[Wswss] WW7D/R's FT-857D 2 meter issue

n6ze at aol.com n6ze at aol.com
Sun Apr 7 15:53:46 EDT 2013



07APR2013
 
Hello Darryl, et al:
 
I have actually gotten parts from Yaesu, particularly things like microphones.
 
You might call their technical people and speak with a 'live' person. This MIGHT help.
 
Seeing that the FT857D is still sold as new by AES/HRO/similar, it shoul;d seem that Yaesu would still support it.
 
I am forwarding this thread to the W6YX  & WSWSS reflectors.
 
bt73Pete, N6ZE in DM04ne today


-----Original Message-----
From: Darryl J. Holman <djholman at u.washington.edu
During last Monday's VHF sprint, it became apparent that my FT-857D went 
somewhat deaf on 2 meters SSB and CW.   Subsequent testing (using 
calibrated equipment) shows that it receives fine on all bands except 2 
meters.

Two meters has lost something around 14db in FM and CW.   A full reset 
did nothing.   I'm guessing that the 2 meter front end is not working.

I pulled the top board and tested a few diodes that are in the 2 meter 
front end.  They seem fine.

The RF amplifier in the front end is a dual gate MOSFET, BB304CDW  (spec 
sheet: http://tinyurl.com/cx8hezz).  I don't know how to test this _in 
situ_, so I think the next step is to simply replace it.

Mouser doesn't have these in stock and they have a message, "End of 
Life: Scheduled for obsolescence and will be discontinued by the 
manufacturer."

So my questions are:

1.  Has anyone had a similar issue of an FT-857/817/897 going deaf on 2 
meters only?  Are there other things I should consider?

2.  Does anyone know of a good source for the BB304CDW?

3.  Does Yaesu sell components like this?   And if so, how long should I 
expect it to take to get the part from them?

Thanks in advance for suggestions.

Darryl, WW7D



 


07APR2013
 
Hello Darryl, et al:
 
I have actually gotten parts from Yaesu, particularly things like microphones.
 
You might call their technical people and speak with a 'live' person. This MIGHT help.
 
Seeing that the FT857D is still sold as new by AES/HRO/similar, it shoul;d seem that Yaesu would still support it.
 
I am forwarding this thread to the W6YX  & WSWSS reflectors.
 
bt73Pete, N6ZE in DM04ne today


-----Original Message-----
From: Darryl J. Holman <djholman at u.washington.edu
During last Monday's VHF sprint, it became apparent that my FT-857D went 
somewhat deaf on 2 meters SSB and CW.   Subsequent testing (using 
calibrated equipment) shows that it receives fine on all bands except 2 
meters.

Two meters has lost something around 14db in FM and CW.   A full reset 
did nothing.   I'm guessing that the 2 meter front end is not working.

I pulled the top board and tested a few diodes that are in the 2 meter 
front end.  They seem fine.

The RF amplifier in the front end is a dual gate MOSFET, BB304CDW  (spec 
sheet: http://tinyurl.com/cx8hezz).  I don't know how to test this _in 
situ_, so I think the next step is to simply replace it.

Mouser doesn't have these in stock and they have a message, "End of 
Life: Scheduled for obsolescence and will be discontinued by the 
manufacturer."

So my questions are:

1.  Has anyone had a similar issue of an FT-857/817/897 going deaf on 2 
meters only?  Are there other things I should consider?

2.  Does anyone know of a good source for the BB304CDW?

3.  Does Yaesu sell components like this?   And if so, how long should I 
expect it to take to get the part from them?

Thanks in advance for suggestions.

Darryl, WW7D



 


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