On Tue, 5 May 2009 14:50:53 -0700
wayne burdick n...@elecraft.com wrote:
Mike Harris wrote:
One nasty winter's day I might just drag out the mod kit again. How
do you
know which end is which on the SMD LED?
DMM :)
Actually, I think the instructions cover this.
73,
Wayne
---
Subject: Re: [Elecraft] K3 on-channel strong signal overload?
|
|
|
| Mike Harris-9 wrote:
|
| One thing to note is that #1400 doesn't have the
| hardware AGC mod installed
|
|
| Are you sure? The hardware AGC mod was implemented around S/N 280 in
| January 2008. The blue (?) dot on the SMD
Hi Mike,
There is a penalty to be paid if diodes are used to clamp the level of
strong signals in a receiver's signal path, and that is the generation of
intermodulation products. In a no-split pile-up situation where two or
more closely spaced strong signals from other callers are in the
Hello all,
Thank you for all the responses and information, and I may look into the
diode option that Wayne suggested.
I like operating HF mobile a lot (just started using the K3 mobile last
weekend), and very often my friends and I will both be using our HF mobile
setups while driving together
Quite a number of radios I know disable pre-amp and enable ATT when the AGC
voltage reaches a certain threshold. A handy way of extending the range of
total AGC with 30/40dB without having to reach for the knobs. Automatically
switched by firmware to catch the first unexpected RF hits.
73'
Paul
That sounds like a way to effectively turn the K3 into an AGC-pumping
monster like my old 756Pro ;)
73,
Dave AB7E
pd0psb wrote:
Quite a number of radios I know disable pre-amp and enable ATT when the AGC
voltage reaches a certain threshold. A handy way of extending the range of
total
The pumping is up to the FW programmer, and his/her choises of threshhold
and delay-times..
73'
Paul
PD0PSB
That sounds like a way to effectively turn the K3 into an AGC-pumping
monster like my old 756Pro ;)
73,
Dave AB7E
--
View this message in context:
Yes, but then you'd mask the weaker signals underneath. Anything that
requires computation, reaction, and delay (variable or otherwise) to
stretch the dynamic range is a non-linearity of one type or other (time
or level or both) that negatively affects the signal handling ability
(either in
needs engaging then the
firmware should do it.
--- On Tue, 5/5/09, pd0psb p.s.bijp...@gmail.com wrote:
From: pd0psb p.s.bijp...@gmail.com
Subject: Re: [Elecraft] K3 on-channel strong signal overload?
To: elecraft@mailman.qth.net
Date: Tuesday, May 5, 2009, 10:20 AM
Quite a number of radios I
So noted on the firmware list. I'll be doing some controlled tests with
very strong signals.
tnx
Wayne
N6KR
On May 5, 2009, at 10:33 AM, Wes Stewart wrote:
I started composing a message yesterday about this and got called
away. Paul has now sort of beaten me to it, but what I had written
Thanks Wayne,Wes,
Nice to see that thinking practical about ways to make K3 even better is
not always interpreted as attacking the K3 concept ;-)
Best 73'
Paul
PD0PSB
wayne burdick wrote:
So noted on the firmware list. I'll be doing some controlled tests with
very strong signals.
...@mailman.qth.net] On Behalf Of wayne burdick
Sent: Tuesday, May 05, 2009 10:42 AM
To: n...@yahoo.com
Cc: pd0psb; elecraft@mailman.qth.net
Subject: Re: [Elecraft] K3 on-channel strong signal overload?
So noted on the firmware list. I'll be doing some controlled tests with
very strong signals.
tnx
Hi Geoffrey,
I guess there are no simple answers to this apart from proper operator
intervention. I guess that is why the buttons are there. I've no
intention of adding any diode clipping, I don't have a problem even with
my S-9+60++ neighbour. One thing to note is that #1400 doesn't have
Mike,
The AGC mod is definitely preferred. The old AGC circuit allows in-band
signals as low as S9 to activate hardware AGC. This would cause desense
if you were using a wide crystal filter but a narrow DSP filter. The
new AGC circuit has an in-band desense threshold of more like S9+20 to
If I add anything like this at all, it will default to OFF in a menu
entry.
First I have to do some tests to see if in fact there's a problem. Then
I have to consider hardware vs. firmware changes, keeping in mind that
only rarely will anyone encounter such circumstances.
73,
Wayne
N6KR
On
Hi Wayne,
Thanks for your comment. I have the stock 2700Hz for SSB and five pole
500Hz for CW which works for me.
Encouraged by some recent comments I've been playing with width and shift
and find that 1800Hz BW centred on 1200Hz on SSB works very well and have
loaded it into profile II.
Mike Harris wrote:
One nasty winter's day I might just drag out the mod kit again. How
do you
know which end is which on the SMD LED?
DMM :)
Actually, I think the instructions cover this.
73,
Wayne
---
http://www.elecraft.com
wayne burdick wrote:
If I add anything like this at all, it will default to OFF in a menu
entry.
First I have to do some tests to see if in fact there's a problem. Then
I have to consider hardware vs. firmware changes, keeping in mind that
only rarely will anyone encounter such
Don't worry, Merv. Any hardware mod we might come up with for handling
extremely strong in-band signals (i.e., from adjacent transmitters)
would have absolutely no impact on K3 performance otherwise. Or we
wouldn't do it.
73,
Wayne
N6KR
On May 5, 2009, at 3:22 PM, Merv Schweigert wrote:
I
Mike Harris-9 wrote:
One thing to note is that #1400 doesn't have the
hardware AGC mod installed
Are you sure? The hardware AGC mod was implemented around S/N 280 in
January 2008. The blue (?) dot on the SMD diode faces toward the front
panel.
73, Bill
--
View this message in
The hardware AGC mod was implemented around S/N 280 in
January 2008.
It wasn't implemented in my SN308. But it is now :-)
Phil - AD5X
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help:
Oliver
I guess Elecraft will have to answer this one. Let us know what they say.
Steve Ellington
n...@carolina.rr.com
- Original Message -
From: orbarrett hoosa...@hotmail.com
To: elecraft@mailman.qth.net
Sent: Monday, May 04, 2009 12:39 AM
Subject: [Elecraft] K3 on-channel strong signal
I have had some similar observations on ten meters. After reading your report
I am inclined to agree with you. I have a station about 5 miles away who I
contact on a regular basis on 10 meters, both SSB and CW. He is usually very
distorted here and I have not been able to understand because
: [Elecraft] K3 on-channel strong signal overload?
I have had some similar observations on ten meters. After reading your
report I am inclined to agree with you. I have a station about 5 miles
away who I contact on a regular basis on 10 meters, both SSB and CW. He
is usually very distorted
I don't think front end overload is your problem. I've had S9 + 45db
signals sound perfectly fine on my K3 with no audio distortion and no
off-frequency artifacts at all. I use the least amount of AGC possible
... AGC THR = 008 and AGC SLP = 000. The only way I've ever experienced
audio
On Sun, 3 May 2009 21:39:55 -0700 (PDT), orbarrett wrote:
I was joined while ragchewing with some friends on 5371.5
by two other friends locally, one operating HF mobile from the same driveway
and another operating from a base rig in the shack (using a backyard dipole
antenna). When either of
G'day,
I have a neighbour, VP8LP only 300 metres away. If I drop onto his
frequency when he transmits the S-meter doesn't have enough digits to
display. Only when my beam is pointing at him do I notice anything
untoward on the audio. This goes away as soon as I switch on the
attenuator or
...@audiosystemsgroup.com
To: elecraft@mailman.qth.net
Sent: Monday, May 04, 2009 1:01 PM
Subject: Re: [Elecraft] K3 on-channel strong signal overload?
On Sun, 3 May 2009 21:39:55 -0700 (PDT), orbarrett wrote:
I was joined while ragchewing with some friends on 5371.5
by two other friends locally, one
On Mon, 4 May 2009 13:36:18 -0400, Randy Downs wrote:
I see distortion with a 40 over signal. 35 to 40 over seems to be when
I see it. Preamp on.
So turn the preamp off! Preamps are for weak signals on the higher HF
bands. Preamps should NEVER be used below 20 meters, and rarely on 20M.
Hi,
Just been looking through my archives. I remembered that there was a
simple mod to the K2 to overcome audio distortion in an extreme overload
environment, I installed it on my K2 and it was totally immune to
co-channel audio distortion when my very near neighbour VP8LP transmitted:
K2 -
On Mon, 4 May 2009 14:12:09 -0400, Randy Downs wrote:
It's on 10 meters. Should I not run 10 meters?
Of course not. Just don't be surprised when several volts of on-
frequency RF causes overload.
73,
Jim K9YC
__
Elecraft mailing
Mike,
That mod to the K2 (which has been incorporated into the new K2s) is
simply a limiter.
If the signal level at the input to the IF amplifier ever increases to
the point where the diodes clip the signal, then distortion will occur.
The clippping distortion may not be noticed on CW, but it
Why are we throwing stones? The K-3 is different than other transceivers that
we have used. In the heat of a contest or chasing DX one does not always
immediately make sense of what is happening. Sharing some observations about
characteristics of Elecraft products along with ways of dealing
I haven't ever experienced a problem with strong on-channel overload
with the K3. But it's possible that you're hitting it with so much
power that you're putting one or more RX stages into saturation,
possibly including the I.F. amp. (In an extreme case, you could even be
exceeding the useful
(In an extreme case, you could even be
exceeding the useful range of the TR switch PIN diodes. The FT817, if
I'm not mistaken, uses a TR relay.)
Some scratch-paper calculations in a 50-ohm system:
Assuming it really is the T/R PIN diodes, they would conduct at just under
one volt. In a
...@horizon.co.fk
Cc: Reflector Elecraft Elecraft@mailman.qth.net
Sent: Monday, May 04, 2009 2:47 PM
Subject: Re: [Elecraft] K3 on-channel strong signal overload?
| Mike,
|
| That mod to the K2 (which has been incorporated into the new K2s) is
| simply a limiter.
| If the signal level at the input
...@audiosystemsgroup.com
To: Elecraft List elecraft@mailman.qth.net
Sent: Monday, May 04, 2009 2:34 PM
Subject: Re: [Elecraft] K3 on-channel strong signal overload?
On Mon, 4 May 2009 14:12:09 -0400, Randy Downs wrote:
It's on 10 meters. Should I not run 10 meters?
Of course not. Just don't be surprised when
randyddo...@gmail.com
To: elecraft@mailman.qth.net, Jim Brown j...@audiosystemsgroup.com
Sent: Monday, May 4, 2009 4:37:01 PM GMT -05:00 US/Canada Eastern
Subject: Re: [Elecraft] K3 on-channel strong signal overload?
40 over is several volts? I thought it was around 5 mili volts. That's what
I am
On Mon, 4 May 2009 21:10:46 + (UTC), k...@comcast.net wrote:
Now, let's hope I managed to get this right. :-)
Nothing wrong with your math. The likely error is in assuming that
ANY S-meter is accurate at the extremes of its range. All the S-
meters I've seen compress both at the top and
--- On Mon, 5/4/09, k...@comcast.net k...@comcast.net wrote:
From: k...@comcast.net k...@comcast.net
Subject: Re: [Elecraft] K3 on-channel strong signal overload?
To: elecraft@mailman.qth.net
Date: Monday, May 4, 2009, 3:10 PM
Good day:
I can't help myself. :-)
The usual
Jim,
I have some questions.
DUH! Why are you surprised by this? You had the K3 set for maximum
sensitivity and then hit it with a 100 watt transmitter. OF COURSE
it's going to overload!
I don't think this is follows naturally. Doesn't the automatic gain
control (AGC) do the same thing as
41 matches
Mail list logo
