External PTT doesn't allow PC Mic audio through to TX

Mark K1LSB · March 2018

On my brand-new-to-me 6300, I'm trying to transmit using an old Shure 520SL "Dispatcher" mic that's plugged into the mic input on my PC. I have the mic's PTT switch plugged into the external PTT on the back of the 6300. I have the AF Input source in SSDR set to "PC". I can get the mic audio to come thru if I'm using MOX or VOX, but not if I use the mic's PTT. The PTT does put the 6300 into TX mode but there's no audio.

I did find another thread in this forum from 3 years ago where another operator had the exact same problem, and Steve N5AC replied that a decision had been made "to avoid causing an issue for the 'pure digital' operators", that "the hard PTT lines will draw audio from microphones while software and MOX will work with the digital data...This way you can use software to key and transmit and then pick up the microphone and talk without continually changing the mic input settings."

I just want to be able to squeeze my mic's PTT and talk. IMO the hard PTT line should allow thru whatever audio source is selected by the AF Input source in SSDR.

It also seems to me that Steve's statement that "the hard PTT lines will draw audio from microphones while software and MOX will work with the digital data" is not consistent with the way SSDR is working today, as the MOX button will let my mic's audio thru but the external PTT will not.

How can I accomplish my desired goal, which is to use the PTT on the mic to transmit audio from the PC?

Please don't suggest that I connect the mic directly to the 6300, as I'm intent on using the EqAPO on the computer to tailor the mic's audio prior to delivery into the 6300's audio stream.

Thanks in advance,

Mark KF5VQY

Mark_WS7M · March 2018

Hi Mark,

Ya that will not work. If you are using PC audio input then you must key either using VOX or the MOX button.

However if you download FRStack there is an option in that program to setup a com port based keying for the MOX. The idea FRStack provides is for a footswitch but it could just as easily work for your hand switch.

Mark

K1DBO · March 2018

Mark,

The hard wired mics have to be keyed with a hardwired PTT and software mics (DAX and PC audio) have to be keyed by software. SmartSDR CAT includes this functionality. Just configure an existing COM port (if you have one) as a PTT port then short pins 7 and 8 together with a PTT switch.

I'm not familiar with what FRStack brings to the party in this regard, but if it's anything like the rest of of FRStack, it's worth checking out.

Push-to-VOX is another option (shameless plug for my own free software). It's a small program that does about the same thing as the SmarSDR CAT PTT function but adds a couple of extra features. It can notice the difference between a quick tap of the PTT and long press. A long press works as expected... keys the transmitter until released. A quick tap, is like a click of the mouse on the MOX button. It engages MOX until the next tap. But for extra fun, instead of toggling the MOX button with the PTT switch, Push-to-VOX will let you choose to toggle the VOX button.

Enjoy!

--Don

Mark_WS7M · March 2018

Don, FRStack is the same. It just detects com port pin shorting and sends the MOX command to the radio.

Mark, Don's stuff is great! His SliceMaster is awesome!

K1DBO · March 2018

Thanks Mark.... nice of you to say.

From day one, the Slice Master to-do list has included entry for adding push-to-vox functionality. I use push-to-vox all the time but havent gotten much feedback on it. So either it just works, or nobody else uses it (or both?

Mark_WS7M · March 2018

To be honest Don I have not tried the push to vox. I'll have to take a look.

Mike va3mw · March 2018

If you search, you will find a post on how to use CAT and a PTT switch I did back in October. Mike

Mark K1LSB · March 2018

Mike, is this the post you're referring to?

https://community.flexradio.com/flexradio/topics/remote-footswitch-how-to-lan-vpn-solution

Mike va3mw · March 2018

That will do it.

Mark K1LSB · March 2018

Thanks. I don't have a DB9/RS232 on my computer so I ordered this:

https://smile.amazon.com/gp/product/B06WLLSDR9/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Should be here in a couple of days.

If I understand your post, after I've set up a COM port in SmartCAT I can use my mic's PTT switch to short pins 7 and 8 on the RS232 connector on my new cable and that should trigger TX in SSDR.

Please correct me if I am wrong.

Thanks again,

Mark KF5VQY

Mark K1LSB · March 2018

Here's what it says in Section 18.2 of the SmartSDR User Guide (Transmitting Using The Default Recording Device):

"To transmit using a microphone connected to the PC, select the PC option from the MIC input menu. This automatically selects the Windows default recording device for your MIC input. Transmit can be triggered using the MOX button on the transmit panel or using VOX, or any PTT input."

I can find nowhere in that section, or anywhere else in that document, any statement that says the PTT disables the audio from the selected recording device. If the PC is selected as the AF Input source, then the audio from the Windows default recording device is what should be streamed. It's as simple as that. The only reference I could find to the contrary is a three year old post from Steve N5AC, who stated that the FRS team decided do things differently because they didn't want to inconvenience some digital mode operators. What? IMO, if digital mode operators want something different then let FRS build them a special place in the software where they can do things the way they like, but leave the most basic rules of operation, the rules that everyone else lives by, alone. If the software authors hold intuitive operation as a deliverable of any value, then leave the most basic rules of operation alone.

Let me put it as simply as I can: In any of the phone/voice modes (i.e., non-DIGx: LSB, USB, AM, FM), the PTT should stream the selected Mic Input source to the TX. To have the system behave in any other way is contrary to any user's grasp of basic rules of operation, and is contrary to the statements found in the User Guide.

I'm not going to tell y'all how much time and energy I wasted this weekend trying to track down my problem of not getting any audio from the PC, even though the User Guide and common sense said I was doing everything right.

EDIT: Doing a document-wide search for "PTT" in the User Guide, I finally ran across a "Note" in Section 20.3 stating "When PTT is depressed while the PC is the selected microphone, the PC microphone will not be used as the source of microphone input. This allows a local microphone to always override a remote PC. To use the PC microphone, the MOX button must always be used as the PTT control."

1) That "note" contradicts the plain language in Section 18.2, with no cross-reference between the two sections.

2) That note effectively removes any option of using the PTT switch on any PTT-equipped mic being used as the Windows default recording device unless the user has some way of making the computer recognize the PTT switch, because the radio won't. And that ain't right. I'll say this one more time: The PTT should stream whatever is selected as the Mic Input source to the TX. Period.

3) There is no warning or notification that appears on-screen to let the user know that the PTT does not work with a PC mic, even when a PC mic is selected as the AF Input source. That ain't right.

Carry on.

Wayne · March 2018

Seems ro me since the mic profiles base on mode that the choice where the audio comes from should be determined there.

The ptt operation should be setable in a transmit profile including how the vox triggers (data or audio)

Just thinking out loud but not really understanding yet.

GraymanPOTA · July 2023

Here I sit a little over 5 years later and I am in the same position as @Mark K1LSB. I want to use my computer mic, the expensive Shure mic that I use for live steaming from my computer with the onboard audio processing and key my radio with a simple footswitch. It is idiotic, that I can not use a simple footswitch to enjoy my investment in a state of the art Flex radio, I now have to go engineer some external option through my computer and rely on a 3rd party software package that may or may not still be supported in the future. No disrespect to the 3rd party software engineers, but not being able to key the radio with a simple contact switch regardless of what audio source is used does not comport with the KISS method and over complicates what should be a simple thing.

KD0RC · July 2023

The PTT input on the back of the radio can be used to key the rig, regardless of the source of the mic input.

If you can give the details of your setup (preferably with a screenshot of SmartSDR) along with what is not working the way you want, we might be able to help. Please also include the model radio and software version. I assume that you are using the radio locally, not remotely.

GraymanPOTA · July 2023

Len,

Thank you for your reply. I have a 6400 and I am using the latest version of the Smart SDR software v3.4.24. I would like to use a footswitch or hand trigger to PTT the radio from the physical PTT port on the back of the radio and use the the default mic from my computer. When the radio is set to use the PC, for the Mic source and the physical PTT is used, the audio does not find its way in to the radio. This appears to be by design.

> @KD0RC said:
> The PTT input on the back of the radio can be used to key the rig, regardless of the source of the mic input.
> If you can give the details of your setup (preferably with a screenshot of SmartSDR) along with what is not working the way you want, we might be able to help. Please also include the model radio and software version. I assume that you are using the radio locally, not remotely.

Mark K1LSB · July 2023

https://community.flexradio.com/discussion/comment/20604442#Comment_20604442

Len,

Incorrect. Per Section 21.2 in the current User Guide:

Note: When PC is selected as the MIC input, transmit can only be initiated by the MOX button in the Transmit panel, or by VOX. The front and rear panel PTT will override the PC MIC input and transmit using the last hard-wired MIC input that was used (MIC, BAL, LINE or ACC).

That situation has remained unchanged in more than 5 years since my last post in this thread.

Mark

WX7Y · July 2023

KD0RC · July 2023

Thanks for the correction... I just realized that I have my foot switch plugged into the back of my homebrew TeensyMaestro which uses the API to key my rig. If I plug my foot switch into the back of the rig, it operates as indicated in the documentation. Sorry for the confusion.

GraymanPOTA · July 2023

If I am understanding this right, I need to cobble together a simple contact switch, to a DB9 serial connection with a 2K resister shorted between two pins to then convert it to USB to trigger a 3rd party application on the computer so it will trigger the MOX button in the Smart SDR software instead of being able to use that same simple contact switch directly connected to the back of the transceiver's PTT port and use the same processed audio through my computer that I use for live streaming and recording. Seems to me that the simple solution is when I use the contact switch connected to the PTT port on the transceiver and have PC selected as the MIC source, that the audio is passed to the transceiver just like it does when I press the MOX button in the Smart SDR software. This SMART SDR software does not seem to smart to me and I am starting to regret my purchase. I am tagging @Mike-VA3MW for awareness.