FT-902 Mods, also FT-901

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WA1FAF:
These mods were developed in the 90's by the "Timtron", WA1HLR.  I have been using my FT-902DM since using a low impedance dynamic mike and Radio Shack 5 band MONO EQ plugged into the "patch" jack on the rear with excellent results.  Here they are:

Receiver mods:

Obtain and install 6kHz crystal filter in AM filter slot.
On IF Board, PB 1704, change C431, 1uf to 10uf, C430, .002 to 470pf disc ceramic

Transmitter mods, all on PB 1705A, AF board.

C533 1uf to 10uf, 25V
C532 1uf to 10uf, 25V
C501 .01 to .001 disc ceramic
C502 1uf to 10uf, 25V
C505 22uf to 100uf 16V
C504 4.7uf to 47uf 6V
C503 1uf to 10uf, 25V
C506 .01, REMOVE
C509 1uf to 22uf 10V, (you can use C505)
C511 1uf to 10uf, 25V
C513 22uf to 220uf 10V
C518 470uf to 1000uf 10V
C515 100uf to 470uf 10V (you can use C518)

These Rice Boxes can sound terrific!  Run 15-20 watts out or drive a linear amp and you'll have a signal you can be proud of!

Mark ("The Faf")
WA1FAF

kb3ouk:
does anyone know if the rest of the caps on those boards are electrolytics, besides the ones listed as disc ceramic? what is C501's value, is it supposed to be mf, pf, uf? and also what is C431 supposed to be? i'm guessing electrolytic, since it doesn't list it as a disc ceramic, but then what is the voltage rating supposed to be? 25 volts like the others similar to it?

Steve - K4HX:
I don't think you'll find too many 10 uF disc ceramics, so it's a safe bet that C431 is an electrolytic. But, if you look in the rig, it should be obvious.

The value of C501 is uF.

For any replacement, just match or increase the voltage rating of the part you're replacing.

kb3ouk:
ok, that's what i thought.

kb3ouk:
ok, another question. i have all the caps i need except for C501. i don't have any .001 disc ceramics, but i did find a .0001 disc. will this make a major difference or cause any problems?

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