Don't forget that an attenuator will also be in the line for the
Receive mode. A few db won't be noticeable, but 10db might be.
72/73,
ed - k9ew
On 9/12/06, Mats Strandberg <sm6lrr@gmail.com> wrote:
> 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
> >
> > _______________________________________________
> > TenTec mailing list
> > TenTec@contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
> >
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