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  • Re: CHASE GPR4403 Laboratory Receiver Service manual PLEASE

    From Tony@83d72b796d91c68f5fa0209d60bf1173@example.com to sci.electronics.repair on Fri Jun 6 00:45:03 2025
    From Newsgroup: sci.electronics.repair

    It was not a design requirement. The original home office spec was for 10 years operation
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  • From Tony@83d72b796d91c68f5fa0209d60bf1173@example.com to sci.electronics.repair on Fri Jun 6 00:45:03 2025
    From Newsgroup: sci.electronics.repair

    At the factory we ran a calibration program. This stepped the receiver every few mega hertz in sync with an accurate sig gen. The receivers internal broadband noise source way turned on every time the receiver was stepped and the resultant receiver output was measured. Any descrepency with the sig gen level at each frequency was stored in rom so it could be added or subtracted to the sig level measurement. I think it is the rom info that gets corrupted over time as the receivers tend to work in all other respects. Bit of a bugger. If I had known people would be using them for home use I would have included a manual cal bypass switch.
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  • From RadioDaze@f247290fbf19244f7dec5ea9207b76bb@example.com to sci.electronics.repair on Wed Jun 11 10:45:03 2025
    From Newsgroup: sci.electronics.repair

    Any details, as to the charger requirements and connector pinout, would be most welcome!
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