Rohde Schwarz R&S UPL Audio Analyzer Renovation

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How does one send Private Messages on this forum
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Dear Bart,

your upl keyboard pcb works!
Many thx! BR, Toni


upl_keyboard_new.jpg
 
You are new and have only posted one public message. To deter private spam/fraud, you need some record of (decent) public posts before moderation is lifted and private messages allowed.

In the meantime you can publicly 'invite' other members to private-message you. And I think the "@DGTLDAV" tag syntax (at-username) will send a notification to that person?
Thank you for letting me know. I really appreciate it. Dave
 
Dear all, I am impressed about this post. All information and member's posts is much appreciated. I am currently discussing a purchase of a faulty UPL unit. Can anybody send me (or post) some unit's internal photos in order to compare and see if something missing from inside? Also if someone has a digital board (at the left) for selling.
Thanks in advance.
Regards from Greece,
John
 
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have a look at first post in this thread. Bjirre has a google drive where you can find many pictures too.
BTW: I have one working and 2 UPL currently in repair including all gimmicks like floppy emulator, freedos, lan via mtcp and ftp server, ps2 socket for keyboard and mouse. Thx to Bjirre for his excellent work to get more UPLs running again.

BR, Toni
 
Dear all, I am impressed about this post. All information and member's posts is much appreciated. I am currently discussing a purchase of a faulty UPL unit. Can anybody send me (or post) some unit's internal photos in order to compare and see if something missing from inside? Also if someone has a digital board (at the left) for selling.
Thanks in advance.
Regards from Greece,
John
As Toni posted, there is a Google Drive with extensive photos of the inside. Alternatively, you could post some photos of your unit and we can tell you what you have (or not).
How “faulty” is it? I think the UPLs rarely have fatal hardware failures (except for the motherboard capacitors possibly) but for a 20 year old instrument it’s not impossible.
 
As Toni posted, there is a Google Drive with extensive photos of the inside. Alternatively, you could post some photos of your unit and we can tell you what you have (or not).
How “faulty” is it? I think the UPLs rarely have fatal hardware failures (except for the motherboard capacitors possibly) but for a 20 year old instrument it’s not impossible.
Indeed. To share my experience, I bought 4 UPL, 3 of them being broken (one just purchased for the B1 option, another one just for the B5) not knowing what was the problem and all been fixed in the end, fully working and quite easily (fuse, display backlight, HDD) so indeed they are well designed machines and difficult to completely destroy.
On top of the amazing job done by Bjirre Feel free to ask questions here and we will gladly help.
 
Thanks a lot all for replies. I will check at G.D. to see all photos and information (there is a lot of it!). Unfortunatley, the unit I am interested for is not available live. I requested from seller to have some photos from inside and see.
I will keep you informed.
One more question, is this unit capable to meassure output RMS power from an audio amplifier in relation with THD?
Regards,
John
 
Thanks a lot all for replies. I will check at G.D. to see all photos and information (there is a lot of it!). Unfortunatley, the unit I am interested for is not available live. I requested from seller to have some photos from inside and see.
I will keep you informed.
One more question, is this unit capable to meassure output RMS power from an audio amplifier in relation with THD?
Regards,
John
It won't measure the power directly, but it can measure the (true) RMS voltage, which you can calculate the output power across a resistive load by P = (V^2) / R. It'll also do THD measurements at the same time if you make CH2 == CH1, then you can set up a THD measurement on CH2.
 
Indeed. To share my experience, I bought 4 UPL, 3 of them being broken (one just purchased for the B1 option, another one just for the B5) not knowing what was the problem and all been fixed in the end, fully working and quite easily (fuse, display backlight, HDD) so indeed they are well designed machines and difficult to completely destroy.
On top of the amazing job done by Bjirre Feel free to ask questions here and we will gladly help.
Thanks once more. If a unit is available, I will be glad to have a proposal (in a PM) to buy it.
John
 
Good morning all. I found a faulty unit. The problem is that during startup, the screen is lit and white. The unit stays in this condition without more progress. Have you a comment about?
Regards,
John
Most likely you have 2 problems: the LCD is dead and the CMOS battery as well.
Try to plug a monitor into the unit, you can see whatever errors the motherboard is throwing. In the unlikely event of a dead motherboard, you can start by replacing all the capacitors on it with low ESR units. I think there’s a thread on EEVBlog with details.
Also check the 6A or 8A glass fuse on the power supply, some units have had bad connections here due to the high current damaging the solder traces and PCB due to excessive heating in the fuse holder.
 
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Got my small pcb's to solder the LED backlight recplacement. Left a constant current circuit from an old project.
The used LED's are LumiLEDs L130-4090001400001 (mouser) in 10 groups parallel of 4 LEDs and one 100R in series. Only R100 is used as current sensor.

led_constant_current_schematic.jpg


led_backlight_replacing_defective_ccfl.jpg


Have fun,
Toni
 
Assuming that the analogue spec for the UPL-B1 is the same as the UPV-B1 (which it is, to my knowledge - despite claims to the contrary), then the loop-back 2VRMS @ 1KHz 20-20K THD+N for the UPV-B1 is -113dBV. My SYS-2722 gets -115dB under the same conditions. If I feed the 2722 oscillator into the UPV inputs, I get the same -115dBV THD+N.

Considering that there are oscillators around such as Viktor's, it makes a non-B1 UPV or UPL a really powerful instrument for relatively little outlay.
 
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