# 4:00 am dumpster dive



## acpeacemaker (Aug 1, 2011)

This was my load I picked up this morning. I will update some as I tear it down. Made me happy....


----------



## acpeacemaker (Aug 1, 2011)

One more


----------



## glorycloud (Aug 1, 2011)

Wow! I bet the gold fingers on the back of that unit will be worth
the effort to drag those bad boys out of the dumpster. 8)


----------



## scrapman1077 (Aug 1, 2011)

Not to mention that most HP stuff I have torn down have had aluminum frames !


----------



## Acid_Bath76 (Aug 1, 2011)

Time to get my jump suit on and start diving for buried treasure That's something!!


----------



## acpeacemaker (Aug 1, 2011)

I did manage to crack one open before I retired my night of fun. It was aluminum framing. Even the outer shell was painted aluminum. It also had a coil of copper about the size of a small football. Most of all the boards were gold plated and or the leads. Plus, three beautiful gold eproms gleaming up at me, as well as other things. I do have a question though as soon as I can get back I'll post a photo for it.


----------



## skeeter629 (Aug 1, 2011)

What kind of place was throwing that stuff away. I wish there were places like that around me.


----------



## acpeacemaker (Aug 1, 2011)

It was from a random warehouse on the industrial side of our town. They went out of business.... I ran into a guy a while back that caters to all the farmers in the surrounding area. He takes their old computer equipment and updates them with new gear. He brings it by the truckload to me for free. Otherwise he has to pay someone to take it. My point is sometimes you have to go outside the box. When it comes though I think being prepared with organization is a big key. Because when you get a pile like that, it multiplies when you start tearing it all down. Buckets, bins, and crates along with a sorting table do great. Sorry I didn't mean to go off track.


----------



## joem (Aug 1, 2011)

acpeacemaker said:


> He takes their old computer equipment and updates them with new gear. He brings it by the truckload to me for free. Otherwise he has to pay someone to take it. My point is sometimes you have to go outside the box.



Joey Likee


----------



## skippy (Aug 1, 2011)

4 am is getting more on the side of really early than really late, but I think it's best not to go at really weird hours. Like past midnight or before 5AM, unless there's a good reason. It can invite trouble with the local police, who may want to make your night unpleasant. 

So many dumpsters are locked or are behind fences now it seems. I used to go a lot and would usually find enough goodies to make it worth my while, but between the diving competition, tradesmen getting in on scrapping, etc, the pickings seem pretty meager. It's pretty darn cool when you find something exceptional though. 

PS Even old test equipment can fetch good money - I hope you looked into it before ripping them apart.


----------



## rasanders22 (Aug 2, 2011)

I got pulled over once after doing a umpster dive. The officer was more worried about me putting stuff in than taking stuff out. I must add that this is a residential dumpster and they have had problems with people dumping stuff in them. Of course sometimes it is stuff I want.


----------



## acpeacemaker (Aug 2, 2011)

On the one that has gold legs it has a silver stripe running through it. Curious what that might be?


----------



## resabed01 (Aug 2, 2011)

That HP test gear was top end stuff in it's day. The amount of engineering that went into those were incredible. Very well built too and the price they asked for them showed it.
Unless they are damaged beyond repair I would see about finding a buyer before scrapping them.


----------



## element47 (Aug 2, 2011)

It is true that any "functional" buyer would pay more for such gear as the gear is likely to yield in PMs, but you are talking some old stuff there in terms of test gear and as far as the disk contollers....forget it.


----------



## skippy (Aug 3, 2011)

It can't be that old... I don't see any nixie tubes 8)


----------



## acpeacemaker (Aug 3, 2011)

This board was sandwiched on mesh between two blocks of aluminum. Wish the hundred was found with it. :lol:


----------



## goldsilverpro (Aug 3, 2011)

> On the one that has gold legs it has a silver stripe running through it. Curious what that might be?



I assume this is what you are talking about - the long narrow stripe on top of the ceramic of the 40 lead side braze packages in the last photo, going from the lid to the left end. These are electrical connections to the lid ring from the #1 lead (I think you can faintly see the number 1 on the ceramic near the bottom left lead). This arrangement is used for plating purposes. It looks like the stripe was cut open near the lid on the 2 with non-gold leads, in order to break the connection. Also, notice the small tab on the left end of 2 of these 40 lead packages. They make internal electrical connection from the pad where the chip is mounted to the #1 lead (I think it's also to the #1 lead, but it may be to a different lead). Here again, for plating (and, testing) purposes. Often, this thin tab is removed by breaking it off with a special tool and all that remains is a notch. This breaks contact of the pad to the #1 lead (or, whatever), when it is not wanted.

I may be off on the lead number connections, but I think everything else I said is correct. Tie bars were originally connected to the tips of all the leads - one on each side. Therefore, for plating purposes, only one electrical connection is needed to connect and plate everything - leads, mounting pad, internal fingers, and lid ring. After plating, the tie bars are trimmed off and this electrically isolates the leads and the internal wire bonding fingers. Then, if desired, the pad and ring connections to a lead(s) can be severed.


----------



## acpeacemaker (Aug 3, 2011)

Thank you GSP for the very informative info. Also, I wanted to thank everyone else for the compliments on my latest find. I have decided to go ahead and tear it down.


----------



## acpeacemaker (Aug 3, 2011)

About every card in this tear down has fingers on both sides. Aside from all the other stuff.


----------



## acpeacemaker (Aug 4, 2011)

I have around 30 transistors out of this load. Some with gold legs and some with nothing showing. In the picture are two different ones. I took one without gold legs and cut the cap off. Can someone tell me what the wires connecting to the chip on top of the gold pad are made of? That gold pad is gold isn't it? Thank you - Andrew


----------



## spcake89 (Aug 6, 2011)

Hey
Looks like you got one heck of a haul there im a dumpster diver as well dont find nearly that quality of stuff though unfortunately i do find my fair share of computer parts though but i take anything electronic i see just in case. again congrats on the beautiful find
sean


----------



## jpdriver1 (Sep 30, 2011)

please excuse the question by a newb, but do you break the boards down into smaller parts before using the acid?


----------



## jimdoc (Sep 30, 2011)

jpdriver1 said:


> please excuse the question by a newb, but do you break the boards down into smaller parts before using the acid?



I suggest you do a few weeks of reading on the forum, and Hoke's book before using the acid.
You may decide to sell your boards and just do the easy stuff.

Jim


----------



## notch (Sep 30, 2011)

acpeacemaker said:


> On the one that has gold legs it has a silver stripe running through it. Curious what that might be?



The top chips are standard 256K EPROMS with a 1994 date code. The bottom chips have proprietary numbers, so it's hard to tell what they are but they were made in the early to mid '80's.


----------



## macfixer01 (Oct 3, 2011)

notch said:


> acpeacemaker said:
> 
> 
> > On the one that has gold legs it has a silver stripe running through it. Curious what that might be?
> ...




Hewlett Packard uses proprietary house numbers on a lot of the chips in their products. You can see from the logos that at least two of those 40-pin chips were actually made by Motorola for HP, but they have the 1820-xxxx HP part numbers on them. Sometimes you might find another of the same board which has a non-house numbered chip on it, or occasionally the house numbered chip may have the original manufacturers part number printed on the bottom side of the chip. I got lucky that way once and figured out what the driver chip was for the pen turret on the HP7475 plotter. It was much cheaper to solder in a new chip than to replace the whole board. It turned out I already had the chip too because it was the same as one Apple used on their disk drive analog cards.

macfixer01


----------



## akgold (Oct 24, 2011)

Yipes! That HP 8970A Noise Figure meter is still in wide use today and is/was worth around $2K. I have a couple of non working units here and can get near a grand for them if I was to sell them. You need to do a little due diligence before ripping items like that apart. Some of the other units were worth more than the metals or components inside them.


----------



## tlcarrig (Oct 25, 2011)

Wow! This is some nice stuff.


----------

