home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
QRZ! Ham Radio 19
/
QRZ Ham Radio Callsign Database - Volume 19.iso
/
modfiles
/
ft847.txt
< prev
next >
Wrap
Internet Message Format
|
2001-11-01
|
4KB
From: Charlie Mazoch <"CharlieM"@Flex.Net.Inc>
Subject: FT-847
Mod to install xtalfilter:
An International Radio xtal filter 2.1Khz wide, 455Khz filter will fit
into this radio. The top of it can be stuck to the diecast housing on
left front of radio looking at the bottom of radio with front facing
forward. I used double sided tape to mount it to the chassis between the
circuit board and chassis.
The pins of filter are facing back and to the top. A couple of short
runs of minature coax and connectors and the ceramic filter on receive
can be replaced. There was a lot of difference using the xtal filter in
place of the original ceramic against strong signals close to the
receive frequency. Model # of filter is #702.
Charlie Mazoch Jr. WA5KVS
2139 Vinita Street
Houston, Texas 77034
charliem@flex.net
YAESU FT-847 ALL MODE HF/VHF/UHF TRANSCEIVER
WARNING! Any modifications made to your equipment are performed at
your own risk. Be aware that these mods will probably void your
warranty.
A modification to open up the radio.
Remove bottom cover..near battery there are 6 solder pads numbered 1
thru 6....pad 1 is already shorted with a chip resistor.....short pads
2 and 3 with solder...check pad 6 and if it has a chip resistor on it
...remove it...this one has to be removed to go out of band on hf and
6m.....replace cover and turn on radio while holding in the lock and
fast buttons....this resets micro-processor and you will also lose all
your memories that you have entered...you will have to reprogram
these....TX coverage will be 1.8-76mhz with no gaps...DO NOT TX BETWEEN
30-36MHZ -- not only is it illegal, but you may damage the HF PA.
Thanks to Tom KF4TRZ, Brent K9WV, and others for sharing this
information.
------------------------------------------------------------
Sirs,
Attached is a text file containing instructions on how to enable the
Yeasu model FT-847 to transmit out of band. I believe this will be of
interest to your readers. Please post this file on your site under
"RADIO MODS." The following text shows the exact contents of the
attached file. Thank you, Jeff Parker KF4SCI
Yeasu FT-847 Out Of Band Modifications
WARNING! There are apparently different versions of the FT-847, as such
some may not modify. Modifications made could void your warranty.
Perform any modification at your own risk. The author assumes no
responsibility whatsoever from the use or misuse of this information.
Please verify and obey local regulations prior to transmitting outside
your license allocations. (c) 5 JAN 00 KF4SCI
Once modified the Frequency coverage of the FT-847 in TX mode is: 1.8
MHz to 76 MHz (no gaps) CAUTION: DO NOT TRANSMIT IN THE RANGE 32 MHz TO
37 MHz AS YOU ARE TRANSMITTING INTO A LOW PASS FILTER AND COULD DO
DAMAGE TO THE POWER AMPLIFIER. 137 MHz to 174 MHz and 410 MHz to 470
MHz
The modifications are as follows ...
Remove bottom cover you should see the backup battery, on the left side
their are 6 solder pads numbered 1,2,3,4,5,6. Pad number one should
already have a 0 ohm chip resistor across it, short pads 2 and 3 with 0
ohm chip resistors, small wire, or a simple solder bridge. Verify that
pad 6 has no chip resistor on it. If indeed it does, remove it. The
radio will not transmit out of band on HF or 6 meters if this
resistor/jumper is left intact. Replace the cover, make all necessary
connections such as power, antenna etc. Now press the fast and lock
buttons simultaneously while powering up the radio. This will reset the
microprocessor resulting in the loss of any memory presets. Your
modification is complete. RF power output should be the normal 100
watts through the six meter band however, output power may diminish to
as low as 20 watts as you reach 70 MHz and beyond. This is normal as no
cause for panic.
137 MHz to 174 MHz and 410 to 470 MHz ranges should produce a
respectable output power of 50 watts.