SCORE! Bought a bunch of stuff on a pallet sale

[tkamiya]

No, I don't remember model numbers....  since I wasn't going to work on it anyway.  I recall; however, there were circular port with like 8 pins.  There were 2 or 4 ports in front.  Rotary encoder knob was little higher than middle of the front panel.  Really odd placement.... I thought.  It's an HP kind.  Does it ring a bell?

In fact, I have something older here and I have no idea even as to how to test it. 

I have a few directional couplers, return loss bridge, home made and brand named, SA and TG.  With it, I can characterize real portion of filters, amplifiers, antennas, etc.  I have yet to master Smith Chart, so imaginary part means nothing to me. 

[Berni]

Well all the brains are inside the display unit as that contains the main CPU and ADC that samples the output of the RF section.

By the way the CPU in these things is built out of 7400 series logic ALUs, latches and gates. No hardware multiply of course.

[tkamiya]

On these, the top section, commonly called a display section is quite a bit more than just display stuff.  It contains I/F section, graticule generation, RF section controller, etc.  So it would be quite a task to recreate it.  The RF section, of course, contains RF stuff only. 


I am not sure if I want to invest another $500 and up to get the LCD display.  Rest of the unit is over 30 years old.  As I work on these, I realize all the capacitors, connectors, and all the stuff that can deteriorate can go any time.  The STUPID cables are causing me some headache.  Over the years, pressure contact surfaces lost springiness that they sometime do funky things.  I really don't think they are worth keep putting more money into.  I think, I would rather get a Rigol with LCD for $1000 more.  That would be a rather nice addition. 


They do have the XYZ output.  So I'm thinking an external display would be nice.  I have few ideas involving few AD converters and a PC.  I also have a plotter, so that can be used as well, EXCEPT the plotter only has a serial input. 

[tkamiya]

No it isn't!  The CPU on B models is 68000 running at 8Mhz.  A model had HP's home grown calculator based CPU.  A to B upgrade was available at one time for something like $5000....

[bitseeker]

Well, that's a shame that the "brains" seem to be going into landfills in large numbers. I guess calling it only a "display" wasn't such a good idea on HP's part, either.

[tkamiya]

and cables....  They end up on Ebay for insane amount of money.  I've managed to DIY the coax cable.  But the BUS cable is something else.  Not being 1-1 connection makes it a complex task to do it right for all the 50 pins.

[tkamiya]

All I've been doing with all of my test equipment is fixing more test equipment.  These are like rabbits.  They multiply in duplicates and triplicates. 

[bitseeker]

Oh, yes. That's a completely normal outcome (or problem, depending on how you look at it).

[SoundTech-LG]

I think I found them (on manual which is not searchable!)

Looks like FRO (Front Panel?) and DGEN (Data Generation) modules....  then I have to unlock the general key then each key?  This is really different from HP that I'm fast becoming familiar with.

Kind of interesting....  Very similar to how German car makers write their manuals...

Yep... here's the photos of the module, and also the Front panel Batt. As usual R/S buries these deeply into the damn thing making it simple to replace Makes it super simple to steer the customer into buying something new, and modern as well, once they quote replacement prices, if they will even look at it at all...  BTW, I had to replace that battery marked 3.46V it would not cut it according to the CAL procedure, and gave ERROR. You may/may not have to do a CAL.