Lecroy AP-1M Input Adapter - Page 1
Forum section: electronics / projects

author: sixtimesseven
author_rank: Frequent Contributor
timestamp: December 15, 2019, 10:18:20 pm
content: Has anyone had a look inside a Lecroy AP-1M Adapter?It looks like a pretty simple 1MOhm series resistor - granted to 5GHz - for about 2000USD so naturally I would like to roll a diy solutions.https://store.teledynelecroy.com/products/ap-1m-1-mohm-adapter

author: DaJMasta
author_rank: Super Contributor
timestamp: December 15, 2019, 10:47:45 pm
content: FYI:"Bandwidth: 500 MHz typical, 350 MHz guaranteed"Haven't looked at one myself, but it's also got the probus interface stuff for autodetection. Not sure if they would bother with cal data, since they probably don't need it, but they also could include a compensation network that matches that of a 1M Ohm scope frontend so it can be properly compensated with a normal 10x probe on the end.

author: sixtimesseven
author_rank: Frequent Contributor
timestamp: December 15, 2019, 11:33:32 pm
content: Quote from: DaJMasta on December 15, 2019, 10:47:45 pmWow, just wow and that for 2k that is almost obscene...Quote from: DaJMasta on December 15, 2019, 10:47:45 pmSo far I haven't integrated the 6pin Probus connector in my adapter design. A bit of a pain that connector... Anyway yes probe compensation would be good.

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 16, 2019, 05:31:41 am
content: i bought 1 @ $250 in hope i can clone it to make complete all 4 channels for my scope, i thought it should be that simple but... after tearing it apart, it seems like its going to be a lost war for me (attached), so i will keep my original unit just in case... you can wait until someone sell in ebay at bargain price... good luck... ps: not that i really need it but just in case, i will use my Rigol DS1054Z for general purpose 1Mohm input. i'm aiming all my money on active wavelink probes (bodies, heads and tips) on all channels, i will need the last one of the probe's body before settling down since last year. ymmv.the singaporean guy who i bought the unit from still have the unit @ $299 you can make him an offer if you want... thats the 1/10X teledyne's price, cheers.https://www.ebay.com/itm/Lecroy-AP-1M-1MOhm-Adapter/323928606545?hash=item4b6ba64751:g:1J4AAOSwAYBdjHpu

author: DaJMasta
author_rank: Super Contributor
timestamp: December 16, 2019, 07:15:40 am
content: Well I guess that settles it - the adapter is a full 1M Ohm frontend, range switching, offset and all.Definitely possible to reverse engineer with those photos.... but no small task, and I suspect the layout means a fair bit towards the response on the high end of the bandwidth.Interesting to me that their approach is just to add an external frontend, but I guess that does give you the best performance by far and basically just gives you a standard full scope input.

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 16, 2019, 09:36:13 am
content: Quote from: DaJMasta on December 16, 2019, 07:15:40 ami guess its too difficult to get 3-6GHz BW with 1Mohm impedance. besides, high frequency circuits will usually work in lower impedance low voltage mode, so building 50 ohm output active/diff probe ±50V with few Kohm impedance input is much more practical, either from enterprise/pro stand point, and from hobbiests diy stand point too. btw yes its possible to reverse engineer. i certainly can do if its 2 layer board, but for 4 layers and up, i dont have x-ray machine and i'm not going to do O(n^2) process for flying probe continuity test on each node, its just not worth my time and schedule atm.

author: sixtimesseven
author_rank: Frequent Contributor
timestamp: December 16, 2019, 01:26:13 pm
content: Quote from: Mechatrommer on December 16, 2019, 09:36:13 amHmm I probably will try a simplified 1MOhm network just to try. I'm not looking so much to get into very high frequency but add the option to use the delicate +-4V inputs as much more general use scope inputs with a divider and possibly some input protection.

author: RamboChen
author_rank: Newbie
timestamp: January 12, 2024, 01:41:50 am
content: Hi, have you read the EEPROM U7(24C02) content? the adapter use PCF8574 as a IO expander, so if i have the EEPROM content, i guess i can DIY One