SERVICE NOTE 005a K9AXN 300Mc oscillation in the SR-2000 and SR-400 series radio's The Hallicrafters SR-2000 is a vintage discreetly wired radio. Like many others of that era the routing of the wiring and location of components was not always exactly the same as the design prototype. As a result, each of these radio's had a slightly different personality. The information within this site is an effort to define the variations that result in different behaviors and provide methods to correct them. This note addresses a frequently occurring 300Mc oscillation pulsed at 1.9Kc. Symptoms include a very low level pitch from the speaker, sounding to be approximately 1.9Kc and a very ragged swept wave form when aligning the 1st I.F. system or using a scope anywhere else in the radio. The following photo's will present the waveform when aligning the I.F. system and the two capacitors that need to be moved apart. The separation need only be 1/4 inch. |