Elecraft › [K3]

K3 spurious

Classic

List

Threaded

10 messages Options

DOUGLAS ZWIEBEL

K3 spurious

Yes, a well known issue for a LONG time...with a SUPER EASY solution.

It is indeed due to the internal speaker.

A year or so ago, I got a call from a local (a couple miles away) that
he had a "spurious" on his K3 (I helped him build it). I listened,
yes it was there. When he switched from the internal speaker to
headphones, it was gone. I think he ended up using an external
speaker which also solved the problem (some guys like speakers!).

de Doug KR2Q
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

srife

Re: K3 spurious

Is there a permanent fix (mod) for this? Not sure whether I have the
problem or not.

Stan Rife
W5EWA

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of DOUGLAS ZWIEBEL
Sent: Monday, December 21, 2009 6:58 PM
To: Elecraft Reflector
Subject: [Elecraft] K3 spurious

Yes, a well known issue for a LONG time...with a SUPER EASY solution.

It is indeed due to the internal speaker.

A year or so ago, I got a call from a local (a couple miles away) that
he had a "spurious" on his K3 (I helped him build it). I listened,
yes it was there. When he switched from the internal speaker to
headphones, it was gone. I think he ended up using an external
speaker which also solved the problem (some guys like speakers!).

de Doug KR2Q
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Zoli Pitman HA1AG-2

Re: K3 spurious

In reply to this post by DOUGLAS ZWIEBEL

This is not a solution. It is a workaround. :)

73, zoli ha1ag

----- Original Message ----
Yes, a well known issue for a LONG time...with a SUPER EASY solution.

It is indeed due to the internal speaker.

A year or so ago, I got a call from a local (a couple miles away) that
he had a "spurious" on his K3 (I helped him build it). I listened,
yes it was there. When he switched from the internal speaker to
headphones, it was gone. I think he ended up using an external
speaker which also solved the problem (some guys like speakers!).

de Doug KR2Q

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

wayne burdick

Re: K3 spurious

Administrator

We're working on it.

Wayne

On Dec 22, 2009, at 12:32 AM, Zoli Pitman HA1AG wrote:

> This is not a solution. It is a workaround. :)
>
> 73, zoli ha1ag
>
>
>
> ----- Original Message ----
> Yes, a well known issue for a LONG time...with a SUPER EASY solution.
>
> It is indeed due to the internal speaker.
>
> A year or so ago, I got a call from a local (a couple miles away) that
> he had a "spurious" on his K3 (I helped him build it). I listened,
> yes it was there. When he switched from the internal speaker to
> headphones, it was gone. I think he ended up using an external
> speaker which also solved the problem (some guys like speakers!).
>
> de Doug KR2Q
>
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Jan Erik Holm

Re: K3 spurious

In reply to this post by Zoli Pitman HA1AG-2

There sure are a lot of workarounds with the K3, the
list is quite long by now.

Jim
-----------------------------
Zoli Pitman HA1AG wrote:

Don Wilhelm-4

Re: K3 spurious

Jim,
Can you be specific about your perception that there are a "lot of
workarounds". I consider this to be the only one.
There are enhancements being worked on - ideas that have mainly come
from requests on this reflector, but those are not hardware related like
this one seems to be.

I wonder why this has not been seen before - surely many have used the
internal speaker over the past 3 years, but then again, perhaps not
often, I use external speakers, and many use headphones.

73,
Don W3FPR

Jan Erik Holm wrote:
> There sure are a lot of workarounds with the K3, the
> list is quite long by now.
>
> Jim
>
>
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Jan Erik Holm

Re: K3 spurious

Yes

Tuning pulses, diod and resistor fix
Lots of spurs here and there, FW workaround fix

IMO that is serious design flaws and and the
fixes are sort of workarounds on the design,
I would not call the fixes enhancements.

Those two just from the top of my head.

On the internal speaker: I never use it when I operate,
I always use a headset or if CW well headphones then.
So for me this thing doesn´t matter since I never use
the speaker.

But there are always "things wrong" with new radios,
flaws in the design, we just need to be objective
about the but my feeling is that most on this list
are far from that.

All in all I´m still happy with the K3 and wouldn´t
like to be without it.

73 Jim SM2EKM
----------------------------
Don Wilhelm wrote:

Julian, G4ILO

Re: K3 spurious

In reply to this post by Don Wilhelm-4

Don Wilhelm-4 wrote

I wonder why this has not been seen before - surely many have used the
internal speaker over the past 3 years, but then again, perhaps not
often, I use external speakers, and many use headphones.

I don't know why, Don. Perhaps it's because you really need a K3 to clearly hear a signal 60dB down at 600Hz separation. :) But I was able to reproduce the effect and hear it on my FT-817.

Set two receivers to CW on the same frequency. Select the narrowest filter on the receiver. Attach the K3 to a leaky dummy load and set the power level such that it produces a strong signal in the receiver without overloading it. Use headphones with good acoustic isolation on the receiver. Tune the receiver so the signal is zero-beated. Then increase the sidetone monitor level. It may be hard to hear, because on my K3 at any rate I needed to increase the monitor to an uncomfortably high level before I could clearly hear the keying through the headphones, and the monitor tended to drown out the spurious signal I was listening for. But by varying the monitor level it was clear that I was hearing a spurious signal separated from the main one by the amount of the sidetone frequency.

I couldn't produce a Spectran plot to illustrate the spurious next to the main signal because distortion harmonics of the main signal (presumably caused by the FT-817 audio stages) masked the weak spurious signal. Someone with a panadapter might be able to see it.

Since I never use more than 100W into fairly poor antennas and normally set the sidetone at a quiet level (4 or thereabouts) I can't see this being a issue for me personally. If a mod is produced to fix this I think it is one more mod that I won't bother doing. But someone who uses high power into a beam and has the monitor turned up loud might well have a problem unless they use headphones or external speakers.

Julian, G4ILO. K2 #392 K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com
* KComm - http://www.g4ilo.com/kcomm.html
* KTune - http://www.g4ilo.com/ktune.html

Guy, K2AV

Re: K3 spurious

In reply to this post by Don Wilhelm-4

I have # 1239. This happened to me the first time I got in a contest
from home with the K3. I usually don't bother using headphones unless
there are other ops around. I got called down on the air by a European
station that was up 500 Hz on 20m at the height of the opening. I was
running 1500 watts. When he called me, his signal was 20 over. The
unwanted signal was down 44 db (later measurement). Assuming I was as
loud to him as he was to me, that would make my signal something like
S5 over there.

The problem of course was that the unwanted signal was stable, clean,
well keyed, and very discrete, not spread out like phase noise.

I had the monitor turned up enough to make it comfortable to use the
internal keyer. Seems I was driving the op up 500 Hz. I reported it
back then. The answer was that there was an engineer assigned to it.

But I also got dual external speakers set up to use AFX. Therefore
the internal speaker was no longer used. Always headphones at the
multi's. So never an issue.

Since I don't customarily bang things off my K3, microphonics were not
a problem.

Also, I learned that if I use the tones from CW keyers driven by MM
over Winkey and run the paddle leads there instead I don't have the
processing delay between pressing paddle and the baud, and I key more
accurately. So now at home I don't use the monitor either.

Out of sight, out of mind. This is probably why it hasn't garnered
more attention.

Also I suspect that Wayne is paying more attention to the nits and
gnats that seem to be the gist of typical complaints, All the Princess
and the Pea kinds of audio complaints. Or the texture of the paint on
panels. What happens when you expand the customer base beyond mojo
drinking K2 kit builders, and some buy the radio as a fashion
accessory.

Wrapping the VCO in a foam that is in turn held by a holder would do
it, but all the solutions are cramped by the tight spaces in there,
and frankly I rather like the small size of all that functionality.
It's likely not nearly so simple as it appears from this distance. It
may have a magnetic component.

73, Guy.

On Tue, Dec 22, 2009 at 8:17 AM, Don Wilhelm <[hidden email]> wrote:

> Jim,
> Can you be specific about your perception that there are a "lot of
> workarounds". I consider this to be the only one.
> There are enhancements being worked on - ideas that have mainly come
> from requests on this reflector, but those are not hardware related like
> this one seems to be.
>
> I wonder why this has not been seen before - surely many have used the
> internal speaker over the past 3 years, but then again, perhaps not
> often, I use external speakers, and many use headphones.
>
> 73,
> Don W3FPR
>
>
> Jan Erik Holm wrote:
>> There sure are a lot of workarounds with the K3, the
>> list is quite long by now.
>>
>> Jim
>>
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

Ken Kopp-3

Amplified speakers / RFI

As a (retired) career two-way radio tech, I can assure
you that Motorola amplified speakers -don't- suffer from
RFI. After all, they are used with radios ... including
HF ... in the 10 - 110 watt category.

In addition to the speakers used by GE / Mororola / RCA,
etc. there are several product lines aimed at the CB market
to be found in (most) truck stops ... along with other useful
radio-related stuff. I have several Barjan's here. Radio Scrap
21-549B's are in the same category. One of these is on my
K2.

If you want "Hi-Fi" audio, KLH 403A's are excellent. These
are marked under a number of brand names.

On the subject of "microphonic" oscillators ... there have been
several radios throughout the years that have had speaker-to-
oscillator coupling issues. I can see where certain sidetone
frequencies, levels and cabinet resonances could really wreak
havoc. (:-))

My K3's internal speaker has never been used, other than for
initial testing.

73! Ken Kopp - K0PP
[hidden email]
http://tinyurl.com/7lm3m5
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html