KPA-500 in Contest Conditions

[Lu Romero - W4LT]

Not a problem here in the 10 months I have owned it.  Temp
never gets above 60 degrees, fans never go into highest
speed. If the SWR is high, it takes care of itself and lets
you know about it with a beep in the headset and some text
on the K3 display screen. The difference in operating Low
Power (where I do most domestic contests) and High Power
(where I do everything else) is one button: The power switch
on the KPA500.  With that button, I am given the choice of
operating a 500w transceiver or a 100w transceiver.

Lu Romero
W4LT
K3/P3/KRX3/KPA500 and a K1

--------------------------

Message: 6
Date: Fri, 12 Jul 2013 08:48:52 -0500
From: Richard Thorne <[hidden email]>
To: Elecraft Reflector <[hidden email]>
Subject: [Elecraft] KPA-500 in Contest Conditions
Message-ID: <[hidden email]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Hows the KPA-500 holding up under contest conditions for SSB
and CW?

I've read the reviews on eham but there was only one that
referenced
performance in contest conditions (and it was favorable).

I'm curious if the temp stays down and if power is lost as
it heats up?

Thanks

Rich - N5ZC

______________________________________________________________
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

[iw1ayd]

Hi all.
The KPA is a good performer. Even when it get at 70C temperature, it
doesn't crank down the power.
It's noisy that's right compared to no noise there is some when it is
hot. But with my previous experience with a 1K-FA by SPE it is much
silent than that. Power is comparable in between the two is comparable,
as the SPE have the specification for RTTY at the same 500W as the
KPA500. But the SPE loose power over time, the KPA500 instead doesn't
lose any power.
It maybe that the noise of the KPA500 is much better as Elecraft use a
big fan, that when scream have a lower pitched tone the the SPE. The SPE
use 8 smallest fan, it have inside much more modules, 3 instead of one,
of the KPA500.
That's why I switched over the two to the Elecraft one amp and I am not
regretting it.

Activity here is substantially only in RTYY: DXing doesn't produce any
remarkable noise; Contesting RTTY make it sounding for sure. But way
better than my older one SPE. You could survive without headphone with
the KPA500.
I have engaged several times the overtemp protection in the SPE in over
4 years of use. I tried to engage the same protection on the KPA500,
RTTY Contest CQing cycle, but after fifteen minutes at 70C I stopped the
test. That's not a scientific and repeatable test, maybe, but it's quite
enough for me.

I don't have a great station here at home but sometime RTTY RUN times
are really interesting as it was on the latest DLDX and before on one of
the 75 baud contest.

Take care also that the late season was 28C to 35C, it's pretty hot here
down with relevant humidity. I am speaking of almost one month since the
switch of the PAs.

For serious RTTY Contesting at legal power limit I would use a vacuum
tube PA.

Not to mention one sure thing, the way as the KPA500 is engineered leave
all the space for a great serviceability. It's not the same for several
other SS PAs.

                     73 de iw1ayd Salvo
______________________________________________________________
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

[RobertG]

I can add a few cents to this one. I've used the KPA500 in the usual big
and in some of the small contests. It works transparently. When running
stations on cw, the temp tends to rise to the mid-to-high 30's C. While
I have no doubt that the temp sensitive fan would speed up to meet the
challenge, I always increase the base fan speed when I know the temp
will be going up, usually to the #4 speed. I believe in prevention
rather than wait for the cure. The fan is loud at #5/#6 speeds. However,
I'm always under the headphones, so I don't hear it at all. The only way
to reduce fan noise would be to use a bigger fan, and that wouldn't be
consistent with the small form factor for the amp. In all, it's a nifty
500w amp that I can live with for the duration. And, needless to say,
it's backed up by Elecraft and this list. IMHO, these last two factors
place it head and shoulders above the rest.

...robert

On 7/13/2013 17:59, iw1ayd - Salvatore Irato wrote:

> Hi all.
> The KPA is a good performer. Even when it get at 70C temperature, it
> doesn't crank down the power.
> It's noisy that's right compared to no noise there is some when it is
> hot. But with my previous experience with a 1K-FA by SPE it is much
> silent than that. Power is comparable in between the two is comparable,
> as the SPE have the specification for RTTY at the same 500W as the
> KPA500. But the SPE loose power over time, the KPA500 instead doesn't
> lose any power.
> It maybe that the noise of the KPA500 is much better as Elecraft use a
> big fan, that when scream have a lower pitched tone the the SPE. The SPE
> use 8 smallest fan, it have inside much more modules, 3 instead of one,
> of the KPA500.
> That's why I switched over the two to the Elecraft one amp and I am not
> regretting it.
>
> Activity here is substantially only in RTYY: DXing doesn't produce any
> remarkable noise; Contesting RTTY make it sounding for sure. But way
> better than my older one SPE. You could survive without headphone with
> the KPA500.
> I have engaged several times the overtemp protection in the SPE in over
> 4 years of use. I tried to engage the same protection on the KPA500,
> RTTY Contest CQing cycle, but after fifteen minutes at 70C I stopped the
> test. That's not a scientific and repeatable test, maybe, but it's quite
> enough for me.
>
> I don't have a great station here at home but sometime RTTY RUN times
> are really interesting as it was on the latest DLDX and before on one of
> the 75 baud contest.
>
> Take care also that the late season was 28C to 35C, it's pretty hot here
> down with relevant humidity. I am speaking of almost one month since the
> switch of the PAs.
>
> For serious RTTY Contesting at legal power limit I would use a vacuum
> tube PA.
>
> Not to mention one sure thing, the way as the KPA500 is engineered leave
> all the space for a great serviceability. It's not the same for several
> other SS PAs.
>
>                      73 de iw1ayd Salvo
> ______________________________________________________________
> 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
>

--
Robert G Strickland, PhD ABPH - KE2WY
[hidden email]
Syracuse, New York, USA
______________________________________________________________
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