Yaesu FT-950 Technical Supplement

Also see for FT-950: Brochure & specs Reference Manual Update Update

Contents

ALIGNMENT-1AlignmentFT-950 Technical SupplementIntroduction and PrecautionsThe following procedures cover adjustments that arenot normally required once the transceiver has leftthe factory. However, If a problem occurs duringnormal operation due to component failure; realign-ment may be required after the faulty componentshave been replaced.We recommend that authorized Vertex StandardTechnicians, who are experienced with the circuitryand fully equipped to repair and align our products,perform repairs. If a fault is suspected, contact theselling dealer for instructions regarding repair. Au-thorized Vertex Standard Technicians have the lat-est information to align all circuits and make com-plete performance checks to ensure compliance withfactory specifications after repairs.Those who do undertake any of the following align-ments are cautioned and proceed at their own risk.Problems caused by unauthorized attempts at re-alignment are not covered by the warranty policy.Vertex Standard must reserve the right to changecircuits and alignment procedures in the interest ofimproved performance, without notifying owners.Under no circumstances should any alignment beattempted unless the normal functions and opera-tion of the transceiver are clearly understood, thecause of the malfunction has been clearly identifiedand all faulty components replaced. The need forrealignment should be determined to be absolutelynecessary.The following test equipment (and a thorough fa-miliarity with its correct use) is necessary for correctrealignment. Most steps do not require all of theequipment listed. The interactions of some adjust-ments may require that more complex adjustmentsbe performed in a sequence. Do not attempt to per-form only a single step unless it is clearly isolatedelectrically from all other steps. Have all test equip-ment ready before beginning, and follow all of thesteps in a section in the order they are presented.Required Test Equipment RF Signal Generator AF Signal Generator Spectrum Analyzer good to at least 1 GHz. Frequency Counter SINAD Meter RF Millivoltmeter Electronic Load Digital DC Voltmeter (high-Z, 1 M-Ohm/V) DC Voltmeter DC Ammeter (20 A) Ohmmeter DMU-2000 Data Management Unit 50-Ohm Dummy Load (100 watts) In-Line Wattmeter (100 watts, 50-Ohm) Linear Detector RF Coupler 4-Ohm AF Dummy Load (3 watts) 1/4-inch 3-contant PlugAlignment Preparation & PrecautionsA 50-ohm RF Dummy load and in-line wattmetermust be connected to the “ANT 1” jack in all proce-dures that call for transmission, except where speci-fied otherwise. Correct alignment is not possible withan antenna.After completing one step, read the following stepto determine whether the same test equipment willbe required. If not, remove the unneeded test equip-ment before proceeding. (except the dummy loadand wattmeter).Correct alignment requires that the ambient temper-ature be maintained constant between 68 °F ~ 86 °F(20 °C ~ 30 °C). When the transceiver is brought intothe shop from a hot or cold environment, it shouldbe allowed time to come to room temperature be-fore alignment. Also, the test equipment must bethoroughly warmed up before beginning.Whenever possible, alignments should be made withoscillator shields and circuit boards firmly affixed inplace.Note: Signal levels in dB referred to in this proce-dure are based on 0 dBμ = 0.5 μV (closed cir-cuit).Important NoticeDo not adjust the alignment menus that are notmentioned in this manual.