Modifications for the Yaesu
FT-101
19-07-1998 FT-101 series, convet 11 meter to
12 meter
Converting 11 Meter band to 12 Meters for the Yaesu FT
101 series ..
Although this procedure hardly qualifies as a "mod" (too
easy), it is certainly useful for the FT 101 series owner. Conversion to the 12
meter WARC band is as simple as replacing a crystal. The 11 meter xtal is
replaced with a 30.52 Mhz 3rd overtone xtal in a HC-25/U holder as specified in
the FT 101 series maintenance manual. No other modifications are necessary as
the new band is close enough to the original that the current components work.
To replace the xtal, remove the oop cover and find the xtal board located at
right front of the rig.
Xtals marked xxxx are standard while oooo are
optional on some units. X5, for the 11m, band is an option and may or may not be
installed.
10B xxxx xxxx 80
10C xxxx xxxx 40
JJY/WWV (1) xxxx xxxx 20
160 oooo xxxx 15
xxxx oooo < X5 the "11 meter" socket
.... xxxx 10A
The xtal was ordered from Marden Electronics (800-222-6093) although it is
probably available from the other companies which offer this type of item. I'll
skip the business details here, but it is cheap. I found fat fingers a hindrance
when yanking the old and insterting the new so I used a hemostat (narrow nosed
locking type device with "seconds" often found in hardware stores, etc.). After
checking with a local ham who monitored my transmissions to make sure I was
where I thought I was, I was in business with 12 meters for my FT
101B.
How'd it go ?? After warming up the rig, I spun the dial a bit on
what has been a mostly dead band this summer. The first station I heard was a
little weak .. AA5QC .. no it's A35QC. I had no idea where that was, but I gave
him a call. It turned out to be JF1WQC vacationing in TONGA, my first African
contact and a 59 report at that! So here's an easy way to add a WARC band and
open new possibilities for DX adventure with your FT 101 series rig. Please let
me know if you have any additional feedback or comments on what has to be one of
the easiest "mods" ever.
(1) This is another story .. note that it is a
receive only band for 10 Mhz .. for now. See Page 70 of the Nov 83 issue of 73
Magazine if you can't wait.
19-07-1998 Replace finals in
FT-101E
There will come a time when the finals in your FT101E
will need replacing. These transceivers were originally equipped with 6JS6C
tubes manufactured by NEC.
This tube's properties are slightly different
from the 6JS6C tubes available today from American tube manufacturers. By the
way, don't bother looking for tubes made by NEC. They got out of the business
several years ago.
In order to use the "American" variety 6JS6's, a
simple modification to the neutralization circuit must be made to the final
section of the transceiver.
The modification consists of replacing the
fixed value 100 pf 1000 VDC mica capacitor with a 10 pf 1000 VDC mica capacitor.
This capacitor, C125, is in series with the 10 pf variable neutralizing
capacitor off of the plate circuit.
If this modification has not already
been completed on your rig, be sure to use a mica or silver mica of at least
1000 VDC. Do not substitute a different type, because the heat in the final
compartment will change the value, and your tubes will fail prematurely. Also,
be very careful to keep all leads short and in exactly the same orientation as
the original capacitor.
Before reneutralizing, open the variable
neutralizing capacitor all the way to minimum engagement and follow the
neutralizing instructions in the manual. While dipping the plate, remember to
adjust the neutralizing capacitor for equal value meter reading peaks (IC
position) on both sides of the dip when tuning the "Plate"
control.
19-07-1998 FT-101 Mod
for 30-meter (10MHz) Transmit
I made several of these mods about
ten years ago but I am a little fuzzy. The FT101 uses 10mhz for its WWV position
but they left out the driver and final coil connections in the transmit section
of the radio. So you either add coils or you can jump the band switch in the
driver portion and the final section.
Connect a jumper from the 20meter
driver coil tab, to the WWV driver tab; and the 40 meter final coil tab to the
WWV final tab.
This will make the driver tune in the 40meter position and
the final will dip around the 20meter position.
A cheap mod for another
band, Good Luck but remember that packet or rtty is continious power so you need
to back off the drive to about 1/3 normal or you will cook the
finals!!!!!!
Terry WA6RNF @ Boise,Idaho