Lyle:
Is remove of L4 on the front panel board and L7 on the KIO3 audio board
official Elecraft modifications?
I'd hate to void my warranty by messing with something that isn't official.
Thanks, Dean Straw, N6BV
Lyle Johnson wrote:
I bit the bullet and removed L4 and L7 this morning.
Is remove of L4 on the front panel board and L7 on the KIO3 audio board
official Elecraft modifications?
Bypassing these two inductors will not impact your warranty.
73,
Lyle KK7P
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You must
Thanks, Lyle.
73, Dean, N6BV
-Original Message-
From: Lyle Johnson (via Nabble)
[mailto:[EMAIL PROTECTED]
Sent: Monday, November 10, 2008 11:52 AM
To: Dean Straw
Subject: Re: [Elecraft] K3 RF Feedback Problem
Is remove of L4 on the front panel board and L7 on the KIO3
I had an RF feedback problem when transmitting in digimodes (TX audio via
LINE IN).
On some bands and at power levels above 20W, my TX audio was distorted.
BTW, my previous TRX did not show this problem in the very same setup.
Similar to MIC, also LINE IN has an RFC in its GND line (L5 on the
decide, it's important to refer to the schematic diagrams prior
to making any K3 modification.
Paul, W9AC
- Original Message -
From: hb9brj [EMAIL PROTECTED]
To: elecraft@mailman.qth.net
Sent: Friday, November 07, 2008 9:46 AM
Subject: Re: [Elecraft] K3 RF Feedback Problem
I had
Subject: Re: [Elecraft] K3 RF Feedback Problem
In fact, several return lines are affected by the same
condition on the KIO3
PCB, including:
L7 - Mic (J20);
L5 - Line In (J21);
L3- Line Out (J22);
L8 - Phones (J19); and
L15 - Speaker (J18).
On the Main DSP PCB, L4 (affecting
L5 - Line In (J21);
L3- Line Out (J22);
These are transformer isolated and not returned to frame or chassis
ground specifically to avoid ground loop problems. The inductors are
there to help keep RF out. These commons are notational - they are
not common with anything.
73,
Lyle KK7P
I have just received my K3 factory built and been playing with it for the
last two days. I immediately discovered RF feedback problem which was cured
by connecting pin 7 of the mike plug to the shell of the connector. I do
plan to use rear mike and audio connectors as well but I am getting a
L5 - Line In (J21);
L3- Line Out (J22);
These are transformer isolated and not returned to frame or chassis ground
specifically to avoid ground loop problems.
Lyle,
That's right. I should have looked off page on the preceding schematic to
see that -- although the issue still stands on the
Lyle -
Thanks for the correction. I saw the description on the schematic and
thought I was doing the right thing. Back in L7 goes, and I will look for
L7 on the KIO3 board.
Monty
I bit the bullet and removed L4 and L7 this morning. It is not
difficult; they are both on the back of the
Hi Monty:
I just added a jumper around (well, actually over) my L4. No need to risk
possible PCB damage by completely removing the RFCs.
73,
Tom N0SS
At 17:50 11/02/2008, Monty Shultes wrote:
I bit the bullet and removed L4 and L7 this morning. It is not
difficult; they are both on the
I just added a jumper around (well, actually over) my L4. No need to risk
possible PCB damage by completely removing the RFCs.
Unless the RFC begins to move under heat and begins bridging to an adjacent
pad or trace. Even when being careful, SMT/SMD parts can slightly shift on
the PCB.
Jim, I've been on travel so apologize for the delayed reply. All I can say is
WOW...I thought I was the only one who had this symptom with the K3! I have
a similar setup with a Heil boom-mic going through a DX Doubler SO2R switch
box, and had horrible SSB distortion on bands above 14 MHz and
I bit the bullet and removed L4 and L7 this morning. It is not difficult;
they are both on the back of the front panel board. I jumpered the pads
with wire. I am now getting superb audio reports from critical local
stations that were guiding me in reducing RF on my audio. My MC-60 mic is
I bit the bullet and removed L4 and L7 this morning. It is not
difficult; they are both on the back of the front panel board.
L4 on the front panel board is related to the issues some folks are
having when using the front panel mic connector with various audio
routers. It can be shorted
Gang,
I'm pulling my hair out over an RF feedback problem with my K3/100, and
wonder if anybody has any ideas? I use an external station controller that
switches key, microphone, CAT, line in/out, etc. between different rigs.
The microphone audio connects to the K3's rear panel microphone jack
Have you tried just running the mic into your K3 without the
external station controller ?
What is that controller ?
73
Stewart G3RXQ
On Sat, 1 Nov 2008 07:57:10 -0600, Dr. James C. Garland wrote:
Gang,
Im pulling my hair out over an RF feedback problem with my
K3/100, and wonder if
anybody
You can't have RF feedback if you are using a dummy load, unless one
of the connectors/leads inside the K3 isn't properly connected -
allowing high levels or RF inside the cabinet.
As per Stewart's comment, have you tried a directly connected mic and
also are you sure that power supply isn't
@mailman.qth.net
Sent: Saturday, November 01, 2008 9:57 AM
Subject: [Elecraft] K3 RF Feedback Problem
Gang,
I'm pulling my hair out over an RF feedback problem with my K3/100, and
wonder if anybody has any ideas? I use an external station controller that
switches key, microphone
in
what's going on that might be causing this.
73, Jamie
WB4YDL
_
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Dr. James C. Garland
Sent: Saturday, November 01, 2008 8:57 AM
To: elecraft@mailman.qth.net
Subject: [Elecraft] K3 RF Feedback Problem
Gang,
I'm
Subject: Re: [Elecraft] K3 RF Feedback Problem
Jim,
This may, or may not be the root cause of your RFI problem, but it is important
to note that the K3 elevates the ground potential on both the front and rear
panel MIC connectors. This is not a trivial issue. L7 is a 100 uH choke
'
Subject: RE: [Elecraft] K3 RF Feedback Problem
Hi Jim:
I’m wondering what external station controller you are using. I’m using a NCS
Multi-Switcher and I ran into very similar issues. I certainly felt (as did
Doug at NCS) that it was a ground loop problem. I used transformer isolated
mike cables
Dr. James C. Garland wrote:
Gang,
I?m pulling my hair out over an RF feedback problem with my K3/100,
and wonder if anybody has any ideas? I use an external station
controller that switches key, microphone, CAT, line in/out, etc. between
different rigs. The microphone audio connects to the
] On Behalf Of James
C. Hall, MD
Sent: Saturday, November 01, 2008 1:13 PM
To: 'Dr. James C. Garland'; elecraft@mailman.qth.net
Cc: 'W. Douglas McDowell'
Subject: RE: [Elecraft] K3 RF Feedback Problem
Hi Jim:
I'm wondering what external station controller you are using.
I'm using a NCS
Thanks very much to Joe W4TV and Ian GM3SEK for their helpful
comments.Here's what I've learned.
1. RF leakage from the K3 into the 12V power cord does not appear to be a
problem, as Ian surmised. Furthermore, as Ian also noted If the PS is allowed
to float and the common negative return
Sent: Saturday, November 01, 2008 5:02 PM
To: elecraft@mailman.qth.net
Subject: RE: [Elecraft] K3 RF Feedback Problem
Thanks very much to Joe W4TV and Ian GM3SEK for their
helpful comments.Here's what I've learned.
1. RF leakage from the K3 into the 12V power cord does not
appear
buss wire.
In my case, RFI problems 100% solved.
Paul, W9AC
- Original Message -
*From:* Dr. James C. Garland mailto:[EMAIL PROTECTED]
*To:* elecraft@mailman.qth.net mailto:elecraft@mailman.qth.net
*Sent:* Saturday, November 01, 2008 9:57 AM
*Subject:* [Elecraft] K3 RF
I know it is good engineering practice often to isolate internal
circuitry from chassis ground. Lab quality signal generators, for example,
usually tie the shell of their RF output connector to the chassis via a
(typically) 100 ohm resistor...
Moreover, designers of instrumentation-grade
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