Modifications for the Yaesu FT-101
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.
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
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.
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
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
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!!!!!!
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