Anyone have a link to the rotar encoder mod for the bitx40 . I dont like the pot and would like to change out.
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Re: Second batch of uBITX shipping?
#ubitx
Is it stuck in Canada?
S.F. Express International
http://intl.sf-express.com
2018-01-29??? 20:10:00
The item is at the Europe Distribution Center,
item arrived at facility
2018-01-31??? 08:04:00
The item is on transport to the country of destination,
shipment in transit,CANADA
2018-02-06??? 14:38:00
The item has arrived in the country of destination,
shipment in transit,CANADA
Today is: 2018-02-18??? 16:38:00
The item is NOT received yet.
It took 6 days for the item to reach Canada from India,
22 days past since then, but it is still traveling in Canada. (:
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Re: BITX QSO Afternoon/Night, Sunday, February 18, 3PM/7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere
Sorry I missed the afternoon session. I'm on 7277 now.
--
John - WA2FZW
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bitx40 amatures srccode build error
I am having build issues with the current code
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Re: Replacing T11 with a BN43-202
#ubitx
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Re: Replacing T11 with a BN43-202
#ubitx
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Re: uBITX AGC - Adafruit TPA2016, A Success!
#ubitx
My Appologies.
In my haste I pasted in the wrong function, I will get the correct one tonight...
I connected the board to the TDA side of the volume control, basically eliminating the TDA chip completely.
Please be aware that the output from the TPA2016 is to be connected directly to the speaker, and NOT grounded at all, this is due to the fact that these outputs are Bridge Tied Load which means you must connect the speakers directly - do not try to connect these outputs to another amplifier!
73 and good luck.
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Re: uBITX AGC - Adafruit TPA2016, A Success!
#ubitx
Where did you insert the board?
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Re: New ideas for the Audio TX/RX pop and PA output stage improvements on ubitx.net
Still confused. I am sure its meant to be a? BN43-202.
Philip G7JUR
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Re: New ideas for the Audio TX/RX pop and PA output stage improvements on ubitx.net
What would the impact be, or changes required, to use a BN43-202?? Again, I'm trying to learn here...so math is appreciated.? My newbie guesstimate (interested to see if I'm right or why I'm wrong) is that they are close enough physically and of the same material that they can be considered the same, especially in light of the +/- 20%? AL
Here are the physical stats:
BN42-202 43 material 0.523" wide 0.296" thick 0.575" high 0.147" diameter holes.
AL=(can't find any)
BN43-202 43 material 0.525" wide 0.296" thick 0.565" high 0.150" holes AL=2200 +/-20%
uH=(AL*Turns2)/1000
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Re: New ideas for the Audio TX/RX pop and PA output stage improvements on ubitx.net
Erhard DF3FY has confirmed that the
correct binocular core is the? BN42-202.?
It was a typing error on his part, and he apologises.
The wire is uncritical, it is simple hookup wire 0.5 mm in
diameter.? The completed toroid fits in the original pad holes.
A corrected diagram and a photo of the PA, which clarifies
everything better than 100 words, will be added to ubitx.net
shortly.
73 Mike ZL1AXG?
Erhard
On 17/02/18 10:10 AM, Mike Woods wrote:
If you look on the home page of you will find
suggestions from Erhard Haertel DF3FY that address:
- Audio Pops on transitions from RX to TX
- Improved output on all bands from the PA stage (using
RDF16HHF1s and a new output transformer and minor changes to
the circuitry).
Erhard had difficulty posting to the BITX20 iogroups list so
wrote to me directly.? I have not tested these mods, but these
are two concerns about the uBITx (loud audio pops and lower
power out above 40m) so I am sure that Erhard would be as
interested as me in any feedback from those trying out his mods.
73 Mike ZL1AXG
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Re: uBITX AGC - Adafruit TPA2016, A Success!
#ubitx
Thanks Nik,
One more thing.? It appears we need a function:
setNoiseGateThreshold(0);
that you may have also added.
Aug
AG5AT
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Re: Bitx40 - receiver works great, but do not transmit
#bitx40help
Good evening, Thanks all for helping, transceiver works great, with a short vertical antenna Comet UHV-6 i have a lot of QSO up to 1300 kilometers during this weekeng. 
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Re: New ideas for the Audio TX/RX pop and PA output stage improvements on ubitx.net
It's funny until the caps pop and the FETs
explode...then it's hilarious.
I've always tried to observe the working voltage
spec. If that's more than sufficient, that seems to be all the
cap engineering I've ever needed for ham work. I've never seen a
current rating for caps I'm likely to use. When I want to
calculate RF current, reactance in Ohms Law works well as you
point out.
Eric KE6US
On 2/18/2018 12:06 AM, Jerry Gaffke via
Groups.Io wrote:
toggle quoted message
Show quoted text
I find that train of thought rather confusing.
Not sure where that 0.3amps average comes from, I'd think you
could just find
the impedance from 1/(2*pi*Hz*Farads) and divide that into the 50
volts RMS to find current
rather than bother with the calculus.
Not at all clear how a 0.1% dissipation spec somehow means a max
of 0.2 Amps at 30mhz.
A few more details would be appreciated.
I think most builders just try some np0's and if they get warm
then replace with a bunch of smaller value caps in parallel.
I'm not aware of any Bitx40 LPF caps blowing out, and I doubt they
are anything special.
Jerry
On Sat, Feb 17, 2018 at 02:11 pm, K9HZ wrote:
The current through a
capacitor is given by I=C*dV/dt so the average current over
time is I=C*int[dV/dt]/t¡ For your example: let¡¯s use a
100pf capacitor in an 30 MHz circuit at 50 VRMS which is
140V P-P.? Iavg = 0.42 * 0.707 = 0.3 amps average.? Now the
spec from that capacitor in your finding is 0.1% at 1 VRMS
at 1MHZ which is 0.00028A * 0.707RMS *1000% = 0.2 Amps
continuous at 30 MHz.? Yikes we are over by 50%!? Note that
this DOES vary with capacitance¡ that¡¯s why the larger the
capacitor, the more current capacity is needed.
?
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Replacing T11 with a BN43-202
#ubitx
Just trying to get ideas on the best place to actually put the bn43-202.? I am curious to know what others have done.? Looking at my board, i think I might put it underneath, affixing it with some silicone.? I will run both the primary and secondary out of the same side.
I am also curious if anyone has just changed T11 and kept the IRF510s.? I wonder if just changing this to a 2:3 turns ratio transformer and adding in the 47pf capacitor will tame the frequency response.
I have a new appreciation for the ladies that actually assemble these radios.? ?
Thanks for any and all replies.
Marco - KG5PRT
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Re: New ideas for the Audio TX/RX pop and PA output stage improvements on ubitx.net
I'm fine with math, and in fact prefer it over some web calculator.? Especially if that calculator
doesn't show formulas or state assumptions.?
I suspect this is quite opaque to most everyone on the forum except perhaps the person who wrote it:
? ? "0.1% at 1 VRMS at 1MHZ which is 0.00028A * 0.707RMS *1000% = 0.2 Amps continuous at 30 MHz"
?
Jerry
toggle quoted message
Show quoted text
On Sun, Feb 18, 2018 at 08:40 am, K9HZ wrote:
Like I said in my original note, if you are uncomfortable with the math, there are many calculators on the internet that work.? Just google them.
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Re: New ideas for the Audio TX/RX pop and PA output stage improvements on ubitx.net
Yes, I suppose for the amateur builder, applying power to your design in and finger testing is an option.? If it doesn¡¯t burst into flames, I suppose its ok?? (In commercial designing we don¡¯t often have that option so we¡¯ll have to stick to our calculus).? It might be wise to invest in one of those IR temperature guns from Harbor Freight Tools for $20 to save your fingertips though! ? For LP design work at the approx.. 10 watt level¡ this just isn¡¯t gonna be an issue unless you are using the wrong filter for the band and the filter is dissipating all of the power.? Once you get to the kW+ region¡ best use your math. ? Like I said in my original note, if you are uncomfortable with the math, there are many calculators on the internet that work.? Just google them. ? To be clear about the specification¡ it says that you would be operating at 0.1% of the full/ capable dissipation properties of the capacitor if it were used in a 50 VRMS circuit at 1 MHz? Using this one data point, you can translate that to any voltage/ frequency point and ratio it to this point to determine what % of dissipation you are operating (designing) at. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton ¨C J68HZ Soufriere, St. Lucia W.I. Rent it: Like us on Facebook! ? Moderator ¨C North American QRO Yahoo Group. ? email:? bill@... ? ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Jerry Gaffke via Groups.Io
Sent: Sunday, February 18, 2018 2:06 AM
To: [email protected]
Subject: Re: [BITX20] New ideas for the Audio TX/RX pop and PA output stage improvements on ubitx.net ? I find that train of thought rather confusing.
Not sure where that 0.3amps average comes from, I'd think you could just find
the impedance from 1/(2*pi*Hz*Farads) and divide that into the 50 volts RMS to find current
rather than bother with the calculus.
Not at all clear how a 0.1% dissipation spec somehow means a max of 0.2 Amps at 30mhz.
A few more details would be appreciated.
I think most builders just try some np0's and if they get warm then replace with a bunch of smaller value caps in parallel.
I'm not aware of any Bitx40 LPF caps blowing out, and I doubt they are anything special.
Jerry
On Sat, Feb 17, 2018 at 02:11 pm, K9HZ wrote: The current through a capacitor is given by I=C*dV/dt so the average current over time is I=C*int[dV/dt]/t¡ For your example: let¡¯s use a 100pf capacitor in an 30 MHz circuit at 50 VRMS which is 140V P-P.? Iavg = 0.42 * 0.707 = 0.3 amps average.? Now the spec from that capacitor in your finding is 0.1% at 1 VRMS at 1MHZ which is 0.00028A * 0.707RMS *1000% = 0.2 Amps continuous at 30 MHz.? Yikes we are over by 50%!? Note that this DOES vary with capacitance¡ that¡¯s why the larger the capacitor, the more current capacity is needed. ?
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Re: New ideas for the Audio TX/RX pop and PA output stage improvements on ubitx.net
History with the Bitx40 doesn't mean much if we're building a LPF for 30mhz.
Especially if we get the power up to 20 or 30 Watts.
But after poking around some I think brand name np0/c0g's from reputable vendors should be fine,?
you don't want junk.? Smaller caps in parallel are a good idea if experiencing trouble with currents.
This guy seem to know what he's doing.? His 1.5kW 30mhz LPF uses a the "1kV type MC22 Mica Capacitor",
perhaps Mouser?598-MC22FF101J-TF.? Can get them at a reasonable price if you want to take this to extremes..??
??http://w6pql.com/a_1.5kw_lpf_for_160-6m.htm
Jerry, KE7ER
toggle quoted message
Show quoted text
On Sun, Feb 18, 2018 at 12:06 am, Jerry Gaffke wrote:
I think most builders just try some np0's and if they get warm then replace with a bunch of smaller value caps in parallel.
I'm not aware of any Bitx40 LPF caps blowing out, and I doubt they are anything special.
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Re: RD16HHF1 in the uBITX
#ubitx
I had not seen the Pennywhistle before. Interesting. With this you could eliminate the IRF510's completely. You would still be left with the fall off in power output from the driver chain as the freq goes up, however. A driver chain with a flatter output is probably where the main focus should be. tim ab0wr On Sun, 18 Feb 2018 08:29:25 +0000 (UTC) "Rahul Srivastava via Groups.Io" <vu3wjm@...> wrote: Hi!
Over years I have used Pennywhistle PA from HPSDR with great success.
The RD15's work extremely well upto 6 mtrs maybe we can try this
configuration with uBITX. TAPR - HPSDR PennyWhistle
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TAPR - HPSDR PennyWhistle
HPSDR - PennyWhistle
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73
Rahul VU3WJM
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Re: RD16HHF1 in the uBITX
#ubitx
Yes the RD15HVF1 part is my ¡°go to¡± low power part because it¡¯s so easy to design around and it behaves very well. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton ¨C J68HZ Soufriere, St. Lucia W.I. Rent it: Like us on Facebook! ? Moderator ¨C North American QRO Yahoo Group. ? email:? bill@... ? ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Rahul Srivastava via Groups.Io
Sent: Sunday, February 18, 2018 2:29 AM
To: [email protected]
Subject: Re: [BITX20] RD16HHF1 in the uBITX? Over years I have used Pennywhistle PA from HPSDR with great success. The RD15's work extremely well upto 6 mtrs maybe we can try this configuration with uBITX. ?
| | TAPR - HPSDR PennyWhistleHPSDR - PennyWhistle |
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Nick VK4PP
Ivan Ilyichev
K9HZ