In the real worl of Radio broadcasting few CE's would try that.. All the
GM's I worked for wouldn't tolerate a transmitter running at less than 100%
or less than maximum allowed modulation. Advertising is sold on ratings, not
the total body count and to Program Directors and GM's, Loud =
ratings.....And they have no time for or interest in the facts and even if
they would be willing to save money on the power and tube bills, it couldn't
be at the expense of perceived ratings.
W6RD
----- Original Message -----
From: "Dr. Gerald N. Johnson" <geraldj@storm.weather.net>
To: <tentec@contesting.com>
Sent: Tuesday, October 30, 2007 12:26 PM
Subject: Re: [TenTec] SB-220 Tubes and QSK
> On Tue, 2007-10-30 at 11:36 -0500, Rob Atkinson wrote:
>> <<<Can you measure 20% at the other end of the path? That's all of 0.8 dB
>> and when propagation changes sometimes more than 10 dB in seconds...
>>
>> 73, Jerry, K0CQ>>>
>>
>>
>> Hi Jerry,
>>
>> The next time you fork out your hard earned dollars for a new 200 w.
>> rig and it only puts out 160 w., I'll expect you to just put up with
>> it because it's only N dB less than spec'd output; the next time you
>> shell out $$$ for a new 100 w. rig and it only puts out 80 w.,
>
> Just a couple tenths voltage drop in the 12 volt supply to the PA will
> cause that much power drop. Can't always get around it, besides it still
> can't be detected at the other end of a path whether local or long
> distance because of propagation path variations and the receiver being
> logarithmic (as are ears) with the smallest meter divisions be 6 dB (4X
> power). Besides running a tube at 80% power ratings tends to seriously
> lengthen its lifetime.
>
>> or the
>> next time you get a new car that's supposed to do 80 mph and it
>> red lines at 64, I'll expect you to just suck it up and accept the
>> degradation in performance with some engineering rationalization.
>
> That's not in a logarithmic time variable medium, that's a linear time
> fixed medium and the difference is very perceivable and measurable.
>
>> By
>> the way, get on the horn and tell the 1A broadcast station that
>> shelled out $250,000 for a new Harris dx50 that it's okay if it only
>> puts out 40 kw carrier instead of 50 and listen to what the C.E. has
>> to say about that.
>
> He would be livid, but if it save him 20% of his power bill and doubled
> tube life (and if the FCC would accept the operation) and only cost 1%
> of his audience, he'd be turning it back. NBS WWV stations run rigs at
> half rated power or less to get extremely long tube life and reliable
> operation. The C.E. of WHO is chewing his teeth up with the number of
> times a day that the signal goes off the air now. Besides measuring
> field strength at a couple miles he CAN detect the reduced power, but
> your receiver can't tell the difference at 1 mile or 1000 miles.
>>
>> 73,
>>
>> rob / k5uj
>
> 73, Jerry, K0CQ
>
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