Vhf aux input? Adaption for a sailor with a speech disability

[Latitudes17]

Hi, I am a newbie to the forums, obviously. Hoping you will be forgiving of my ignorance.

I am looking for a vhf radio that can send computer generated or pre-recorded responses or hails. I have cerebral palsy and my speech is not always clear. I can program a tablet or whatever to produce the audio, but I don’t know enough about vhf “stuff” to link the aux feed to the radio.

Also, using the radio normally with a mic, you need to push/hold a button while transmitting. Can this be automated when using aux audio?

Or am I going down the wrong path; should I explore a nmea enabled vhf? What functionality is added by having the vhf on the nmea bus? I am all wired with nmea 2000; adding the vhf would be simple enough.

All thoughts and ideas appreciated! Thanks!

-Hannah (trawler, USVI)

[smac999]

the nmea 2000 does not help you here at all.

most likely you'd need to have something custom made for this.

something could probably be easily made to input audio to the vhf via the headphone jack of the ipad. but you'd have the push the tx button yourself.

of course you could also just hold the ipad infront of the vhf mic and hold the button. which requires nothing new. but would be a pain.

getting something to talk and push the button would require something more computerish with plc controls or something to push the button. possible an interesting project for someone to try.

not firmilur with what you have. it is only the voice coming out that is hard to understand or the way you talk. if it's just the voice you might be able to use a throat mic? if your throat acts normally while talking.

[ka4wja]

Hannah,
1) I saw your query yesterday, and my first thought was "too bad you weren't a ham operator, and desired a 'voice keyer' in your ham radio" ---- 'cuz there are quite a few ham rigs that have these built-in!
But, there are no Marine VHF radios with this capability...


Then, I went ---- "Ah ha"...how about a "stand-alone voice keyer"...or a "voice keyer ap"??
Either one will work for you...
Although, neither will key the radio for you automatically, as this would be a radio function (not the voice keyer function)....
{and, as I wrote, there are ham radios that CAN do these things, there are no Marine VHF Radios that do..}

Depending on your exact application and your operating, one might be better than the other....that's something I don't know...

Originally Posted by Latitudes17

Hi, I am a newbie to the forums, obviously. Hoping you will be forgiving of my ignorance.

I am looking for a vhf radio that can send computer generated or pre-recorded responses or hails. I have cerebral palsy and my speech is not always clear. I can program a tablet or whatever to produce the audio, but I don’t know enough about vhf “stuff” to link the aux feed to the radio.

Also, using the radio normally with a mic, you need to push/hold a button while transmitting. Can this be automated when using aux audio?

Or am I going down the wrong path; should I explore a nmea enabled vhf? What functionality is added by having the vhf on the nmea bus? I am all wired with nmea 2000; adding the vhf would be simple enough.

All thoughts and ideas appreciated! Thanks!

-Hannah (trawler, USVI)

2) A "stand-alone voice keyer", such as the MFJ-434B (~ $239), connects to any radio, between the microphone and radio....
(a professional would probably need to wire-up/solder the connections for you, as most marine VHF Radios have specialized mic connectors and additional mic cord wiring that most ham radios do not, so I don't believe there are pre-made cables that would allow you to easy-peasy plug-n-play....but, any radio tech could wire this up for you in less than an hour [probably 10 - 15 minutes], and charge you ~ $100 or less...)

https://mfjenterprises.com/products/mfj-434b

https://www.eham.net/reviews/view-product?id=563

https://www.dxengineering.com/parts/mfj-434b

This will give you the ability to record and send 5 different messages, totally 75 seconds (meaning an average of 15 seconds per message)....

You would simply press the Push-To-Talk button on the microphone, and then press the desired "message" button....and, it transmits your desired message, easy-peasy...

And, can also record RECEIVED audio from your speaker (if you have it wired-up that way), so you can "play-back" something important, if needed (but, this will reduce/eliminate your outgoing message capability)

It's a bit of a "clunky" approach, but it will work!


3) A "voice keyer" ap, such as Wolphi, might be a more versatile approach, as you could use it anywhere on any boat / any radio...
https://play.google.com/store/apps/d...hl=en_US&gl=US

I think there are other "voice keyer" aps, but this is the only one I've heard anyone talk about...



4) There are also some "voice keyer" software packages in some ham radio logging software, etc....and used-to be a couple stand-alone voice-keyer software suites as well (like the VKE... https://www.eham.net/reviews/view-product?id=777 )



5) Now, if none of these options appeal to you, as this is a rather unique situation and as you're outside of the US (yeah USVI is in the USA, but damned remote and more of a independent 3rd world nation that some might like to admit?)...so...
So, maybe look outside-the-box a bit....maybe look at a big, fancy ham radio (with built-in Voice Keyer) that can be modified to operate on the VHF Marine band?
Again, not a great approach, and not one I'd ever recommend in any other situation, but here I don't mind...


I do hope this helps.

fair winds

John


P.S. NMEA (whether NMEA0183 or NMEA2000) is of no help here....but, I do recommend that you have a modern Class D DSC-FM-VHF radio....(and, if you don't have an AIS system on-board, and will be buying a new VHF, you may want to buy one with a built-in AIS receiver....although, this has nothing to do with the situation you're asking about, just adding some additional recommends...)

[tkeithlu]

Welcome to the forum, Hannah.

You can bypass holding the PTT switch with VOX, as on this headset:

https://www.westmarine.com/buy/stand...-ptt--17674227

With only wiring that I understand you can handle, you could rig a PTT switch that was operated by your foot or elbow, or for that matter by pressing your palm against the panel.

A microphone attached to your computer speaker plus a remote PTT is one reasonably reliable solution.

I'd be tempted to disassemble a VHF radio microphone, hopefully one that does not also control a bunch of bells and whistles. I would hope that I could wire the input to the VHF directly to my computer speaker wires, and the PTT switch to a convenient location. Someone with more electronics knowledge than me may go "no,no, hell no," due to impedance differences, but I've certainly seen it done in PA systems.

By the way, to add on KA4WJA's as-usual very knowledgeable response, I hope that you get a AIS transmitter as well as receiver. Gotta tell them we're out there.

[MikeHoncho]

There has to be someone out there that has experienced this before and solved it. . Have you done research in other forums associated with MS also. Much respect to you for overcoming . I’ve used voice activated mics that also have a large push to talk button that you can use with your palm. These are for portable hand held radios( think fire service) they work exceptionally well. Doesn’t solve your text to voice issue but might be a alternative.

[marshmat]

This is an interesting problem, Hannah; thank you for bringing it up!

Regarding NMEA 2000 integration: This will not solve your problem. N2K integration on VHF is, at the most basic level, just for GPS position data so that the VHF-DSC distress function will transmit an accurate position. On some fancier units, the VHF can receive GPS & AIS data and put that on the N2K bus for other devices to use. Or it can accept VHF-DSC calling instructions from another device, eg. a chartplotter, that has an AIS target displayed with a "Call this ship on VHF" button. But that's about as far as it goes.

Radios like you describe, that can accept either a line-level speech synth input or a voice microphone input, do exist. The Coast Guard uses them at shore stations. They are not marketed or generally available for private use, because it is – in general – illegal to transmit anything other than voice, DSC, and AIS on the Maritime VHF band. And some moron would inevitably try to patch in a music player and turn an underutilized channel into a pirate radio broadcast.

So one source of information would be to track down a local Coast Guard radio operator, and tell them: "I have cerebral palsy, so speaking clearly enough for VHF radio is extremely difficult. I can communicate with you much more clearly if I type into a speech synthesizer. Would the kind of VHF radio you use for broadcasting weather warnings, etc. be able to accept headphone-level or line-level inputs from my speech synthesizer, and if so, where would I look to buy one that would be legal for shipboard use?"

Another option would be to look at modifying a standard radio. Now, I must caution you here that modifying a type-approved radio is generally frowned upon by the kind of bureaucrat who issues radio licences. And using any non-standard mic will almost certainly void the radio's warranty. But it is not terribly difficult, and you are making a good case that your mods will significantly improve safety by making you better able to call for assistance, and to assist others in distress when called upon.

The transmit signal chain is, in general: Microphone --> Mic amplifier --> Modulator --> Pre-drive amplifier --> Power amplifier --> Antenna

In most marine VHF setups, the mic amplifier also provides spectral shaping that's necessary for proper modulator performance. So your only options to couple in your speech synth are by audio coupling – radio's mic held against speech synth's speaker – which is passable in a pinch, but kind of sucks. Or, by electrically connecting the line-level AF signal from the speech synth ahead of the mic amplifier, which involves a roughly 50 dB difference in signal strength that has to be corrected.

So you're looking for a circuit that can interface with (probably) 3.5mm stereo headphone on one end, which is expecting to drive perhaps 1 to 5 volts and 5 milliwatts into something around 16 or 32 ohms. And on the other end, is outputting a signal that closely resembles whatever that radio's native microphone spits out. You'll probably want a transfer switch to allow it to use either the mic or the speech synth; directly connecting both of them at once will likely cause problems.

It'll help if you choose a radio that's popular, widely supported, and whose service manuals ( eg. https://www.manualslib.com/manual/87...01.html#manual ) are readily available.

I'm afraid I don't have a design for such a circuit handy. But they do exist off-the-shelf for pro audio use (eg. https://www.shure.com/en-US/products/accessories/a15la ) which, with the help of a ham operator or recording studio engineer, might reduce your entire problem to just a matter of making custom patch cables between different mic and line connector types.

[ka4wja]

FYI, there ARE many systems that could work...and quite a few that are "off-the-shelf", but these are not designed for outdoor/marine use at sea (they are desktop PC-based, and radios are commercial-type, such as those used by coast stations), as well as others that are tablet-based, and laptop-based, that are portable....

But, it is the consumer-type Marine Radio that needs to be adapted to these systems...AND...

And, these systems need to marinized....not just because of moisture / salt water, etc....but, primarily because of the motion / mobile operations....

I suspect that one of the mobile tablet-based systems (like used for the disabled in wheel chairs) could be adapted well to this...
But, getting it all hooked-up to a marine VHF radio, isn't "plug-n-play"....it will be a custom designed system!



BTW, there are off-the-shelf / semi-custom radio systems for the blind and some graphical-systems for the deaf....but, I'm unaware of any off-the-shelf for someone with cerebral palsy??
This could be a cool project....
If I was in the USVI, I'd be helping you out on this....it really looks cool!


Fair winds and PLEASE let's see if we can actually make this work...
And, for this to happen, please share more info (what comms you need, where will you be boating/sailing, what exact needs do you have in regards to speech?)
Sorry, I mean no disrespect, it's just that I don't know these things....

Take care.

John


EDIT: Just saw that Matt Marsh and I wrote similar things....
Great minds think alike?

[marshmat]

John - I'm not finding anything "plug and play", unfortunately. But I suspect that one could wire up an adapter that'd fit between the existing mic and the radio.

You'd have a switch (4PDT?) that would switch the MIC +/- and PTT +/- lines between the existing mic (i.e. pass-through, works exactly as the factory original) and the speech synth interface circuit.

The interface circuit would consist of a line input jack from the speech synth (eg. an iPad's line/headphone output), routed through a Line-Mic adapter (eg. Shure A15LA) wired for unbalanced monophonic mode. Then you'd add an off-the-shelf vox circuit (eg. scavenged from a ham headset, or built from scratch such as https://www.electroschematics.com/simple-vox/ ) to monitor the speech synth's signal and trigger the PTT switch.

It'd take a bit of testing, but it seems (at first glance) like it should work, and you're just cutting and splicing XLR patch cords and connectors to whatever semi-proprietary connector the radio maker used, not designing or assembling analog AF or RF circuits.