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1502: Difference between revisions
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Undo revision 29487 by Cmulkey (talk)
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and there are [[Russian tunnel diodes|Russian substitutes available]]. The primary fast pulse TD (CR1703, Tek [[152-0489-00]], | and there are [[Russian tunnel diodes|Russian substitutes available]]. The primary fast pulse TD (CR1703, Tek [[152-0489-00]], | ||
21 mA, 1.5 pF) is simply no longer available. The closest Russian replacement is GI308E, it requires soldering to the original heatsink. | 21 mA, 1.5 pF) is simply no longer available. The closest Russian replacement is GI308E, it requires soldering to the original heatsink. | ||
If you want to design a replacement, I suggest looking at Analog Devices ADCMP580, and Starecki and Misiaszek's paper, | |||
''[http://www.ise.pw.edu.pl/~tomi/papers/wilga2006_50ps.pdf Low cost programmable pulse generator with very short rise/fall time]''. | |||
There appears to have been an optional "static suppressor" in a BNC M-F package, Tek [[011-0132-00]], used to protect the sampler and TD. It's pretty obscure. The BNC connector on later 1502s contained an internal shorting bar that shorted the center conductor to the shell with no mating connector installed. In use, it was to short out the connecting cable so that any static on the line would be discharged before opening up the BNC connector to the internals of the TDR. Often, this shorting bar would break off, rendering the connector unable to discharge a cable to be connected. Replacing this BNC connector (or any front-panel component, for that matter) is a laborious process involving resealing the front panel for waterproofing. The original 1502 and 1503 were the first Tektronix instruments to be fully waterproof (with the X-Y Module installed) such that it could actually be operated while submerged to a shallow depth. The front panel sealing is a very involved process utilizing several different silicone (grease and RTV) products to do the job. Tektronix produced a separate instruction manual specifically for waterproofing details of the 1500-series. | There appears to have been an optional "static suppressor" in a BNC M-F package, Tek [[011-0132-00]], used to protect the sampler and TD. It's pretty obscure. The BNC connector on later 1502s contained an internal shorting bar that shorted the center conductor to the shell with no mating connector installed. In use, it was to short out the connecting cable so that any static on the line would be discharged before opening up the BNC connector to the internals of the TDR. Often, this shorting bar would break off, rendering the connector unable to discharge a cable to be connected. Replacing this BNC connector (or any front-panel component, for that matter) is a laborious process involving resealing the front panel for waterproofing. The original 1502 and 1503 were the first Tektronix instruments to be fully waterproof (with the X-Y Module installed) such that it could actually be operated while submerged to a shallow depth. The front panel sealing is a very involved process utilizing several different silicone (grease and RTV) products to do the job. Tektronix produced a separate instruction manual specifically for waterproofing details of the 1500-series. | ||
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==Replacement== | ==Replacement== | ||
MOHR Test and Measurement manufactures a direct replacement to the 1502B and 1502C using an updated version of the same pulser/sampler. Any procedures or recorded waveforms are repeatable using the MOHR TDR.''[http://www.mohr-engineering.com/ct100 CT100B TDR Cable Analyzer]''. | |||
==Manuals== | ==Manuals== | ||