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Fwd: Topband: Fw: 3d2kj

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K1LI

Fwd: Topband: Fw: 3d2kj

Can anyone help the team on Fiji?

Rys - I will follow up with a response from the reflector if I see it.

73 -- Brian -- K1LI

---------- Forwarded message ----------
From: Ryszard Tymkiewicz <[hidden email]>
Date: Mon, Oct 12, 2009 at 2:04 AM
Subject: Topband: Fw: 3d2kj
To: [hidden email]

I'm sorry I attache longer text here but our friends on Fiji have serious
problems.
Below text were sent to Elecraft too but because of holidays I'm not sure if
they will be able to read it now.
Maybe someone will be able to help them?

73 Rys
SP5EWY

=========================================================

Dear Sir,
My callsign is 3D2KJ (SP5DRH at home), We are on a dx-pedition on Fiji
with the main
interest to activate 160m. We have here two rigs: K2 and K3 in use. The
last night we have encountered a serious trouble with our K3 (S/N 1739)
Since that time, we are observing short (a few seconds) lost of power on
160m, while CW is used. This behavior concerns ONLY 160m! That happens
with a small power level being set at 6W, as we are using this rig to
drive an external PA. Then, the output returns to the previous level,
with a short view of a full bar on the LCD display. We tried to find if
it occurs on TUNE position as well, but it looks that it happens very
rarely there. The rate of this behavior seems to be unpredictable but it
is sometimes a few times within a minute! On other bands everything is
OK. It looks, moreover, that the
rig produces sometimes some spurious signals on 160m resulting an odd
behavior of our home made PA, while using a K2 instead of K3 solves the
problem.
This makes us unhappy since this failure might jeopardize our program.
Since one of us
(3d2mj – home sp5eaq) is an engineer in electronics, we have
performed several tests and we are now convinced that the nature of the
problem is of K3. We re-initialized the rig and nothing changed.
The transceiver is loaded with the low SWR input of the PA but the same
problem happens if it is loaded just with an antenna. Any local external
support is impossible, we have basic tools (including soldering iron),
some spare parts (but not K3 origin) and an AC/DC meter. There is a
possibility that the problem began during a crash of PA during
transmition without load (failure of antenna). The
PA has been then repaired, but soon we found the K3 problem. It might be
just a coincidence since before we had used 15W of drive.
73 de 3d2kj&3d2mj
==========================================================
_______________________________________________
Topband mailing list
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http://lists.contesting.com/mailman/listinfo/topband
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wayne burdick

Re: Topband: Fw: 3d2kj

Administrator

Rys,

Sounds like you may have an LPA problem, but there may be a simple
work-around. If necessary I can send you modified firmware based on
test results. Also: Have you tried running transmit gain calibration?

Please contact me directly -- I'll check my mail frequently.

Wayne
N6KR

----
http://www.elecraft.com

On Oct 12, 2009, at 8:01 AM, Brian Machesney <[hidden email]>
wrote:

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Don Ehrlich

Re: Fwd: Topband: Fw: 3d2kj

In reply to this post by K1LI

I'm not guru enough to call myself an authority but my first reaction to the
symptoms is that the PA crash damaged one or both diodes at the output of
the K3 that detect forward and reverse power. The rig intermittently
throttles itself back when it 'thinks' the output is too high or swr too
high.

Don K7FJ

> Can anyone help the team on Fiji?
>
> Rys - I will follow up with a response from the reflector if I see it.
>
> 73 -- Brian -- K1LI
>
> ---------- Forwarded message ----------
> From: Ryszard Tymkiewicz <[hidden email]>
> Date: Mon, Oct 12, 2009 at 2:04 AM
> Subject: Topband: Fw: 3d2kj
> To: [hidden email]
>
>
> I'm sorry I attache longer text here but our friends on Fiji have serious
> problems.
> Below text were sent to Elecraft too but because of holidays I'm not sure
> if
> they will be able to read it now.
> Maybe someone will be able to help them?
>
> 73 Rys
> SP5EWY
>
> =========================================================
>
> Dear Sir,
> My callsign is 3D2KJ (SP5DRH at home), We are on a dx-pedition on Fiji
> with the main
> interest to activate 160m. We have here two rigs: K2 and K3 in use. The
> last night we have encountered a serious trouble with our K3 (S/N 1739)
> Since that time, we are observing short (a few seconds) lost of power on
> 160m, while CW is used. This behavior concerns ONLY 160m! That happens
> with a small power level being set at 6W, as we are using this rig to
> drive an external PA. Then, the output returns to the previous level,
> with a short view of a full bar on the LCD display. We tried to find if
> it occurs on TUNE position as well, but it looks that it happens very
> rarely there. The rate of this behavior seems to be unpredictable but it
> is sometimes a few times within a minute! On other bands everything is
> OK. It looks, moreover, that the
> rig produces sometimes some spurious signals on 160m resulting an odd
> behavior of our home made PA, while using a K2 instead of K3 solves the
> problem.
> This makes us unhappy since this failure might jeopardize our program.
> Since one of us
> (3d2mj – home sp5eaq) is an engineer in electronics, we have
> performed several tests and we are now convinced that the nature of the
> problem is of K3. We re-initialized the rig and nothing changed.
> The transceiver is loaded with the low SWR input of the PA but the same
> problem happens if it is loaded just with an antenna. Any local external
> support is impossible, we have basic tools (including soldering iron),
> some spare parts (but not K3 origin) and an AC/DC meter. There is a
> possibility that the problem began during a crash of PA during
> transmition without load (failure of antenna). The
> PA has been then repaired, but soon we found the K3 problem. It might be
> just a coincidence since before we had used 15W of drive.
> 73 de 3d2kj&3d2mj
> ==========================================================
> _______________________________________________
> Topband mailing list
> [hidden email]
> http://lists.contesting.com/mailman/listinfo/topband
> ______________________________________________________________
> 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
>

Richard Squire - HB9ANM

Re: Fwd: Topband: Fw: 3d2kj

In reply to this post by K1LI

Brian,

I don't know what kind of home-made PA they are using but if it it's the tetrode kind with a non-tuned input, it may very well be that the PA incident they describe generated VHF oscillations which damaged the K3's 160m band filter. This happened to an HB9 friend who had to replace two relays in the final stage of his FT-1000MP after arcing in his home-made tetrode PA had occurred.

See: http://www.kk5dr.com/swampednetworks.htm

Now I always have an LP filter inserted between the K3 and the PA (not home-made, it's an ACOM1000 but also a tetrode type with a "swamped" input).
If this is the case, I'm afraid our friends on Fiji will have to use the K2 on Top Band and the K3 on the other bands until they get home.

Richard - HB9ANM

<quote author="Brian Machesney">
Can anyone help the team on Fiji?

Rys - I will follow up with a response from the reflector if I see it.

73 -- Brian -- K1LI

Richard - HB9ANM

Jim Brown-10

Re: Topband: Fw: 3d2kj

In reply to this post by wayne burdick

On Mon, 12 Oct 2009 09:02:36 -0700, Wayne Burdick wrote:

>Please contact me directly -- I'll check my mail frequently.

Please don't start a thread on this, but I would like to observe
that there's probably not another company on the planet whose Chief
Engineer/Owner would respond directly, or as quickly to the problem
of an individual user half way around the world.

BTW -- 3D2KJ was my #100 on 160M Saturday morning.

73,

Jim K9YC

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

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