[Kenwood] TL-922/TL-922A on the WARC Bands

2003年1月12日 20:11:14 -0600

Its messy designing a plate RF choke to cover 1.8 to 30 MHz or even 3.5
to 30 MHz. Its common in the older designs especially to have series
resonances (from the distributed C of the coil) that were tweaked to be
in between the original pre WARC ham bands. WARC bands make it more
difficult to stow those resonances. One solution Collins used on
continuous coverage amplifiers was to use two or three different chokes
in series so that the second and third chokes would have high impedance
where the first one went series resonant. Some of the more classic
chokes didn't even allow for 15 meters since that was a new band in the
50s. That gap was a hand place to put the unwanted series resonance.
Any amplifier designed and made before WARC bands could and likely will
have a plate choke problem when operated on some WARC band.
73, Jerry, K0CQ
-- 
Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
Reproduction by permission only.