‰ NOW 40 WPM ‰ TEXT IS FROM JULY 2014 QST PAGE 63‰ THAT I BUILD A SWITCH TO FLIP THE ANTENNAS OPERATION BACK TO A LOWBAND DIPOLE. THAT REQUIRED REINTRODUCING THE BALANCED LINE OUT FROM THE MFJ 941 VERSA TUNER AND FEEDING THE CENTER OF THE DIPOLE WITH A BALANCED LINE. THEN, FOR 160 METER OPERATION, THE LEADS WOULD HAVE TO BE ELECTRICALLY SHORTED AGAIN TO ACT AS A VERTICAL. FIGURE 2 SHOWS THE SCHEMATIC, WHICH USES A SIMPLE DPDT RELAY. NOTE THAT THE ELECTRICAL SHORTING OF THE LEADS HAPPENS AFTER THE COIL AND BEFORE THE RE EXTRA HOLES IN THE PANEL. CRYSTAL PHASING 2R0 I WAS SOMEWHAT SURPRISED YET GRATIFIED AT THE OVERWHELMING RESPONSE I GOT TO MY APRIL 2014 QST ARTICLE ON CRYSTAL PHASING. AS I OFTEN SAY IN MY TECHNICAL WRITINGS, I DONT EXPECT TO BE THE LAST WORD ON THE SUBJECT, BUT I AM MORE THAN HAPPY TO BE JUST THE FIRST WORD ON A SUBJECT IF IT FOMENTS LIVELY DISCUSSION. ITS OBVIOUSLY BEEN A LONG TIME SINCE ANY MENTION OF THIS CLASSIC FILTER HAS BEEN MADE IN QST OR ANY OTHER RECENT PUBLICATION. I HAD MADE A SOMEWHAT PARENTHETICAL COMMENT ABOUT THE FACT THAT MOST BOAT ANCHORS DIDNT HAVE THE INHERENT STABILITY OR BANDSPREAD TUNING RATIO TO TAKE FULL ADVANTAGE OF THE EXTREMELY NARROW BANDWIDTHS OF THE PHASED CRYSTAL. I ACTUALLY PREFER TO CALL IT THE NEUTRALIZED CRYSTAL, BECAUSE AT ITS CORE THE PHASING CAPACITOR DOES NOTHING MORE THAN NEUTRALIZE THE HOLDER CAPACITANCE, ALLOWING THE CRYSTAL TO OPERATE IN A PURE SERIES RESONANT AND VERY SHARP MODE. AS IT TURNS OUT, FROM THE FEEDBACK IVE RECEIVED, THE MISMATCH BETWEEN TUNING RATIO AND SELECTIVITY IS FAR MORE DRAMATIC THAN I HAD GUESSED, FOR MOST RIGS OF THAT VINTAGE. UNLESS YOU HAVE A SAFECRACKERS TOUCH, YOURE MORE BAND, THEN THE RESULTING AUDIO SIGNAL WILL BE HEARD ON BOTH SIDES OF ZERO BEAT, BUT IF IT IS OUTSIDE OF THE PASSBAND THAT WILL NOT OCCUR. AND FINALLY, HEARING THE SIGNAL ON BOTH SIDES OF ZERO BEAT HAS NOTHING TO DO WITH THE IF FREQUENCY BEING 455 KHZ. IT WILL OCCUR AT ANY IF FREQUENCY. THE ARTICLE DESCRIBES THE XTAL PHASING AS CONTROLLING THE VARIABLE BANDWIDTH OF THE FILTER. ACTUALLY, AS DESCRIBED ABOVE, THIS CONTROL POSITIONS THE REJECTION NOTCH WITHIN THE FILTER PASSBAND, BUT IT DOES NOT OTHERWISE ADJUST THE OVERALL SELECTIVITY. THE ARTICLE SAYS THAT MANY CRYSTALS IN OLDER RECEIVERS HAVE FAILED. I HAVE RESTORED MORE THAN 25 RECEIVERS WITH CRYSTAL FILTERS DATING BACK TO 1936, AND I HAVE YET TO FIND A FAILED CRYSTAL. ONE NEEDED TO BE CLEANED BECAUSE CIRCA WORLD WAR II ERA WATERPROOFING WAX HAD CREPT INSIDE THE HOLDER ONTO THE CRYSTAL BUT NONE HAD FAILED. SO I DOUBT THATS A WIDESPREAD PROBLEM. IF YOU DO NEED A REPLACEMENT, WHICH THE ARTICLE SAYS IS HARD TO FIND IN A HERMETICALLY SEALED PACKAGE, GO TO WWW. INRAD. NET/ OR TO WWW. AF4K. COM/ CRYSTALS. HTM, WHERE 455R0 KHZ CRYSTALS ARE OFFERED FOR 30. FINALLY, I OFFER ANOTHER USEFUL HINT. IF YOU FIND TUNING WITH YOUR CRYSTAL FILTER TOO SHARP, ADD AN EXTERNAL VERNIER DRIVE TO YOUR TUNING DIAL. OLD TIMERS POSITIONED A VERNIER ON AN L BRACKET SUPPORTED FROM THE BOTTOM OF THE RECEIVER TO AVOID ‰ END OF 40 WPM TEXT ‰ QST DE W1AW ƒ