TG1010A dead output channel

[tom66]

The local hackspace has been donated a TTi TG1010A DDS generator.  I want to repair it, as the output channel is dead.  Unit powers on but no output and no relay click.

Checked some rails, +24V, +15V and -15V all dead.  Two 500mA fuses blown so replaced those which restored relay function and the rails. Output now stuck at -12V.

Checked the output board (it's on a separate card for some reason) and two opamps/drivers have two rather nice holes in them, so I suspect someone has forced a few too many volts up the output and killed these.  Checking the signal into the output board shows it is present, so best guess is that section is working OK and just the output opamps are dead.

Problem is I can't identify the parts.  They are in MSOP8,  capable of 10MHz output into 50 ohms,  and operate from a +/-15V supply.  Output saturated to -12V in fault condition, which MAY be a sign that they are not rail to rail, but could also be an artefact of the damage.  Best guess is Linear Tech from their package as LT are fond of MSOP8.  However only matching part is a current feedback amp (LT1396), which has an inadequate supply rating so seems unlikely.  Moving away from LT, pinout roughly appears to match THS3110 (Vs+, Vs-, output and input on correct side) again current feedback amp so unsure if this is the correct type of amp for this circuit.

There's also an LM6181 amplifier on the board. This appears intact.  It is a CFA as well.

Have asked TTi for a schematic but no reply yet.  Anyone have a schematic for this unit?  It is not the same as the TG1010,  but there appears to be a bit of commonality.

Any ideas? Thanks

[tom66]

Anyone wondering I asked TTi and they provided the service manual.  Uploaded below.

The part is THS3001.

[scopeman]

The local hackspace has been donated a TTi TG1010A DDS generator.  I want to repair it, as the output channel is dead.  Unit powers on but no output and no relay click.

Checked some rails, +24V, +15V and -15V all dead.  Two 500mA fuses blown so replaced those which restored relay function and the rails. Output now stuck at -12V.

Checked the output board (it's on a separate card for some reason) and two opamps/drivers have two rather nice holes in them, so I suspect someone has forced a few too many volts up the output and killed these.  Checking the signal into the output board shows it is present, so best guess is that section is working OK and just the output opamps are dead.

Problem is I can't identify the parts.  They are in MSOP8,  capable of 10MHz output into 50 ohms,  and operate from a +/-15V supply.  Output saturated to -12V in fault condition, which MAY be a sign that they are not rail to rail, but could also be an artefact of the damage.  Best guess is Linear Tech from their package as LT are fond of MSOP8.  However only matching part is a current feedback amp (LT1396), which has an inadequate supply rating so seems unlikely.  Moving away from LT, pinout roughly appears to match THS3110 (Vs+, Vs-, output and input on correct side) again current feedback amp so unsure if this is the correct type of amp for this circuit.

There's also an LM6181 amplifier on the board. This appears intact.  It is a CFA as well.

Have asked TTi for a schematic but no reply yet.  Anyone have a schematic for this unit?  It is not the same as the TG1010,  but there appears to be a bit of commonality.

Any ideas? Thanks

Did you get the unit fixed? It is a great generator. I hope you get it working.

It is the same as a Wavetek 29 IIRC. You can get a great waveform creation software from TTI's website that can upload data from scopes and then upload them to the generator. You can also draw waveforms freehand with the mouse or create them from mathematical equations.

You can find it here:

http://resources.aimtti.com/software/waveform_manager_plus_v4.13.zip

I would look on www.ko4bb.com where you will find firmware that I uploaded some time back.

Good Luck!

Sam
W3OHM

[tom66]

Still working on it, awaiting parts from Digikey which should be here by Monday hopefully.