VFO/VCO Installation

Compliments of Firestik^® Antenna Company Technical Support Team

Copyright ^© 2005 Firestik^® Antenna Company

1. If your crystal oscillator (radio) uses crystals that are grounded to chassis, then the special coax cable that came with the VFO/VCO can be inserted into the crystal holder. Be sure that the center of the coacial cable is on the HOT side and the shield in on the GROUND side. Make firm connections. 2. If your crystal oscillator (radio) circuit has a floating ground, then the center of the cable should be inserted in the HOT side of the crystal holder and the shield connected to the closest DC negative ground location. If harmonics or squeals occur, make sure that the shield is going to a DC ground and that the center of the cable is going to the HOT side of the crystal holder. 3. With most "sideband only" radios, the shield of the VFO/VCO has to go to the DC ground of the radio's circuit board. If you plug the shield of the VFO/VCO into the crystal socket, you may introduce problems such as harmonics, frequency drift, bleedover or VFO frequency interference on all channels of the radio. In order to maintain frequency stability, let the VFO/VCO warm up for at least one-half hour. If uncertain about grounding configuration, use the crystal HOT side for the cables center conductor and ground the shield to the radios negative DC ground on the circuit board. ** Re-created from archived documents for historical purposes.