开云体育

From: [email protected] [mailto:[email protected]] On Behalf Of Max Donoghue
Sent: 13 July 2022 19:25
To: [email protected]
Subject: Re: [YaesuFT847] Schematics?

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The voltages at Q4001 look good, as do the measurements at Q4006.

Does the 285mA reading seem reasonable considering Q4006 is not putting any power out? Yes Bias current for linear operation, it could go to 300mA for perfection!

I think Q4001 is good based on the signal strength into the handheld.? Possibly a break in the RF path between Q4001 and Q4006? I read where solder joints have been known to crack. There is not much than can go wrong between Q 4001 and Q4006, cracked cap maybe, you really need to signal trace, i.e is the signal far larger than, 50mW in 3 watts out is a power gain of? 18dB Q4001 provide many Watts into the final device, check solder around Q4001.

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BR Andrew

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