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Showing posts from July, 2017

A New Line of Transceivers ~ DifX

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Dissing the Dishal Filter(AKA Ditching the Dishal Filter) 07/27/2017 ~ Updated with some additional data. Several months ago I started a project that would use a filter designed using the Dishal method. I have finally concluded that it is time to say Basta. For those who claim they have a working filter I suggest you go back a fully evaluate what you really have. A short review of my reasons for Dissing (Ditching) the Dishal. After resolving the issue that every time I downloaded the software my virus checker put the Dishal.exe file in quarantine (not a good sign) I started off with a 6 crystal filter. That did not end well! Then I shifted to a 4 crystal filter and the curve below is the result of the second effort. This is a real plot of my data and from what I see, it has the classic Dishal shape and far different than my plot of the failed six crystal filter. For reference purpose I have now added what the theoretical 4 Pole. Dishal Plot should result based on my data

Mind you I d…

A New Line of Transceivers ~ DifX

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A New Transceiver on the Air! * Some updates added on 7/11, 7/12, 7/13, 7/14, 7/15, 7/16, 7/22

 
I frequently have several transceivers in work at any one time and eventually some event occurs that causes me to actually finish off one of the rigs. It was really hot this past weekend in SoCal and so that was the triggering event -- there is just something cool about working in a garage that is running a hot 90 degrees F or for those who use the " other standard " we're talking 32.2 Degrees C.



Here are some highlights of this DifX [Different from a Bitx]:
The size is 4X6 by 2 inches high. [For reference purposes the Bitx40 board is 25 square inches not including the display and controls.] I wouldn't call this micro-sized but Mini-Sized is probably OK. A bit of fudging here as I happened to have a 4X6X2 inch aluminum chassis that became the case enclosure. I bought this chassis years ago with the plan for a one "toob" CW transmitter --but who does CW anymo…

A New Line of Transceivers ~ DifX

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Homebrewing a Chassis, Cases and EnclosuresMake your Rig Look as good as it Sounds! There is just something about a rig that has that finished look when it has a painted case. Yes, it is something that came out of your garage or workshop but there is no reason why it can't look "finished". Long ago I adopted "Juliano Blue" and perhaps there was an unconscious bent to that decision based on my very early solid state experiments with the distinctively Blue CK722 transistor. Go Blue! Of late I am not satisfied with a project unless it resides in a Blue Case --a Juliano Blue Case. So how do you get to the point of homebrewing a chassis, cases or enclosures. The first part is the right tools --no you don't need a $250 K CNC mill but for about $50 you can purchase a bench type metal break from Harbor Freight.

When I bought mine about 10 years ag they could be had for about $25. The type I have is 18 Inches long. The next thing you need is some stout metal bars in va…