[RTTY] A technical question (DigiKeyer)

[jchutcheson at comcast.net]

Hi Jacek:

I have not used the DigiKeyer, but having built a number of rather poorly designed interfaces over the years (hi), I would be surprised if the interface caused such extensive damage, unless, perhaps, you got a very nasty ground loop problem.  Do you have a single point ground for your station?  Either way, can't say that I've ever heard of anyone having an interface do so much damage, but perhaps others on this list have.

Is it possible that something went wrong with you antenna system?  I have an IC-746, and if the built-in tuner is turned on when feeding into an external tuner, you can do some damage.  Even there, however, the worst I've seen happen is a couple of diodes being blown, nothing like the kind of damage you describe.  Very sorry to hear it.

73,

Joe, KB1CJ


-------------- Original message ----------------------
From: Jacek Janusz <jj at galaxy.uci.agh.edu.pl>
> 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
> 
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