We had a Tek 1502 time domain reflectometer (TDR) in the shop. I had little experience with it, but I soon found out how incredibly useful it was. I could shoot the RF cable at the base of these monstrous LPA antennas and see all the impedance transitions through the 10 connections in the 105' path.
The biggest benefit I found with the TDR is its ability to clearly display sections of water contamination and degraded connections. I don't have any other TDR-type equipment (I read that the Fieldfox has an optional TDR function, but mine only has the CAT). I also have an Anritsu S332D, and like the Distance-to-fault/VSWR function, which I used frequently, along with the TDR.
I encountered some DC voltage when I connected to a wrong port (which had the B+ running through the cable to power the antenna amplifier), which I assume smoked the "unobtainium" tunnel diodes. I think to fix that I'll have to gamble on some of the 1502's on eBay advertised as not working, and hope that there are some salvageable parts.
So I bought a 1503 TDR off eBay, but have found that it is nowhere-even-close to being as useful as my 1502. I don't know the condition of the eBay 1503, but I ran the 1503 diagnostics and it had no errors. The pulses at the high and low impedance parts of a test cable look like what's depicted in the user manual-all I see displayed is an upclock (open) that drops back down to the middle, or downclock (short) that rises back up to the middle .
This is nothing like the display of the 1502's "fingerprint" showing all the impedance deviations (such as the aforementioned LPA antenna sections) within a short distance. When there's an open, the 1502 shows a steep upclock and a high plateau. When there's a short, the 1502 shows a steep downclock and low plateau. But other than those extremes, the 1502 tells a great story: I see a variable impedance over time, indicative of the impedance changes as the cable transitions to the antenna hardware (load coils, connectors, changes in cable impedance (50 ohm cable, to metal airline, to 93 ohm cable, etc.).
Does this huge difference between the displays I'm getting from my 1502 and 1503 suggest that the 1503 has a problem? Would it be a correct statement that the 1503 is more suited for just looking for shorts and opens in a cable path? Thanks for any insights.
Mike