Derek :?
Regarding the SOTABEAMS DSP filters.
I have a couple of the dual-bandwith ones. The General filter (2.5Khz/300 Hz) is installed in my BITX40
and the CW filter (1khz/300Hz)? in my uBITX. Both are working very well. To others looking for a CW filter solution you, would be very hard
pressed to find an audio filter that works better than this, especially at this price. Performance far exceeds any analog audio filter I have ever used.
https://www.sotabeams.co.uk/audio-filters-and-more/
On the uBITX I removed the yellow wire from the AF Gain pot and connected that to the input of the filter. The output of the filter
is connected? back to the pot where the yellow wire was, via a series 0.1 uF capacitor (this is to isolate DC voltage present on the filter output).?
What I ended up doing in the end is using a?3PDT switch to switch the filter in and out and a separate SPST switch to toggle between WIDE/NARROW bandwidth.
The three poles on 3PDT are used to switch the filter input, filter output and supply voltage to the filter. BTW the filter is powered from 12V
via a small power-line filter (two 220uF electrolytic caps to ground with a series 12 Ohm resistor between them) to prevent any "garbage"
from getting back into the 12V supply (this is a precaution).??
You will want to install the signal LED as that makes a great tuning indicator. It will flash?on and off with the CW signal when a station
is tuned in close to the center of the filter bandwidth.?
By grounding RB12 on the filter board you can increase the filter gain. This doesn't actually increase the output of the filter, it decreases the
minimum signal required to?get full output from the filter. You might want to play with this to see which you prefer. I went with grounding it, as that allows a lower
setting of the AF Gain control when the filter is engaged and it sounded a lot better to me. This could be wired to yet another SPST switch?
to make it selectable.? It might be desirable to be able to unground RB12 to reduce the internal filter gain on very strong signals.?
I
don't have my uBITX in a permanent enclosure yet so I haven't decided if I will use a switch for RB12.?
Best of luck and let us know how you make out.?
Michael VE3WMB?
P.S. With a "brick-wall" audio filter like the SOTABEAMS DSP,? it is IMHO actually desirable to not have AGC or at least be able to turn AGC off.
Without AGC you don't get "AGC pumping" caused by a strong adjacent signal within the IF filter passband, but outside of the AF filter?
passband.?I have actually used my BITX40 in a few casual contests on CW and it works amazing well with the filter in the 300hz position.?
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Re: ubitx troubleshooting help - low power after irf510 replacement
It would be nice to know what is and is not good from Tayda as they have low prices and low cost shipping.guress sometimes you git what you pay for...
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Hi Guys:
I am looking for the newest version of the Ubitx manager and where to download it.
Thanks and 73 Ross Bell K7RSB
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Re: Raduino Clone kit from W0EB-N5IB
#ubitx
Now that I've seen the difference between a uBITX Raduino and the BITX40 Raduino, I checked my stock and I can easily supply my Raduino Clone to the BITX40 users with the 5 pin "Molex" style plug to mate with the factoryt supplied connector to the BITX40's power & oscillators.?
The prices listed on my website would be the same for either the uBITX or BITX40 versions.? The only differences would be an unprogrammed NANO and the 5 pin header instead of the 16 pin right angle header for the BITX40 version - if interested, contact me via the link on the website and let me know which version you would like.
Jim Sheldon, W0EB
http://www.w0eb.com
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On Fri, 17 Aug 2018 23:08:03 -0700 "jfein2000 via Groups.Io" <jfein2000@...> wrote: Hi, glad to hear I'm not the only one experiencing this problem. I'm wondering if the ADC in the Raduino is programmed wrong in the default software? I'm going to try putting in the KD8CEC firmware (software) revision and see if adjusting the ADC settings fixes it. By the way, are you using a metal or plastic chassis? If plastic, what are you using as a ground point? The schematic shows the yellow wire from the Raduino (Raduino ground) also connected to chassis ground. Maybe we are missing a proper chassis ground to the yellow wire? Is the negative power input wire a suitable chassis ground? Or is there a better ground connection point? It almost seems like the intermittent cw happens because the Raduino ground is floating around, sometimes triggering the ADC, sometimes not. Thanks, Joe Hi just finished assembly noting that the comments on connecting the keyer jack and I do have the resisitor and blue lead connected to the tip.? However the keyer does not key.? Intermittently it will begin sending di dah di dah etc and then stop but is not responsive to the key at all. I am currently trying it with a straight key.? Also doesn't seem to be any power output when it does send di dah.? Any suggestions would be much appreciated.
It tunes fine and I hear stations on the air although the audio is good, volume seems understated as well.
thanks
Jeff
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Re: uBITx intermittent cw transmit
I just posted this issue as well before I saw this message on topic.? I have exactly the same problem.? Voltage does drop to zero when contacts are closed.? Has anyone been able to debug this issue if it is the Arduino?? Thanks Jeff
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Hi just finished assembly noting that the comments on connecting the keyer jack and I do have the resisitor and blue lead connected to the tip.? However the keyer does not key.? Intermittently it will begin sending di dah di dah etc and then stop but is not responsive to the key at all. I am currently trying it with a straight key.? Also doesn't seem to be any power output when it does send di dah.? Any suggestions would be much appreciated.
It tunes fine and I hear stations on the air although the audio is good, volume seems understated as well.
thanks
Jeff
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Re: ubitx troubleshooting help - low power after irf510 replacement
Here's a clue:
International Rectifier gave up on building IRF510's years ago.
toggle quoted message
Show quoted text
On Fri, Aug 17, 2018 at 08:57 PM, Sean W7SKD wrote:
Here¡¯s how this ended up going: ?I saw no damage to any traces, no damage to any components really. I replaced the IR marked irf510s (sourced from Tayda) with Vishay Silconix marked irf510s (from Arrow) and everything is back to normal functioning. I don¡¯t know if the IR parts were actually ¡°bad¡± but they were certainly different.?
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Re: ubitx compared to Elecraft or Xiegu for spurs
#ubitx
Allison, Sunil and others,
I was involved in? design? of Anan transceivers. Getting the filters right did involve lot of work. Isolation, trace impedance and via size all contributed to filter response. PCB layout also had some impact on gain of PA chain across the HF bands to 6 mtrs. First production run boards came out after 3 iterations. Another issue was getting a low and straight line on the noise floor upto 6 mtrs but that is another story. ? Capt Sunil was first VU customer and he ended up paying more than the Dx cost for the radio.. the local VAT.??
Farhan visited me and was witness to LDMOS PA development.
Rahul VU3WJM
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Re: ubitx troubleshooting help - low power after irf510 replacement
Here¡¯s how this ended up going: ?I saw no damage to any traces, no damage to any components really. I replaced the IR marked irf510s (sourced from Tayda) with Vishay Silconix marked irf510s (from Arrow) and everything is back to normal functioning. I don¡¯t know if the IR parts were actually ¡°bad¡± but they were certainly different.? Pics of of the parts below - Vishay on the left? 
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¡°It¡¯s a competent enough device assuming the circuit around it is correct.¡±? Therein lies the rub.? The IRF510 requires more attentive circuitry around it to offset Miller capacitance effect than a nicely designed RF transistor like the RD15VHF1¡ So some of that ¡°noise¡± may be backed up by theory.
? ?
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Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of ajparent1/KB1GMX
Sent: Friday, August 17, 2018 8:56 PM
To: [email protected]
Subject: Re: [BITX20] #bitx40help BITX40 LSB Winlink ? First the code (Arduino sketch)had to be changes to set the 5351 to the needed range for 20M.
That is both the LO and the BFO as needed.? You will need the 40M sketch to do that.
The 40M band pass filter gets changed to 20M, Look for the schematic of the older bitx20
series for values.
Then the 40M low pass filter needs to be changed.
Ignore any noise about changing the IRF510s.? I have run those to over 70mhz at?
high power (20W at 13.8V).? ?Its a competent enough device assuming the circuit
around it is correct.
>>The magic is in the ladder/BFO combination, which shears off the carrier and unwanted sideband, while passing the wanted sideband.??
Only half true.? The balanced modulator is to remove the carrier, the filter passes the desired
sideband (strips the other).
Allison
-- ¡_. _._
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The Bitx40 works just fine on 40m with the IRF510, no need for major surgery. Also, no issues with spurious emissions (an issue for the uBitx).? Best to get started using the Bitx40? with stock firmware and no mods. But as you may have discovered, the frequency jumps around a bit, and USB operation is not an option. Allard has two different versions of his firmware ? ?? Once the stock rig is working, try Allard's bitx40 firmware. You should at least add the Function button, and remove C91 an C92? as he suggests. This will allow you to choose either a low side VFO for LSB or a high side VFO for USB. For example, assume we are receiving at 7.2mhz The crystal filter is centered at 11.997mhz The crystal controlled BFO is perhaps at 11.9975mhz. The VFO is at 11.9975 - 7.2 = 4.7975mhz, and we get LowerSideBand To flip to upper sideband, the VFO moves to 11.9975 + 7.2 = 19.1975mhz and the BFO stays put. Here's a a few old posts describing what is happening? ? ?? /g/BITX20/message/24724? ?? /g/BITX20/message/26707?p=,,,20,0,0,0::Created,,24724,20,2,0,5050215? ?? /g/BITX20/message/25360You may someday wish to try Allard's bitx40-raduino-v2 firmware. This will require a few minor mods, but driving the BFO from the si5351 gives much more control over the rig. In particular, it allows you to flip sidebands by moving the BFO down a few khz to the other side of the crystal filter, the VFO staying put. Jack will find that making the Bitx40 work on 20m is a significant bit of work. Much more involved than just changng the firmware. You will need new firmware, new filter at L1,L2,3,? also a new filter at L6,L7. Also the board is not laid out well for 14mhz, so the power amp won't deliver much. Good luck sorting all that out, though it has been done. Jerry, KE7ER
On Fri, Aug 17, 2018 at 05:31 PM, Timothy Fidler wrote:
JM there is a whole lot of information here around this BBS in various corners.? see right down bottom of this post...
(public version of post sent privately a while back)?
Extra filters can come from Kees Talen who sells little PCBs for this purpose .? Moto appn note AN267 is? your friend for this design.? KT sells parts .. you do the design.
you will need to change out the IRF PA for a? proper Mitsi HF or VHF Mosfet. The pinouts don.'t align as Flowers found out but he worked out a kludge - eg wiring the RF transformer direct to the drain of the RDHH16.? The fact that the? Source and tab on the RDHH16 and 15 Mosfets are the same simplifies some of the rework and of course makes heat sinking a lot easier. Those Mosfets are avail at reasonable prices as in just over 5 usd plus freight from "cecil the parts place". DIZ,? the toroid king used to stock them but >....no more.
? There is a V2 version two that involves?hardware mods- BEWARE.??Best have a backup plan like a second Raduino or a clone so you can always fall back to plan A.
?
? ?is a new load of software that may do many things you want. It also contains a whole lot of fixes and includes CW capability.
In terms of display for both 40 and 20 m with a dual band design (??)? this item (search for 6 digit freq counter) from??might solve your problem $13 USD without a recode job. you use the frequency counter in native mode to display frequency in 20m operation and the original Bitx display for 40 m operation? (sounded like a good idea at the time ).
Type 43 material is pretty lossy above? 7 Mhz.(can forward data) there are magnetics which if you change? them out will make a difference.? ?Flowers got 6W out he says with only the Mosfet change.? Without that change he was getting less than 2 W out.
MOtorola design note AN267 is your friend for? designing the New output filter.? (Kees supplies parts not designs)
===============================================================================
With six watts you can drive plenty of amps that will give you 50W+? out?
Just The guts of this amp come up from time to time on Ebay as just PCBs all ready to go but no case? for region of $80 USD. It uses an MRF-186 dual RF mosfet? ..beware imitations esp beware of SMPS mosfet kits .? Crude as hell but it works and is hard to kill it seems. Somebody in PRC obviously lucked into a whole lot of surplus Motorola parts at bargain prices
There are some reviews of it on Austr. websites./blogsites?
======================================================================================
/g/BITX20/topic/bitx40_convert_to_20_meters/5162026?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,5162026
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Re: ubitx compared to Elecraft or Xiegu for spurs
#ubitx
Comparing a multi-thousand dollar commercial radio product to the uBITX is silly.
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First the code (Arduino sketch)had to be changes to set the 5351 to the needed range for 20M.
That is both the LO and the BFO as needed.? You will need the 40M sketch to do that.
The 40M band pass filter gets changed to 20M, Look for the schematic of the older bitx20
series for values.
Then the 40M low pass filter needs to be changed.
Ignore any noise about changing the IRF510s.? I have run those to over 70mhz at?
high power (20W at 13.8V).? ?Its a competent enough device assuming the circuit
around it is correct.
>>The magic is in the ladder/BFO combination, which shears off the carrier and unwanted sideband, while passing the wanted sideband.??
Only half true.? The balanced modulator is to remove the carrier, the filter passes the desired
sideband (strips the other).
Allison
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Re: ubitx compared to Elecraft or Xiegu for spurs
#ubitx
>>>I had a quick look at my KX3 on the specan and its really clean.? Will have to do better test when I get?some ?time :)
73's VK5ZBR
Over the years I have had the chance to check out most all of the Elecraft lineup.
For pit FD site the are the preferred radio for being clean (all models).? The look
good on bandscopes.? The acid test is two of them on the same band running
phone and CW and not having mutual interference.
That and look at the specs.
Allison
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Re: Spurious Emission Measurement on stock uBitX
Iz oos, Arv, and all...
That test was CW mode so harmonics would be the prime issue.? It is required
to be SSB? for the spurs (and harmonics) to appear.? Its the difference between
how one is done CW is direct Frequency against the other SSB which is converted
fro 45mhz to the signal frequency.
If you do not keep track of the mode you will run off lost into the weeds.
Allison
|
JM there is a whole lot of information here around this BBS in various corners.? see right down bottom of this post...
(public version of post sent privately a while back)?
Extra filters can come from Kees Talen who sells little PCBs for this purpose .? Moto appn note AN267 is? your friend for this design.? KT sells parts .. you do the design.
you will need to change out the IRF PA for a? proper Mitsi HF or VHF Mosfet. The pinouts don.'t align as Flowers found out but he worked out a kludge - eg wiring the RF transformer direct to the drain of the RDHH16.? The fact that the? Source and tab on the RDHH16 and 15 Mosfets are the same simplifies some of the rework and of course makes heat sinking a lot easier. Those Mosfets are avail at reasonable prices as in just over 5 usd plus freight from "cecil the parts place". DIZ,? the toroid king used to stock them but >....no more.
? There is a V2 version two that involves?hardware mods- BEWARE.??Best have a backup plan like a second Raduino or a clone so you can always fall back to plan A.
?
? ?is a new load of software that may do many things you want. It also contains a whole lot of fixes and includes CW capability.
In terms of display for both 40 and 20 m with a dual band design (??)? this item (search for 6 digit freq counter) from??might solve your problem $13 USD without a recode job. you use the frequency counter in native mode to display frequency in 20m operation and the original Bitx display for 40 m operation? (sounded like a good idea at the time ).
Type 43 material is pretty lossy above? 7 Mhz.(can forward data) there are magnetics which if you change? them out will make a difference.? ?Flowers got 6W out he says with only the Mosfet change.? Without that change he was getting less than 2 W out.
MOtorola design note AN267 is your friend for? designing the New output filter.? (Kees supplies parts not designs)
===============================================================================
With six watts you can drive plenty of amps that will give you 50W+? out?
Just The guts of this amp come up from time to time on Ebay as just PCBs all ready to go but no case? for region of $80 USD. It uses an MRF-186 dual RF mosfet? ..beware imitations esp beware of SMPS mosfet kits .? Crude as hell but it works and is hard to kill it seems. Somebody in PRC obviously lucked into a whole lot of surplus Motorola parts at bargain prices
There are some reviews of it on Austr. websites./blogsites?
======================================================================================
/g/BITX20/topic/bitx40_convert_to_20_meters/5162026?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,5162026
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Re: Ubitx - Increased voltage to finals thru middle wire on power plug...no effect
Hi Adrian,
is there a current limit somewhere in the rig?
Kevin Rea
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Re: Ubitx - Increased voltage to finals thru middle wire on power plug...no effect
hi Adrian, no I do not have any current limiting that I know of I'm powering the 12 volts with 5 amp and then I'm powering the sitter lead of the power connector with a 5 amp at 23 volts and I am getting 23 volts at the finals. Still ,no difference in output.
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Re: #ubitx SSM2167 mic compressor speaker feedback issue - resolved
#ubitx
Thanks Kevin.
Tim, I didn't write down the results but I remember noting that the average power was more than twice as without the compressor.
73, John
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Jim Sheldon
MadRadioModder