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u1176

Member Since 16 Mar 2009
Offline Last Active Aug 13 2014 02:08 PM
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Posts I've Made

In Topic: XTI 6000 Filter Bank

13 August 2014 - 02:12 PM

From the link that you included, K1/2 Service Portion of Manual;


Conditions:
—Amplifier output assembly MUST be room temperature
(72 degrees F/21 degrees C)
—No input signal
—No load
Procedure: Monitor TP51 found on the Output Assembly.
Center oscilloscope to view lower right portion of
waveform. Adjust R25 on each Output PWA for sharpest
squarewave edges (see Figure 5.1). Figure 5.2
shows “Underlap” (under adjustment). Figure 5.3 shows
“Overlap” (over adjustment). If too much time is taken
Figure 5.1 Correct Overlap Adjustment
Figure 5.2 Underlap
Figure 5.3 Excessive Overlap
to perform this procedure the Sleep circuit may cause
the amplifier to go into standby. A brief input signal
(no load) will bring the amplifier out of Sleep mode.

This seems like a very straight forward procedure.
What would be the equivalent test point identifier on the XTi 6000?
Is this adjustment regularly performed, does it sometimes drift out of spec?

Thanks again Alain, I hope others may benefit from this thread.

Alain.

A.

In Topic: XTI 6000 Filter Bank

13 August 2014 - 01:59 PM

Alain,

Thank you very much for the detailed reply.
It's fairly obvious that my limited electronics knowledge lies mainly in linear PSU's and analog amplification schemes.

I will leave the amplifier as is as your answer has satisfied my query.

I will do more research on Balanced Current Amplifiers and will read the service manual on the link that you inlcuded.

Thanks again for taking the time.

Alain.

In Topic: XTI 6000 Filter Bank

13 August 2014 - 10:45 AM

Posted ImagePosted ImagePosted Image

Avi, if you look at the pictures this may better explain what I meant by 'short loaded'.

Alain, thanks for the reply. I wasn't expecting more output power from this experiment so much as a more sustained output in the low end, such as you might encounter with more reserve energy form a larger filter capacity.


The caps are 200 WV, I have not had a close look at the PCB traces, nor tested the voltages, nor do I have access to a schematic currently but I'd have to assume that they are either arranged in series pairs or that you meant that the rails were +82.5VDC < 0 > -82.5VDC (XTi 6K) and +102.5VDC < 0 > -102.5VDC (IT8k) respectively with caps arranged from rail to ground.

Is there any technical reason why I couldn't try this even as a comparative experiment?

Thanks again in advance for your indispensable technical expertise.

Alain.