Anything known about these SRF772 transistors?

Discussion in 'Amateur Radio Amplifiers' started by K5AHH, May 1, 2021.

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  1. K5AHH

    K5AHH Ham Member QRZ Page

    Hi, all. The other day, I received a TPL 5010A linear amplifier that I thought would be the perfect match for my Realistic HTX-100 10 meter radio. All I could find spec. wise, is a picture of the amplifier on the internet, and what is printed on the side of the amp. It reads: Frequency: 21-30Mhz, Carrier Power Output 60W, PEP power output 140W, Modulation AM/FM/SSB. The two finals are Motorola SRF772. I obviously know the specs. of the amplifier, but can find absolutely no information about these transistors, or what an equivalent to them would be in case they ever go kaput. So, has anyone heard of them? No luck here. Thanks.

    Attached Files:

  2. WA4SIX

    WA4SIX Ham Member QRZ Page

    To my recolection, SRF transistors usually had 4 digits.

  3. K5AHH

    K5AHH Ham Member QRZ Page

    Every single SRF I have seen have ONLY had four digits. Possibly a misprint but still a mystery! Lol. I emailed TPL a while back, but there was no record of the amplifier according to the guy that replied.
  4. WA4SIX

    WA4SIX Ham Member QRZ Page

    Just to throw pasta against the wall, I used SRF2072s back in the day that were in the range you have. Check out that datasheet.
    They were the smaller die size & similar to an MRF454 in spec. They were cheap, so good to buy in bulk & blow up in experiments.
    Also, that amp does not have ferrite transformers & should be used for one band, as tuned. The ferrite transformers made for broadbanded operation.

  5. WA4SIX

    WA4SIX Ham Member QRZ Page

    I just noticed how small the leads are. Never seen one of that die size with those skinny leads.

  6. KA9JLM

    KA9JLM Ham Member QRZ Page

    The part number could be a "In House" Number, Where the part is made for them.
  7. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Sure could.

    Every semiconductor manufacturer including Motorola did that. If an OEM bought a sufficient quantity of parts, they'd make up a new P/N for them and print them all that way to protect the OEM agreement (so users couldn't go back to Motorola to buy parts, they'd have to buy them from the OEM for whom Motorola made them).

    Really common, and could be the case here.

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