4-PACK NOS QRP CRYSTALS 18pf HC49/s 3999.5 KHZ (stamped 4.0 mhz)

Description

YOU ARE PURCHASING ONE LOT OF FOUR 75M CRYSTALS. 18 pf 4.0 MHZ HC49/S.
ON MY OLD KENWOOD RECEIVER THE DIGITAL READOUT IN LSB/CW MODE IS 3998 KHZ. IN USB MODE I GET A READOUT OF 4001 KHZ. SO THE SPLIT COMES OUT AT 3999.5 KHZ, IF MY RECEIVER IS CORRECT.
I REALIZE THESE ARE ON THE BAND EDGE SO YOU'LL HAVE TO DECIDE IF YOU WANT TO TAKE THE RISK AND DO SOME EXPERIMENTING. THE FREQUENCY IS SOMEWHAT DEPENDENT ON CIRCUIT LOADING AND WILL MORE LIKELY FALL BELOW THE ACTUAL STAMPED FREQUENCY. IF SO, THEN YOU ARE INSIDE THE UPPER 75M LIMIT OF 4.0 MHZ.
I WAS ABLE TO PARALLEL 2 OF THESE AND GET THEM IN THE CAVITY OF A FT-243 CRYSTAL HOLDER, WITH GOOD RESULTS. VERY STRONG OSCILLATOR OUTPUT FROM MY HOMEBREW DESKTOP OSCILLATOR CIRCUIT.
IN MY EXPERIENCE, IN DOUBLES (2X IN PARALLEL) THESE WILL DO FINE IN LOW POWER QRP TRANSMITTERS, IN THE 1 TO 3 WATT RANGE. I CAN SOMETIMES GET UP TO 5 WATTS FOR INTERMITTENT DUTY BEFORE CHIRP AND WARBLE BEGINS. AND, EVEN AT THAT LEVEL, WITH CAREFUL TUNING OF THE ANTENNA LOADING CIRCUIT I CAN USUALLY CLEAN UP THE TONE.
I'VE USED THE 49S CRYSTALS IN SEVERAL HOMEBREW CW TRANSMITTERS, AND IN SOME CASES THEY WILL EVEN TAKE FULL POWER (I.E. IN DOUBLES). WITH CAREFUL PLATE TUNING, THEY WORK GREAT IN MY AMECO AC-1 6V6 TRANSMITTER.
THESE ARE NOS, NEVER USED. THE DIMENSIONS ARE ABOUT 10 X 4 X 3 MM. AGAIN, I'VE HAD GOOD SUCCESS WITH THE HC49/S CRYSTALS, BUT NO GUARANTEES AS TO HOW THEY WILL WORK IN YOUR CIRCUITS. I FIGURE AT .00 AND FREE SHIPPING, THE RISK IS FAIRLY LOW.
SHIPPING TO THE UNITED STATES ONLY.