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#1
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![]() see http://home.att.net/~jacksonharbor/lfconv.htm Jackson Harbor Press kit - $12 for the basic kit (10 to 300 khz to HF) with the crystal included, parts and circuit board etc. They take paypal etc. hope this helps bobm -- ************************************************** ********************* * Robert Monaghan POB 752182 Southern Methodist Univ. Dallas Tx 75275 * ********************Standard Disclaimers Apply************************* |
#2
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Bob,
Thanks for the info. Do you have any experience with this kit? One question I have is the since the converter has a simple local oscillator, will the "readout" be accurate and will the frequency be "stable"?? Thanks Jim Bob Monaghan wrote in message ... see http://home.att.net/~jacksonharbor/lfconv.htm Jackson Harbor Press kit - $12 for the basic kit (10 to 300 khz to HF) with the crystal included, parts and circuit board etc. They take paypal etc. hope this helps bobm -- ************************************************** ********************* * Robert Monaghan POB 752182 Southern Methodist Univ. Dallas Tx 75275 * ********************Standard Disclaimers Apply************************* |
#3
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![]() "Jim" ) writes: Bob, Thanks for the info. Do you have any experience with this kit? One question I have is the since the converter has a simple local oscillator, will the "readout" be accurate and will the frequency be "stable"?? Thanks Jim A crystal controlled converter is a very old scheme to add coverage to an existing receiver. Since it's crystal controlled, there would have to be very odd circumstances for it to be unstable. All you do is add the frequency of the crystal to the frequency displayed on the receiver. It's easy so long as the crystal in the converter is a nice even frequency. In the analog days, the calibration of the dial would likely be more significant than the exact frequency of the crystal. With digital redout receivers, this is likely somewhat of an issue, since while the crystal will stay on frequency, in the circuit it may oscillate at a slightly difference frequency from the marking on the case. If you're lucky, the converter has a trimmer capacitor for this sort of adjustment; all you'd have to do is tune in the oscillator frequency with your receiver and see if it's on frequency. If not, then you adjsut the trimmer. If there's no trimmer, you still take note of the crystal frequency in the receiver, and use that knowledge to adjust your mental readout. If it's 1KHz off from the marked frequency, then you know you know you will have to add or subtract that amount (depending on the direction of the offset) when looking at the receiver's readout. Michael Bob Monaghan wrote in message ... see http://home.att.net/~jacksonharbor/lfconv.htm Jackson Harbor Press kit - $12 for the basic kit (10 to 300 khz to HF) with the crystal included, parts and circuit board etc. They take paypal etc. hope this helps bobm -- ************************************************** ********************* * Robert Monaghan POB 752182 Southern Methodist Univ. Dallas Tx 75275 * ********************Standard Disclaimers Apply************************* |
#4
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![]() there is not a trimmer capacitor in the crystal circuit IIRC, though you could probably add one if needed. You have (or I had) a choice of 3 crystals and bands, and I picked the 10.000 Mhz crystal since I could check it against WWV and it would be a handy item for use as a frequency reference if I ever junked the kit ;-) You will want a well shielded housing if you live in an urban area with powerful transmitters (AM..) nearby. In bad cases, an outboard low pass filter might be needed (see ARRL handbook for circuits etc.). Many of the digital dials on moderate cost digital receivers are not zero beat-able against WWV, and BFO settings etc. may interact as well, so an approximate readout is all most of us will get anyway ;-) hth bobm -- ************************************************** ********************* * Robert Monaghan POB 752182 Southern Methodist Univ. Dallas Tx 75275 * ********************Standard Disclaimers Apply************************* |
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