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Is "Line Out" on Maestro/6400 REALLY Line Out?

Lu Romero
Lu Romero Member ✭✭
edited January 2020 in Maestro

I'm working with Maestro and a 6400, integrating a remote operation.  I keep finding little niggling "differences" in the way Flex systems operate.  

Here is a vexing problem:

Every other transceiver I have ever used that has a "Line Out" connector supplies audio at a fixed level. This is so the receive audio can be sent to an external device WITHOUT IT BEING AFFECTED by the AF Volume control. 

6400/Maestro does this differently:  All three audio outputs from the control panel (Phones, Line Out and Pwr Spkr) are variable, and are controlled in parallel by the front panel VOLUME control. 

This TOTALLY defeats the purpose of having a Line Out facility on this system:  The purpose of Line Out is to supply receiver audio INDEPENDENTLY AND AT A PRE-SET LEVEL to external devices for the purpose of demodulation (For example, a RTTY Decoder, a CW Reader, an external audio recorder to record QSO's for Contest adjudication).

Ive searched here on the forums and have found over 10,000 mentions of this going back several years. It appears that this is the way it is in Maestro, and, I assume, in the 6400M with the internal "Maestro-esque" control panel.

Is there any way in software (or hardware) to make this output independent of the volume control like every other transceiver that has this feature for the purpose I outline above?

Frustratingly yours

Lu Romero - W4LT
Tampa FL


  • Craig_KØCF
    Craig_KØCF Member ✭✭✭
    edited January 2020
    Yes, that is what DAX is for. It provides multiple audio outputs for other software such as MMTTY or WSJT-X. The outputs are adjustable in the DAX app, but do not vary with any other setting.
  • Lu Romero
    Lu Romero Member ✭✭
    edited January 2020
    I understand.  However, how do I connect a DAX feed to an external audio recorder for Contest adjudication?  Yes, while it is possible to use a computer application and maybe route a DAX feed to it INTERNALLY in the same PC one is using to run a contesting log application, this adds yet another service that must run in the PC, using up yet more PC resources.

    All that is required is simply a non variable output that is not controlled by the front panel volume **** so as to get a "clean feed" into an external hardware audio recorder (which then frees the PC for more important work, like send CW manage the log, post spots in the band map, log QSO's and control the transceiver. 

    Its a simple application... But a needed one.

    Not everything can be done in software efficiently.

  • Craig_KØCF
    Craig_KØCF Member ✭✭✭
    edited January 2020
    Why use an external recorder? There are software recorders available that do the job. In addition, some contest loggers have this function built in.
    Note that DAX uses very little PC resources. Any reasonably modern PC can handle it easily. This is the beauty of the whole Flex system: NO external audio cables, which are always a possible entry point for RF interference.
  • Lu Romero
    Lu Romero Member ✭✭
    edited January 2020
    Yes, DAX uses very little resources, Craig...

    I am aware that loggers like N1MM+, which is what I/we use, have built in capability for recording. 

    But recording all the audio in a computer that is also running a contest logger, generating CW internally, posting spots to internal bandmaps of a minimum of two slices, steering the SO2R controller between the two slices, managing the logging database inserts and dupe calls, Playing out the memories for CQ and exchange, displaying the spectrum of the slices on the screen and managing a recording application may be asking too much of a PC.

    Yes, I can display the slice spectrum and waterfall on Maestro... 

    Also, even recording in low bit rate MP3 does take a little bit of disk space over, say, 48 hours, right? 

    And, in a remote environment, RFI is not a factor.

    Your suggestions are great for normal operating. I'm not trying to belittle the suggestions, which are all valid.  However, can you walk in my shoes for a while to understand why this is needed?

    Lu W4LT
  • Bill -VA3WTB
    Bill -VA3WTB Member ✭✭✭
    edited January 2020
    Lu, Flex makes us think differently from the old school way of doing things. When we think Flex Radio we should be thinking software. The entire Flex system is designed around software and many software apps. It is hard to get used to.
  • Lu Romero
    Lu Romero Member ✭✭
    edited January 2020

    Well, then a remote operation in a WRTC environment will automatically disqualify Flex transceivers, as the adjudicator will be at the mercy of the operator's volume control.  

    I have no problem with doing things in software. I made a great living doing that for 41 years. But not all solutions are managed well in software inside a PC. In the great shift from tape to digital editing in news broadcast production, all that moving the video/audio to a computer from a tape deck did was move the bottleneck from the individual edit suite to the playout server.

    OK, I'll move on from this and accept it as "the way it is".  However, these outputs, which are identical, are mislabled.  They should be labeled "Audio out 1, 2, 3" since they are all identical.

    "Line Out" on Maestro really isn't "Line Out", which was my original point.

    Lu W4LT
  • James Whiteway
    edited January 2020
    There is a  buffered "LIne out" for each of the left & right powered speaker outputs on the HD-15 female connector on the rear of the radio. (page 7.3.5 of the User's manual) Since it says for the powered speaker outputs, I'm not certain it's actually line level. But, maybe it could work for you.

    The connector is the same as a VGA connector. So, if you have a VGA cable laying around, it might be an easy way to get it hooked up.

  • James Whiteway
    edited January 2020
    Sorry, I just reread your original post. It would appear the outputs on the HD-15 would not help.

  • Neal Pollack, N6YFM
    Neal Pollack, N6YFM Member ✭✭
    edited January 2020
    No, it is not asking too much for any reasonable PC made in the last 5 years.  Of course, reasonable means matching the chosen PC to the job, just like matching a tractor or truck to a job.    Those of us that want fast decode and heavy tasks like photoshop or video editing, choose a PC with at least a core i5 or core i7 CPU chip.
    There are many people who rush out to BestBuy and purchase the "sale special" PC for $499, which is typically a core i3 or celeron (think like ripping 6 of the 8 spark plug wires off your car), and then wonder why it takes 15 minutes to boot, and 5  minutes to open a web browser.  But I digress.....

    Wait, not done, you mention a little disk space?    Have you noticed that 4 TB (Terabyte) disk drives for your PC are approx $100 at Costco?  

    Examples of disk space usage when recording and editing at different quality settings:
    • 44100 Hz, 32-bit, stereo = 20 MB of space per minute. 44100 Hz and 32-bit are Audacity's default quality settings
    • 44100 Hz, 16-bit, stereo = 10 MB per minute. CD quality
    • 22050 Hz, 8-bit, mono = 1.25 MB per minute. This would be generally acceptable for speech recordings from lower quality sources
    So, let's see, your 48 hours, times 60 minutes = 2880 minutes.  At 16-bit recording above, that's 10mb times 2880 minutes, or a total of 28,880 MB.   Last time I checked, that fits FAR WELL within a multi terabyte C: disk drive.
    REF:  1 TB = 1,000,000 Megabytes

    If you have a mid to fairly powerful modern PC (last 5 years or so), with 8 to 15 GB of memory, then it can run all of the above that you mention, and MORE.

    There is a simple reason you will never get a fixed level line out from a Maestro;  By design, it is a shell and knobs and switches, wrapped around a DELL tablet, and interfaced via the USB port.    I never met a tablet with anything other than a headphone jack for audio.   Consider that.  Not even a firmware change is going to change that.

    So, step back, think outside the box, and realize that DAX Audio provides what you want, and DAX Audio can be recorded on the PC like any other audio, very easily, for free, with NO impact to the other tasks you are doing.  And, plenty of us here are more than happy to help and answer any questions, including what software to record with (I like Audacity since it is free and powerful and flexible).

    DISCLAIMER:   Some hams are so tight that their legs squeek when they walk.  If someone is running a 12 year old PC that cost $100 at the flea market back then,  it likely can't even run modern antivirus software without running out of memory and horse power, let alone open and run other applications.     [A model-T Ford looks like a car and has 4 tires like a car, and a motor.   But don't compare it to a modern Mustang or F-150 Pickup Truck.]

    As technologies are changing, there are different ways of doing the same old things that we used to.  We can achieve the same result, but sometimes have to look at it differently, or via newer tools.

    Keep asking questions and we will all keep trying to help.

    Happy New Year.

  • Neal Pollack, N6YFM
    Neal Pollack, N6YFM Member ✭✭
    edited January 2020
    No argument.   Audio out 1, 2, and 3, is accurate.
  • Lu Romero
    Lu Romero Member ✭✭
    edited January 2020
    It would be interesting to see if the Maestro Volume control ALSO controlled the levels on the HD-15 connector on the back of the RF deck.  I bet not. Just like local sidetone under N1MM F-Keys control from Maestro, another small challenge to overcome.  

    Same DB15 as VGA uses, but more than likely very different cable connectivity.  Some VGA cables have internal bridging. I wouldn't use a VGA cable for this, even if the connector fit. Elecraft has the same issue in their rigs.


    -Lu W4LT-
  • Lu Romero
    Lu Romero Member ✭✭
    edited January 2020
    Thank you, Neil, for the highly detailed information! Great answers!  I am in agreement with your computer system opinions.

    I will make this, hopefully, my last comment.  Nice day here... Want to go outside!

    So that you know, my main computer for this application is a Lenovo W530 with 8 core i7 processor, Win10 Pro, 16GB RAM, a 500GB SSD, N1MMLogger, and a separate VM running VE7CC AR Client for cluster access (and to keep the processes separate).  I can add RecAll for audio recording from a DAX or even OBS Studio to record screen and audio concurrently. Probably what I'll have to do.  

    And I agree about technology being in constant motion. Moore's law is even being overtaken in many ways by the constant march of improvements.

    However, as a former Broadcaster to whom 5 Nines was essentially failure, I like to spread the failure domain across different devices.  Putting all my eggs in one PC basket just goes against my training. Shall I tell you the story about a news operation in the North East who went with non linear editing, newsroom computer and transmission presentation with no videotape backup that had to go back to handwritten scripts on legal pads and no story video when their dual redundant newsroom computer based presentation system's software crashed? Why?  They forgot to turn off Windows Update in two of their servers.  They were forced to do two of their newscasts that day from the parking lot of the station using a live truck. Lucky it was the noon and the 5:00 show.  God was their lighting director that day.

    But that's beside the point, and not what we are discussing here.

    I understand the way Maestro is packaged; I'ts the annoying reason why you hold the power button down for 5 seconds, release it and stay in the dark about if you pressed it long enough to start the tablet (Until you see the subtle change in the screen and see the Win10 "worm" on the blue screen)... Gee, wouldn't it have been nice to have a "pilot light" come on when you press the button?.  Yeah, that cant be done due to the architecture. I get it.

    However, in this case, the solution is very simple. Take the audio coming from the tablet's audio output, and send it to a op amp with two outputs.  One output goes to the Volume **** which then manages the level either by controlling a VCA or by good old DC levels.  This output feeds another op amp that feeds the "Pwr Spkr" socket and the "Phones" socket in parallel.  The other side of the first op amp then goes to either to another VCA with an adjustable **** in the back of the panel or to a simple resistor H Pad with values chosen to match 10mV/+4VU consumer audio levels.  This, in turn sends FIXED LEVEL audio to the jack in the back of the control panel labeled "Line Out".  Then its really Line Out!

    In a WRTC environment, this in turn, would feed the judge's mixer with FIXED LEVEL audio where the judge would then have independent level control of his feed vs being at the mercy of the operator's headset level.

    Crude, but effective.  And it gives you "real" fixed level Line Out functionality. Probably adds less than a quarter dollar to the overall cost of the product.  I'm sure Flex's COS margin is in the high 80's, so is this the reason this was not done? Or maybe nobody asked the customer?  Or nobody though that Line Level should be at a fixed level like every other transceiver?  Are we being "different" for the sake of being "different"?

    And it would make dumb old fashioned analog me happy, as I could connect the horrible analog input of my ancient and trusty contest companion, a Zoom H2 SDHC audio recorder, with fixed level audio so as to judge my performance in a contest by listening to my technique.

    I'm all for change.  I'm not all for change for the sake of change.  I'm a believer in the Scotty  paradigm: "The more complex you make the plumbing, the easier it is to stop up the drain." 

    Simply put: If the computer has a serious issue, every running app has to restart. In the case of running SSDR and everything else within a PC, its moot, because EVERYTHING STOPS, including the radio. So maybe I'm being too judgemental here.

    Just that it would be nice to call that output what it is... Its something that I should have asked about during my presales research, and i didn't, so its my fault. But, **** it, don't call it Line Out, because it is not.


    Lu - W4LT

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