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Idea for future versions of BITX
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I will be doing the same, reading about filters on QRP-Labs. 73 Ken VA3ABN On Mon, Jan 16, 2017 at 1:37 PM, VE7BEE <obeebe@...> wrote: Thanks Ken for the info , will check the posts and see what I can find . Was on QRP- labs site reading up on filters last night . |
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Thank you Klaus and others for the links and info , I have the day off today and have been playing around with the BITX40 on the bench this morning . I successfully changed the VFO freq to test rx on 20 m by using a 2.010 Xtal I had laying around. By replacing the VFO coil with the 2.010 xtal and bypassing the receive BPF I am able to receive BOTH 14 Mhz signal and 10 mhz signal (of course with no filtering ¡) from signal generator . Moving on to 20 m BPF on receiver . Any one know an easy mod to existing one on the board ??
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Ashhar suggested replacing the 40m 100pf caps to 22pf for 20m, some time a go. 73 Ken VA3ABN On Mon, Jan 16, 2017 at 3:02 PM, VE7BEE <obeebe@...> wrote: Thank you Klaus and others for the links and info , I have the day off today and have been playing around with the BITX40 on the bench this morning . I successfully changed the VFO freq to test rx on 20 m by using a 2.010 Xtal I had laying around. By replacing the VFO coil with the 2.010 xtal and bypassing the receive BPF I am able to receive BOTH 14 Mhz signal and 10 mhz signal (of course with no filtering ¡) from signal generator . Moving on to 20 m BPF on receiver . Any one know an easy mod to existing one on the board ?? |
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9a3xz
for example ;) and? and? do it your self...dont buy ;) 9a3xz,Mikele? 2017-01-16 21:02 GMT+01:00 VE7BEE <obeebe@...>: Thank you Klaus and others for the links and info , I have the day off today and have been playing around with the BITX40 on the bench this morning . I successfully changed the VFO freq to test rx on 20 m by using a 2.010 Xtal I had laying around. By replacing the VFO coil with the 2.010 xtal and bypassing the receive BPF I am able to receive BOTH 14 Mhz signal and 10 mhz signal (of course with no filtering ¡) from signal generator . Moving on to 20 m BPF on receiver . Any one know an easy mod to existing one on the board ?? |
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20 METER MODS continued - I have replaced the BPF caps as follows - C2 , C4 and C6 with 20 pf as that was all I had in the junk box . Then I found had better receive results when I changed C6 to 18 pf . I left the others at 20 pf . I then reworked the VFO . Changed C95 to 680 pf and increased the inductance of L4 to 13.5 uh ( from the junk box ) . This put me in the ballpark with a VFO freq range of about 2.2 MHZ . The receive results were instant copying SSB sigs on a 40 m dipole with open wire and a tuner . Do not know about the sensitivity yet , but it does receive on 14.2 MHZ ! ?The extra capacitance at C95 has decreased the band coverage by the varactor . With more inductance at L4 and reducing C95 to 50 pf the coverage should be quite good with a 10k 10 turn pot. Will save that for another day .?
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DuWayne Schmidlkofer
For a couple projects I am working on I have been trying a small STM32 board? I found on e-bay and other locations.? It is commonly known as the blue pill. http://www.ebay.com/itm/STM32F103C8T6-ARM-STM32-Minimum-System-Development-Board-Module-For-Arduino-D-/112035273840?hash=item1a15d29c70:g:CioAAOSwMNxXaqSp Same width as a Nano and a just a little longer.?? STM 32 processor running at 72 MHz., 20kb ram? 65kb or 128 kb program memory.? Available for under $4 from several sellers.? The sample sketches I have tried seem to work well.? In the process of trying a QVGA TFT display with it. DuWayne KV4QB |
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Jack Purdum
DuWayne: Does this use the Arduino IDE for code development, including the libraries? Also, it seems to have a micro B USB connector, which I assume supplies the voltage for the unit. When powered without the USB, does it take 5V or 3.3V on input? Jack, W8TEE From: DuWayne Schmidlkofer <duwaynes@...> To: [email protected] Sent: Saturday, January 14, 2017 5:42 PM Subject: Re: [BITX20] Idea for future versions of BITX For a couple projects I am working on I have been trying a small STM32 board? I found on e-bay and other locations.? It is commonly known as the blue pill. http://www.ebay.com/itm/STM32F103C8T6-ARM-STM32-Minimum-System-Development-Board-Module-For-Arduino-D-/112035273840?hash=item1a15d29c70:g:CioAAOSwMNxXaqSp Same width as a Nano and a just a little longer.?? STM 32 processor running at 72 MHz., 20kb ram? 65kb or 128 kb program memory.? Available for under $4 from several sellers.? The sample sketches I have tried seem to work well.? In the process of trying a QVGA TFT display with it. DuWayne KV4QB |
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Yes the stm32 board can use the Arduino, and the libraries I tried seem to work as expected. There are several other libraries that I am in the process of trying out. It can be powered through the micro USB port, or there is a vin pin on the board. I have only programmed using a USB to serial adapter or STLink. Next thing I need to try is loading a Arduino compatible boot loader for the USB port. Do not know how much time I will spend on it for now, have a project I want to finish first. For that I am going to use a Teensy 3.2
DuWayne -- DuWayne? KV4QB |
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DuWayne, thanks for the heads up on this one. it looks like one could put the regular linux kernal on this. - f On Wed, Jan 18, 2017 at 7:12 AM, DuWayne Schmidlkofer <duwayne@...> wrote: Yes the stm32 board can use the Arduino, and the libraries I tried seem to work as expected.? There are several other libraries that I am in the process of trying out.? It can be powered through the micro USB port, or there is a vin pin on the board.? I have only programmed using a USB to serial adapter or STLink. Next thing I need to try is loading a Arduino compatible boot loader for the USB port.? Do not know how much time I will spend on it for now, have a project I want to finish first. For that I am going to use a Teensy 3.2 |
DuWayne Schmidlkofer
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