This is a generic linear amplifier RFI kit for DC powered amplifiers. Works on many popular amplifiers including:
Specially designed for the Elecraft KPA500 linear amplifier used with the KX3 and similar transceivers.
Included are the following chokes and installation guidelines:
Included are the following chokes and installation guidelines:
RF Input:F240 ring – 5-9 turns of RG-58 size through center
RF Output:FSB-1 (Big Clamp on) – 3 turns of RG-8 size cable
PA KEY Cable:FSB-1/2 – multiple turns through choke – ½” diameter hole
AC Power Line:F240 ring – 5-6 turns through center
Computer/RS232/AUX Cable:FSB-1/2 – multiple turns through choke – ½” diameter hole
Also make sure you connect a good RF ground to the amplifier ground post.
50 ohm coax to 75 ohm balanced output baluns are useful for low (< 1 wavelength) dipoles exhibiting 75 ohm characteristic impedance or for matching to balanced ladder line whose endpoint impedance is near 75 ohms.
50 ohm coax to 75 ohm CATV coax connections are easily done with a 1.5:1 unun with SO-239 connectors on input and output. Likewise 50 ohm coax to unbalanced verticals or loads near 75 ohms can be matched with a 1.5:1 unun.