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You can only go Positive with the SDR kits VFO...
On Thu, 9 Feb 2017 at 6:30, marjannorm@... <marjannorm@...> wrote: Hi, when you put in the IF frequency, you did remember the negative off-set didn't you? kind regards Norm vk5gi McLaren Vale South Australia
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Hi Fred, I would very much like the Sketch ?for the BITX-40 ... I would then try having a play around with it, Although my programming is very rusty for sure ...
Regards
On Thu, 9 Feb 2017 at 1:06, Dr Fred Hambrecht <AAR4MI@...> wrote: The formula for upper and lower sideband is explained in the sketch. Simply uncommenting a few lines and adding the Fbutton will allow you to switch between U/L SSB. I am setting mine up this way to allow USB for use on MARS. Mars uses USB regardless of frequency. I am also encoding split mode. This has been a total blast and a learning experience playing with this BITX40. ? v/r Fred W4JLE ? From: [email protected] [mailto:[email protected]] On Behalf Of Lawrence Macionski via Groups.Io
Sent: Wednesday, February 08, 2017 12:41
To: [email protected]
Subject: Re: [BITX20] SDR kits VFO ? QUOTE- "If you set the VFO frequency to 26 MHz, the sideband is automatically inverted. You will not need to move the BFO from LSB to USB for 14 MHz". Then if that is true then setting the VFO frequency to 19Mhz? (19-12=7) will invert- (USB) for 7Mhz? Then enabling Digital modes?? Something the Raduino could do? Advise.... de W8LM -KANSAS
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Marc, Look in the Files section, possibly second page, for "BitX40 sketch using new si5351 library v2 "? The sketch and library are in there.? It's the Raduino sketch with two words changed to suit the new v2 library.
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Rob G4NQX
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Thanks Rib, Ile fire up the PC when home and have a Decent look .... The smart phone is OK but limited ...?
Regards?
On Thu, 9 Feb 2017 at 10:01, G4NQX <tasmod@...> wrote: Marc, Look in the Files section, possibly second page, for "BitX40 sketch using new si5351 library v2 "? The sketch and library are in there.? It's the Raduino sketch with two words changed to suit the new v2 library.
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Rob G4NQX
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Thanks Rob, Ile have a decent look later , Fire up the PC , Only so much I can do with the smart phone ..
Regards
On Thu, 9 Feb 2017 at 10:01, G4NQX <tasmod@...> wrote: Marc, Look in the Files section, possibly second page, for "BitX40 sketch using new si5351 library v2 "? The sketch and library are in there.? It's the Raduino sketch with two words changed to suit the new v2 library.
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Rob G4NQX
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Hello all, A friend of mine has SDR Kits DDS VFO + working Bitx40, and I asked him about solution. He confirmed what?Jerry, KE7ER said: add 20-30pF cap and and also maybe to rewind L5 coil. You need to "pull down" freq by 3 kHz, and you will be able to hear LSB. No other settings on DDS is needed. Regards,
Dragan, 4O4A
Bitx40 with Raduino
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You can download a copy from . It is well commented to aid in understanding the program. The software to compile it and upload to the VFO is available is free as well. Like you I just started with mine a few weeks ago and in addition to the BITX40 I bought a kit off of Amazon that comes with a number of sensors and programming examples that will be a learning experience in itself. ?The description is not in agreement with the programming and you will have to make pen and ink corrections to the sketch description. Randy, K7AGE has posted a pinout diagram that is correct and is in the groups history. ? In addition to fooling around with the BITX I am playing with designing a digital artificial horizon using a 2.8¡± TFT display for use on an experimental aircraft. ? The programming takes me back to my NASA days when we were trying to land on the moon with a computer with less power than the Arduino. ?Unlike today, we had to shoehorn everything into 4K. While the stack is limited even with all my changes I still have 40% left. ?I promise your head will swim with all the projects you realize you can do with the Arduino. ? V/R Fred W4JLE ? ? ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Marc Jones via Groups.Io
Sent: Thursday, February 09, 2017 02:40
To: [email protected]
Subject: Re: [BITX20] SDR kits VFO ? Hi Fred, I would very much like the Sketch ?for the BITX-40 ... I would then try having a play around with it, Although my programming is very rusty for sure ... Marc 'Gw0wvl' .. ? On Thu, 9 Feb 2017 at 1:06, Dr Fred Hambrecht The formula for upper and lower sideband is explained in the sketch. Simply uncommenting a few lines and adding the Fbutton will allow you to switch between U/L SSB. I am setting mine up this way to allow USB for use on MARS. Mars uses USB regardless of frequency. I am also encoding split mode. This has been a total blast and a learning experience playing with this BITX40. ? v/r Fred W4JLE ? From: [email protected] [mailto:[email protected]] On Behalf Of Lawrence Macionski via Groups.Io
Sent: Wednesday, February 08, 2017 12:41
To: [email protected]
Subject: Re: [BITX20] SDR kits VFO ? QUOTE- "If you set the VFO frequency to 26 MHz, the sideband is automatically inverted. You will not need to move the BFO from LSB to USB for 14 MHz". Then if that is true then setting the VFO frequency to 19Mhz? (19-12=7) will invert- (USB) for 7Mhz? Then enabling Digital modes?? Something the Raduino could do? Advise.... de W8LM -KANSAS
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Fred:
I, too, am playing around with a TFT display and have posted a picture of it. (It's changed a bit since then.) It's for a 2.4" mcufriend.com display and I've just changed the code so it auto-sizes for displays between 2.4"-3.95". The bad news is that the Nano does not have the stack/heap space needed for the code+library, so I am using a Mega 2560 Pro Mini. It has a footprint that is about half the size of a regular Mega. If you'd like to see the software, contact me off list using the QRZ dot com email.
Jack, W8TEE
From: Dr Fred Hambrecht <AAR4MI@...>
To: [email protected]
Sent: Thursday, February 9, 2017 10:50 AM
Subject: Re: [BITX20] SDR kits VFO
You can download a copy from . It is well commented to aid in understanding the program. The software to compile it and upload to the VFO is available is free as well. Like you I just started with mine a few weeks ago and in addition to the BITX40 I bought a kit off of Amazon that comes with a number of sensors and programming examples that will be a learning experience in itself. ?The description is not in agreement with the programming and you will have to make pen and ink corrections to the sketch description. Randy, K7AGE has posted a pinout diagram that is correct and is in the groups history. ? In addition to fooling around with the BITX I am playing with designing a digital artificial horizon using a 2.8¡± TFT display for use on an experimental aircraft. ? The programming takes me back to my NASA days when we were trying to land on the moon with a computer with less power than the Arduino. ?Unlike today, we had to shoehorn everything into 4K. While the stack is limited even with all my changes I still have 40% left. ?I promise your head will swim with all the projects you realize you can do with the Arduino. ? V/R Fred W4JLE ? ? ? ? Hi Fred, I would very much like the Sketch ?for the BITX-40 ... I would then try having a play around with it, Although my programming is very rusty for sure ... Marc 'Gw0wvl' .. ? On Thu, 9 Feb 2017 at 1:06, Dr Fred Hambrecht The formula for upper and lower sideband is explained in the sketch. Simply uncommenting a few lines and adding the Fbutton will allow you to switch between U/L SSB. I am setting mine up this way to allow USB for use on MARS. Mars uses USB regardless of frequency. I am also encoding split mode. This has been a total blast and a learning experience playing with this BITX40. ? v/r Fred W4JLE ? ? QUOTE- "If you set the VFO frequency to 26 MHz, the sideband is automatically inverted. You will not need to move the BFO from LSB to USB for 14 MHz". Then if that is true then setting the VFO frequency to 19Mhz? (19-12=7) will invert- (USB) for 7Mhz? Then enabling Digital modes?? Something the Raduino could do? Advise.... de W8LM -KANSAS
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Before hijacking this thread: ever looked at a Nextion display. Lot's of logic/drawings can be put in there, only need to send/receive values from the Arduino, minimal overhead.
And using the processor capacity of the lcd more and the arduino less. Only react on input, and it is touchscreen also so less buttons needed on the arduino/bitx40 side.
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I may have screwed up. ?Looks like it needs to go up 3khz, not down as I previously claimed. Sounds like the SDR Kits VFO assumes the VFO is always on the high side of the IF. ?So the signal from the SDR Kits VFO is 12+7=19mhz, where the Raduio is at 12-7=5mhz. ?In the 19mhz case, a rise in VFO frequency causes a rise in operating frequency: ?19.2-12=7.2mhz. ?In the 5mhz case, a rise in VFO frequency causes a fall in operating frequency: 12-5.2=6.8mhz. ?That's what Norm meant by "negative offset". ?Perhaps the SDR Kits VFO doesn't know about negative offsets and so is stuck with using a 19mhz on the Bitx0, in which case shifting the BFO frequency a few khz with a soldering iron is the best bet. ?
This paragraph is for those who really want to bottom out on the reasoning here: ?There's 4 variables: ?The operating freq (7mhz), the IF crystal filter passband center (lets assume it's 12.000mhz), the BFO freq (assume 11.998mhz), and the VFO freq (assume near 19 mhz, that's easier to think about than the 5mhz case). ?The IF crystal filter would be pretty hard to move, I doubt that's happening. ?That diode ring mixer up front combines the 7mhz received signal (where 7mhz is the freq of the carrier, if it had one) with 18.998mhz from the vfo, and gives the crystal filter a shifted down replica of the incoming SSB signal, the suppressed carrier of which is at 11.998mhz, exactly where the BFO is. ?The upper sideband of this 11.998mhz SSB signal is a little bit up in freq from the suppressed carrier, so the 2khz wide crystal filter only allows through the upper sideband. ?If we whack at the BFO to move it to 12.002mhz, and adjust the VFO up a bit to put the suppressed carrier of the SSB signal into the filter at 12.002mhz also, we will get the lower sideband coming through the filter. ?When we use the 5mhz VFO from the Raduino, the received signal presented to the crystal filter is mirrored through the magic of that negative offset mentioned above, the highest frequency components of the incoming 7mhz signal are down in the 12mhz copy, the lowest frequency components are up in the 12mhz copy. ?So the upper and lower sidebands get swapped when we use a 5mhz VFO to receive 7mhz. ? > ?Dr Fred Hambrecht: ? Feb 8???#21771 ?The formula for upper and lower sideband is explained in the sketch. Simply uncommenting a few lines and adding the Fbutton will allow you to switch between U/L SSB.?I have not looked at the sketch. ?But that Raduino code has no way to change the BFO frequency from 11.998mhz to 12.002mhz (unless we do a hardware mod to the board to use a spare Si5351 channel to drive the BFO instead of the 12mhz crystal oscillator). ?So the only way Raduino code could possibly flip to the other sideband is by moving the Si5351 VFO from 5mhz to 19mhz. ?That code is not going to do anything when using the SDR Kits VFO.
Getting back to Marc, he said: ?"Jerry I can confirm the VFO ?output is ?at 4.8 to 5 MHz" I can't imagine any way to flip sidebands other than to move either the BFO or the VFO (but moving both will get you back to where you started). ?Ok, could be one of those two possibilities, or demonic possession. ?Or me not quite having this figured out. ?He apparently didn't mess with the BFO. ?So my best guess remains that his SDR Kits VFO was sending out 19mhz. ?Probably not worth forcing the SDR Kits VFO to give a 5mhz signal if it doesn't know about negative offsets, because as the displayed VFO frequency rises, the frequency of the received 7mhz signal will be falling. ?Not very convenient. Jerry,, KE7ER
On Thu, Feb 9, 2017 at 06:54 am, Dragan Djordjevic 4O4A wrote:
A friend of mine has SDR Kits DDS VFO + working Bitx40, and I asked him about solution. He confirmed what?Jerry, KE7ER said: add 20-30pF cap and and also maybe to rewind L5 coil. You need to "pull down" freq by 3 kHz, and you will be able to hear LSB. No other settings on DDS is needed.
?
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In my sketch:
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bfo-(vfo * SI5351_FREQ_MULT)
vfo is what you see on the display, the multiplier is there for getting it ready for the SI5351 library to understand it to be unsigned long value.
Bfo has the values:
LSB = 1199850000ULL;
USB = 1200150000ULL;
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Your SDR kit has to generate the bfo value nothing more and you enter it on the BITX40 at the place of L4 (which has to be removed).
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SI5351 library also has a correction sketch which you could run. A good frequency counter is needed.
This correction value (function) is then run 1x (in your sketch).
?
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This setup also removed the USB/CW band reversal.
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Hope this helps (if I understood your problem correctly)
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Ron ¨C PA3FAT
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So the BFO has a fixed value of 11.9985 or 12..0015mhz, it is up to the user to whack at L5 and C103 to set the appropriate frequency. Your BFO values work if using the Raduino with a VFO output freq of 5mhz. ?They get swapped if the VFO is at 19mhz.. I believe the SDR Kits VFO doesn't know about "negative offset", so the best way to receive a 7mhz signal is to have it emit a 19mhz VFO signal. > ?vfo is what you see on the display,? I assume the display is showing 7mhz. ?And that the Raduino VFO is actually sending out 5mhz. ?If you are talking about the SDR Kits VFO and some sketch for that beast, I have no idea what it is displaying. > Your SDR kit has to generate the bfo value nothing more and you enter it on the BITX40 at the place of L4 (which has to be removed).
Your SDR kit is generating the VFO, ?not the BFO. ?The BFO is set by L5 and C103. ? But yes, the SDR kit is doing nothing more than injecting a 19mhz VFO signal into the DD connector near L4. ? I think.
Jerry
On Thu, Feb 9, 2017 at 09:09 am, ron van doremalen wrote: bfo-(vfo * SI5351_FREQ_MULT)
vfo is what you see on the display, the multiplier is there for getting it ready for the SI5351 library to understand it to be unsigned long value.
Bfo has the values:
LSB = 1199850000ULL;
USB = 1200150000ULL;
?
Your SDR kit has to generate the bfo value nothing more and you enter it on the BITX40 at the place of L4 (which has to be removed).
?
?
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Jerry,
Sorry can't follow you. What are you aiming at with a VFO of 19Mhz.
The Bitx had a 4.8-5.0 vco in the beginning.
An IF of 12Mhz
And receiving intention between 7.0-7.2 (with DDS not that limited)
The only thing you need to inject in the BITX40 is thus a 4.8-5.0 signal. L4 removed and nothing more has to change to rx/tx.
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There are two ways to get 7.0 - 7.2 MHZ(This RF).
BFO is fixed at 11.998600 MHZ(approx).
BFO - RF = 11.998600 - 7.0 - ?= 4.9986 to 4.7986?
or
BFO + RF = 11.998600 + 7.0 = 18.998600 to 19.198600
73
Ken VA3ABN
On Thu, Feb 9, 2017 at 1:55 PM, ron van doremalen <ronvandoremalen@...> wrote: Jerry,
Sorry can't follow you. What are you aiming at with a VFO of 19Mhz.
The Bitx had a 4.8-5.0 vco in the beginning.
An IF of 12Mhz
And receiving intention between 7.0-7.2 (with DDS not that limited)
The only thing you need to inject in the BITX40 is thus a 4.8-5.0 signal. L4 removed and nothing more has to change to rx/tx.
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All
Someone should ask SDR Kits to modify their firmware to allow the negative offset. The QRP Labs VFO kit didn't support negative IF offset either but when I learned of the people wanting to use it for the BITX40 I made the necessary firmware enhancement. I know SDR Kits owner very well, he's a good friend of mine - and I'm sure he would be helpful!
73 Hans G0UPL
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Hi Ken, I've tried it all and more with this SDR kits VFO, None of it works .
Regards?
On Thu, 9 Feb 2017 at 19:27, Ken <chase8043@...> wrote: There are two ways to get 7.0 - 7.2 MHZ(This RF).
BFO is fixed at 11.998600 MHZ(approx).
BFO - RF = 11.998600 - 7.0 - ?= 4.9986 to 4.7986?
or
BFO + RF = 11.998600 + 7.0 = 18.998600 to 19.198600
73
Ken VA3ABN
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You are correct, and the SDR Kits VFO can probably do this. ?I don't have one, but the SDR Kits VFO apparently doesn't know about negative offsets, so as you tune up from 7mhz, the SDR Kits display will show the frequency decreasing. ?That's fine if you are ok doing the subtraction in your head or on a hand calculator, but a bit inconvenient. Example: ? 7.000mhz ssb is mixed with 5.000mhz vfo to create 12mhz IF 7.200mhz ssb is mixed with 4.800mhz vfo to create 12mhz IF
For the receive frequency to go up from 7.000 to 7.200, the VFO must go down from 5.000 to 4.800. The SDR Kits VFO doesn't know how to subtract, so it will show a frequency that is decreasing. At least, nobody here has yet figured out how to make it subtract.
Jerry, KE7ER
On Thu, Feb 9, 2017 at 10:55 am, ron van doremalen wrote:
The only thing you need to inject in the BITX40 is thus a 4.8-5.0 signal. ?
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Dollar to a donut it involves little more than changing a variable from unsigned long to signed long.
Jack, W8TEE
From: Jerry Gaffke via Groups.Io <jgaffke@...>
To: [email protected]
Sent: Thursday, February 9, 2017 2:47 PM
Subject: Re: [BITX20] SDR kits VFO
You are correct, and the SDR Kits VFO can probably do this. ?I don't have one, but the SDR Kits VFO apparently doesn't know about negative offsets, so as you tune up from 7mhz, the SDR Kits display will show the frequency decreasing. ?That's fine if you are ok doing the subtraction in your head or on a hand calculator, but a bit inconvenient. Example: ? 7.000mhz ssb is mixed with 5.000mhz vfo to create 12mhz IF 7.200mhz ssb is mixed with 4.800mhz vfo to create 12mhz IF
For the receive frequency to go up from 7.000 to 7.200, the VFO must go down from 5.000 to 4.800. The SDR Kits VFO doesn't know how to subtract, so it will show a frequency that is decreasing. At least, nobody here has yet figured out how to make it subtract.
Jerry, KE7ER
On Thu, Feb 9, 2017 at 10:55 am, ron van doremalen wrote:
The only thing you need to inject in the BITX40 is thus a 4.8-5.0 signal. ?
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Do you have a scope?
If you do, set VFO to 5 MHZ. Scope the VFO signal at T2 with a x10 probe. You're going to need a signal around 1.4 v peak to peak.
73
Ken
On Thu, Feb 9, 2017 at 2:33 PM, Marc Jones via Groups.Io <gw0wvl@...> wrote: Hi Ken, I've tried it all and more with this SDR kits VFO, None of it works .
Regards?
Marc ?'Gw0wvl'... On Thu, 9 Feb 2017 at 19:27, Ken There are two ways to get 7.0 - 7.2 MHZ(This RF).
BFO is fixed at 11.998600 MHZ(approx).
BFO - RF = 11.998600 - 7.0 - ?= 4.9986 to 4.7986?
or
BFO + RF = 11.998600 + 7.0 = 18.998600 to 19.198600
73
Ken VA3ABN
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Are you using an offset in the SDR VFO?
73 Ken
On Thu, Feb 9, 2017 at 2:33 PM, Marc Jones via Groups.Io <gw0wvl@...> wrote: Hi Ken, I've tried it all and more with this SDR kits VFO, None of it works .
Regards?
Marc ?'Gw0wvl'... On Thu, 9 Feb 2017 at 19:27, Ken There are two ways to get 7.0 - 7.2 MHZ(This RF).
BFO is fixed at 11.998600 MHZ(approx).
BFO - RF = 11.998600 - 7.0 - ?= 4.9986 to 4.7986?
or
BFO + RF = 11.998600 + 7.0 = 18.998600 to 19.198600
73
Ken VA3ABN
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Marc Jones
Dragan 4O4A