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I've recently built a SDR kits VFO (3.5 to 160 MHz) .. It's working fine, But when I connect it to my BITX-40 the LSB is flipped to USB .. I've put the IF as 12.0 MHz and the VFO range is 4.8 -5 MHz .. To cover 7.0 -7.200 ... Any ideas why it flips the Sideband ?
Regards Mark
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Mark,
You need to set the IF to 11998000 because you subtract the BFO frequency from the IF. Joel? KB6QVI
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On Feb 7, 2017, at 5:46 AM, Marc Jones via Groups.Io < gw0wvl@...> wrote: I've recently built a SDR kits VFO (3.5 to 160 MHz) .. It's working fine, But when I connect it to my BITX-40 the LSB is flipped to USB .. I've put the IF as 12.0 MHz and the VFO range is 4.8 -5 MHz .. To cover 7.0 -7.200 ... Any ideas why it flips the Sideband ?
Regards Mark
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What worked for me is 1.99985
At 07/02/2017, you wrote:
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Show quoted text
Mark,
You need to set the IF to 11998000 because you subtract the BFO frequency
from the IF.
Joel
KB6QVI
On Feb 7, 2017, at 5:46 AM, Marc Jones via Groups.Io
<
gw0wvl@...> wrote:
I've
recently built a SDR kits VFO (3.5 to 160 MHz) .. It's working fine, But
when I connect it to my BITX-40 the LSB is flipped to USB .. I've put the
IF as 12.0 MHz and the VFO range is 4.8 -5 MHz .. To cover 7.0 -7.200 ...
Any ideas why it flips the Sideband ?
Regards Mark
|
Oops it was 11.998500
At 07/02/2017, you wrote:
toggle quoted message
Show quoted text
What worked for me is 1.99985
At 07/02/2017, you wrote:
Mark,
You need to set the IF to 11998000 because you subtract the BFO frequency
from the IF.
Joel
KB6QVI
On Feb 7, 2017, at 5:46 AM, Marc Jones via Groups.Io
<
gw0wvl@...> wrote:
I've
recently built a SDR kits VFO (3.5 to 160 MHz) .. It's working fine, But
when I connect it to my BITX-40 the LSB is flipped to USB .. I've put the
IF as 12.0 MHz and the VFO range is 4.8 -5 MHz .. To cover 7.0 -7.200 ...
Any ideas why it flips the Sideband ?
Regards Mark
|
Raj,
Everybody's is different, 11998000 is just a starting point recommended by Farhan. Joel? KB6QVI
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Show quoted text
On Feb 7, 2017, at 6:12 AM, Raj vu2zap < vu2zap@...> wrote:
Oops it was 11.998500
At 07/02/2017, you wrote:
What worked for me is 1.99985
At 07/02/2017, you wrote:
Mark,
You need to set the IF to 11998000 because you subtract the BFO frequency
from the IF.
Joel
KB6QVI
On Feb 7, 2017, at 5:46 AM, Marc Jones via Groups.Io
<
gw0wvl@...> wrote:
I've
recently built a SDR kits VFO (3.5 to 160 MHz) .. It's working fine, But
when I connect it to my BITX-40 the LSB is flipped to USB .. I've put the
IF as 12.0 MHz and the VFO range is 4.8 -5 MHz .. To cover 7.0 -7.200 ...
Any ideas why it flips the Sideband ?
Regards Mark
|
Interesting. Any ideas on how to integrate this in with the Raduino so we can operate USB to do data modes?
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You can make a dual bander 40 M and 20 M easily by changing the Band pass filter and the LPF. If no significant harmonics then without LPF it is an easy task.
On Tue, Feb 7, 2017 at 8:13 PM, <KD2BBW@...> wrote: Interesting. Any ideas on how to integrate this in with the Raduino so we can operate USB to do data modes?
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Build an off board dual band BPF. For 40m use same values. For 20m I use different values for the components.
73
Ken VA3ABN
On Tue, Feb 7, 2017 at 9:46 AM, Satish Chandorkar <satish.vu2snk1@...> wrote: You can make a dual bander 40 M and 20 M easily by changing the Band pass filter and the LPF. If no significant harmonics then without LPF it is an easy task.
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Without the code to hand to look at I believe the bfo is set low side, you could invert and use high side. You then need to add switching.? Not difficult but a revamp.
--
Rob G4NQX
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Hi Joel, I've tried all sorts of different frequencies in the IF fir the SDR VFO, If I take ?the frequency just below 12 MHz all that happens is that ?Transmit /Receive frequency is off by a few KHz .. Etc... So the display on the SDR kits VFO might show 7.100 but I'm actually on 7.098 .. But still on USB . and visa versa ..but all the time it USB..
On Tue, 7 Feb 2017 at 14:12, Raj vu2zap <vu2zap@...> wrote:
Oops it was 11.998500
At 07/02/2017, you wrote:
What worked for me is 1.99985
At 07/02/2017, you wrote:
Mark,
You need to set the IF to 11998000 because you subtract the BFO frequency
from the IF.
Joel
KB6QVI
On Feb 7, 2017, at 5:46 AM, Marc Jones via Groups.Io
<
gw0wvl@...> wrote:
I've
recently built a SDR kits VFO (3.5 to 160 MHz) .. It's working fine, But
when I connect it to my BITX-40 the LSB is flipped to USB .. I've put the
IF as 12.0 MHz and the VFO range is 4.8 -5 MHz .. To cover 7.0 -7.200 ...
Any ideas why it flips the Sideband ?
Regards Mark
|
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.
- f
On Wed, Feb 8, 2017 at 7:13 PM, Marc Jones via Groups.Io <gw0wvl@...> wrote: Hi Joel, I've tried all sorts of different frequencies in the IF fir the SDR VFO, If I take ?the frequency just below 12 MHz all that happens is that ?Transmit /Receive frequency is off by a few KHz .. Etc... So the display on the SDR kits VFO might show 7.100 but I'm actually on 7.098 .. But still on USB . and visa versa ..but all the time it USB..
Marc Gw0wvl
On Tue, 7 Feb 2017 at 14:12, Raj vu2zap
Oops it was 11.998500
At 07/02/2017, you wrote:
What worked for me is 1.99985
At 07/02/2017, you wrote:
Mark,
You need to set the IF to 11998000 because you subtract the BFO frequency
from the IF.
Joel
KB6QVI
On Feb 7, 2017, at 5:46 AM, Marc Jones via Groups.Io
<
gw0wvl@...> wrote:
I've
recently built a SDR kits VFO (3.5 to 160 MHz) .. It's working fine, But
when I connect it to my BITX-40 the LSB is flipped to USB .. I've put the
IF as 12.0 MHz and the VFO range is 4.8 -5 MHz .. To cover 7.0 -7.200 ...
Any ideas why it flips the Sideband ?
Regards Mark
|
Thankyou, I shall try 26 MHz when I get chance ....
Much appreciated .
On Wed, 8 Feb 2017 at 14:14, Ashhar Farhan <farhanbox@...> wrote: 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.
- f
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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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Yes, a 19mhz vfo will move a Bitx40 from LSB to USB. ?And your simplest solution, assuming you can easily set that VFO to 26mhz. ?Should just work. Another way is to drive the BFO from a spare Si5351 channel so you can move the carrier down few khz to where the filter lets through the upper sideband, leave the VFO where it's at. ?A somewhat more intuitive approach, and allows the BFO to be centered in the crystal filter passband for debug or CW. ?Requires a change to the Raduino code, and a wire from the Si5351 into the BFO, but I think eventually this is the best way forward. Jerry
On Wed, Feb 8, 2017 at 09:41 am, Lawrence Macionski wrote: setting the VFO frequency to 19Mhz? (19-12=7) will invert- (USB) for 7Mhz? ?
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Should read: ? ?assuming you can easily set that VFO to 19mhz.
On Wed, Feb 8, 2017 at 10:12 am, Jerry Gaffke wrote:
assuming you can easily set that VFO to 26mhz. ?
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Offset set to 26.000 MHz results in a dead BITX-40... No RX, No TX ... I'm really not getting anywhere with this SDR kits VFO.. I've tried Putting in numerous frequencies for the IF , ?None result in ?a 7 MHz Frequency that is on LSB .?
On Wed, 8 Feb 2017 at 17:41, Lawrence Macionski via Groups.Io <am_fm_radio@...> wrote: 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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I've tried using a 19.0 MHz IF from the SDR kits VFO I have, It results in a Dead BITX-40 .. No RX no TX .
On Wed, 8 Feb 2017 at 17:41, Lawrence Macionski via Groups.Io <am_fm_radio@...> wrote: 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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That's not a 26mhz "offset". ? You want zero offset, set the VFO for 26 mhz going out. I have no idea if your VFO can emit 26mhz. If that fails, you could return the VFO to 5mhz as it was, and add a variable cap at C103 to bring down the frequency by 3khz or so. ?Not sure how much capacitance would be required, I assume well under 100pf. ?
On Wed, Feb 8, 2017 at 10:14 am, Marc Jones wrote:
Offset set to 26.000 MHz results in a dead BITX-40. ?
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USB is already in the Raduino software, just not implemented.
--
Rob G4NQX
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Do you have a scope? The signal at T2 should be around 1.6 volts peak to peak. I found that at the higher frequencies, C91 and C92 were attenuating the signal from the SI5351.
This occurred when setting up for 20m with 26 MHZ - 11.99860 MHZ.
73
Ken VA3ABN
On Wed, Feb 8, 2017 at 1:29 PM, Marc Jones via Groups.Io <gw0wvl@...> wrote: I've tried using a 19.0 MHz IF from the SDR kits VFO I have, It results in a Dead BITX-40 .. No RX no TX . On Wed, 8 Feb 2017 at 17:41, Lawrence Macionski via Groups.Io 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 Jones
Joel Caulkins/N6ALT
Raj vu2zap
Satish Chandorkar