@mailman.qth.net Listelecraft@mailman.qth.net
Subject: Re: [Elecraft] K3 Hum on Audio...
Date: Thu, 02 Feb 2012 10:24:07 -0800
Thank you, Tony!
I had developed a maddening audio hum suddenly, and couldn't find the cause.
The curious thing was that it was WORSE when no mike was plugged
@mailman.qth.net
Subject: Re: [Elecraft] K3 Hum on Audio...
Date: Thu, 02 Feb 2012 10:24:07 -0800
Thank you, Tony!
I had developed a maddening audio hum suddenly, and couldn't find the cause.
The curious thing was that it was WORSE when no mike was plugged into the jack
on the back panel.
Based on your
@mailman.qth.net List elecraft@mailman.qth.net
Subject: Re: [Elecraft] K3 Hum on Audio...
Date: Thu, 02 Feb 2012 10:24:07 -0800
Thank you, Tony!
I had developed a maddening audio hum suddenly, and couldn't find the cause.
The curious thing was that it was WORSE when no mike was plugged
--- k6...@me.com wrote:
From: Lew Phelps K6LMP k6...@me.com
To: Elecraft@mailman.qth.net List elecraft@mailman.qth.net
Subject: Re: [Elecraft] K3 Hum on Audio...
Date: Thu, 02 Feb 2012 10:24:07 -0800
Thank you, Tony!
I had developed a maddening audio hum suddenly, and couldn't find the cause
On 2/3/2012 12:43 PM, Guy Olinger K2AV wrote:
This is an endemic uncurable problem.
Maybe not. One mechanism I suspect, based on the symptom that it
happens with the Line Input turned up, is magnetic coupling into the
unshielded audio transformer on the Line Input. That coupling is nearly
Hi Jim,
For a price and/or sufficient work and enough expertise, it might be
possible to shield anything. There is that mu-metal stuff. But mostly
that level of induction from something pulling that much current into
microphone level devices is a really really hard cure, hence
uncurable in
On 2/3/2012 9:25 PM, Guy Olinger K2AV wrote:
There is that mu-metal stuff. But mostly
that level of induction from something pulling that much current into
microphone level devices is a really really hard cure, hence
uncurable in quotes.
From the symptoms, it was coming into the LINE
: elecraft@mailman.qth.net
Subject: Re: [Elecraft] K3 Hum on Audio...
Jim,
Well, I would call it mostly a buzz. Also, the only near magnetic field of
the KPA500 power transformer is off, I mean powered off and unplugged, so
that does not seem to be the problem.
I just ran another test
-boun...@mailman.qth.net] On Behalf Of Phil Hystad
Sent: Friday, January 13, 2012 12:54 PM
To: j...@audiosystemsgroup.com
Cc: elecraft@mailman.qth.net
Subject: Re: [Elecraft] K3 Hum on Audio...
Jim,
Well, I would call it mostly a buzz. Also, the only near magnetic field of
the KPA500 power
.
Usually the break was at the connector, but sometimes it's in the mic,
depending upon which end had the best strain relief. Even found a broken
wire inside the cable on rare occasions.
73,
Ron AC7AC
-Original Message-
Subject: [Elecraft] K3 Hum on Audio...
When the sun rose today
inside the cable on rare occasions.
73,
Ron AC7AC
-Original Message-
Subject: [Elecraft] K3 Hum on Audio...
When the sun rose today and it seems that my K3 decided to put some hum on
my audio. During a quick SSB contact tonight on 80 meters I was told there
was hum on my
On 1/13/2012 9:20 AM, Phil Hystad wrote:
Unfortunately, it is in both mics but not as strong in the Yamaha CM500 mic
as in the MH2 but it is present.
Clarification question. Is it HUM (pure 60 Hz), or BUZZ (mostly
harmonics of 60 Hz)? If it's HUM, I would suspect magnetic field
coupling
Jim,
Well, I would call it mostly a buzz. Also, the only near magnetic field of the
KPA500 power transformer is off, I mean powered off and unplugged, so that does
not seem to be the problem.
I just ran another test with everything disconnected, including ground and
coax. With the K3 in
Jim Brown-10 wrote
On 1/13/2012 9:20 AM, Phil Hystad wrote:
Unfortunately, it is in both mics but not as strong in the Yamaha CM500
mic as in the MH2 but it is present.
The K3 has unshielded audio transformers at all the audio inputs and
outputs, and an unshielded transformer is a
I just did one more test. I hooked up my little 4-cell Li nano-phosphate
battery to the input. Turned on the K3 and did the test again with the K3 in
TEST mode. Same hum occurs. With this experiment, the only thing plugged into
the K3 is the MH2 microphone itself and all AC in the room is
When the KPA500 is in standby, I assume that its AC mains is still
connected. Have you tried pulling the KPA500's mains plug to narrow
the search?
Is your P3 sitting between the KPA500 and the K3?
73,
Geoff
LX2AO
On January 13, 2012, at 18:20 +0100, Phil Hystad phys...@mac.com wrote:
snip
From: Barry N1EU barry.n...@gmail.com
To:
Sent: Friday, January 13, 2012 9:58 AM
Subject: Re: [Elecraft] K3 Hum on Audio...
Jim Brown-10 wrote
On 1/13/2012 9:20 AM, Phil Hystad wrote:
Unfortunately, it is in both mics but not as strong in the Yamaha CM500
mic as in the MH2
,
depending upon which end had the best strain relief. Even found a
broken
wire inside the cable on rare occasions.
73,
Ron AC7AC
-Original Message-
Subject: [Elecraft] K3 Hum on Audio...
When the sun rose today and it seems that my K3 decided to put some
hum on
my audio. During
Hi,
Equipment with non-ferrous enclosures are vulnerable to picking up magnetic
fields from linear power supplies. I found this out with my TT Corsair II,
and the solution was to put the power supply on the other side of the radio,
away from the audio circuitry.
The steel cabinets of the
As noted in a previous post, I disconnected EVERYTHING. Nothing on the back
panel of the K3 at all except for a Li-nano-phosphate battery as my power
source. All AC off at the breaker panel for this room. The only electrical
equipment on was my K3 via the battery and my Macbook Pro laptop
I've been ignoring this thread, but your last post piqued my interest.
Several questions require answers before I can go on. Just note that while
we tend to concentrate on the last new thing, the workbench and
instruments and their connections have far too often been the entire
problem. You
'
Subject: Re: [Elecraft] K3 Hum on Audio...
Ron,
I have been able to do more tests. Unfortunately, it is in both mics but
not as strong in the Yamaha CM500 mic as in the MH2 but it is present.
This morning I double checked all connections (most in the back). This
includes the key out
Guy,
Thanks for not ignoring my problem any more and lending a hand :-)
Answers to your 1) 2) 3) 4) questions below...
On Jan 13, 2012, at 11:09 AM, Guy Olinger K2AV wrote:
I've been ignoring this thread, but your last post piqued my interest.
Several questions require answers before I
Wow - this is strange!
1) Are all the K3's enclosure screws tight? Have you tried tapping or
lifting the K3 while listening to the hum (looking for an intermittent
connection)?
2) Does the hum remain if you key the rig in CW mode?
2) If you move the K3 and battery supply to a different
Good luck Phil. That last part really suggests something loose in the mike
cord as I suggested at first.
Ron AC7AC
-Original Message-
Ron,
OK, now it appears I was mistaken when I said that that the hum was in both
mics. I think I flubbed something up in my previous test due to the
Ron,
Well, I just had a quick SSB chat with Clyde (AA7WC) (pre Noon Time net on 40
meters) and asked specifically for audio report with possible hum. His report
was no hum, clear good sounding audio, with S7 signal.
So I am suspicious of my florescent lights in the garage although they are on
: [Elecraft] K3 Hum on Audio...
Ron,
I have been able to do more tests. Unfortunately, it is in both mics but
not as strong in the Yamaha CM500 mic as in the MH2 but it is present.
This morning I double checked all connections (most in the back). This
includes the key out to the KPA500, the plugs
: [Elecraft] K3 Hum on Audio...
Ron,
I have been able to do more tests. Unfortunately, it is in both mics but
not as strong in the Yamaha CM500 mic as in the MH2 but it is present.
This morning I double checked all connections (most in the back). This
includes the key out to the KPA500
so you unplug the mike input to K3 the hum goes away
when you plug into the K3 mike input the hum is there ?
I would think you have a bad mike/cord/connecter
Bob K3DJC
On Fri, 13 Jan 2012 11:31:38 -0800 Phil Hystad phys...@mac.com writes:
Ron,
Well, I just had a quick SSB chat with Clyde
bob,
I am not sure if you understand my previous problems I was reporting. The hum
has nothing to do with the mic plugged into the K3 or not (obvious if the mic
is not plugged in, there is no problems). But, the hum comes with PTT transmit
and not merely because the mic is plugged in.
Phil, which firmware version are you using? I was using the beta 4.47 and
I developed audio problems the other night, After I deleted 4.47 and went
back to the latest production firmware all was fine. Sorry if this has
already been discussed - I just read this thread.
73 Bill NZ0T
On Fri, Jan
No one mentioned the firmware level but I am not on any beta version. I am at
MCU firmware level 4.39.
73, phil, K7PEH
On Jan 13, 2012, at 12:33 PM, NZ0T wrote:
Phil, which firmware version are you using? I was using the beta 4.47 and
I developed audio problems the other night, After I
On Fri, 13 Jan 2012 12:26:47 -0800 Phil Hystad phys...@mac.com writes:
bob,
I am not sure if you understand my previous problems I was
reporting. The hum has nothing to do with the mic plugged into the
K3 or not (obvious if the mic is not plugged in, there is no
problems). But, the
On 1/13/2012 10:30 AM, Phil Hystad wrote:
I disconnected EVERYTHING. Nothing on the back panel of the K3 at all except
for a Li-nano-phosphate battery as my power source.
Was your antenna connected? If so, where is the coax shield connected
to ANYTHING -- the earth, other gear, at a tower,
Jim,
In answer to your first question below, that particular test NOTHING was
connected other then the battery to provide power. That included the antenna.
I will read your paper -- maybe it will describe hum and buzz as to how they
sound different. If you know of a good audio stream
Let's call it buzz. If it was AC power hum the main components would be
60, 120 and 180 Hz. Cutting 400 Hz and below would have made it
significantly better. When the K3 is running on batteries without ANY
mikes and other connections, it has NO way to produce 60/120/180 Hz related
to AC house
Guy,
Thanks for the comments. Later on I might experiment to see if I can purposely
reproduce the buzz by methods you mention.
Yes, my test condition was using ABSOLUTELY no AC and no nearby AC or AC
artifacts. No charger on the battery but then again I had AC switched off at
the breaker
Please multiply the voltage by 10 in the sentence below where I am describing
the battery. I think I rushed to quickly to drop in that decimal point.
And, thanks for all the help and comments from others. I always learn a lot in
these trials.
phil
On Jan 13, 2012, at 2:41 PM, Phil Hystad
When the sun rose today and it seems that my K3 decided to put some hum on my
audio. During a quick SSB contact tonight on 80 meters I was told there was
hum on my audio. This surprised me because yesterday I was involved in two
different SSB QSOs where I was particularly interested in audio
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