Hi Gang
Here's a suggestion on the FT1000D APF mod.
Take the BOARD out - buy the three surface mount resistors that must be
installed (in place of what's there) and if you are not comfortable doing
micro soldering - have it done by a professional.
Here locally, I have HAM CENTRAL and there is a fellow there named Eric who
had an optical loup and a really professional soldering station.
5 minutes with Eric and I had the three SMT resistors installed.
Putting the board back into the Ft1000D is not all that hard - all the jumper
harnesses are pretty simple to re-connect as well as putting the screws back
to hold the board in the radio.
Rick is right - the improvement is WELL worth the effort.
If the APF in your D sounds muffled - has a broad peak (or no PEAK) - you
NEED this mod.
If CW signal levels actually DROP when you engage your APF - or if the peak
seems to muffle the signals into oblivion, then you NEED this mod.
With the correct values in place, there is a DISTINCT, SHARP CW peak around
9-10PM on the face of a clock - with the APF control engaged - and weak CW
signals on Topband literally LEAP out of the radio.
Since I posted this mod some years ago, I have learned that Yaesu has at
LEAST 5 combinations of resistors on that board - depending upon which
version/release of the radio it happens to be.
The very best set of ones were in there during the late 1991-early 1992
production era. Since then, they have been experimenting with all kinds of
values.
But, if you install the ones recommended in the mod, you will find your radio
restored to about what was there in the 1991/1992 period.
I personally cannot stand the APF in a D that is set up without the proper
values.
Finally, the history of why this all happened is almost comical. The truth of
the matter is that some early FT1000D customers complained that the original
values caused the CW sigs to RING in a D with the APF on and PEAKED properly.
(So Yaesu started experimenting with different value SMT resistors in order
to lower the effective "Q" of the audio peaking filter).
The complaint about ringing is somewhat true if you listen on SPEAKER at HIGH
volume levels. But personally, I have never found this to be a valid
complaint. If you listen with phones on and at comfortable audio levels,
this MOD really does the trick on weak sigs that we often find on Topband.
Some years ago, KA1PE (now K1GUN) used to say that on VK9XY long path at his
sunset, the signals would come up from 449 to about 569 with the APF engaged.
I know this to be true from personal use at my station - so if you are game,
this is a MOD well worth making if your APF doesn't do much when you turn it
on on your FT1000D.
Good luck and hope this us useful to someone out there.
73 JEFF
K1ZM/VY2ZM
K1ZM@aol.com
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