[CQ-Contest] RE: Topband: Installing the W8JI Keying Mod for the FT-1000 (D)
W6IZT at aol.com
W6IZT at aol.com
Fri Dec 20 14:45:08 EST 2002
I did the W8JI mod to my FT1000D earlier this week. I was a bit stumped by the initial instructions as I wasn't sure that the 1.5k resistor was supposed to go between the base and the collector. Once I drew a diagram of the circuit it became clear to me.
I checked the resultant RF envelope with my scope and was pleased to see an RF envelope with rise and fall times consistent with click-less keying.
I recommend this mod to anyone using a FT1000.
From: topband-admin at contesting.com
[mailto:topband-admin at contesting.com]On Behalf Of K1ZM at aol.com
Sent: Thursday, December 19, 2002 1:14 PM
To: topband at contesting.com; cq-contest at contesting.com
Subject: Topband: Installing the W8JI Keying Mod for the FT-1000 (D)
I am posting this to the reflectors because I think it may help others in
executing W8JI's keying mod to the FT1000 (D) model.
Briefly, let me comment on this radio versus the MP and the MARK V.
I've taken a look at the BEFORE and AFTER scope traces of the keying in the
versus the MP and Mark V - and a "stock" D looks about the way an MP or MARK
V looks AFTER having installed the W2VJN current production mod.
Given that fact, it was questionnable in my mind whether to tear into my
radio at all - but then, I took a look at the scope trace of what a W8JI
MODIFIED "D" keying waveform looks like and the difference is so dramatic,
that I just decided to go ahead and "suck it up" and go for it....
Now, please note - these notes refer to an FT1000D - and not to the MP or
Mark V. Admittedly, modifying those radios requires more work....but
happily, taking care of things on the D is really quite a simple matter.
As W8JI has noted, the mod goes on the AF board at seven pin connector J3024.
The good news is that you do NOT need to take the board out of the radio to
do the mod. It can be done by just "floating" the required components above
the board and then insulating them when done in order to ensure they do not
short out into nearby components should they shift position over time.
I did as Tom said and cut the wire going to pin 2 on J3024 (this is the
second pin from the RIGHT) when viewing this connector with the radio upside
down with the front panel facing toward my chest.
You want to follow this wire into the harness and cut it so as to leave about
1.25" of wire remaining on pin 2 of J3024. Then pull the harness side of the
wire out carefully to expose a similar length of wire.
I made up a little "jig" of the 2N3904, with the 1.5k 1/2 watt resistor
connected between the base and the collector of the transistor - and tinned
the emitter to accept a "tacked on" connection.
The third component required is a 10UF electrolytic at 25v, the negative
side of which must go to ground. Perhaps not the NEAREST point - but
certainly the EASIEST and most accessible point at which to find chassis
ground and mount the cap is at a mounting screw for the AF board in the
middle of the board on the front panel side. This is about 2 inches to the
LEFT of where the cut wires wind up - and it is also an open area allowing
plenty of room for the cap to float above the board.
I chose an axial lead cap for this project (largely because its long leads
were useful to me in spanning the distance involved) and mounted it flush
onto a solder lug. This I placed under the board mounting screw noted above
negative side of the cap almost directly on the lug. Then I dressed the
positive axial lead with sleeving and passed it UNDER an intervening wiring
harness in order to get the plus side of the cap into the general vicinity
where the two wires resulting from the cut to pin 2 at J3024 would reach.
Once this has been achieved, it is a straightforward process to tack the
short wire from pin 2 to the emitter of the transistor and the flying harness
lead to the collector. The positive lead of the 10UF cap is most easily
tacked on last and I should note that it is this lead that suspends the mod
in mid air above the AF board. As an added measure to insulate the mod from
all other components around it, I placed some pvc electrical tape over the
top and bottom of the mod - just in case.
One other point worthy of mention is that it is a good idea to bend the
solder lug up at a 45 degree angle right at the screw to ensure no adjacent
foil traces wind up being jumpered when you tighten the screw to hold the lug
in place. I also aimed the 10UF cap into an open area on the board - where
just floats out of harms way from nearby components. It is easy to see how
to do this when looking at the board - and also easy to pass the positive
axial lead UNDER the harness to the right in order to make the connection to
the base of the transistor where it meets one side of the 1.5K resistor.
I have now done this mod twice in the last 24 hours - the first time, because
I was feeling my way, took about 2 hours. Much of this time was spent just
getting my radio out of where it is sandwiched into the 160M operating
positon - and then getting it hooked up again. The second time doing the mod
took just about an hour - which includes taking the radio out of its
operating position and then rehooking up the station again.
The BEST news was hearing K9DX's comments this morning on Topband. Johjn
said it sounded great to him. Hmm - now I only have a few more of these to
do......but then it's over with.
Hopefully, this amplification of Toms' excellent post on March 9, 2001 is
useful to anyone out there with an FT1K "D". It was not hard at all to do
this mod folks - not hard at all and the results are indeed compelling enough
to make the effort more than worthwhile.
My thanks to W8JI for taking the lead in getting the word out on this
K1ZM at aol.com
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