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- RaspberryPi-4-HamRadio
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Re: New file uploaded to Raspberry_Pi_4-Ham_RADIO
Thomas Noel
¿ªÔÆÌåÓýGood source for LPF for RaspberryPi transmitter is ? ?Click on ¡°Place Order¡± and go down to item 12,? This design has the needed low insertion loss to keep the Pi power output usable. You need to buy a filter for each band you intend to use, but at $8 US can¡¯t complain too much. Very easy kit to complete. You will need to add connectors to Pi and antenna Tom kf7rsf |
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Re: New file uploaded to Raspberry_Pi_4-Ham_RADIO
Do you have a schematic for a more minimalist (less parts) bpf or lpf only? Whats the power output unamplified when you just hang a wire off gpio output? Is the amp somewhat required after a filter to retain any reasonable power?
I am placing my order for the newest pi b+ today.
Are the H variables in the chart set in software? Im on a phone hard to see the whole pdf I havent taken a good look at it yet.
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Re: legal use
Low-pass filter and WSPR information for PiFM:
? ---In Raspberry_Pi_4-Ham_RADIO@..., <km4efp@...> wrote : What needs to be done to a stock pi with this program(nbfm) to be legally used on the ham bands?Including additional narrowband configuration or low pass filters?I want to build a fox hunt transmitter. Maybe wspr |
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Re: New file uploaded to Raspberry_Pi_4-Ham_RADIO [1 Attachment]
Have you considered making a PCB of this circuit that would attach directly on top of the Raspberry Pi? You would have to decide on the model B or B+ as the layout is a little different. Any idea as to the cost of the parts to build this, minus the PCB? Max KG4PID From: "fotografale@... [Raspberry_Pi_4-Ham_RADIO]"
To: Raspberry_Pi_4-Ham_RADIO@... Sent: Friday, September 19, 2014 5:26 AM Subject: [Raspberry_Pi_4-Ham_RADIO] Re: New file uploaded to Raspberry_Pi_4-Ham_RADIO [1 Attachment]
?
Hi,
it is essential to add a low bass (or band pass) filter to reduce the harmonics. The raspberry output contains high odd harmonics, up to many hundreds of MHz. You can search the web for online filters calculators, schemes, examples etc. I've developed my own circuit (attached here) that is not only a filter but also an amplifier. The active component is a MMIC RF 50 Ohm in-out amplifier, able to deliver about 300mW; it's the ECG003 by WJ. The filter has the proper response to achieve a flat output from about 80 to 160 MHz, considering the Raspy output level and the presence of the ECG003 amplifier, and attenuates the harmonics over 160 MHz. I've checked that my prototype delivers about 300mW at 145MHz and the higher of the harmonics is -50dBc. Concerning the spurious (problem that appears only over the 6m band, and negligible at lower frequencies) the only thing you can do is to use a high sample rate setting: for example 44 or 88kHz. Please consider the downside that it degrades the modulation quality (due to lowering the frequency resolution), so the sampling rate must be chosen for the best compromise. How narrow or wide the modulation is depends on the deviation factor you can set by the command line parameter in NBFM. I usually set a deviation of 4kHz, that is good for ham radio use, but the final deviation depends also on the amplitude of the audio file. If you can apply a compression and a clipping to the audio file maybe you could achieve the best results. Best 73s! Ale IK1PLD |
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Re: New file uploaded to Raspberry_Pi_4-Ham_RADIO
Hi,
it is essential to add a low bass (or band pass) filter to reduce the harmonics. The raspberry output contains high odd harmonics, up to many hundreds of MHz. You can search the web for online filters calculators, schemes, examples etc. I've developed my own circuit (attached here) that is not only a filter but also an amplifier. The active component is a MMIC RF 50 Ohm in-out amplifier, able to deliver about 300mW; it's the ECG003 by WJ. The filter has the proper response to achieve a flat output from about 80 to 160 MHz, considering the Raspy output level and the presence of the ECG003 amplifier, and attenuates the harmonics over 160 MHz. I've checked that my prototype delivers about 300mW at 145MHz and the higher of the harmonics is -50dBc. Concerning the spurious (problem that appears only over the 6m band, and negligible at lower frequencies) the only thing you can do is to use a high sample rate setting: for example 44 or 88kHz. Please consider the downside that it degrades the modulation quality (due to lowering the frequency resolution), so the sampling rate must be chosen for the best compromise. How narrow or wide the modulation is depends on the deviation factor you can set by the command line parameter in NBFM. I usually set a deviation of 4kHz, that is good for ham radio use, but the final deviation depends also on the amplitude of the audio file. If you can apply a compression and a clipping to the audio file maybe you could achieve the best results. Best 73s! Ale IK1PLD |
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Re: New file uploaded to Raspberry_Pi_4-Ham_RADIO
I want to make a fox hunt transmitter on 2m vhf band. Does the current software require a low pass filter to reduce harmonics? Can you show me what you guys use as a low pass filter or antenna setups. And does this software conform to HAM narrowband standard out of the box? Basically I need to know what extra configuration or hardware will be required to legally use this program in the ham bands.
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Re: HELP!!!!! ax25 setup issues
Jay Land
Thanks for the direction. I have emailed him more times than? I can count and he has been outstanding with help. I am to the point in trouble shooting that I believe it is the PIC on the TNC. A new PIC should be here next week and I will be back at it. I did get Tue ax25 working thanks to Charles. Jay On Sep 14, 2014 8:18 AM, "iz5fsa@... [Raspberry_Pi_4-Ham_RADIO]" <Raspberry_Pi_4-Ham_RADIO@...> wrote:
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Re: Question of telnet
David Hamill
"Lambert Timmermans" k6run wrote:
There is no reason to have to torture yourself with command line FTP. Filezilla works fine for FTP with most Linux systems. I didn't know it handles the SFTP protocol, which RPi is set up to use; you learn something new each day! The program I currently use to transfer files between Windows and RPi is WinSCP: In place of telnet, it's advisable to use PuTTY: Both are free open-source applications. David |
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Re: Question of telnet
If you want to be really flash, check out this how-to:
? ---In Raspberry_Pi_4-Ham_RADIO@..., <aj26scm@...> wrote : Hello, All; ?Im currently working on a bbs project on one of my pi's. Once I get it running and figures it out I want to try hooking into my broadband hamnet routers I have set-up. |
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Re: Question of telnet
First things first - what version of linux are you using.
If Raspbian, take a look at the tutorials at (for example) ? or
? ---In Raspberry_Pi_4-Ham_RADIO@..., <k6acj@...> wrote : I have not used telnet or FTP for a long time and would like to use it to transfer files from the Pi to Windows XP, would anyone be willing to write a few command lines here for getting or putting files from WinXP to the Pi, many thanks. |
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Re: Question of telnet
¿ªÔÆÌåÓýsshd is on by default, simply use winscp or putty from windows. google search and download for windows.?-------- Original message -------- From: "k2dms@... [Raspberry_Pi_4-Ham_RADIO]" Date:09/07/2014 12:11 PM (GMT-08:00) To: Raspberry_Pi_4-Ham_RADIO@... Subject: [Raspberry_Pi_4-Ham_RADIO] Re: Question of telnet There is no reason to have to torture yourself with command line FTP. Google "filezilla client download", download it, install it, run it. Then click on menu... File->Site Manager... "New Site" Enter the IP address or hostname of your Pi Protocol SFTP LogonType Normal User pi Password (the password) Click Connect The left side is your PC's filesystem, the right side is the pi's. Double click on any file to transfer it to the other side. And remember, "right click" is your friend. |
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Re: Question of telnet
There is no reason to have to torture yourself with command line FTP.
Google "filezilla client download", download it, install it, run it. Then click on menu... File->Site Manager... "New Site" Enter the IP address or hostname of your Pi Protocol SFTP LogonType Normal User pi Password (the password) Click Connect The left side is your PC's filesystem, the right side is the pi's. Double click on any file to transfer it to the other side. And remember, "right click" is your friend. |
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