[CQ-Contest] `150 watt limit question

Jukka Klemola jpklemola at gmail.com
Tue Jul 4 09:39:27 EDT 2017


100W output is adequate for nearly all today's transmitters.

IMD properties for the expensive transceiver boxes are much better than at
200W out.
These hams set the power output to 100W. They set it to 100W because they
can.
Everything is well inside the specifications.

For the hams with less fortune, 100W is just the right amount of power so
they get all juice out of the power supply and radio stays operational
through the contest.
Everything is just within the specifications.

Then there are the hams with less fortune but plenty creativity, who modify
their transceivers and force the power supply to output overly much current.
Everything outside specifications.

The power meter shows 124 Watts! Sad side is the 24 Watts is all over the
band, not on the 'output channel'.

Their output is outside the specifications.
They spread around the bands with overly spreading signal. In engineering
terms, they show much poorer IMD spec.
Their radios suffer all kinds of symptoms and the radio lifetime expectancy
is often less than a contest.


There sure is logic in 100W limit.
100W limit suits the typical hams just fine.



Frank dives into memories .. year .. year 1982.. crystal controlled
transmitter. 4.5 or maybe 5W out of a BLY88.

I like more the modern radios with frequency dials than my first XTAL TX.


73,
Jukka OH6LI


2017-07-04 8:13 GMT+03:00 <donovanf at starpower.net>:

> In 1959, my first Field Day, 150 watts input power was one of the
> multiplier categories.
>
> During the 1960s it was hanged to 200 watts input power
>
> Twenty years later is was changed again, to today's 150 watt output power
>
> 73
> Frank
> W3LPL
>
> ----- Original Message -----
> From: donovanf at starpower.net
> To: John Geiger <af5cc2 at gmail.com>
> Cc: CQ-Contest Reflector <cq-contest at contesting.com>
> Sent: Mon, 03 Jul 2017 17:39:47 -0400 (EDT)
> Subject: Re: [CQ-Contest] `150 watt limit question
>
> Back in the 1950s and 1960s a pair of 807s or 6146s ran 150 watts INPUT.
>
> 73
> Frank
> W3LPL
>
> ----- Original Message -----
> From: John Geiger &lt;af5cc2 at gmail.com&gt;
> To: CQ-Contest Reflector &lt;cq-contest at contesting.com&gt;
> Sent: Mon, 03 Jul 2017 13:19:36 -0400 (EDT)
> Subject: [CQ-Contest] `150 watt limit question
>
> It appears that for the ARRL contest, and maybe for CQ contest, 150 watts
> is the break point between high and low power.  Does anyone know why that
> limit was set?  It would seem that changing it to 200 watts would make more
> sense, in that low power would be barefoot, and high power would be with an
> amp (or with a Yaesu FTDX9000MP barefoot).
>
> It seems that there are 3 radios that doe 150 watts barefoot-the Kenwood
> TS950, the Icom 781, and the JRC JST-245.
>
> There are quite a few radios that do 200 watts barefoot-Yaesu FT1000D,
> Yaesu FT1000MP MK5, Yaesu FT2000D, Yaesu FTDX9000D, Yaesu FTDX9000C, Yaesu
> FTDX5000, Icom 775, Icom 7800, Icom 7700, Icom 7851, Kenwood TS990.
>
> That is one reason why 200 watts seems to be a more logical dividing point,
> but what do I know?
>
> 73 John AF5CC
> _______________________________________________
> CQ-Contest mailing list
> CQ-Contest at contesting.com
> http://lists.contesting.com/mailman/listinfo/cq-contest
>
> _______________________________________________
> CQ-Contest mailing list
> CQ-Contest at contesting.com
> http://lists.contesting.com/mailman/listinfo/cq-contest
>
> _______________________________________________
> CQ-Contest mailing list
> CQ-Contest at contesting.com
> http://lists.contesting.com/mailman/listinfo/cq-contest
>


More information about the CQ-Contest mailing list