03-07-2014, 11:22 PM
Greg, when you peaked the IF with the generator did you adjust for max AVC or max audio tone at the speaker? I have always found the AVC method the most accurate. Unless you keep the signal level very low, its hard to accurately align for max audio tone.
Early radio alignment procedures always specified the tone method for two reasons. One was that it was applicable to radios without AVC which were fairly common back then. Second very few people had VTVMs, and the 1000 ohms per volt meters which were available loaded the detector too much for accurate results.
But when high impedance VTVMs became popular in the 40's, the AVC peaking method became prevalent. I always do alignments for max AVC regardless of the original specified procedure, unless of course the set has only a manual gain control and no AVC.
Early radio alignment procedures always specified the tone method for two reasons. One was that it was applicable to radios without AVC which were fairly common back then. Second very few people had VTVMs, and the 1000 ohms per volt meters which were available loaded the detector too much for accurate results.
But when high impedance VTVMs became popular in the 40's, the AVC peaking method became prevalent. I always do alignments for max AVC regardless of the original specified procedure, unless of course the set has only a manual gain control and no AVC.