[OKDXA] On Power...

[N5OK]

Kim,

Mine varies with the mode and circumstances.  I have an AL-1500 and it will
run a KW key down for hours.  However, I haven't used it in several years.
I mostly used it to work CW on 160M.  It hasn't been plugged in since I got
the KPA500.  I also used it back when I was contesting.  It went on when
the contest started and off when it was over.

On CW and SSB I run the KPA 500 at 400W any time that I am on.  That's
because I'm there only to work a new band country.  For casual operating I
use FT8 and FT4.  Usually I run 100W.  If it is a new band country and
there is a pileup, I will run 400 to 450W depending on the band.  I do
monitor the temperature on the KPA500 and if it starts getting too high, I
will back off on the power.

Being retired, I am able to chase DX when most folks are at work which
means often there isn't a pileup.  In that case, usually 70W will do it.

I have busted pileups with 100W when props are good but it really isn't fun!

Hope this helps...   73, Coy

Coy C Day, N5OK
20685 SW 29
Union City, OK 73090
H(405) 483-5632 C(405) 448-2368
n5ok at arrl.net


On Wed, Apr 13, 2022 at 11:12 AM Roger Simpson <rksimpson1 at cox.net> wrote:

> Kim:
>
> I always run with an amp but I normally don’t run more than 200 watts. My
> problem is that I run FT8 most of the time and compared to any other mode
> it has a very high duty cycle.  With FT8 you don’t need really high power
> but because of the high duty cycle – i.e. 100% for 15 seconds followed by
> 0% for 15 seconds – you really need a linear. I have found that running
> several hundred watts on FT8 is “more or less” the same as running 1KW on
> SSB in terms of duty cycle and the tendency of your linear to shut down due
> to overheating.
>
> Here are some examples of what I have learned.
>
> Setup A – ICOM7600 barefoot.  I can run FT8 but I have to keep power down
> to around 50W or the rig will overheat and shutdown.  Maybe the shutdown
> will happen after say 15 minutes to 30 minutes.
>
> Setup B – ICOM7600 with ICOM PW-1 linear. The PW-1 is the only solid state
> linear that I know of that will run FT8 at 300 watts or more for hours on
> end.
>
> Setup C – ICOM7600 with Ameritron MFJ 1306 linear. If I run FT8 with this
> setup at more than 250W the linear will shut itself down due to overheating
> after about five to  ten minutes.
>
> Setup D  -- ICOM7600 with ACOM 2100 linear. This linear uses a 4CX1000
> vacuum tube final. I usually run a 300W when trying to contact DX station
> running FT8 F/H mode. I can run for an indefinite amount time with this
> setup calling FT8 F/H at 300W. I could probably run more than 300W with
> this setup but I never do. I have been running with this setup for the last
> year or so. I bought the ACOM from DX Engineering. With this setup I stand
> a very good chance of breaking even the biggest pileup if I am persistent.
> This is going to be the setup for trying to work Bouvet and Crozet – both
> of which I need for ATNO. I have never had a shutdown with my ACOM 2100 due
> to overheating but it will shutdown right away to protect itself when I
> have no antenna or wrong antenna for the band I’m trying to run on. .
>
> Bottom line when running high duty cycle FT8. If you get a linear:
> Seriously consider getting one that can tolerate HIGH duty cycle. Probably
> the old Alpha linear that advertised “brick on key” at 1KW would be FB for
> FT8.
>
> 73    Roger   K5RKS
>
> Sent from Mail for Windows
>
> From: Kim Elmore
> Sent: Wednesday, April 13, 2022 10:22 AM
> To: Oklahoma DX Association
> Subject: [OKDXA] On Power...
>
> I've a question for the group: how often do you QRO for a DX contact vs
> the usually 100 W? I tend to try 100 W first and if I'm clearly making
> no progress, I'll run QRO (except for 30 m). Am I being a masochist? Do
> those of you with almiost all of 'em worked simply turn on the amp when
> you turn on the rig and run full smoke all the time, or do you pick and
> choose?
>
> 73,
>
> Kim N5OP
>
> --
> Kim Elmore, Ph
>
> Kim Elmore, Ph.D. (Adj. Assoc. Prof., OU School of Meteorology, CCM, PP
> SEL/MEL/Glider, UAS, N5OP, 2nd Class Radiotelegraph, GROL)
>
> /“I occasionally play works by contemporary composers and for two
> reasons. First to discourage the composer from writing any more and
> secondly to remind myself how much I appreciate Beethoven." – Jascha
> Heifetz/
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