[GreenKeys] question on interfacing an ST8000

[Dino Papas]

Ok Eugene, good deal.  One final note, if you can't get MMTTY to work  
you may want to consider the HAL DS-RTTY Win application since it's  
written especially to control the ST-8000 (just data, not the remote  
control function).  It is pretty pricey for sure but it solves a lot  
of problems of trying to get a dumb terminal program to do the things  
you may want to do.  I hadn't thought of MMTTY, hmmmm, I'll have to  
look at that.

73 -- Dino KL0S

On 23Feb2009, at 9:36 PM, <eugene at hertzmail.com> wrote:

> Thanks for note, Dino. Here are my responses (consolidated here).
>
> The exciter is a harris RF-1310. It requires RS232 input for the FSK.
> However, I suspect instead of +/-12V 0/+5 or 0/+8 would do fine.
>
> For the data terminal, I will likely use my PC (sacrilege!) So  
> hyperterm
> etc.  Or maybe MMTTY using com port instead of audio, I have to figure
> it out.
>
> Good point on the PTT function.  This could be very convenient. I  
> assume
> that once I start typing it will key the exciter etc.
>
> I hadn't realized that the ST-8000 will convert from ascii to  
> ITA-5. If
> that is the case, then I can see a real nice benefit in using the
> ST-8000 when transmitting. Sounds like I probably could use  
> hyperterm if
> that's the case.
>
> I fully agree with you. On receive the ST-8000 is indispensable.  I  
> was
> trying to better value the transmit side when a transmitter natively
> supports FSK keying with rs232 as input.
>
> Thanks, Dino. Much appreciated!
>
> Eugene
>
>
>
> -----Original Message-----
> From: greenkeys-bounces at mailman.qth.net
> [mailto:greenkeys-bounces at mailman.qth.net] On Behalf Of Dino Papas
> Sent: Monday, February 23, 2009 8:54 PM
> To: greenkeys at mailman.qth.net
> Subject: Re: [GreenKeys] question on interfacing an ST8000
>
> Eugene -- some thoughts.  My ST-8000 is interfaced to my TS-940S via
> the 4-pin "Xmtr" rear-panel jack on the ST-8000; it's strapped for
> FSK (pins 1/4) and PTT (pins 2/3) [page 30].  It operates in the
> "open collector" FSK keying mode.
>
> 73 -- Dino KL0S
>
> On 23Feb2009, at 8:17 PM, <eugene at hertzmail.com>
> <eugene at hertzmail.com> wrote:
>
>> I've been reading the manual on the ST-8000 and planning for its
>> interconnection in my station.  My question concerns the use of
>> FSK.  My
>> exciter has an RS232 input for FSK data.  When it receives RS232  
>> data,
>> it will transition between mark and space frequencies as defined in
>> the
>> exciter using dip switches to define the shift.
>
> What kind of rig are you running?  A lot of the rigs with a "FSK" jack
> only require a dry contact switch closure to toggle between Mark and
> Space
> tones.  The ST-8000 will provide open collector, +5 V or +8 V keying
> and you
> set the dip switches (S2 and S4) accordingly (Page 29).
>
>> My question is this. If a transmitter already supports FSK as in
>> input,
>> then why wouldn't I just connect my RS232-TxD line from my data
>> terminal
>> to the FSK line of the transmitter? Why would I need the ST-8000 to
>> take
>> the data input of the terminal and output the FSK data to the
>> transmitter?
>
> What kind of data terminal are you using?  Computer serial port or a
> dedicated
> terminal device?  One reason to consider is that the ST-8000 will
> accomplish
> the PTT function for you.
>
>> Now, there are some reasons that I could envision. For example, if  
>> the
>> data terminal only spoke 7 bit ascii and I needed to key the
>> transmitter
>> for ITA-5. That would make sense. But I do not believe that the
>> ST-8000
>> provides such a translation function of codes.  My understanding is
>> that
>> my terminal software running on a PC (for example) needs to toggle  
>> the
>> RS232 port in a 5-bit fashion for the ST-8000 to then toggle its FSK
>> line in a 5-bit fashion. Right?
>
>> Now, I know there are other reason why I might want to send my output
>> data through the ST-8000 instead of connecting the RS232-TxD line
>> to my
>> FSK input line on my receiver, for example if I were changing
>> speeds. I
>> know the ST-8000 can do that (regeneration?).
>
> Yes, the regeneration feature will convert Baudot to ASCII and vice
> versa
> and do speed conversion as well.
>
>>
>> Bottom line though. Assuming I am not using any speed change function
>> and assuming my PC terminal software can support toggling the RS232-
>> TxD
>> line in 5-bit words (using the appropriate ITA-5 code) then am I  
>> right
>> that the ST-8000 isnt doing much for me?
>
>
> Well, if you're using the ST-8000 as your modem (for both receive and
> transmit)
> then it in fact is doing everything for you.....again, need to know
> more about the rest
> of your setup.  On receive you need the ST-8000 obviously to do the
> conversion
> from audio tones to pulses to be decoded by whatever application
> you're using.
>
>
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