[1000mp] FSK interface using opto-isolators

[Art Searle W2NRA]

Hi Pete,

I assume you do know that for semi-breakin VOX must be on, right?

73,
Art
W2NRA

----- Original Message ----- 
From: "Pete Smith" <n4zr at contesting.com>
To: "All about Yaesu 1000mp" <1000mp at mailman.qth.net>
Sent: Friday, December 03, 2004 12:17
Subject: Re: [1000mp] FSK interface using opto-isolators


>I tried an optoisolator interface for CW with my Mark 5, and found that the 
>CW opto did not pull the key line low enough to trigger the 
>semi-break-in -- I got CW sidetone but no actual RF.  No doubt this could 
>have been solved by someone who knew what they were doing.  But there 
>definitely is enough current to drive an ordinary optoisolator, at least in 
>a desktop port, judging by my experience.
>
> 73, Pete
>
> PS -- I have never had any problem with ground loops involving the serial 
> or parallel port on my computer and my Mark 5, except for the sound card 
> to microphone connection.  An isolation transformer solved the problem 
> there.  And before anyone writes to ask why I didn't use a back panel 
> audio input, I use the connection for stored voice messages in phone 
> contests, and wanted to be able to route the audio through my SO2R box, 
> along with PTT.
>
>  At 06:30 PM 12/2/2004, you wrote:
>
>
>
>>
>>  Hi Group,
>>
>>Is it possible to use opto-isolators to generate both the Shift and PTT 
>>using the computer serial Com port? If so, what would the value be for the 
>>resistor be to operate the LED? More important, does the serial port have 
>>enough current to drive an opto-isolator? I plan to operate RTTY using 
>>FT1000 Mk5 Field and opto-isolators would completely eliminate any ground 
>>loops.
>>
>>  Thank you,
>>John V.
>>
>>
>>
>>
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