W0UI's

 Restoring a Yaesu FT-401b

20-tube High Power Amateur Radio HF Transceiver

- This is still a developing work, check back from time-to-time - 
L-to-R: FT401b, IFR FM/AM-1200s service monitor, Tektronix 2246 Oscope, older VTVM

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I am not sure what the right "Crystal Filter" is for (it is apparently not the stock CW filter). Does anyone know what it is?
 
       

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OWNERS MANUAL FOR Yaesu FT-401b HF transceiver
Pages 1-10 - Pages 11-20 - Schematic Diagram

I am preparing to begin restoration / realignment on my three FT-401b transceivers.
I expect to post comments and photos of my efforts on this page.
QUESTION:  Has anyone successfully restored / realigned one and have any tips to share with me?

 Please send me your comments, ideas or thoughts:  CLICK HERE TO EMAIL WOODY 

CAUTION: LETHAL VOLTAGES EXIST THROUGHOUT THIS RADIO.
YOU MUST AT ALL TIMES EXERCISE UTMOST CAUTION 
AND USE ALL SAFETY PRACTICES.
ONE CARELESS MOMENT IN THIS RADIO COULD EASILY KILL YOU.
I make my information available for general information only and 
am not responsible for any injury or death related to it's use

I suggest you review all ARRL materials related to radio service safety before starting this project.

GETTING STARTED: 
- This is still a developing work, check back from time-to-time - 
From the manual, we start by preparing to align the Transmitter Circuit.
Note that right off the bat there is at least 600 volts on this lug of the transformer.
BE CAREFUL AT ALL TIMES... One mistake could easily be fatal to you.
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STEP ONE:
Obviously, you want the radio unplugged from all power sources and capacitors drained before starting this project.
It wants us to disconnect the 600 volts at the Rectifier.
NOTE that the 600 volts appears AT LEAST two other places (on the board and transformer, below)

(a picture of this location is still pending)
 
It wants us to carefully unsolder connections on the bottom of the 6kd6 power amplifier tubes, too.


STEP TWO:



- This is still a developing work, check back from time-to-time - 
If you have experience or ideas about restoring a silver-faced Yaesu, please email me.
CLICK HERE TO EMAIL WOODY 

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All personal comments, pictures copyright 1996-2011 - R. Linwood (4L RANCH)
LAST MODIFIED:


Since 16 Nov 2009:


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