Anritsu MT-8801C Refurbishment - Page 1
Forum section: electronics / testgear

author: G0GCD
author_rank: Newbie
timestamp: March 22, 2023, 08:52:10 pm
content: Hi,I've just acquired one of these beauties and looking for any advice on the following refurbishments streams:1. Battery replacement - I think that the original is a BR3032 with solder tags. These are a little difficult to come by, so I'm planning to use a CR2032 in a holder. Any comments about whether this is appropriate or whether there's a better solution?2. Backup the Config Card - I've purchased an adaptor card with a 64MB Compact Flash installed. I'm struggling to find an adaptor so that I can read the original card and back up the image before loading to the newer CF card. Any pointers/advice on this process?3. Restore the display brightness - for this I'm planning to use some led strips specifically designed to fit where the current CFL tubes are. To do this little job means stripping the display out. Anything I should watch for?4. Replace the floppy drive - it looks like there's a unit (SFR1M44-TU26/-DU26) that will drop in to the same bay, allowing the use of USB sticks to lift data from the analyser. I'm thinking that this is best used for downloading the screen captures (to place in the station archive) but is this the best way? Would it be better to just locate some floppies and use an outboard 3.5in drive to transfer the images to my network? In fact, has anyone tried this?5. Recap - strongly recommended by several people. There doesn't seem to be any circuit diagrams in the public domain Does anybody have a list of capacitor values/sizes already about to save me identifying each one in turn?Anything else that I should do? Any help gratefully received....ThanksJohn

author: 5q5r
author_rank: Contributor
timestamp: March 23, 2023, 08:32:04 am
content: On the battery part, the BR3032 seems to be rechargeable, unlike a regular CR2032? Might be an issue.

author: G0GCD
author_rank: Newbie
timestamp: March 23, 2023, 06:43:17 pm
content: 1. BatteryThanks 5q5r - I understood the B and C to describe the type of Lithium Cell - B describing lithium polycarbon monofluoride and C lithium manganese dioxide, both non-rechargeable. Allegedly, the B has a lower capacity but also lower self discharge - recommended for SRAM backup.However, you have prompted me to recheck my sources.. you can't be too sure. To get me going, I am going to transplant a CR2032 into there and see just how long it lasts. The CR2032 is *much* more readily available!RegardsJohn4. Floppy driveI'm reaching the conclusion that it would be cheaper and less risky to obtain an external floppy drive for my laptop and use floppies to transfer data. There doesn't seem to be a ready supply of the SFR1M44-DU26 in the UK and certainly a shortage of verifiable information about them (apart from them being Plug n Play - oh yeah, heard that before!). I'm sure that I can find some floppies somewhere (I've thrown hundreds away myself :-( ).

author: G0GCD
author_rank: Newbie
timestamp: March 24, 2023, 04:28:33 pm
content: For anyone following this...1. BatteryHave completed this.. CR2032 works fine but I'm unsure how long it will last. The original battery is/was BR3032 with tags attached (type G according to Panasonic) but I can't find a source of those.I might try a BR2032 when this battery expires.... but otherwise, case closed.2. Backup the config cardI'm really struggling to find any product which mentions 'writing' to the card. There's loads of readers out there, but (of 5 suppliers) no-one can answer if their unit can actually be used to write to an ATA card. Should be obvious, I think? Can anyone point me to a product that they know works to extract an image and write it to another card?Best wishesJohn

author: G0GCD
author_rank: Newbie
timestamp: March 30, 2023, 09:56:05 pm
content: OK, all was going well, then....As previously described, the battery is replaced, as is the display tube. I started to play with it to make some meaningful measurements.Until yesterday, it all worked fine, then, towards the end of the day, I discovered that the Signal Generator was outputting a signal about 20dBm low (when compared with another signal generator). I used a ham radio transceiver - the other signal generator reported 12dB SINAD about right for the specifications (~-115dBm), the Anritsu was about 20dBm low (~-93dBm).Today, it's nearly 100dbm out (12dB SINAD at ~-15dBm) - the spectrum analyser only shows a very strong signal and the TX power measurement isn't reading anything. The readings are the same when when using the AUX or the MAIN inputs. There's been no significant power presented to either input / output.My only concern is that whilst replacing the display tube, I disconnected an SMA connector from the attenuator unit at the underside front and this connector doesn't feel properly seated. (Unit marked 339H40998A D59090 A01). I can't get it to mate fully. Could this be the problem?I've checked my leads / adaptors and cross checked that the radio still responds to a reading of -115dBm from the other Signal Generator.Any pointers as to where to start diagnosis, please?ThanksJohn(I have a copy of the MT8802A Service Manual)

author: G0GCD
author_rank: Newbie
timestamp: April 01, 2023, 07:52:58 pm
content: One step forward.....So, I found that card A10 hadn't been secured properly; it tried to drop out when I turned the unit over. So, I've undone and re-seated all of the cards and found a replacement securing crew for A10.I've also stripped open the S-ATT unit and checked that the previously mentioned connector isn't damaged .. the centre pin is attached firmly.I put it all together with no change, so walked off in disgust.Two hours later - it's working.So I'm back to everything being within acceptable tolerance - except the signal generator output, which is reading about 10-12dBm low. The power meter IS reading ok. The spectrum analyser also reads the power level correctly.Any advice on how/whether I can adjust the signal generator level up?ThanksJohn G0GCD