The sheer volume of what I forget is staggering!! Since I owned an Omni-VI+ last I have altered my CW operating to using a low tone CW offset (450-500Hz) due to advancing tinnitus. I just received a
Jerry, Its a 221. Had to find anymore. I'm looking for one myself. 73, Charlie, K4ZRJ _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting
You might also want to look into the InRad #753. It's for a lower tone CW, but is 400 Hz wide Dave WA3MKB Jerry, Its a 221. Had to find anymore. I'm looking for one myself. 73, Charlie, K4ZRJ _______
-- Jerry: Thanks for letting me know another reason why I now prefer a low freq. side tone. All these years I was blaming it on planes; guns and loud women. Cw (60 yrs worth) never crossed my mind. N
Somewhere along the line I got the notion that the difference between the filters centered at 750 Hz and centered at 500 Hz was only the capacitors on the filter board. Did I make this up or can anyo
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Fri, 09 Oct 2009 13:29:22 -0600
More properly its the frequency of the crystals that set the center frequency, the capacitors set the coupling between crystals, and the bandpass. Dragging the crystals with different capacitors migh
I divided 250 Hz by 9 million Hz and got 0.00002778. I suppose I must then move the decimal two places to the right, or 0.002778% to get the percentage of change needed to move a 9 MHz crystal 250 Hz
Just knowing the value of the capacitors is not enough. That would assume that identical crystals were used in both the high-tone and the low-tone filters. We cannot make that assumption. Therefore,
Hi Mike, I have noticed that most, if not all, of the crystals in Ten-Tec filters have colored markings on them that appear to have been made with a felt tipped pen. My theory is that someone at the
Gee, I defer to you experts. It is quite possible that you are wrong but we'll never know, will we? Maybe we could move the carrier oscillator 250 Hz? _______________________________________________
I've built crystal lattice filters (and others) in the past. I also have books on designing them, Basically you are all correcr ! You CAN pull them with capacitors. It WILL change the input and outpu
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sun, 11 Oct 2009 12:28:20 -0600
In the ladder filter, both the crystal series resonant frequency and the Q of that resonance is critical. I think a high Q crystal comes from how close the faces of the (AT cut) crystal are to parall