Fluke 6060A/AN Uncal Error

[davorin]

Hello

Anyone an idea what the flashing "Uncal" means on a Fluke 606A/AN Signal generator?

When pressing "Status" it displays the error code "000 000 440"

[davorin]

Hmm...running the self test with "SPCL 0 2" reveals in the display "012 000000 060"

Not meaningful to me as well (o;

[eb4eqa]

Hello,

The UNCAL can be caused by unlocked PLL or unleveled output. You can check the UNCAL by following 4D-16 procedure in the user/service manual. I scanned from paper and bookmarked it myself:

http://www.rbarrios.com/manuals/

Let us know how it goes.

Roberto EB4EQA

[davorin]

Thanks Roberto...I already read through that section which is still unclear to me.....

According to the above mentioned status code I think it means (I guess to combine the bit fields from the status code)

400 RF output off
040 RPP tripped

But I miss in the service manual how to debug the RF output off/RPP tripped error...

[davorin]

Already found something...well..had to fix my HP 3456A first (o;

Going step by step through the calibration instructions in chapter 4 where the first steps are to measure the power supply outputs...

And?

TP3 has a short circuit to GND where it should have +15V....fed by a LM7815 voltage regulator...input of the regulator is fine....around +20V....
And according to the schematic the +15V goes to controller A2A7 (whatever that is) and to the RPP controller (no clue what this is either ;o)

[Mr Simpleton]

RPP isn't that Reverse Power Protection... maybe someone did send in a wee bit too much power into the generator??

My take is that the error code you see is a combination of both
   000 000 400 RF output off
   000 000 040 RPP tripped
____________
= 000 000 440

[davorin]

Well....I have to follow the +15V rail and disconnect one by one and see when the short circuit doesn't appear anymore...

Hope I don't have to remove the big output board under the big aluminum shield (o;

[davorin]

Removed last night the controller board, HPIB interface, the big thingie above the controller and measured the resistance between +15V and GND while plugging the modules back in one by one...

As everything was plugged back in...I couldn't see any short circuit anymore...and the error is now gone when pressing "STATUS" on the front panel (o;

Only thing I missed was to order a F-type plug to BNC cable ;-)

[davorin]

Hmmm...the output signal looks crap:

Set at 100kHz and 0.5V output, no modulation....

[davorin]

I must have a self healing version of the Fluke synthesizer....

Now I just let it run for a while and the output looks more cleaner now, though the output is too high as it is set for 1V:

[philpem]

I must have a self healing version of the Fluke synthesizer....

Now I just let it run for a while and the output looks more cleaner now, though the output is too high as it is set for 1V:

Have you got a 50-ohm feedthrough terminator on the output?

Most RF signal generators are designed to output into a 50-ohm load -- if you run them unloaded, the voltage level will be too high and you might see some waveform distortion too.

The Tek AWGs we have at work usually output double the indicated voltage into a Hi-Z load, unless they've been configured for a Hi-Z load (the power-on default seems to be 50 Ohm). I must confess I'm not entirely sure what an RF generator would do as I don't have one to test with.

[davorin]

This popped into my mind as well late in the evening (o;

I just connected it to my DSO without any load...and from the peak/peak voltage around close to +/- 3V it makes sense...
1V RMS is +/- 1.41V peak/peak, so doubling that is then +/- 2.82V...

Let's see how long this device runs without showing any more errors (o;

[davorin]

Hmm....what type of connector is it anyway?
The manual just mentions a "RF standard connector"....

Only thing I find from local distributor which might match it is a so called UHF connector....

[Mr Simpleton]

Even without looking my guess is you have a N-connector at the output!
In a pinch you may temporarely mate the connector using BNC, but it will not stick.

http://www.wa1mba.org/rfconn.htm

[davorin]

Ordered some N and BNC connectors...

Hmm...wasn't aware my DSO can do 50Ohm input...

When I let run the 6060A/AN @ 1MHz and 1V output, it displays +/- 2.8V peak/peak with 1MOhn input....
with 50Ohm though only +/- 0.6V peak/peak...

[davorin]

Yepp...crap Chinese probe cable (o; Not meant for 50Ohm....

Connected 2 * 100R in parallel directly to output and now it's correct with +/- 1.4V pkk

[Technotronic]

I own one of these, very beat up condition and it didnt power up last week. Turns out it was a 10uF/35V cap inside the synth
chassis shorted. Installed in 1985, 38 yrs with 37v on it , its failed. I replaced with an electrolytic and now powers up but
theres no signal output and have the uncal error with status 004 which is "amplitude unleveled" ?

Is there suppose to be a battery in these to keep memory?