signal not Found ?
Thanks Mark, ya I did all that but did just see this so I will try next. Instrument firmware expects the cal output signal to be 300 MHz ± 2 MHz.Sometimestheinstrument default data is not able to
By KB2LMN · #151221 ·
Re: 8594E Cal Signal not Found ?
The workaround for the "Cal Signal Not Found" error is covered in the Assembly Level Repair manual. If you had to reload all the correction constants, I would start with the "Analyzer Initialization"
By Mark Litwack · #151220 ·
8594E Cal Signal not Found ?
After replacing battery I entered the Time Base Correction, Frequency Response Correction & Step Attenuator Corrections. Now when I go to perform Cal Freq or Cal Amptd I’m getting a Cal Signal Not
By KB2LMN · #151219 ·