[Yaesu] Yaesu FT897D and full duty cycle modes Changing susbjects

Thu Jul 13 23:19:43 EDT 2017

JT modes aren't in FLDIGI. JT modes come from Joe Tayler software and 
produce considerable performance with very weak signals. Like moon 
bounce with 100 watts and single yagis where CW or SSB would require 1.5 
KW and 8 or more yagis on VHF. JT modes get their performance from slow 
data speeds, single tones on multiple frequencies, and significant 
forward error correction.
More conventional digital modes like PSK31 perform well at 25 watts with 
most 100 watt rated radios and generally when those rigs are run at 
higher power the distortion products show up in the receiver display at 
the other end of the contact and often cause the user of higher power to 
be chastised by the receiving station.
Getting the computer based FLDIGI working with a rig isn't hard, but 
there are potential signal levels that have to be set properly and often 
it helps to have the two signal paths transformer isolated to prevent 
ground loops and hum from the ground loops. The FT-857D and 897 are 
handy having a miniDin connector that takes in line level and puts out 
line level so a simple cable to the computer sound card is all that is 
needed. Otherwise the speaker or headphone output is about ten times the 
voltage the sound card line input can handle, and the sound card output 
is way more than ten times the voltage the transmitter microphone input 
can take. One solution for other rigs is sold by RigBlaster, but i've 
not have good results with my 857d and a RigBlaster box.
73, Jerry, K0CQ
On 7/13/2017 7:26 PM, Ron Youvan wrote:
> John Geiger AF5CC wrote:
>>> Can the FT897 be used at 100 watts for full duty cycle modes like
>> JT65-where it would transmit for 1 minute straight, receive for a minute
>> straight, then back to transmitting for another minute? I looked in the
>> manual and didn't see anything about reducing power for the digital
>> modes.
>>> I wouldn't want to transmit at full power for very long with the
>> FT100D or
>> FT857D, but thought that the FT897D might be able to dissipate the heat
>> better since it is larger.
>> Changing subjects;
> I am trying to learn how to get FLDIGI to work properly, so I am new
> to the digital HAM world, but: (I am restricted to LINUX!)
> (Among dozens of modes I do not find JT anything!)
>> I thought all of these new fangled digital modes achieved great success
> using only 25 (or so) Watts TPO, more or less?
> So why is 6 dB more than that necessary?