RTTY
[Top] [All Lists]

Re: [RTTY] A technical question (DigiKeyer)

To: "'Jacek Janusz'" <jj@galaxy.uci.agh.edu.pl>,<rtty@contesting.com>
Subject: Re: [RTTY] A technical question (DigiKeyer)
From: "Joe Subich, W4TV" <w4tv@subich.com>
Date: Thu, 27 Sep 2007 11:40:46 -0400
List-post: <mailto:rtty@contesting.com>
Jacek, 

I'm sorry to hear about the  problem with your FT-1000MP. 

It is highly unlikely that the failure is related to the 
microHAM DigiKeyer.  The audio section (USB) of DigiKeyer 
is transformer isolated from the radio.  The computer side 
of DigiKeyer icludes high voltage opto-isolators between 
the USB interface and DigiKeyer's internal controller and 
the control signals (PTT, FSK and CW) between the controller 
and radio are open collector transistors at low level (+5V) 
circuits in the FT-1000MP.  

Between the high voltage opto-isolators between the USB 
interface and controller and isloation transformers between 
the audio inputs and the USB sound circuits, the isolation 
between computer and radio is many hundred volts.  

If you were powering DigiKeyer from the +13.8 V output of 
FT-1000MP (normal operation), the radio includes a 200 mA 
fuse that would prevent any problem with DigiKeyer from 
effecting the radio.  

Finally, the AFSK output of DigiKeyer is a maximum 4 V P-P 
(necessary for some other manufacturer's radios) but even 
that level would not cause a problem with the FT-1000MP as 
the ALC would limit the output (even though it would be 
very "dirty").  

Failure of the FT-1000MP output transistors is more likely 
caused by a failure in the radio power supply, antenna 
system  or a problem in the output filter board.  

73, 

   ... Joe Subich, W4TV 
       microHAM America 
       http://www.microHAM-USA.com 
       http://groups.yahoo.com/group/microHAM 
       support@microham.com 
 


 

> -----Original Message-----
> From: rtty-bounces@contesting.com 
> [mailto:rtty-bounces@contesting.com] On Behalf Of Jacek Janusz
> Sent: Thursday, September 27, 2007 7:50 AM
> To: rtty@contesting.com
> Subject: [RTTY] A technical question (DigiKeyer)
> 
> 
> 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
> 
> _______________________________________________
> RTTY mailing list
> RTTY@contesting.com
> http://lists.contesting.com/mailman/listinfo/rtty
> 
> 

_______________________________________________
RTTY mailing list
RTTY@contesting.com
http://lists.contesting.com/mailman/listinfo/rtty

<Prev in Thread] Current Thread [Next in Thread>