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OT electronic part help needed Motorola SWA101 amplifier IC

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  • OT electronic part help needed Motorola SWA101 amplifier IC

    Hi All,

    Way off topic but I am at the end of my rope and am hoping someone can help.

    I have an older piece of Motorola radio test equipment, a radio service monitor, that has blown a couple of output amplifier IC's. This equipment was new about 1984 and is long out of support by Motorola. I have Googled my fingers off and can not find any info on these parts. They seem to show up on the broker search sites, but no data available and I only need 2 and a couple of spares. This piece of equipment was the first I bought new and it has sentimental value so I would like to repair it.

    Now for the specifics that I know...

    The IC looks like a T-005 case metal transistor but is actually a very wide-band amplifier. Approximately 100Khz to 1Ghz. Based on the circuit it probably only has 5-10 Db of gain across the range and would be very flat in its response curve. The maximum output power would be around +15 Dbm at 50 ohms. It is a 3 terminal device, input, output and ground with DC power (+5 volts) fed on the output pin. The markings on the case are as follows:


    M Motorola logo
    SWA101
    412

    The second one is marked the same except the 412 is 425 so I am assuming that is a date code. In the Motorola service manual for the equipment both parts have the same part number but the only description is IC Amplifier.

    If anyone has any old Motorola data books or any ideas I would appreciate any help you could provide.

    Thanks in advance.
    Robin
    Robin

    Happily working on my second million Gave up on the first

  • #2
    I have the Motorola linear data book from that time period. I will have a look.
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    • #3
      Evan,

      Thanks for taking the time.
      Robin

      Happily working on my second million Gave up on the first

      Comment


      • #4
        It isn't in the databook. I suspect it isn't an IC as they don't use that prefix for ICs. It is more likely something like a broadband darlington transistor pair.
        Free software for calculating bolt circles and similar: Click Here

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        • #5
          A short look at the most likely of my data books indicates that an actual "Motorola" part of that time would usually have an MC prefix. There are exceptions. It can be a "motorola part" without having been made by Motorola.

          However, parts with "101" in them I recall as being fairly common IF amplifier parts. Although typically having 6 leads, some were different.

          One assumes that a 3 lead part must get its power through a load coil or resistor on the output, as you say, which makes it a very simple circuit indeed.

          I'll look some more later, I have some general non-motorola IC data books from the year 0.
          1601

          Keep eye on ball.
          Hashim Khan

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          • #6
            My collection of Motorola Master Selection guides from 1976 thru 1980's do not appear to show that part, if it is indeed an RF amp. Very few Mot parts are not "MC" prefixed, as I mentioned above.

            It may well be someone else's part that the radio folks decided was best. The logo may not indicate the true origin, and the part number may not correspond to anything in a catalog.

            Or, it may not be quite what you think, possibly a specialty transistor.

            Unfortunately, in either case, it might be hard to run down. Probably easier by searching for parts of the type you think it is, in various old databooks. There is a good chance the numbers on it are not catalog numbers.

            Might be wrong, but haven't found it so far.
            1601

            Keep eye on ball.
            Hashim Khan

            Comment


            • #7
              If this was a special part made for the manufacture of the equipment then it will not be listed in any of the substitution books or online.

              Manufactures very often take a common item and have the manufacture of that item give it a special number just for them. This keeps people like you and me from buying an over the counter part and repairing the equipment ourself. The $1 item is called a special part and sold for $30. This is very common Honeywell is well known for this trick to make themself RICH.

              If you have a good part you can some times do a few electronic tests and find out what will work as a substitute.

              Your best bet is go to the electronic forum and post your question there under General Electronics Chat. http://www.electro-tech-online.com/
              Last edited by gary350; 06-05-2011, 07:30 PM.

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              • #8
                And I believe that now Motorola semi is taken over by Freescale and ONsemi which may muddy the water.
                Max.

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                • #9
                  The part is listed in a few online sites as a Motorola part but unfortunately no datasheets are to be found.
                  Free software for calculating bolt circles and similar: Click Here

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                  • #10
                    Someplace called "Speedbird", apparently in Australia, or at least hosted there, claims to have some.

                    Originally posted by MaxHeadRoom
                    And I believe that now Motorola semi is taken over by Freescale and ONsemi which may muddy the water.
                    Max.
                    Actually those are the names of the spinoff companies that Motorola created as dumping grounds for their components divisions....... Mot split the power stuff into "On Semi", along with some of the other items, and pushed the uP stuff generally into Freescale. Some of the rest seems to have been sold off to Vishay, Diodes Inc, and possibly others, a practice also followed by companies including IR.

                    Those are ways of getting rid of divisions that do things you don't want to do anymore, or that have products which are too far off the cutting edge, but still have sales volume.

                    The part in question may, or may not, have been made by Mot. If so, it was not in any of the contemporaneous Master list of Motorola parts, so it apparently was not widely sold, or at least not widely marketed.

                    Possibly the radios division got it made special by the semi division. Wouldn't be the first time that happened when a company has several disparate divisions.
                    1601

                    Keep eye on ball.
                    Hashim Khan

                    Comment


                    • #11
                      Thanks for taking the time to look for info for me. You are all hitting the same wall that I have. A little background on this amplifier....

                      It is in a piece of test equipment that has the ability to transmit and receive from 500 Khz to 1 Ghz, AM or FM. The parts in question are in the transmit amplifier which is also used as the local oscillator for the receiver. The amplifier chain consists of 5 amplifiers. The first 3 are SWA100's and the last 2 are the SWA101's. The manual states that the 5 chip chain has a gain of 25 Db. The output of the last amplifier would need to be greater than +10 Dbm as the output of the equipment is specified as +10 and there are 2 relays and 2 SMA connectors between the last amp and the output connector.
                      Almost all of the semiconductors in this equipment are Motorola, and common parts at that. I have another one of the same service monitors, just a little newer that I opened up and it has the same parts just different date codes. The Motorola test equipment division will not offer any info as the equipment is "past end of life support" . This is a major reason why I don't recommend Mother M's radios to my customers. Don't get me wrong, I understand things get old and outdated, or parts are no longer manufactured, but this part seems to be an exception. I have never had such problems at least finding reference to an electronic part.

                      Anyway... Rant Off

                      Thanks to all of you for taking the time to look. If anyone is interested I can scan that section of the schematic for you to look at.

                      Best Wishes,
                      Robin
                      Robin

                      Happily working on my second million Gave up on the first

                      Comment


                      • #12
                        The schematic might be helpful. There may be an acceptable sub for the part, although in RF that is far less "doable".

                        As for "MM" saying the unit is "past life support", they are only one among thousands.

                        The very same will occur with many of the test equipment manufacturers, who have a policy of active data and spare parts destruction with regard to old equipment. This is a newish phenomenon, last 15 years or so, apparently driven by liability concerns, as well as the claimed "huge" cost of maintaining stocks and information.

                        Genrad was the first to inform me of that. I was told that all old parts were scrapped, and all information was destroyed a year or two prior to my inquiry.

                        Despite "all" information being destroyed, the guy there did send me a copy of their drawing of the battery pack (which was my inquiry), so they apparently retain enough manufacturing info for defense purposes.
                        1601

                        Keep eye on ball.
                        Hashim Khan

                        Comment


                        • #13
                          The "SWA" part of the number is revealing (I've worked with Motorola parts since the 70'ies and still am with Freescale).
                          A Motorola part number where the first letter is "S" is a mostly custom part for a US customer.
                          A Motorola part number where the first letter is "Z" is most often a custom part for a Europen customer.

                          That being said, a device called (just an example) MWA123 would be completely in line with the Motorola standard numbering system for high frequency devices back in that time.
                          You wouldn't find MWA101 (vs. SWA101) as a standard part in any catalog, though.

                          What usually happened was, that a customer (in this case, another division of Motorola) would say, "Hey, great new standard device (here, MWA123), just what we need! However, we need at tighter/lower/higher/different specifications on these exact parameters. Could you select parts for us?"

                          And Motorola would say, "Sure, and then we reissue this part as SWA101", which is then an exclusive for you.

                          The only chance I see is for you to go back and look at the old "MWA" parts and see if you find something looking likely (pinout, supply voltage etc.).
                          But bear in mind that the standard part (if you find it) probably has wider specs than the selected parts you have in your equipment.

                          Good Luck,

                          Benta.

                          Edit: a quick search on "Motorola MWA" turned up this:
                          http://www.fdatasheet.com/MWA/MWA-230.html
                          However, the RF devices were always a pain to get data on...
                          Last edited by Benta; 06-06-2011, 06:48 PM.

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                          • #14
                            Thanks, Thanks and more Thanks...

                            First off, Thank You to all who have replied and taken time to help.

                            Benta,
                            Your info on the MWA series and Motorola's custom or special pick and numbering method have answered some BIG questions. Based on your information I looked into the MWA series of amplifiers and I think I have found the answer. It appears that the MWA330 is the generic source of the SWA101. It also follows that the driving amplifier, a SWA100 is a MWA 320 (possibly a MWA310). While now obsolete, the MWA330 is available at a cost that will make it worth a try. Fortunately, even with this being a very high performance piece of test equipment, I can easily live with any imperfections a MWA330 might cause verses the hand picked part. There are even current components which would work with some minor circuit changes.

                            Again, Thanks to all of you for the help and I will update the post with the results to let you know.

                            Now, back to making chips, not IC's .
                            Robin

                            Happily working on my second million Gave up on the first

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                            • #15
                              Interesting.... As I suspected and mentioned indirectly, it is NOT an "IC" at all, but a single transistor with biasing etc components included, all on a "hybrid" circuit, which would be a thinfilm........ ceramic substrate with the resistors and wiring printed on it, and the transistor attached as a chip.

                              That being the case, if the part were truly unobtanium, one could conceivably construct one with small (possibly402 size) SMT resistors and a suitable transistor.
                              1601

                              Keep eye on ball.
                              Hashim Khan

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