waterfall heat distribution

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Don Taylor

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Sep 28, 2021, 11:21:28 PM9/28/21
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hello!  My waterfall has more red above 1500 than below.  My dial/rig display freq is 7.177 USB.  Is this normal or does it suggest a BFO setting issue? like maybe the audio bandpass is not flat between 300 and 3K?  

Does this matter? Is it good enough? 

 I have great RX/TX on all the other digital modes with WSJTX/FLDIGI, and even my SSB works (when I use it once in a blue moon...hahah).  

The rig is a homebrew, so anything could (and likely is) marginally working, hahah.

here is a vid of the rig (watch only if you are really bored. hahah)


thanks for any help!!

Don
km4udx

km4udx DV waterfall specturm offcenter maybe.JPG

Mooneer Salem

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Sep 29, 2021, 3:37:01 AM9/29/21
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Hi Don,

I've seen similar happen before with other radios except with the red on the other side of the waterfall from how it looks for you. I think it'll work okay but the only way to find out is to try to receive and transmit over the air signals :)

Thanks,

-Mooneer K6AQ

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Peter Reichelt

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Sep 29, 2021, 3:57:04 AM9/29/21
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Hi Don
 
You have indicated that you are on a dial frequency of 7.177 USB. Note that FreeDV users normally follow the SSB convention of USB above 10 MHz and USB below 10 MHz. 

To contact another station both need to be on the same sideband

Regards

Peter VK5APR

Don Taylor

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Sep 29, 2021, 8:59:19 PM9/29/21
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okay, I'm a dope. I thought it was digital so all USB. Gurrr...hahah.  The heat distribution looks much better on LSB, so I assume I am good to go on LSB. Thank you for the head slap. hahah.

Next question...the audio display shows +/- .2 divisions.  see pic below.  Is this enough to modulate the digital signal, or do I need to figure out how to up the mic gain/volume into DV app?

km4udx DV waterfall specturm LSB this time.JPG

km4udx DV voice waveform defection +- .2 divisions.JPG

Thanks again for all the help!!!

km4udx
Don

Bob Morris

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Sep 29, 2021, 11:13:16 PM9/29/21
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You may also want to check your peak and average power.  I run about 50 watts average that gives me 90 peak and I need to use the slider to get that set.  You don’t want to see any ALC indication.   My audio display tends to run higher then what you are showing.

Bob. W0EG


Don Taylor

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Sep 30, 2021, 12:29:44 AM9/30/21
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I have a very primitive “riglet”, with no AGC, ALC, variable filters, etc. 

And only 10-15 watts on a good day going downhill. Hahah. 

When I click PPT, I get full deflection of the old SWR/PWR meter without any mic input. I assume this is expected, yes?  Speaking into the mic doesn’t change the RF power output level. 

I’m going to try again tomorrow (today?) before   6:00PM ET on 7177. Digital fingers crossed. Hahah. 

Don
Km4udx


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Mooneer Salem

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Sep 30, 2021, 2:29:10 AM9/30/21
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Hi Don,

In the absence of an ALC meter, I'd adjust the output audio level to the radio until the radio produces just below maximum RF output. As for microphone input, I usually target peaks at 75-90% according to the OS volume mixer and seem to do okay with that. Hope this helps!

Thanks,

-Mooneer K6AQ

Bob Morris

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Sep 30, 2021, 7:34:05 AM9/30/21
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Correct,  no power change with modulation.  Depending on the mode, 6 to 12 dB difference between peak and average.  You generally want the average to be less then half of your radios peak capability.  Kind of like AM.

Don Taylor

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Sep 30, 2021, 9:51:24 AM9/30/21
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Okay, this is really a stupid question....when I click PTT, I appear to get full output. No mic input required. If I disconnect the mic, same deal...PTT sends full output done the ol antenna. Is this normal or do I have some issue here to work first?

Don Taylor
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Bob Morris

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Sep 30, 2021, 10:54:06 AM9/30/21
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That is normal, like keying a mike on FM.

Don Taylor

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Sep 30, 2021, 12:21:13 PM9/30/21
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