Hello, Newbie here. I have a couple of old FEI FE-5650A rubys (one is Opt 3, and the other is Opt 3 & Opt 12) both of which I literally dug out of a garbage can. One is marked 'bad' and the other has no markings. I have not attempted to put power on the units as I would prefer to have a look see on the schematics first and also, to know what the various options provide. Opt 12 is not listed on any literature that I have, while Opt 3 = 5 MHz Out. Looked around the 'Net on/off for several years for info, I've found a few tid bits here and there, etc. Although I have tracked down a marketing flyer and a service manual (TM-0107 Dtd Feb 1998), which depicts board silk screens, while the document does not actually contain any electrical schematics of the PCB boards. Does anyone know of or can point me to any available schematics for these old rubys? With the can removed I noticed a multi-throw DIP switch, anyone know what those settings do? Also, on sht 12, Fig 4, block diagram, depicts a "serial digital input" into a block titled, "Serial Interface", and I did track down a FE-5650A RS-232C hack, does anyone know if those signals are brought out to the DB-9 connector, perhaps via pins 6 & 9 which are marked N.C.? Thanks in advance, walt w.

Hi, there's a link to information on the Time Nuts archive: https://time-nuts.febo.narkive.com/Bhntgkdy/changing-fe-5650a-frequency Schematics might not be included, FE seem to have kept those close to their chests. If the link to the ZIP file fails, archive.org might still have it. On Thu, 3 Mar 2022 at 10:55, xtronus--- via time-nuts < time-nuts@lists.febo.com> wrote: > Hello, > > Newbie here. > > I have a couple of old FEI FE-5650A rubys (one is Opt 3, and the other is > Opt 3 & Opt 12) both of which I > literally dug out of a garbage can. One is marked 'bad' and the other has > no markings. I have not attempted > to put power on the units as I would prefer to have a look see on the > schematics first and also, to know what > the various options provide. Opt 12 is not listed on any literature that I > have, while Opt 3 = 5 MHz Out. > > Looked around the 'Net on/off for several years for info, I've found a few > tid bits here and there, etc. > > Although I have tracked down a marketing flyer and a service manual > (TM-0107 Dtd Feb 1998), which depicts > board silk screens, while the document does not actually contain any > electrical schematics of the PCB boards. > > Does anyone know of or can point me to any available schematics for these > old rubys? > > With the can removed I noticed a multi-throw DIP switch, anyone know what > those settings do? > > Also, on sht 12, Fig 4, block diagram, depicts a "serial digital input" > into a block titled, "Serial Interface", and I did > track down a FE-5650A RS-232C hack, does anyone know if those signals are > brought out to the DB-9 connector, > perhaps via pins 6 & 9 which are marked N.C.? > > Thanks in advance, > > walt w. > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > an email to time-nuts-leave@lists.febo.com > To unsubscribe, go to and follow the instructions there. > -- Clint. M0UAW IO83 *No trees were harmed in the sending of this mail. However, a large number of electrons were greatly inconvenienced.*

Hi FEI tended to “hang on” to model numbers through many generations of devices. I suspect this made marketing a lot easier. It does not make working out “what do I have here” very easy these many years later. They never intended any of these devices to be field repairable. Their customers never had any interest in repairing a device in the field. We live in a world of “send it back to the factory” for repairs. This is true of a wide range of items and has been true for decades. Typically the big issue with most Telecom Rb’s ( the FEI’s very much included) is drift of the internal crystal oscillator. You tweak a trimmer and get it in range. The problem unit now works ok. Next up are exploded electrolytic caps. These are often rattling around inside the housing. Fun !!! Bob > On Mar 3, 2022, at 7:17 AM, Clint Jay <cjaysharp@gmail.com> wrote: > > Hi, there's a link to information on the Time Nuts archive: > > https://time-nuts.febo.narkive.com/Bhntgkdy/changing-fe-5650a-frequency > > Schematics might not be included, FE seem to have kept those close to their > chests. > > If the link to the ZIP file fails, archive.org might still have it. > > On Thu, 3 Mar 2022 at 10:55, xtronus--- via time-nuts < > time-nuts@lists.febo.com> wrote: > >> Hello, >> >> Newbie here. >> >> I have a couple of old FEI FE-5650A rubys (one is Opt 3, and the other is >> Opt 3 & Opt 12) both of which I >> literally dug out of a garbage can. One is marked 'bad' and the other has >> no markings. I have not attempted >> to put power on the units as I would prefer to have a look see on the >> schematics first and also, to know what >> the various options provide. Opt 12 is not listed on any literature that I >> have, while Opt 3 = 5 MHz Out. >> >> Looked around the 'Net on/off for several years for info, I've found a few >> tid bits here and there, etc. >> >> Although I have tracked down a marketing flyer and a service manual >> (TM-0107 Dtd Feb 1998), which depicts >> board silk screens, while the document does not actually contain any >> electrical schematics of the PCB boards. >> >> Does anyone know of or can point me to any available schematics for these >> old rubys? >> >> With the can removed I noticed a multi-throw DIP switch, anyone know what >> those settings do? >> >> Also, on sht 12, Fig 4, block diagram, depicts a "serial digital input" >> into a block titled, "Serial Interface", and I did >> track down a FE-5650A RS-232C hack, does anyone know if those signals are >> brought out to the DB-9 connector, >> perhaps via pins 6 & 9 which are marked N.C.? >> >> Thanks in advance, >> >> walt w. >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send >> an email to time-nuts-leave@lists.febo.com >> To unsubscribe, go to and follow the instructions there. >> > > > -- > Clint. M0UAW IO83 > > *No trees were harmed in the sending of this mail. However, a large number > of electrons were greatly inconvenienced.* > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-leave@lists.febo.com > To unsubscribe, go to and follow the instructions there.