7YR772 Ch= 7B09A
Majestic Radio & Television Co.,(post 1932)
- Land
- USA
- Hersteller / Marke
- Majestic Radio & Television Co.,(post 1932)
- Jahr
- 1948 ?
- Kategorie
- Rundfunkempfänger (Radio - oder Tuner nach WW2)
- Radiomuseum.org ID
- 197252
SAMS Photofact
Klicken Sie auf den Schaltplanausschnitt, um diesen kostenlos als Dokument anzufordern.
- Anzahl Röhren
- 7
- Hauptprinzip
- Superhet allgemein; ZF/IF 455 kHz
- Wellenbereiche
- Mittelwelle, keine anderen.
- Spezialitäten
- Plattenspieler und Tonbandgerät
- Betriebsart / Volt
- Wechselstromspeisung / 110-120 Volt
- Material
- Gerät mit Holzgehäuse
- von Radiomuseum.org
- Modell: 7YR772 Ch= 7B09A - Majestic Radio & Television Co
- Form
- Tischgerät, Truhenform, meist mit Deckel (NICHT Schrägpult).
- Bemerkung
- Radio with Phono and Wire Recorder.
- Literatur/Schema (4)
- Photofact Folder, Howard W. SAMS (Set 42, Date 7/48, Folder 4812-17)
- Autor
- Modellseite von Ernst Erb angelegt. Siehe bei "Änderungsvorschlag" für weitere Mitarbeit.
- Weitere Modelle
-
Hier finden Sie 418 Modelle, davon 174 mit Bildern und 358 mit Schaltbildern.
Alle gelisteten Radios usw. von Majestic Radio & Television Co.,(post 1932)
Forumsbeiträge zum Modell: Majestic Radio &: 7YR772 Ch= 7B09A
Threads: 1 | Posts: 5
I'm working on my Majestic 7B09A, my first full restoration. As I am going through the unit doing a recap, I have run across a capacitor that I think is the dreaded "death cap", but I'm not sure. It's C14 (.1 uf, 250 volt), which the Photofact lables as a "Line Isolation" capacitor. It's tied between chassis ground (as is one side of the input AC) and B-, with a 220K resistor across it. I'm attaching the schematic for reference and I've circled the section in question.
I'm thinking this cap needs to be replaced with a Safety Cap. I researching them, it appears that only X2 caps come in the .1 value, which would make this application "across the line". However, the connection to B- is causing me confusion, as this point is the only reference to B- and uses the Earth Ground symbol, which is used throughout the rest of the chassis circuitry.
Is B- actually a DC circuit ground point and the .1 cap is providing noise filtering between it and the AC line?
Man, I've got a lot to learn, but this is so much fun!
Anlagen
- Majestic 7B09A Schematic (288 KB)
Bob Poole, 15.Dec.20