On Sat, 20 Feb 2010 11:13:53 -0500, Craig Roberts wrote: >HOWEVER, the power meter is now acting up and no amount of >re-calibration will help. Forward power readings are fine -- but keying >the transmitter in the reflected power postion causes the meter needle >to drop below zero. This also happens in the forward power position when >the rig's keyed with carrier or mic gain control at minimum.
Craig, The zero reference voltage for the meter comes from the 2nd IF/Audio board. This should not change between RX and TX, so you may need to check the zero adjust (R1128) as described in section 3-2 (S-Meter adjustment) of the service manual. This adjustment, as well as several others in the radio, rely on proper setting of the +10V. If the +10V has changed or been adjusted, you will need to re-align the S-Meter/ACG adjustments, and probably the fixed passband adjustments as well. The +10V adjustment is the first adjustment in the service manual, and must be accurately set before any further alignment is preformed. Hope this helps. 73 -Jim -- Ham Radio NU0C Lincoln, Nebraska, U.S.S.A. TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A, HyGain 3750, IBM PS/2 - all vintage, all the time! "Give a man a URL, and he will learn for an hour; teach him to Google, and he will learn for a lifetime." HyGain 3750 User's Group - http://groups.yahoo.com/group/HyGain_3750/ http://radiojim(dot)exofire(dot)net http://incolor.inetnebr.com/jshorney http://www.nebraskaghosts.org _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
