tektronix tds754A FAN

[romantao]

Hi!

I recently got hold of a tektronix tds754A on ebay for a very nice price with SPC failure which i quickly repaired by changing the attenuator hybrid relays.

I noticed however that the fan is quite noisy and so i wonder if is there any fan replacement "recomended" with similar airflow rates but quieter operation noise. Found recomendations for lecroy in this forum but nothing regarding the tek 5/6/7xx.

regards

[nctnico]

These scopes are quite noisy. If your scope has a big fan then your already have an ultra low noise version you can't even buy. But maybe somebody changed the fan. Which brand/part number is mounted in your scope?

[romantao]

mine has a comair rotron JQ24F4V 24V 0.25A. Yes its huge!

[nctnico]

That is the original. Unfortunately fans in that size don't come quieter. I once tried replacing such a fan with a similar sized fan from PAPST (with lots of resistors in series to reduce the speed) but that did not result in any improvement for the amount of noise.

[leppie]

Ouch, that is huge fan... in an odd package

Wonder why the scope needs 235CFM+ airflow...

[dxl]

Hmm, maybe add a fan speed regulation based on temperature? I own a TDS784D, and the temperature critical things are Acquisition (The DEMUX chips get really hot) and probably the Power supply.

If you ever want to hear real noisy fans, power up a HP70000 Spectrum Analyzer.

[AndyC_772]

Ouch, that is huge fan... in an odd package

Wonder why the scope needs 235CFM+ airflow...

Because it dissipates about 400W, that's why. My TDS754D did a great job of keeping the lab warm in winter.

Not so much fun on a warm summer day, though.