Setup And Operation - Yaesu FTM-6000R Manual

external reference oscillator running at 49.152 MHz.
See the figures in the PTRX-9700 review in this
issue for more details on the board's location and
connections.
49.152 MHz is not exactly a common reference fre-
quency. That said, TCXO and OCXO modules are
available that can provide this frequency, but GPS-
disciplined options are also readily available. Leo
Bodnar offers GPSDOs that are programmable to
work at nearly any frequency between 400 Hz and
810 MHz, including the Mini Precision GPS Reference
Clock (miniGPS, as labeled), reviewed here. Paired
with the Reference Injection Board, the miniGPS pro-
vides a great solution for GPS-locking the IC-9700,
and one that works seamlessly with the Radio Analog
PTRX-9700 that's also reviewed in this issue of QST.
Installation
The Reference Injection Board installs easily inside the
radio. The process is simple; the most time-consuming
part is taking the bottom cover off the radio. Follow
these installation steps:
1) Remove all connections from the radio. Remove the
bottom cover.
2) Peel off the black spongy cover on the reference
input shield. Leo Bodnar recommends affixing it
elsewhere inside the radio, but I removed it from my
radio.
3) Remove the screws on the main board that are
marked 10 and 11. Install them in the two blank
holes on the Reference Injection Board.
4) Install the Reference Injection Board using the sup-
plied hardware.
5) Install the supplied SMA extension cable between
the injection board and the rear panel 10 MHz refer-
ence input. Alternatively, connect it using a supplied
cable with the PTRX-9700 board.
6) Reinstall the bottom cover.
Reconnect and test the radio. Its operation should be
unaffected by installing the board. It's not until you con-
Bottom Line
The Leo Bodnar miniGPS and Reference Injec-
tion Board provide a simple, affordable method
of locking your IC-9700 to a GPS referenced
clock for improved frequency stability and
accuracy. High stability really matters, espe-
cially for digital mode operating, and this setup
provides it in a small, well-designed package.
nect the 49.152 MHz reference that you'll see a differ-
ence in operation.
The board is held in place with two screws and two
spacers. The screws are longer than the factory ones
to accommodate positioning the board above a per-
forated shield, where the injection board couples
49.152 MHz energy into the radio.
Leo Bodnar's attention to detail is evident in the
board's design. The factory screws thread into two
holes in the board for permanent storage. Should you
ever decide to remove the Reference Injection Board,
you can remove those screws from it, remove the
board, and place the screws back into the main board
— a nice touch.

Setup and Operation

You don't need any test equipment to align and use the
Reference Injection Board with the miniGPS receiver.
You'll need to configure the miniGPS to supply the cor-
rect reference frequency, using the configuration soft-
ware available from the Leo Bodnar product page. It's
available for Windows or Mac OS X (see Table 2).
Connect the miniGPS to a USB port using the sup-
plied mini USB cable, and the supplied GPS antenna
to the SMA GPS port. Then open the software and
you should see a display similar to the one shown in
Figure 6. If you're using the Mac application, the view
is different but includes the same information, plus
additional graphical elements, including a satellite
map of the current GPS position.
Set the frequency to 49152000, and then click the
button in the right-hand pane. This saves the
update
Figure 6 — The­32­mA­output­setting­is­recommended­by­Leo­
Bodnar­for­driving­the­IC-9700­Reference­Injection­Board.­The­
utility­(available­from­the­miniGPS­product­page­for­Mac­and­
Windows) requires only setting the output frequency, as shown.
www.arrl.org QST August 2022 47