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National NCL-2000 Time Delay Relay (K4), Part # A51411 Used

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MPN:
A51411
Condition:
Used
Shipping:
$6.00 (Fixed Shipping Cost)
$29.99
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Description

National NCL-2000 Time Delay Relay (K4), Part # A51411 Used

This is the plate power time-delay relay (K4) in the National NCL-2000 HF linear amplifier. It provides a warm-up delay (approximately 60–75 seconds) before allowing plate voltage to be applied to the 8122 tubes, protecting them during filament warm-up. It is a thermal (thermostatic) delay relay with a 12V heater, SPST-NO contacts. It physically resembles a miniature vacuum tube and plugs into a socket behind the front panel.
 
 
"Original National NCL-2000 Time Delay Relay (K4) – Part # A51411 Genuine factory time-delay relay pulled from a working National NCL-2000 linear amplifier. This is the critical warm-up relay (approx. 60–75 seconds) that protects your 8122 tubes by delaying plate voltage application. • SPST-NO contacts
• 12V heater
• Miniature tube-style, plugs into socket behind front panel
• Lights the READY indicator when timed out
 
 
Key Specifications
  • Function: Normally open time-delay relay (closes after delay)
  • Heater: 12V AC (or compatible)
  • Delay: ~60–75 seconds (one-minute nominal)
  • Contacts: SPST-NO (Single Pole Single Throw, Normally Open)
  • National Part: A51411 
  • Mounting: Octal or similar miniature tube socket
  • Purpose: Prevents premature application of high voltage; lights the "READY" indicator when timed out
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