[Antennas] From transmission lines to tuners

Thu, 19 Dec 2002 17:30:14 -0600

Wonder why every tuner I've ever seen or used has NOT had a cooling
fan? Or even a ventilated cabinet?

Wonder if all the info about "tuner loss" is maybe a little inflated?
A KW into a tuner with 60% loss means that the tuner must dissipate
600 watts - not likely. Even 20 watts of continuous power loss would
make the tuner cabinet too hot to touch in a few minutes.

Models of typical tuner configurations with realistic Q values for the
components show typical losses in the fractional-dB range, as one
might expect. Of course, this was for "sensible" tuner applications,
NOT loading a 5 ft whip at 1850 KHz with a KW.

73/72, George
Amateur Radio W5YR -  the Yellow Rose of Texas
In the 57th year and it just keeps getting better!
Fairview, TX 30 mi NE of Dallas in Collin county EM13qe
K2 #489  IC-765 #2349 IC-756 PRO  #2121 IC-756 PRO2 #03235

----- Original Message -----
From: "A10382" <[email protected]>
To: "Antenna reflector list" <[email protected]>
Sent: Thursday, December 19, 2002 3:24 PM
Subject: Re: [Antennas] From transmission lines to tuners

> While it's impossible to have true 100% efficiency, the tuners
tested had
> losses as high as 60% on some bands -- and these were the 'better
quality'
> tuners.