[RTTY] A technical question (DigiKeyer)

[Jacek Janusz]

Hello everybody,

This is my first posting to this group and I am not sure if you talk
only about the contests and nothing about hardware/software/technical
subjects? If yes, then just please ignore my question.

I've got namely a problem with cooperation of my modem and the rig. I've got
the DigiKeyer modem from Microham and I wanted to use it with FT-1000 MP MK-V
transceiver. I've installed the software and connected the modem
correctly to computer and transceiver, accordingly to the instruction.
Everything was done succesfully. Before this I've connected all hardware
elements like modem, computer, power supply, transceiver with a cables
to a common ground place. Additionally I've added a ferrite rings to
the computer cables like keyboard, mouse, USB cable. I've started the
MMTTY software, configured correctly, I was able to receive the
signal. I set the output power to 50% of maximal, i.e. about 100
watts. When I tried to transmit the signal, it took about 20-30
seconds and then suddenly the transceiver has switched self off. Then
there was no more possiblility to turn it on since there is a short circuit
inside the transceiver and the power amplifier transistors are broken.
Before I've done this RTTY QSO that finished with crashed trx, I've
done many CW and SSB QSOs and everything worked correctly. Is this
possible that the modem (my model exactly) is internally not isolated between trx
and computer and it made this failure, or there is something other wrong
with the modem? What can be the reason of this issue?
Previously I've used TS450S/AT with simpler modem and DOS application
that did its RTTY job perfectly and I've never seen any problems with
rig or computer. Maybe the newer rigs are more sensitible hi.


Best regards,
Jacek, SP9NWB