511/Repairs
| Symptom | Cause | Fix |
|---|---|---|
| +225 V out of regulation | C70 (bumblebee) leaky C72 (bumblebee) leaky |
replace C70 replace C72 |
| +450 V out of regulation | C69 (bumblebee) leaky | replace C69 |
| no sweep | V15 (6C4) marginal | swap V15, V10 (sweep output) / eventually replace |
| HV low (1500 V max, 1800 nom.) | ||
| intensity does not vary with control | ||
| vertical amplifier inoperable |
Bumblebee capacitors
C1 Fixed PT .01 µf 400 V trigger input C2 Fixed PT .01 µf 400 V trigger 2nd stage C7E Fixed PT .022 µf 400 V sweep range C11 Fixed PT .047 µf 400 V -GATE output C13 Fixed PT .01 µf 600 V sweep speed pot bypass C15B Fixed PT 920 pf 400 V sweep timing (1%) C15C Fixed PT .01 µf 400 V sweep timing (1%) C15D Fixed PT .1 µf 400 V sweep timing (1%) C15E Fixed PBT .1 µf 400 V sweep timing (1%) C17 Fixed PT .1 µf 400 V sweep magnifier V11 input C19.1 Fixed PM .1 µf 400 V sweep magnifier V11 grid bypass C19.2 Fixed PM .1 µf 400 V H output V14 grid bypass C20 Fixed PT .5 µf 400 V sweep coupling C24 Fixed PT .001 600 V H output neon bypass C25 Fixed PT .001 600 V H output neon bypass C40 Fixed PT .1 µf 600 V AC coupling "via cond" C41 Fixed PT .1 µf 600 V vertical amp (V17) input C43 Fixed PT .1 µf 600 V vertical preamp (V16) input C46 Fixed PT .1 µf 400 V vertical preamp (V16) output C48 Fixed PT .01 µf 400 V vertical amp (V17) screen decoupling C50 Fixed PT .1 µf 400 V vertical amp (V17) output C53 Fixed PT .1 µf 400 V vertical output V18 plate to CRT C55.1 Fixed PT .1 µf 400 V vertical output V19 grid decoupling C56 Fixed PT .1 µf 400 V vertical output V19 plate to CRT C58 Fixed PT .1 µf 2000 V CRT gate C59 Fixed PT .1 µf 2000 V CRT cathode C60 Fixed PT .1 µf 400 V Intensity pot bypass C69 Fixed PT .01 µf 400 V +450 V regulator feedback C70 Fixed PT .01 µf 400 V +225 V regulator feedback C72 Fixed PT .01 µf 400 V +225 V regulator reference C74 Fixed PT .01 µF 400 V HV oscillator feedback C77 Fixed PMC .5 µf 2000 V -1500 V filter PMC paper metal cased PM paper molded PBT paper bathtub PT paper tubular