BBD tester

[armdnrdy]

Here are the examples of the add on boards that I worked up. The middle ziff socket is depicted for reference and is not on the add on board. This position will be occupied by socket pins that will "plug" into the center zif socket of the tester.

This is the MN3001, 2, 4, 10 board.



The next board only tests the MN3011. This is a very specialized BBD which includes six tapped outputs. This board incorporates a 1P12T rotary switch set for 1P6T to test each of the six outputs. Each position of the rotary switch is labeled with the stage number for each output.
Even though this BBD is not very common and builds using it are few and far between...I plan to experiment with a flanger build based on the ADA STD-1.

[fendman]

Hey Larry, that will be an expensive enclosure in the UK. There is a Serpac UK subsiduary company.  I was just looking at their postage

prices...anything under £100 is £10   So i didn't ask for a quotation    Would have to look at something close to those measurments from other 

sources.

Thats life.. you guys in the Apple are really lucky with component prices

Mike

The console instrument enclosure here would probably do? http://www.bitsbox.co.uk/boxes.php

Thanks for that Scruffie...I missed whats been going on just lately on this thread. Its been quiet for a few weeks and then bingo!!

Its great to see Larry is still right into this project, I am pleased others are interested as well.

Mike

[armdnrdy]

I just received the heat sink in the post today so....it's game on again!

[fendman]

I just received the heat sink in the post today so....it's game on again!

Thats great!! Hey Larry  a lot of people won't want to build this project, but just think, how many people would like to know if their BBD's are the real thing

Mike

[newperson]

Thanks for sharing all your great work with this project.  How far away are you from having a confirmed working layout?  I am looking forward to putting this together and testing out some ICs.

[armdnrdy]

I'm pretty confident that the layout on reply #28 will work when built.
That's the circuit that I have verified working on my bread board.
I should be finished with the first tester (positive voltage) by this weekend.
The only thing that I haven't tested is the SAD1024 configuration for the Zif board. Before building the Zif board, I'll throw a 1024 on the bead board for testing.

I'm currently putting together the small power supply board and the heat sink mounted on the outside rear of the enclosure.
The tester is in the final stretch!

[armdnrdy]

Okay,

I'm making a bit more progress.

I found the time today to work on a few more details on the BBD tester.

I just tested a SAD1024 in the serial configuration that's depicted in the schematic on reply #38.

When I pushed the start button the numbers kept running. I adjusted the bias up a bit....no change.
I bumped the bias down and the display would stop at 1052-1060.
I lowered it a bit more and the display now lands on 1024, the correct amount of stages for a dual 512 stage BBD connected in series.

The bias setting for this particular SAD (1.7V) was much lower than for the MN32XX series. (around 4V)

Was I ever worried about possibly smoking a perfectly good SAD IC? 
Naw...remember...somebody has to test the bullet proof vest for the first time. 

[Fender3D]

Naw...remember...somebody has to test the bullet proof vest for the first time. 

Yep
but always while testing jelly bullets 

[armdnrdy]

I finally finished this thing! 

It was a monster!

Here's some pics of the finished product.

Video coming soon....when I get some free time.

[newperson]

Wow, that looks great.  Would love to see a video of it in action and a finally confirmed build report so I could put one together myself.

[fendman]

Yes!!! ditto on the above.. Great to see it finished Larry and look fwd to the video.

Mike

[Govmnt_Lacky]

Looks AWESOME Larry!!!! 

Do you still plan to do one for the negative voltage BBDs? (MN300X) I think THAT would be a hot ticket item 

[armdnrdy]

Thanks, thanks, and thank you.

Greg,

Yes I plan to build the negative voltage tester as well but...I want to take a break from Testerland to finish a few other things first.

I agree that the negative tester is more useful.
I started with the positive tester because I felt that using BL3207s for experimenting/breadboard work would be less costly if I made a few mistakes.  

Disclaimer:
No BBD was harmed in the design, build, or implementation of this tester.

A note on the positive voltage tester's usefulness......
Last night I came across two MN3205s that I purchased from a seller on ebay.
I sourced them for an analog delay build for a friend's son.
When I finished the build, inserted the BBDs, they started getting hot.
I double checked everything.
I ordered some BL3205s Cool Audio V3205s from a U.S. supplier, installed them, no problems, no heating up, and had delay.

Yes..they are relabeling the MN32XX series BBDs as well!

[Lurco]

Never heard of BL3205 (Belling) !

[armdnrdy]

Never heard of BL3205 (Belling) !

The replacement BBDs were V3205s not BL3205s. You are correct sir.

[armdnrdy]

I was just playing around with the tester and discovered something useful about this circuit.

With the Bias control turned down, hit the Start button and the numbers will continue to roll because the BBD isn't properly biased and won't pass the sine wave properly to stop the counter. Now this much I knew.

But what I didn't know is: as the numbers are rolling you can slowly turn up the bias and the numbers will stop.
This is the point where the BBD starts passing the sine wave. This is a good starting reference point for the Bias control.

You then hit Reset, and Start again for the BBD stage.
When testing more than one BBD of the same series and stage the bias for the first BBD should be pretty close (for testing) for the rest of the lot of BBDs under test.

[GodSaveMetal]

OK I´M interested in a NEGATIVE BBD one´s; thank man this circuit is amazing, very useful; I stay tuned!!!!

[Scruffie]

Where are we on this Larry? This is invaluable test equipment with the current BBD market

[armdnrdy]

Hey Scruffie,

I assembled the low voltage BBD tester with the three boards (switch board, ziff socket board, and the display board) wired in the case, and for some reason the display result wasn't as accurate as when I had part of the circuit on the breadboard.

(typical....it worked until I boxed it up!)

I worked on it for a while, adding pulldown resistors in a few sections, but nothing seemed to solved the problem.

So...I decided to put it down for a while and get some other projects out of the way. I'm sure that when I revisit it soon..I'll find a fix.

[Fender3D]

...(typical....it worked until I boxed it up!)


So...I decided to put it down for a while and get some other projects out of the way. I'm sure that when I revisit it soon..I'll find a fix.

Yep
nothing's better than give it some... delay...