Please click your language flag. Bitte Sprachflagge klicken.


Information - Help 
ID = 56945
Tube type:  Double Diode-Triode   Text 
Identical to 535-A
Similar Tubes
Normally replaceable-slightly different:
Other class quality (otherwise equal):
  1659 ; 2A6

Base 6-Pin-Base U6A, old, USA Top contact with a cap.
Was used by Technology / Measurement
Filament Vf 2.5 Volts / If 0.8 Ampere / Indirect / Specified voltage AC/DC

The voltmeter of the Boonton Radio Corp. Q-Meter type 260A uses a unique calibrated tube, this 535-A, especially made, or selected from a 1659, for Boonton by RCA. It bears the 1659 designation on the glass with a specially marked base. (Low grid capacitance and low grid current are prime requirements as it operates as a leaky-grid detector with a 100M ohm grid-cathode resistance.)

Information source - - Manufacturers Literature   Boonton Manual

461~~3.png 535-A: Telefunken Werkstattbuch
Wolfgang Bauer

Just Qvigstad
Usage in Models 1= 1953 ; 1= 1954??

Quantity of Models at with this tube (valve, valves, valvola, valvole, válvula, lampe):2

Collection of



You reach this tube or valve page from a search after clicking the "tubes" tab or by clicking a tube on a radio model page. You will find thousands of tubes or valves with interesting links. You even can look up radio models with a certain tube line up. [rmxtube-en]

Data Compliance More Information