| Products > Test Equipment |
| HP/Agilent 1675x logic analyzer card memory up-hack |
| << < (3/22) > >> |
| texaspyro:
--- Quote from: MarkL on September 26, 2017, 03:14:46 pm --- Good memory! That seems to be the recipe! I took one of my 16534A cards and swapped R809 and R810. It became a 16533A. Using a 0dB reference point at 10Mhz, the 16534A had a -3dB point at 623MHz (not bad - I hadn't measured this before). When it became a 16533A the -3dB point was reduced to 346MHz. So, even back then it seems HP was doing their artificial limits on BW. Someone with a card manufactured as a real 16533A should double check this to make sure there's no other changes needed. --- End quote --- I originally found those resistors when, many years ago, I bought a couple of expansion chassis that had 4 x 16533A's in them. Last night I dug out a defective 16534A that I tried to back-grade to a 16533A to see if that made a difference (didn't) and spotted the swapped resistors. I originally thought the resistors were by one of the PGA chips... That was probably a different board I was remembering. |
| fisafisa:
Thanks. I will try the modification. |
| DocBen:
Hi there, I can confirm that a 16740a can be converted to a 16742a by removing one resistor. I used a picture of a 16742a. I also tried to convert it to a 16752b but that failed, probably because I only have 1.5k resistors and I think the resistors create a voltage divider so I probably had the wrong voltages. I will try again once I have some 1k resistors. |
| DocBen:
Yatta! So I have finally gotten around to try to get a 16740a to be a 16752b. On my third attempt I succeed. (keep in mind however this just passes the self tests. I havent made any actual measurements with it so it might fail when doing actual work) from R735 to R82: - -RR-RRR- does it. (- open, R well, you know) I used 1K 0.1% Resistors just like they are used on the board |
| MarkL:
Wow, that's interesting! Of the many possibilities for ID upping, I would have ranked the 16740A --> 16752B as having one of the least chances of actually working. Does your 16740A have the same amount of memory populated as a 16752B? The 16752A has 34 x Micron 48LC4M16A2-8E (4M x 16). |
| Navigation |
| Message Index |
| Next page |
| Previous page |