Valve Gallery - Tuning Indicators (3)

Valves: EM80, EM81,EM84, DM70.

Shown above is a EM80 tuning indicator from Mullard.  This was developed in the 1950s, two "curtains" would form in the semi-circular topped area seen above as as signal was tuned in.  Approx 75mm height with 6.3v heater and B9A base. Shown above is a Mullard EM81.  Not wildly different from the EM80 left, but including it gives the opportunity to include a side view.  Approx 75mm height with 6.3v heater and B9A base.

Shown above is a Mullard EM84, uses during the latter half of the 1950s.  Here a phosphorescent strip glows along the white area clearly seen above depending on signal strength.  Height of 82mm with B9A base. Shown above is a Mullard DM70.  Extremely small tuning indicator, where signal strength is indicated by the length of green line in the exclamation mark.  Used from the late 1950s onwards, approx height of 47mm with .. base.

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