Inhaltsverzeichnis
Collins R-390/URR
Manufactured by Collins Radio Comp., Cedar Rapids.
The R-390 is a military communications receiver that was introduced as a succossor to the Collins R-388 It was introduced in the mid-fifties; unlike the R-390A, the set is equipped with LC / coil filters and not the legendary mechanical filters.
Technical data
* Principle: triple conversion superhet, IF 17.5 - 25 MHz / 3 - 2 MHz, 455 kHz / FM 10.7 MHz * Operation modes: A1 with BFO, AM (A3) * Frequency range: 0.5 - 32 MHz * Frequency display: mechanical - digital display, 100 Hz * Frequency memory: none * Signal strength indicator: S-meter * Signal processing: RF gain, AGC 3x, noise limiter, SSB add-on optional * Features: * Sensitivity: AM (A3) <1 μV / Selectivity: 100 Hz, 1 / 2 / 4 / 8 / 16 kHz (-6/-60 dB)
Technical principle
Valve complement
V201 (6AJ5, 1st RF amplifier); V202 (6BJ6, 2nd RF amplifier); V203 (6C4, 1st mixer); V204 (6C4, 2nd mixer); V205 (6C4, 3rd mixer);
V401 (6AJ5, 1. 1st crystal oscillator); V402 (6AJ5, 2nd crystal oscillator);
V501 (6BJ6, 1. IF amplifier); V502 (6BJ6, 2. IF amplifier); V503 (6BJ6, 3. IF amplifier); V504 (6BJ6, 4. IF amplifier); V505 (6BJ6, 5. IF amplifier); V506 (6AK6, 6. IF amplifier); V507 (12AU7, detector); V508 (5749, BFO); V509 (6BJ6, AGC amplifier); V510 (6BJ6, limiter); V511 (12AU7, AGC time constant); RT512 (3TF7, voltage regulator);
V601 (12AU7, LF preamplifier, squelch); V602 (12AT7, AF preamplifier); V603 (6AK6, AF output stage); V604 (6AK6, AF amplifier line out); V605 (6082, voltage regulator); V606 (6082, voltage regulator); V607 (6BH6, D-C amplifier); V608 (5651, voltage reference); V609 (5651, voltage reference);
V701 (5749, VFO);
V801 (26Z5, rectifier); V802 (26Z5, rectifier);\
V901 (12AU7, crystal calibrator); V902 (12AU7, multivibrator).