RT 35
0 A / URC-14
  • AN/URC-11 (UHF) and AN/URC-14 (VHF) were introduced in 1954 as replacements for the somewhat larget URC-4 that operated on both the VHF and UHF energency frequencies.
  • The original versions have 6 subminiature tubes and two germanium transistors. 
  • The A versions have 5 subminiature tubes and two germanium transistors. 
  • All operate from the same battery as URC-4.
  • It appears that the miltary's transistion to UHF was well underway.  Consequently, there seems to have been more URC-11's built than 14's.
  • My unit is serail number 253.  Note the hand-scribed U.S. Air Force contract number.
  • There are reports that URC-14's, without Air Force contract numbers, were include in commercial airline survival kits.
  • Set was originally tuned to 121.5 MHz.
  • More info here:

Power supply was constructed in a surplus CY-1210/U case.  Eight AA-cells power a fly-back converter to supply 100 VDC.  C-cell, on left, powers the tube filaments.
Interior of the URC-11 is virtually identical to the URC-14.  The two transistors are currently in my URC-14.
URC-11 or URC-14 Schematic
  • This is the URC-11 schematic.  The URC-14 is virtually identical except for the tuned circuits.
  • Crystal, Y1, was  60.75 MHz.
  • URC-11 doubles this frequency in V2 and doubles again in V3 for an output of 243 MHz.
  • V4 is the super-regenerative receiver.
  • Drawing shows caps added to each tank circuit to pull the radio DOWN to the 220 Mhz ham band.
  • URC-14 doubles in V2 and V3 is a straight power amp for an output of 121.5 MHz.
  • To move the URC-14 UP to the 144 MHz ham band I added no caps, and removed one turn form each coil.
  • I'm using a 72.125 MHz 5th-overtone series-resonant crystal in an HC-49 holder from International Crystal Manufacturing for an output of 144.250 MHz, the de facto MRCA official 2-meter AM frequency.
A couple more drawings:
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