Tektronix TDS520B Hack / Upgrade to TDS620B ? - Page 1
Forum section: electronics / testgear

author: sorenkir
author_rank: Regular Contributor
timestamp: November 30, 2014, 11:27:54 am
content: Hello group,I have seen interesting hack/upgrade data in the following thread :https://www.eevblog.com/forum/testgear/tek-tds-3054b-vs-tds-744a/I have a TDS520B, 2 channels 500MHZ 1GS/s. I think I could see if an "upgrade" to TDS620B (same BW and number of channels but better sampling rate) is possible.Configuration resistors for TDS520B on acquisition board are (see photo):BID0=R1061 missing, BID1=R1062 soldered, BID2=R1063 missing, BID3=R1064 soldered --> 1010Configuration resistors on processor board are (see other photo):ID0=R17 soldered, ID1=R15 missing, ID2=R13 missing, ID3=R12 soldered --> 0110NVSIZE0=R9 soldered, NVSIZE1=R7 soldered --> 00(signal names as per TDS520B Component Service Manual pdf p269 & 297)I had no chance with finding board pictures for TDS620B on Google.Does anyone by chance have this configuration resistors data or photos of acquisition board (bottom side) & processor board ?Thanks,Michel.

author: nctnico
author_rank: Super Contributor
timestamp: November 30, 2014, 12:12:57 pm
content: These scopes are completely different so I strongly doubt such a hack is possible. The TDS600 series are realtime sampling oscilloscopes with very short memories.

author: sorenkir
author_rank: Regular Contributor
timestamp: November 30, 2014, 12:52:05 pm
content: nctnico, I think you are right on the architecture point.Anyway, TDS520B has 2 samplers operating each @ 500MS/s. Maybe there is a configuration that allows them to operate @ 1GS/s (that's what happens when a TDS744A, 4 samplers @ 500MS/s, "becomes" a TDS784A, 4 samplers @ 1GS/s, as some reported in the other thread) ?Unfortunately, that config. does not seem to correspond to any model. So maybe a dead end.Michel.

author: sorenkir
author_rank: Regular Contributor
timestamp: December 03, 2014, 02:21:25 pm
content: Hello,I have seen on the photos of a TDS724A acquisition board that the configuration resistors are exactly the same as for my TDS520B (in this post:TDS 724A saga, dead H2462H, many questions, please help !!!) !So the complete model definition probably includes the processor board configuration...Does anyone have a close-up of the configuration resistors (R12 to R17 near U2000) of the processor board of a TDS 724A ?Thanks in advance,Michel.

author: nctnico
author_rank: Super Contributor
timestamp: December 03, 2014, 04:03:08 pm
content: Attach a dip switch and try the combinations to see if the firmware in your oscilloscope supports other models.

author: sorenkir
author_rank: Regular Contributor
timestamp: December 13, 2014, 02:21:02 pm
content: Hi,I have tried to remove R12 on processor board which seems the only difference between a TDS520B configuration and a TDS724A (apart from colour display hardware which is not present in TDS520B). The acquisition board is the same with the same configuration resistors.The scope booted with a banner indicating TDS724A. But the display had some parts blinking quickly.Also, the acquisition and position control were inoperative. The limitation to two live channels remains. Plus a truncated nvram related message in the error log (WARNING: 600 remote nv memory ac...).So, there must be something else (but I have tried !)...Michel.

author: tinhead
author_rank: Super Contributor
timestamp: December 13, 2014, 11:31:01 pm
content: the only diff between TDS520B and TDS724A are on processor board and in nvram (TDS5 enabled/disabled). So when you already playing, try the next model, TDS782A. Change the processor board first back to TDS520B and then acq board from 5 to 1, maybe the firmware will not check the nvram anymore.

author: sorenkir
author_rank: Regular Contributor
timestamp: December 20, 2014, 04:25:49 pm
content: Hello,I have tried whattinheadsuggested : processor board as TDS520B and acquisition board as TDS782A (by adding a strap on R1063 --> acq id=1).I managed to have a TDS xxx on the banner screen !This model is capable of 2GS/s with only one channel active (whereas TDS520B goes only to 1GS/s). That's what I was expecting.But :The two DACs do not interleave properly at 2GS/s, see photo. Calibration is required...A side effect of this configuration is that the TDS xxx is not recognized by the WaveStar software.I don't think that a 2 channels monochrome model with 2GS/s acquisition capabilty exists, so I fear that no solution exists for this issue.Michel.