Re: Tekprobe 1103 PSU mod. advice


Mark Litwack
 

Hi Ancel,

Ok, a couple of pennies... Here's a project that's similar to what you're considering. Maybe you can use it as a starter:

https://www.eevblog.com/forum/circuit-studio/example-project-tektronix-tekprobe-adapterbreakout/msg1201386/#msg1201386

There's also this one, which has more of the power supply design you mention, but it doesn't mount to the scope's BNC:

https://www.eevblog.com/forum/projects/tektronix-tekprobe-power-supply-for-agilent-rigol-and-other-oscilloscopes/msg624284/#msg624284

-mark

On Sat, Feb 22, 2020 at 09:59 AM, Ancel wrote:


Hi all:
I am considering a project create a more convenient '1103' Tekprobe capability
for augmenting common O'scopes compatibility with the Tekprobe BNC interface.
My idea is to make compact individual TekProbe adapters to directly attach to
the BNC Probe inputs on O'scopes with no BNC cabling which degrade probe
performance with the stock 1103.
Given the common USB interface on modern O' scopes, I hope to use that as the
DC power supply to create the required +/-15V & +/- 5V required. An RJ45 cable
can carry the power from the USB boost SMPS supply to the new Tekprobe BNC
adapter. In this way the PSU SMPS 'noise' is isolated from the O'scopes BNC
input and can be managed by common mode chokes if required, while the twisted
pair should carry the clean power to the TekProbe adapters.
For older 'pre-USB' scopes, a ubiquitous 5V 'phone' power bank offers
convenient power.

So final outcomes are...convenient single BNC Tekprobe adapters not requiring
a Mains AC supply while offering improved signal fidelity/bandwidth and a
voltage ref. back light LED on each O'scope BNC adapter to validate the
precision voltage power function.

I have not included the '1103' offset voltage option due to size issues. It
might be possible but do you guys feel it is necessary?
Given the retail of the 1103's seem to range from $150 thru $450 USD these
days, I feel a compact $50 option is possible, with the benefit of improved
performance and V.reg.

Penny for your thoughts.....

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