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Re: BitX Operators Map, condition? Update for Builders Fest B4 Jan 6
Thanks again for providing the map, and thanks if you updated or put yourself on the map for the first time. I will use this map to visually show the distribution at least known thru this map of Ham Builders....practially all over the world. ?
I was going to do a new map for those entering the Hombrew Show and Tell and Contests, even and especially for those who are sending just images and the back story of their Builds. To further illustrate where this sharing was coming from. ?Well, I am not having much luck with that. ?Just not enough time for me to figure it out, I waited too late, actually didn't think of it fast enough....oh well....maybe next year....after all, what is the point of any of these efforts that are likely to grow Amateur Radio groups, especially clubs? Its to get more help? NO....but it can be a good side benefit....someone else will want to see the same thing happen....like look how many are on this site every day.....just amazing....and a lot of fun.....speaking of which....look what is on my bench besides my BitX40 (my operating one) up on the shelf, down on the lower shelf are two locals from this talk group: W7RLF Ryan Flowers of miscdotgeek.com fame and fortune....and very recognizable is WB5YYM Randell Curtis own expandable BitX40.....I had a QSO with BitX40 months ago....how cool is that....from Arkansas to East TN....shooting off of a galvanized fence wire antenna Randell radios....because he has a whole station custom hand made by him.....a Forty 9er, an external Amp in a matching metal case also, and has been featured in a SolderSmoke blogpost......and he is a big Dr. Jack Purdum W8TEE Fan and follower of his projects. ?These radios will be at the Builders Fest, even though their owners won't....that is if they get out of my shack..... |
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Re: Tuner? Well Sure!
¿ªÔÆÌåÓýMFJ.? Huh. Glad to see them using science for a change. ? I¡¯m a little old school when it comes to RF design, and particularly with matching circuits like a tuner.? The best tuners I¡¯ve ever owned were military tuners¡ specifically the old Collins 601 and the Harris RF-2601 devices.? If you are a study of these devices you know that the control circuits for the tuners operated essentially transform space with phase and amplitude information to effectively minimize SWR by determining the right transform to make the input see a purely resistive load.? Is that hard to do?? Nope.? You just have to think in a different coordinate system. ?Rather than go into several pages of background here, for those interested¡ there is a wonderful and complete chapter on this very subject in Sabin & Schoenike¡¯s book ¡°Single Sideband Systems and Circuits¡±, Chapter 16.? This book is a must for the serious RF designer.? You can get it off Amazon.? Other chapters in the book will answer questions like why you don¡¯t see grounded gate power amplifiers (a recent topic here), and why the very best IMD and linearity in an RF amplifier comes from a tube design in grounded screen configuration (common in broadcast transmitters¡ the cathode is at minus screen potential!).? Yikes! ? I¡¯ll put together a paper on the various loads the tuner will match once I have all of the calculations done.? Off the top of my head, it should match real impedances of 2ohms-10Kohms and reactances of +/-8Kohms.? I¡¯ve configured the capacitor bank to sit on either side of the inductor to complete the entire transform space (read that work for those really low impedance antennas that are usually not covered by antenna tuners). ? The hardware for me is a breeze¡ what is not so easy for me is figuring out the Raduino side¡ for display and setting¡ like Power, SWR, Bypass, frequency for memories, etc.? I may just build in all these things and ask someone else who is more familiar with the uBITx code to help out.? I have decided to make the tuner an I2C device though¡so that should help with the communications.? I originally was gonna use RS232 (makes it work with a lot of other radios then too¡ and even stand-alone) I2C is better for integration. ? I should have the hardware drawings dome tomorrow¡ ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton ¨C J68HZ Soufriere, St. Lucia W.I. Rent it: Like us on Facebook! ? ? email:? bill@... ? From: [email protected] [mailto:[email protected]] On Behalf Of Gordon Gibby
Sent: Friday, December 29, 2017 6:37 PM To: [email protected] Subject: Re: [BITX20] Tuner? Well Sure! ? If you guys can come up with something that works, it might provide a chance for Asher to provide employment for many many more people. ? Remember the most recent MFJ products measure impedance and use smith chart type calculations to predict the solution in jump to it quicker. ?? ? ? But that is not at all beyond the capabilities of many on this forum. ?
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Re: Bezel
¿ªÔÆÌåÓýFresh out of CNC machines¡. But it¡¯s a good thought. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton ¨C J68HZ Soufriere, St. Lucia W.I. Rent it: Like us on Facebook! ? ? email:? bill@... ? From: [email protected] [mailto:[email protected]] On Behalf Of Arv Evans ? Bill? K9HZ It seems that anybody with a CNC milling machine might be able to precisely cut a suitable bezel.? Those with 3D printers should also be capable of making one, or many. A bit more complex approach might be to make a cage for a router base that controls the cuts, and thus can make accurately cut out bezels, or LCD holes in chassis panels. Arv? K7HKL ? |
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Re: Bezel
¿ªÔÆÌåÓýHere¡¯s a photo of the 6302010 used on my DDS VFO/Signal Generator.? The 6102010 looks the same but mounting is different. Mike K5ESS ? From: [email protected] [mailto:[email protected]] On Behalf Of K9HZ
Sent: Friday, December 29, 2017 3:52 PM To: [email protected] Subject: [BITX20] Bezel ? I searched but did not find the answer to this question:? Has anyone found a nice looking bezel for the 1602 LCD in the kits? Something in addition to that black metal thing attached to the LCD to fill the space in the front panel. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton ¨C J68HZ Soufriere, St. Lucia W.I. Rent it: Like us on Facebook! ? ? email:? bill@... ? |
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Re: Power output decreases as a function of frequency?
#bitx40
Could be something with L1-3. Temporarily bypass the filter and try another test.
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I have one board with the filter centered a bit and gives less power higher up the band but we work only till 7.2MHz. It could be the output filter also. Raj At 30-12-2017, you wrote:
Bottom line up front: |
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Re: ALE, WINLINK and uBitX
I always remind hams that plastic coated wire will not have free air velocity factor. So the resonant
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length will be shorter than the theoretical length. My 40M dipole made intentionally with UV resistant plastic coated wire is just 28 ft long on each side. Raj At 29-12-2017, you wrote:
Arvo -- very cool! |
Craig Thibodeaux
K9HZ
Raj vu2zap