Hello Jerry,
Thank you indeed for all useful information. I should remember all those
things from physics classes, but I have been into sales of building
materials all my life, so you needed to refresh my memory :)
Best regards,
Mats
2006/9/12, Dr. Gerald N. Johnson <geraldj@storm.weather.net>:
>
> On Tue, 2006-09-12 at 15:27 +0200, Mats Strandberg wrote:
> > Hello!
> >
> > I am the happy owner of a Ten-Tec 509 that according to the manual
> should be
> > capable of delivering 3 Watts RF Output.
> >
> > In the Swedish Portable Contest, there is a Power Multiplier that
> demands
> > the RF output to be less than 1 Watt.
> >
> > Can anyone supply me with information of suitable Power attenuators that
> > could be used to reduce the 3 Watts down in several steps, for example
> > 1,5W/1W/500mW/100mW?
> >
> > Thanks in advance for any possible help.
> >
> > SJ6R - Mats
>
> There are tables of attenuator resistor values in many radio handbooks,
> ARRL and some RSGB included and sometimes formulae for designing them.
> Use 2 watt metal film resistors and they will handle all your power.
>
> You need 3 dB to get from 3 to 1.5 watts, 5 dB to get from 3 to 1 watt,
> 3 dB more to get from 3 watts to 1/2 watt and ten dB to get from 1 w to
> 0.1 watt. All can be cascaded in any order so long as all are built with
> 2 watt resistors.
>
> The closer you match the resistor values to the computed values, the
> more accurate the attenuation will be, so looking for closer precision
> than 20% tolerance resistors can help that precision. I worked up
> computer programs once for picking attenuation values using standard
> value resistors and trimming impedance with more than one resistor in
> the center element of the T, but its in CP/M and hard to access these
> days.
> --
> 73, Jerry, K0CQ,
> All content copyright Dr. Gerald N. Johnson, electrical engineer
>
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