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[KC8Y]

I'm kinda familiar with psk31 & Olivia modes.

Now, plan to experiment with using rtty; is FSK or AFSK most used/easier?

Think this idea was asked before, can't remember. 

Ken KC8Y

[N0IU]

If you are running those other modes, you are good to go for AFSK RTTY.... depending on what software you are using.

Some software, like MMTTY, can do either AFSK or FSK, but....

Is your radio capable of doing FSK RTTY? If it is, it will most likely be looking for the RTTY keying signal and PTT on an ACC (Accesory) port on the back of the radio. In the case of MMTTY, you will need to get the signal from an RS232 serial port or through a USB-to-serial converter or adapter cable to that ACC port.

Rather than re-invent the wheel, Don AA5AU (one of the foremost RTTY contesters in the world) has done an excellent job of explaining the ins and outs of serial interfacing on his website: http://www.aa5au.com/rtty/fsk-interface/

Running FSK RTTY is definitely worth looking into!

[KC8Y]

Thank you, for the great RTTY info.  Will definitely check-out that site, MMTY, & my rig (ic-7200).  I'm  in favor of FSK; use FLDIGI for the other modes.

Maybe even catch you on digitral, sometime.

Ken KC8Y

[N1ZZZ]

The major advantage of FSK is using the built in filters that are available in the rig. 

The issue is usually FSK is operated LSB and many soundcards operators are on USB.  Sometimes you have to use the RTTY-r mode to get the mark/space to match.  The other issue, as mentioned before, is that you have to rewire the interface to get the signal to the FSK pin on the ACC/data jack. 

I don't operate RTTY enough to bother with FSK, so I just use AFSK and the same interface as the other digital modes.

73
Jeremy N1ZZZ

[AA6YQ]

The major advantage of FSK is using the built in filters that are available in the rig. 

The issue is usually FSK is operated LSB and many soundcards operators are on USB. 

If you temporarily reverse your signal and politely explain that the convention in RTTY is for the Mark tone to be transmitted on a higher frequency than the Space tone, which for most radios means "use LSB", such operators will quickly switch sidebands, or configure their RTTY application to invert both their transmitted and received signals. I rarely encounter anyone operating "upside down"; most ops figure it out on their own when no one responds to their calls.

       73,

              Dave, AA6YQ

[KG5AHC]

Hello Ken, I am using RTTY FSK mode on my ICOM 7200 and like it very much. Hope that you have it working as well. I constructed the interface cable for SEND and FSK keying based on designs I found on the internet. I use MMTTY for this method at this time. Picked up the knowledge I needed mostly from the AA5AU website.  Having no trouble communicating with other RTTY stations so far. Generally speaking, I use the Mark frequency offset of 2125 Hz and make sure my demodulator is fixed on that same offset.. I spin my radio VFO to the signal I want to talk to, and don't worry too much about the frequency number on the radio's LCD. 

73's,
Jeff KG5AHC

[AA6YQ]

Hello Ken, I am using RTTY FSK mode on my ICOM 7200 and like it very much. Hope that you have it working as well. I constructed the interface cable for SEND and FSK keying based on designs I found on the internet. I use MMTTY for this method at this time. Picked up the knowledge I needed mostly from the AA5AU website.  Having no trouble communicating with other RTTY stations so far. Generally speaking, I use the Mark frequency offset of 2125 Hz and make sure my demodulator is fixed on that same offset.. I spin my radio VFO to the signal I want to talk to, and don't worry too much about the frequency number on the radio's LCD. 

By convention, the frequency of a RTTY signal is defined as the frequency of that signal's Mark tone. When operating FSK, your transceiver's dial frequency is the Mark tone of the RTTY signal you are receiving or transmitting. This is helpful to know when you agree to meet someone for a RTTY QSO on 14080, or when pursuing a QSO with a RTTY DX station spotted on 21085.

Some ops like using MMTTY's "point and click" capability, in which you can click on a RTTY mark tone on its waterfall or spectrum display and, with AFC enabled, immediately begin decoding the selected RTTY signal. Were you using AFSK transmission with NET enabled, you'd immediately be able to transmit (though that would be a bad idea if the selected Mark tone was less than ~1500 Hz). With FSK, however, you must first QSY your transceiver to align its FSK Mark tone with that of the RTTY signal you selected. MMTTY doesn't provide this capability, but there are several digital mode applications that employ the MMTTY engine and provide a one-click "align" function to QSY your transceiver as described.

      73,

              Dave, AA6YQ

[KC8Y]

RE:  KG5AHC-Jeff

Thank you, for your response on 4-7-16.

I'm very interested in your setup?

I do not have my system working, yet.  I use the Signalink & FLdigi-software for PSK31 & Olivia, but I use the ACC port on back of the rig.  My pc has USB ports.  I will use MMTTY-software for FSK use.

 I am handicap, hence cannot build anything.  Can you OR do you know of anyone that can build an interface cable for Send and FSK keying

Could not find your email address via QRZ.

Ken KC8Y

[N0IU]

My suggestion (which is worth what it cost you - $0.00) is to use an interface from W3YY: http://www.w3yy.com/fsk.htm. I have been using one of these with my IC-7410 for several years (along with MMTTY) and it works flawlessly. According to his website, this interface board will also work with the IC-7200.

As you will also see on his website, he offers them fully assembled. If you are interested, my suggestion is to write W3YY (Bob) w3yy@cox.net and explain your station setup and situation so he can tell you exactly what you need.

Yes, the W3YY interface is quite a bit more "robust" than the simple interfaces on AA5AU's page, but it does use opto-isolators so there is no electrical connection between the computer and the radio.

Good luck!

[KG5AHC]

RE:  KG5AHC-Jeff

Thank you, for your response on 4-7-16.

I'm very interested in your setup?

I will reply in detail to your email on QRZ but a few notes here. I am using the transistor cable design because I had the parts on-hand to build one. I use a commercially available USB-COM port adapter cable because my computer does not have built in 9 pin com port.  I have not observed any problems with the common ground wire in my FSK cable between the radio and the computer. Since I am using the radio's built-in soundcard and CI-V control cable, I do not use a Signalink device. The built-in USB on the ICOM 7200 is one of its best attributes (among many other good ones).

73 for now, 
Jeff KG5AHC

[N0IU]

I use a commercially available USB-COM port adapter cable because my computer does not have built in 9 pin com port.

If KC8Y has a desktop computer, he can do as I have done and install a serial card. The one I have in my current PC is a dual port PCI Express card that cost less than $15 which I am guessing is probably less than you paid for your adapter cable! I am running Windows10 and getting the drivers for the card was no problem.

I have one port hooked up to my W3YY interface for FSK RTTY and the other port for CW. For that port, I did make one similar to the one on AA5AU's website with a single transistor and resistor. I built mine on the back of the DB9 connector and it fits nicely in a plastic shell.


(Please do not make fun of my soldering skills!)

I could have made one just like this with two transistors and two resistors for the FSK RTTY side, but that would be like trying to put 10 pounds of sugar into a 5 pound bag!