Re: Severe hum that was not there before - SOLVED
Well when I get home I will reprogram the radio module to another freq and see what happens. Probably something simple like that. Just funny it wasn't there before but maybe a neighbor got something that is loud.?
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Re: Severe hum that was not there before - SOLVED
Can you try a different power supply?
How are you switching off the SHARI? Are you removing power from the power supply or an inline switch in the USB power lead (meaning the PS is still on, just with no load)?
Just to be 100% clear, the issue is that only when the SHARI is powered on, no matter if it is transmitting or receiving, it 'emits' RFI in the form of a hum that is heard on nearby receivers. Correct?
What is the receiver tuned to/what band? HF, VHF or UHF, and is your SHARI a VHF or UHF model?
Can you maybe relocate the SHARI to be away from the receiver it's interfering with?
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On Dec 18, 2022, at 08:30, Scott VA4SMC <smcmbca@...> wrote:
?But noise is the Shari, as soon as I shut it down the receiver drops.?
To TAARA, that's what I don't understand. The Shari TX light goes out (no longer transmitting) but the noise is still there until I shut down the Pi. I wonder if it is Pi.?
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Re: Severe hum that was not there before - SOLVED
Hello Scott,
It may not be the answer you want, but I think one thing I would
try is changing frequencies and listen for a frequency that
doesn't have any noise, even with the squelch open. Program the
Shari for that frequency. It may not fix the problem, but it may
solve it.
Mick - W7CAT
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----- Original Message -----
From: "Scott VA4SMC"
To: [email protected]
Sent: Sunday, December 18, 2022 06:51:10 AM
Subject: Re: [SHARI] Severe hum that was not there before
> But noise is the Shari, as soon as I shut it down the
receiver drops.
>
> To TAARA, that's what I don't understand. The Shari TX light
goes out (no longer transmitting) but the noise is still there
until I shut down the Pi. I wonder if it is Pi.
>
>
>
>
>
>
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Re: Severe hum that was not there before - SOLVED
Are you sure the hum isn't from something else entirely just on that
frequency coincidently? If it does it with the shari shut off, either
it's that or the power supply for the shari. Remindes me of the time I
was at a VE session and one of the VE's decided to charge his cell
phone since he wasn't using it anyway, the second he plugged it in, a
noise that sounded like FM static with the squelch down, came out of
the PA system through the whole facility louder than anything I've
ever heard in my life. I think it was quite a while before we could
hear right again it was so loud, we unplugged the phone about 10
seconds later. I don't think anyone's plugged anythign in like that in
there again. No explaination for that one.
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On 12/18/22, Scott VA4SMC <smcmbca@...> wrote: But noise is the Shari, as soon as I shut it down the receiver drops.
To TAARA, that's what I don't understand. The Shari TX light goes out (no
longer transmitting) but the noise is still there until I shut down the Pi.
I wonder if it is Pi.
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Re: Severe hum that was not there before - SOLVED
But noise is the Shari, as soon as I shut it down the receiver drops.?
To TAARA, that's what I don't understand. The Shari TX light goes out (no longer transmitting) but the noise is still there until I shut down the Pi. I wonder if it is Pi.?
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Re: Severe hum that was not there before - SOLVED
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Re: Severe hum that was not there before - SOLVED
If the noise is enough to keep the squelch open on the HT, why not reprogram the frequency on the Shari to move away from the interference?
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Re: Severe hum that was not there before - SOLVED
IF using CTCSS (and should be) what frequency? May try a
different frequency. If your Shari has stopped transmitting, then
it sure wouldn't seem to be that since the transmitter is off.
Mick - W7CAT
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----- Original Message -----
From: "N8AR"
To: [email protected]
Sent: Thursday, December 15, 2022 11:41:14 AM
Subject: Re: [SHARI] Severe hum that was not there before
> A couple of comments:
>
> You said "I recorded the audio through the node and it is
crystal clear."? I assume this is a file of the audio being sent
to your HT created by turning on the recording capability as
suggested previously.
>
> You also said, "Starting this morning after the node
connected and announced ip address the hum was so bad the radio
was still receiving after the shari stopped transmitting."? But if
the node has stopped transmitting and your HT is still receiving
then the noise is probably coming from something else, is always
there and you must not be using PL.
>
> Please confirm and elaborate a bit on this.
>
>
>
>
>
>
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Re: Severe hum that was not there before - SOLVED
Be sure to use ferrite beads on the PI power supply. This help me immensely?
On Thu, Dec 15, 2022, 1:27 PM Scott VA4SMC < smcmbca@...> wrote:
It's not when I am transmitting. It is when the node is transmitting to my radio. Either there is something wrong with the node or the pi. Can't tell.?
?
?
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Re: Severe hum that was not there before - SOLVED
A couple of comments:
You said "I recorded the audio through the node and it is crystal clear."? I assume this is a file of the audio being sent to your HT created by turning on the recording capability as suggested previously.??
You also said, "Starting this morning after the node connected and announced ip address the hum was so bad the radio was still receiving after the shari stopped transmitting."? But if the node has stopped transmitting and your HT is still receiving then the noise is probably coming from something else, is always there and you must not be using PL.
Please confirm and elaborate a bit on this.
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Re: Severe hum that was not there before - SOLVED
It's not when I am transmitting. It is when the node is transmitting to my radio. Either there is something wrong with the node or the pi. Can't tell.?
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Re: Severe hum that was not there before - SOLVED
Tried the battery to power, same as before.?
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Re: Severe hum that was not there before - SOLVED
Are you transmitting in close proximity
to the SHARI? If you are try using a very low wattage output.
Sometimes this can cause a hum in your transmit audio.
-Fred, KD5FMU
On 12/10/2022 8:51 AM, Scott VA4SMC
wrote:
Hi, can anyone provide some help on a new issue. My Shari Pi3U has
been working terrific up until yesterday when I started getting a
severe hum on receive. Tried moving the node around the house and
still the same. I have the ferrites on the power supply and it is
a raspberry supply. Like I said it was working great up until
yesterday. Anyone one else have this issue and what was the fix?
73?
Scott VA4SMC
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Re: Severe hum that was not there before - SOLVED
Thanks Steve. Starting this morning after the node connected and announced ip address the hum was so bad the radio was still receiving after the shari stopped transmitting. Only way to stop the noise from the radio was to unplug the node from the wall. I will try the battery.?
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Re: Severe hum that was not there before - SOLVED
Also, try replacing the USB power cable with one known to support more than the current required by the Raspberry PI.? Not all USB cables can provide that level of current, and some fail over time with flexing. Connectors also can fail.
I had noise/hum on a similar Raspberry PI node and discovered I needed a new, better USB cable from my 12V BUCK converter.
David McAnally
WD5M
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Re: Severe hum that was not there before - SOLVED
A spectral analysis of the noise indicates that it is AC power related.? I see peaks at major 299, 409, 683, 955.1228, 1502, 1774 and higher.? See attached JPG file.
The signal with noise your HT is demodulating is most probably caused by the RF from you node being pulse amplitude modulated by a poorly filtered power supply running off the AC line.
One possibility is that yur antenna on the node has failed.? Did you try a different one?
If that is not the proble, I suggest that you start by powering your node off of a battery.? The kind we use to recharge a cell phone works great.?
If that doesn't work, start unplugging anything powered by AC in the room.? It could also be caused by a bad LED or CFL lighbulb.? I once had a problem like this with a CFL lighbulb that would not light but it would still radiate interference when illuminated with RF.
Of course you could always take the node to a different location to confirm that the problem is being caused by a local interferer.
Steve - N8AR
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Re: Severe hum that was not there before - SOLVED
Hi, thanks again for the help so far. I recorded the audio through the node and it is crystal clear. The attached file is recorded through my phone from the radio speaker. Any thoughts?
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Re: Severe hum that was not there before - SOLVED
On Tue, Dec 13, 2022 at 09:33 AM, Scott VA4SMC wrote:
I swore I replied to you fellas
This site is moderated and each post must be approved by the administrator.. I think he was shoveling snow, because both of your posts saying you were sick appeared right after each other.. Larry W8LM Mulvane, Kansas, ...... NO SNOW HERE!!
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Re: Severe hum that was not there before - SOLVED
Will do, see what I hear.?
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Re: Severe hum that was not there before - SOLVED
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Steve-N8AR
Freddie Mac-KD5FMU
David McAnally, WD5M
Larry Macionski