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Looks like Ashhar is going to space...
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Re: K5BCQ uBITX Relay Switched LPF/BPF board
Hi Kees.
Do you care to elaborate as to what you think the problem is regarding insufficient isolation?
Thanks.
Nick
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2.8" Color TFT display with mouse control
#ubitx
OK, the TSW team now has our 2.8" color TFT screen operating fully with both a keyboard and a mouse for control. ?With the BITeensio card and this display you no longer have to touch the screen at all and the encoder/function button is only necessary for setting the keyer speed and sidetone frequency when you don't have a scroll wheel on your mouse. ?The software is in the source code sketches directory on the www.w0eb.com website's files section. ?In the picture, the little yellow dot right below the decimal point of the bottom frequency display is the mouse cursor. ?See the write up on the website for more information. ?There are several short videos on mouse operation on the website as well.
?
Jim - W0EB 
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I do have a buffer board but its in the FT-840. I added a 220 ohm resistor in series and I am no longer effecting the radio receive with the SDR connected, not hearing a difference plugged/unplugged. The waterfall is a little cleaner. The spikes or spurs are a bigger issue right? I usually see that on my other rigs if I do use gain in the SDR or a LNA, but gain is 0 on the SDR, is there some gain coming from where I tapped? ? I also get bad IMD, I hear radio stations in the background no matter where I tune and it gets worse from 40 and below. Ill be exploring that soon, the BCI filter should make for more improvement when I install it. I also removed the ? Joe ? 
? ? ? Sent from for Windows 10 ?
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From: iz oosSent: Tuesday, September 25, 2018 3:58 PM To: [email protected]Subject: Re: [BITX20] IF OUT ? I think Joe uses a buffer board which should be the best way to tap it. And alternative is using another 3904 (emitter-follower) . The gain in the RTL I have can be reduced by 42db via the software. ? Il 25/set/2018 21:32, "Joe Puma" <kd2nfc@...> ha scritto: Thank you Allison. That sounds like a good experiment, I¡¯ll give it a go.? ?
On Sep 25, 2018, at 12:58 PM, ajparent1/KB1GMX <kb1gmx@...> wrote:
Joe,
Keep in mind a RTL-SDR is not an insensitive receiver.? Its good enough on its own.
so putting the gain and mixers of the ubitx ahead of that means the noise floor is
increased by the effective gain or about 10-14db or so.? None of which helps hear
signals better as the IF amp it self has a noise figure of maybe 4-6DB.
So yes, much cruft.
To use it effectively as a panadaptor the SDR gain has to be turned down so the noise is
the baseline at or near the bottom of the spectrum display or a light background on the
waterfall.? Otherwise all you see is the noise and the signals will not stand out.
You likely need a buffer (or reduce loading) as well as tapping at that point is like putting
two load (resistors) in parallel and the receiver has less signal or effective gain.? The buffer
could be as simple as a series resistor from that point to the coax for the SDR.? Since the
SDR already sees too much cruft so lowering the signal (series resistor) will improve the
view and also lower the load on the IF to regain signal.? Values likely are in the range
of 50 to 500 ohms and try by substitution?may be easiest way.? Its a useful experiment
and so try a 470 ohm for a starting point (may be too high).
Allison
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I think Joe uses a buffer board which should be the best way to tap it. And alternative is using another 3904 (emitter-follower) . The gain in the RTL I have can be reduced by 42db via the software.
Il 25/set/2018 21:32, "Joe Puma" < kd2nfc@...> ha scritto: Thank you Allison. That sounds like a good experiment, I¡¯ll give it a go.?
Joe On Sep 25, 2018, at 12:58 PM, ajparent1/KB1GMX < kb1gmx@...> wrote: Joe,
Keep in mind a RTL-SDR is not an insensitive receiver.? Its good enough on its own.
so putting the gain and mixers of the ubitx ahead of that means the noise floor is
increased by the effective gain or about 10-14db or so.? None of which helps hear
signals better as the IF amp it self has a noise figure of maybe 4-6DB.
So yes, much cruft.
To use it effectively as a panadaptor the SDR gain has to be turned down so the noise is
the baseline at or near the bottom of the spectrum display or a light background on the
waterfall.? Otherwise all you see is the noise and the signals will not stand out.
You likely need a buffer (or reduce loading) as well as tapping at that point is like putting
two load (resistors) in parallel and the receiver has less signal or effective gain.? The buffer
could be as simple as a series resistor from that point to the coax for the SDR.? Since the
SDR already sees too much cruft so lowering the signal (series resistor) will improve the
view and also lower the load on the IF to regain signal.? Values likely are in the range
of 50 to 500 ohms and try by substitution?may be easiest way.? Its a useful experiment
and so try a 470 ohm for a starting point (may be too high).
Allison
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Thank you Allison. That sounds like a good experiment, I¡¯ll give it a go.?
Joe
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Show quoted text
On Sep 25, 2018, at 12:58 PM, ajparent1/KB1GMX < kb1gmx@...> wrote: Joe,
Keep in mind a RTL-SDR is not an insensitive receiver.? Its good enough on its own.
so putting the gain and mixers of the ubitx ahead of that means the noise floor is
increased by the effective gain or about 10-14db or so.? None of which helps hear
signals better as the IF amp it self has a noise figure of maybe 4-6DB.
So yes, much cruft.
To use it effectively as a panadaptor the SDR gain has to be turned down so the noise is
the baseline at or near the bottom of the spectrum display or a light background on the
waterfall.? Otherwise all you see is the noise and the signals will not stand out.
You likely need a buffer (or reduce loading) as well as tapping at that point is like putting
two load (resistors) in parallel and the receiver has less signal or effective gain.? The buffer
could be as simple as a series resistor from that point to the coax for the SDR.? Since the
SDR already sees too much cruft so lowering the signal (series resistor) will improve the
view and also lower the load on the IF to regain signal.? Values likely are in the range
of 50 to 500 ohms and try by substitution?may be easiest way.? Its a useful experiment
and so try a 470 ohm for a starting point (may be too high).
Allison
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Re: Faster tuning encoder
MPJA has them and not very expensive....?
see....? ?
That is a 100p/turn unit and works well for me in other applications.? At $16.95 its a consideration.
However! Warning, not all of the Arduino code bases out there will follow a 400 Pulse/turn
encoder unless interrupt driven.? ?I know this as I have a bunch of commercial and
industrial optical encoders that use that rate.? The listed 100p/t did work well with?
the later codes that respond well to the mechanical encoder.
Note those are much larger than the little fragile things.
Allison
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Re: K5BCQ uBITX Relay Switched LPF/BPF board
Kees,
That Rigol with tracking generator is the a really good tool.? Build up a return loss bridge for SWR
measurements out to the machines max 1.5ghz.? There are several good and easy designs on the
'net.? Likely you will end up making a bunch of "fixtures" for testing various things.
Another handy item are the Minicircuits and Qbit block amps for times when 0dbm is not enough
as well as a good Narda or Bird 30db power attenuator of the 50W or 100W sizes.
Sorta like bench power tools like mills and lathes, you get that then the other gadgets start to appear. ;)
Allison
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Joe,
Keep in mind a RTL-SDR is not an insensitive receiver.? Its good enough on its own.
so putting the gain and mixers of the ubitx ahead of that means the noise floor is
increased by the effective gain or about 10-14db or so.? None of which helps hear
signals better as the IF amp it self has a noise figure of maybe 4-6DB.
So yes, much cruft.
To use it effectively as a panadaptor the SDR gain has to be turned down so the noise is
the baseline at or near the bottom of the spectrum display or a light background on the
waterfall.? Otherwise all you see is the noise and the signals will not stand out.
You likely need a buffer (or reduce loading) as well as tapping at that point is like putting
two load (resistors) in parallel and the receiver has less signal or effective gain.? The buffer
could be as simple as a series resistor from that point to the coax for the SDR.? Since the
SDR already sees too much cruft so lowering the signal (series resistor) will improve the
view and also lower the load on the IF to regain signal.? Values likely are in the range
of 50 to 500 ohms and try by substitution?may be easiest way.? Its a useful experiment
and so try a 470 ohm for a starting point (may be too high).
Allison
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Thanks Iz, I like the waterfall for a visual representation, it helps me hunt for signals and get a sense of band conditions.? So what you described is taking the IQ and turning it into audio to get a visual representation. Fair enough. You guys are too smart for me, I¡¯ve been learning everyday since I¡¯ve been ¡°assembling¡± this uBitx.?
Joe
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On Sep 25, 2018, at 10:34 AM, iz oos < and2oosiz2@...> wrote: I don't see what might be the purpose of using an RTL dongle. It's 8bits ADC limits its dynamic range to a mere 48db or so. Otherwise tapping is a good idea. All the points you have identified might be good depending on the hardware between the uBitx and the PC. For instance if you would use just an opamp, an oscillator, a 7dbm passive mixer (no IQ, just to convert between 12 an 96khz depending on the soundcard) and an audio step up transformer the tap before the 12Mhz would perfectly make sense to me not only to have just a slightly bigger visual picture of the signals around but to use the PC as the main receiver.
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Re: K5BCQ uBITX Relay Switched LPF/BPF board
A little delay in shipping the 6x LPF board (if you have paid and want your money back, just send me a private email).
The problem is that the Port to Port (S12/S21) Isolation of the LPF board is too low. To be really effective, it needs to be in the 60-70dB range (or as high as you can get it) for a blank LPF board and for a populated LPF board. The existing LPF board is about 40-50dB. I have another pass coming from EasyEDA which should be better.?
Recently received my new Rigol 815SA-TG and it has been most helpful.
Sorry about the delay.
73 Kees K5BCQ
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Re: Faster tuning encoder
Thanks for the info Jack. ?I'm going to spend a few bucks and try them out.
Tom
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Re: I find This Shorted Circuit on Raduino, here the pics..plz Help?
#ubitx-help
Hi Fabien,
I watched your video, and it seemed to me that the only problem was that the SSB stations were not tuned in yet.? I would do this test:
1.? Set the BFO to 11.997.000
2.? Make sure your are in the correct mode for the band (LSB for 80m and 40m, USB for 20m and above)
3.? Set your tuning steps to 100 Hz
4.? Tune around to find a few good strong SSB signals and slowly try to tune one in so that the voices seem natural
5.? Don't worry about where your dial reads when the station voices sound natural -- not all operators have exact VFO display so the may operate on any fraction of a kHz (also your master calibration may not be done yet but that should only matter for your display, not for the rig's operation)
6.? Remember also, sometimes operators use the opposite sideband for some reason
Another test you can make it to set your rig on just band noise (no signal anywhere near).? Then record the signal on your computer.? The do a spectrogram of the recording and see where the "hump" appears.? It should appear between 300 Hz and 2700 Hz.? I can give you more details if you want to try this.? I think the Elecraft company also has a good description of how to do this in their manual for the K2, or just on their site.
73 and guten tag,
Mark.
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I don't see what might be the purpose of using an RTL dongle. It's 8bits ADC limits its dynamic range to a mere 48db or so. Otherwise tapping is a good idea. All the points you have identified might be good depending on the hardware between the uBitx and the PC. For instance if you would use just an opamp, an oscillator, a 7dbm passive mixer (no IQ, just to convert between 12 an 96khz depending on the soundcard) and an audio step up transformer the tap before the 12Mhz would perfectly make sense to me not only to have just a slightly bigger visual picture of the signals around but to use the PC as the main receiver.
Il 25/set/2018 04:07, "Joe Puma" < kd2nfc@...> ha scritto: I think I found a good tapping point. C215 before the filter and shield to ground. C216 seemed like there was a lot of noise, I don¡¯t think it was more signal, just more noise. C214 looked ok but had the classic dip in the center that I even see on my commercial rig when I tapped the IF. Noise floor was also higher then 215 is that what we call ¡°cruft¡±? ? Only thing is at c215 when my SDR is plugged in the audio and noise seems to drop a little. Cant say if it¡¯s a attenuated signal but there is a difference when the sdr is plugged in. maybe I need something to buffer the connection?? I use this on my FT-840 ? I do have the full signal now and bot the IMD is messy. I see now why I hear AM stations everywhere on 80 and 40. ? ? Connected to 210, check the dip to the left. ? 
? Connected to C215 ? 
? ? Wider View IMD = Yuck, ??BCI filter is Next! ? 
? Joe ? ? Sent from for Windows 10 ? ? When used in matched pairs, the dots should be together.
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Re: Amplifier chain design - best practices
OK,
Just making sure the corrected version went out.
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Re: I find This Shorted Circuit on Raduino, here the pics..plz Help?
#ubitx-help
Whaaaooo! Super much thanks again at all HAM here which helping me with new comments, so very thankfull for all!!
I have made an little video yesterday late evening at 18.45utc (in germany 20.45uhr) because i want test this Signal from an near AM Radio station, and in germany was at 17-19UTC (19-21uhr in Germany) one Radio Station which was the closest i can find yesterday at the postet website which i can find, and again i would say thanks for this website info !! Nice really, that can be used for other test or even listen to Radio station in all Band and time..
So i have make this video here which should showing up the whole problem with the disordered SSB voice sounds like in 80m Band an the test with no finding AM Radio Station at the 3.765mhz at correct time.. and even the LSB/USB versus issue at 7.074 FT8 signal it show in the video..
I hope this is usefull - here is the link
please sorry my english in the video wasn't good i was a bit nervous and my first video a made ever upload to youtube..
i test the settings again which here postet and when anyone have new facts which shows up in my video please post here,too !
Thank you ALL and i want talk back in 2 hours when i'm at home
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Re: Ubitx version 4 speaker impedance?
?My bad, I was not paying enough attention when I ordered the speakers. And what I did order, and receive, are 40mm not 2"/52mm.
?No matter, they will still work reasonably well. ?Wayne WA2YNE
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Re: I find This Shorted Circuit on Raduino, here the pics..plz Help?
#ubitx-help
Fabian, The factory c code sets the USB calibration to?11997000 if out of range (as would be the case if not yet calibrated), so this would be a good first choice. For another reference point on variations, my ubitx's factory EEPROM settings:?
EEPROM_HEX_DUMP:
? ? |? ?0? 1? 2? 3? 4? 5? 6? 7? 8? 9? A? B? C? D? E? F
----------------------------------------------------------
0? ?|? EC 9D 02 00 FF FF FF FF 72 08 B7 00 FF FF FF FF
10? |? FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
?
#else // use values
? ?#define MASTER_CAL 171500 // 0x00029DEC
? ?#define LSB_CAL 0? ? ? ? ?// ?not used?
? ?#define USB_CAL 11995250? // 0x00B70872 (would be set by code if out of range to 11997000)
? ?#define SIDE_TONE 0? ? ? ?// ?not used?
? ?#define VFO_A 7150000? ? ?// default value from orig code
? ?#define VFO_B 14200000? ? // default value from orig code
? ?#define CW_SIDETONE 800? ?// default value from orig code
? ?#define CW_SPEED 100? ? ? // default value from orig code
#endif
Regards, Gary
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Nick VK4PP
Jim Sheldon
sdr freak