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[IC-7000] I hear audio in the speaker when transmitting

Randy Thomson
 

In the "old days" this could occur when a tube in the audio output developed
"microphonics." That is, a slight vibration of the tube would vibrate an
element inside the tube, causing the mechanical energy to be converted to
electrical energy. In solid state electronics, that's more rare, but still
possible. It can sometimes be traced to a marginal connector, a bad solder
joint or a cracked board, where the components still make contact, but
vibration varies the resistance of the connection.



Randy - K5MW



From: ic7000@... [mailto:ic7000@...] On Behalf Of
notcoldenough
Sent: Sunday, January 27, 2013 3:30 PM
To: ic7000@...
Subject: [IC-7000] I hear audio in the speaker when transmitting





I just purchased a used IC 7000. When I transmit, I hear my voice in the
speaker or headphones. It is a faint crackly reproduction of my voice. The
speaker monitor menu is set to "off", so in theory at least, there should be
no sound during transmitting.

The problem occurs in all bands, on both my antennas, and even while using
my dummy load. The only way I have been able to stop it is to reduce the
transmit power to 10%.

I cleaned the fuses, and even tried the power cable from my Kenwood. No
difference.

I removed the tuner from the antenna circuit. No change.

Added split core ferrites to all leads on the radio. no change.

One odd thing I noticed is that when I lightly touch the headphone plug, the
radio amplifies the sound of my touching the plug and outputs that sound
into the speaker. And yes, I verified that headphone was plugged into the
correct jack on the radio.

I have run out of things to check, so I plan on returning the used IC 7000
to the vendor. I am considering buying a new 7000, but I wanted to ask this
group if other users hear audio while transmitting.

Thanks in advance for your responses.

John
KC0UUT

Marty
 

Hi John,

I'm curious to know if the problem was ever resolved. As of yesterday my 10 year old 7000 just began having faint scratchy audio when I transmit on HF SSB, CW, and RTTY mode (more like a frying hiss) coming from the speaker, internal or external. The symptom goes away if I reduce the output power to around 50% or lower.  AM is OK, but I suspect the lower output doesn't trigger the noise.  No problem on VHF or UHF.   For those who will comment... the faint scratchy audio and/or noise, depending on transmit mode, is there all the time, antenna or dummy load.  It's not RFI.  Ground is good, mic doesn't need to even be plugged in for it to happen on CW when keyed.

-Marty
N6PRX

Steven Linley
 

RF getting into audio?  Could be you have a corroded ground.


On 6/2/2018 04:00 PM, Marty wrote:
Hi John,

I'm curious to know if the problem was ever resolved. As of yesterday my 10 year old 7000 just began having faint scratchy audio when I transmit on HF SSB, CW, and RTTY mode (more like a frying hiss) coming from the speaker, internal or external. The symptom goes away if I reduce the output power to around 50% or lower.  AM is OK, but I suspect the lower output doesn't trigger the noise.  No problem on VHF or UHF.   For those who will comment... the faint scratchy audio and/or noise, depending on transmit mode, is there all the time, antenna or dummy load.  It's not RFI.  Ground is good, mic doesn't need to even be plugged in for it to happen on CW when keyed.

-Marty
N6PRX

Mystic Treg
 

Look at the sound card settings.  Are you listening to the 'recording device'?


J Tregre,
KD8M,
on behalf of
Her Imperial Majesty,
Mystic, Kitty

On Sat, Jun 2, 2018 at 7:42 PM, Steven Linley <linleysa@...> wrote:

RF getting into audio?  Could be you have a corroded ground.


On 6/2/2018 04:00 PM, Marty wrote:
Hi John,

I'm curious to know if the problem was ever resolved. As of yesterday my 10 year old 7000 just began having faint scratchy audio when I transmit on HF SSB, CW, and RTTY mode (more like a frying hiss) coming from the speaker, internal or external. The symptom goes away if I reduce the output power to around 50% or lower.  AM is OK, but I suspect the lower output doesn't trigger the noise.  No problem on VHF or UHF.   For those who will comment... the faint scratchy audio and/or noise, depending on transmit mode, is there all the time, antenna or dummy load.  It's not RFI.  Ground is good, mic doesn't need to even be plugged in for it to happen on CW when keyed.

-Marty
N6PRX


c_j_dawsonuk
 

Have you got the Monitor function turned on? It is buried in the menu settings.

Colin
M0GMK

Marty
 

This is not a ground issue. It is repeatable on the test bench. It's present in the internal speaker when connected only to a dummy load with nothing but the power supply and a paddle attached. It will happen on CW and SSB with mic or external audio input even without the mic connected.  On SSB, it doesn't matter if the mic is in the front jack or the rear, or not at all.  This was not occurring the night I shut it off and was noticed the next morning when I turned the rig on. 

It's not monitor audio.  That's definitely off.  When monitor is on the audio in the speaker/phones is clean.  This is scratchy sounding, and on CW it's almost like a sizzle.  (similar to the arcing sound of a tuner capacitor) I'm going to investigate further and record it. 

k4pwo <k4pwo@...>
 

Try this... open the rig and loosen then thighten all the board mounting screws. Do the same with interconnection cables.
Put it back together and test...

Perry K4PWO 



Sent from my Sprint Samsung Galaxy S7 edge.

-------- Original message --------
From: Marty <n6prx@...>
Date: 6/5/18 7:26 AM (GMT-06:00)
To: ic7000@groups.io
Subject: Re: [ic7000] [IC-7000] I hear audio in the speaker when transmitting

This is not a ground issue. It is repeatable on the test bench. It's present in the internal speaker when connected only to a dummy load with nothing but the power supply and a paddle attached. It will happen on CW and SSB with mic or external audio input even without the mic connected.  On SSB, it doesn't matter if the mic is in the front jack or the rear, or not at all.  This was not occurring the night I shut it off and was noticed the next morning when I turned the rig on. 

It's not monitor audio.  That's definitely off.  When monitor is on the audio in the speaker/phones is clean.  This is scratchy sounding, and on CW it's almost like a sizzle.  (similar to the arcing sound of a tuner capacitor) I'm going to investigate further and record it. 

N Pop
 

Hello, 

My IC7k does the same. For the moment just in few bands and from 70% of power up.
Everything is in place and tight. 
I remember that i had this noise on solid state audio power amplifier while was tested on dummy load. 
In that time the source was located on finals and all the units with this noise fails.

73, Nic

John Rupprecht K3NOQ
 

Are you using the same jumper cable to connect to both the antenna and the dummy load?  If your answer is yes, Try a different jumper cable and make sure the shield is properly soldered to the PL-259(s).  I have encountered several situations where the shield was improperly soldered, or not soldered at all to the connectors.  Also beware of crimped PL259 as some users will use a pair of pliers or another wrong tool to attempt the crimp which eventually can become faulty due to electrolysis or corrosion building up inside the connector due to the Wimpy Crimpy. I also own a IC-7k of similiar vintage and have not experienced this fault.   Good Luck...//73// John K3NOQ/K5 (today)

...

Marty
 

As it turns out, this problem was caused by my 10 year old Samlex SEC1223 power supply.  After checking the radio on the bench once again I connected it to an Astron power supply.  No more issue.  Connected my 7000 back to the Samlex and monitored the DC supply on the scope. It had lots of noise on the DC when transmit power peaked. After inspection of the power supply I discovered three 2200 mfd 25V capacitors that had bulged and leaked black goo out the top.  I ordered replacements for the capacitors.  Hopefully the little Samlex supply will be good as new again after the replacement.   -MD N6PRX