Testing max data throughput on a BreadBoard

Testing max data throughput on a BreadBoard

After I repaired the Tektronix Bert tester PB200 I can finally do a test which I wanted to do for a long time. And that is to test the max data throughput of a breadboard. So in other words: What is the max speed at which data can travel through a breadboard (BB) without any errors ?

I came up with two tests:

      • The first test is to use a couple of rows on the BB
      • The second test is to use a power rail

Preparing the first test

The test setup is quite easy, just a few wires on a bread board. I didn’t put the wires across the whole length of the BB, at that point a lot of other stuff comes into play. Just by adding a few wires I get (roughly) an idea what the impact of extra connections is.

And to get an initial impression I started the test with just connecting the probes to a BB and measure the data transfer. This gives me a base line of 80 Mhz.

Next I prepare the BB as follows:

As can be seen just a couple of connections to generate some contact resistance. The BB and wires will add some capacitance too.

The test results of the first test

This results in:

It’s somewhat hard to read from the reflecting screen, but the max throughput I got after running this test for a couple of hours is around 77Mhz. So compared to the earlier test, adding a couple of wires resulted in a loss of 11Mhz. Which is quite a loss.

But note that this is is quick test. I didn’t use a loaf of 50Ohms, and I used a good quality BB (BusBoard Prototype Systems BB830).

Setting up the second test

The second test looks like:

Once this is setup I ran the test. When a test fails it looks like:

When an error occurs I lower the frequency, and reset the error. And the end

Results of the second test

I could get a max throughput of:

So it’s very close to 80 Mhz. However in a real case scenario don’t expect to send data across with this high speeds. In reality I ques somewhere around 10 Mhz till 40Mhz is more realistic.

Repairing a Tektronix BP200 BERT tester – part two

An attempt to fix the primary side of the PSU

I started  to measure and test several components, and found some diodes which where shorted. Replaced them. However I could not measure any voltages after the full bridge rectifier. Some components are mounted on large heat-sinks. Removing them to get access to the components and be able to read the markings or to test them out of circuit, would be a pain.

Fighting with this power supply for a couple of evenings, I decided to take another route. In the meantime the alternative PSU was delivered. After comparing both the PSU’s together I noticed that only one voltage rails was different.

Modifying an PSU

Since fixing the primary side of the PSU would be very difficult to do, I started to look at the secondary side. Both the PSU’s are from the same series. So I figured the manufacturer probably used a couple of zener diodes, and resistors to control the output voltage. So I started to swap out diodes and resistors which where different and which I could relate to the voltage rail I wanted to adjust.

The moment of truth

I powered to PSU up, and measured all the good voltages (they where a little higher, but that’s okey since no load is attached.). I decided to go for it, and placed the PSU on top of the chassis, so I could test the PSU without going through the rather complex method of installing the PSU.

And after connecting the main power, and flipping the power switch, the PB200 came back to live.



A few quick tests showed me that the generator and analyzer are working without any problems. And I refitted the PSU back into the PB200.