Re: Tell me your favorite uBitx mods
Careful with those $0.85 RD16HHF-1's
Often some random switcher FET with fresh paint.
Google "fake RD16HHF"
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On Mon, Jan 1, 2018 at 08:03 pm, Dave Bottom wrote:
Maybe a shift to Mitsubishi RD16HHF-1 MOSFET is worth a try. ...? They are everywhere from $5 each here in the US to US $0.85 (China) in lots of 10.
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Re: Tell me your favorite uBitx mods
RE CW Keying.I saw the post about the contact resistance and that was understood from how it works - both my 50 year old Vibroplex and my Begali behave the same and contacts are clean on both. My 50 year old Vibroplex was actually lower resistance than my gold plated Begali before cleaning both.? LOL?
This seems to be a timing/delay issue? Simply holding either sends continous strings of dits or dahs, but not until this delay takes place does it start. It is necessary to hold the contact closed for far too long when sending at say 25 WPM.? Longer than the dit character is at 25 WPM. Try sending "when" and it is necessary to wait too long for the "e" to be sent or it isn't and the word is not understood.?? I know this is probably not a self completing keyer, but my 1966 Unijunction keyer (7 parts) isn't either and it has weight and space adjustment as well as speed and works better if not keying this radio. The delay for sending the character must change with CW Speed setting.?? If this delay is not adjustable or cannot be eliminated this will be a problem even using a straight key or an external keyer when sending at speeds above 10 wpm.?
Dave WI6R
On Mon, Jan 1, 2018 at 8:28 PM, Raj vu2zap <rajendrakumargg@...> wrote:
At first I had some erratic keying. The contacts of my vibroplex paddle
had to be cleaned as the contacts were
showing a few 100 ohms and this was freaking out the Raduino. The keying
is done by the resistance across the
input.
I agree with erratic tuning. Sudden jumps is annoying and is waiting to
be tackled at my bench.
Raj
At 02-01-2018, you wrote:
3 Days getting familiar with
the MicroBITX...
CW Keying as is - isn't really usable.?? Critical on the fix it
list.
It misses the first dit or even dah and the faster you send with the
paddle, and the longer you send the worse it gets.
10 WPM is barely usable with errors and 25 to 30 WPM (typical CW speeds)
it is completely unusable.
Whether this is RF riding on the paddle inputs or code changes necessary
I don't think has been resolved.? ?
A little more time with these to sort this out - time will tell if
anything external needs to be dealt with.
Erratic Tuning - Erratic Operator?
Tuning seems a bit erratic and I don't know if a better operator or a
better quality encoder would help.?? LOL
It can start stepping at 200 to 400 KHz to MHz when moving across an
Amateur Band at what seems like steady tuning speed?
This really shows up when moving from CW portion to Phone portion of the
band (e.g. 7.025 to 7.280).
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You might consider making the relays a separate board from the controller. That what it could be built with different relays or for different power levels. A bit more expensive for an additional board but I could see the basic controller used for several different applications.? Just a thought.
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Re: Tell me your favorite uBitx mods
I was an easy one to think of, I recently setup a Raspberry Pi with a TNCPi. ?The board has one connector and two adjustments that need access from above. ?I wanted my custom board to be the top most board so I made holes for the adjustments and connector. ?What¡¯s particularly screwy about this is if you want two TNCs you can install two board but they make no provision for adjusting the lower board.
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Yaknow, I hadn't even thought about that... adding holes to the PCB for a screwdriver to pass through :)? Good catch clark!
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Re: Variable power control
The Nano and other AVR Mega based MCUs do not have DAC outputs. ?The AnalogWrite function sets a PWM. ?So that pin is switching between 0 and 5V with an average value proportional to the programmed value. ?It can be filtered to produce a DC signal. ?But it might require a lot of filtering, and the size of the caps might get big depending on what frequency is being used.
I¡¯ve been thinking about using a Micro Chip MCP4725. ?It¡¯s a 12 bit DAC interfaced with I2C. ?This would give you a nice DC signal with very low parts count.
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Take a look at this,?
I am trying to figure out a way to use this inline with the PA power supply to be able to control the output power from software. Just brainstorming, but if you had a spare pwm pin and buffered its output with some capacitors into a transistor controlling the power rail, it might be doable. But I am really new to all this and am just looking at projects to try when my kit comes in.
Someone feel free to poke a hole in this and save me from wasting an afternoon if this isn't on the right track for a software controlled solution...
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Re: Tell me your favorite uBitx mods
Yaknow, I hadn't even thought about that... adding holes to the PCB for a screwdriver to pass through :)? Good catch clark!
On Mon, Jan 1, 2018 at 8:42 PM, Clark Martin <kk6isp@...> wrote: As far as alignment is concerned, if the new board has holes over the locations of the Pots on the uBitX board then that at least can be done without service cables or board removal.
On Jan 1, 2018, at 6:56 PM, Jerry Gaffke via Groups.Io < jgaffke@...> wrote:
This new board will hide all the parts on the uBitx, servicing will require a cable set to split the boards.
Might be better to flip over the uBitx.
Alternately, mount the new board under the uBitx with any surface mount components facing down.
?
-- Martin Held - AE7EU
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?
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Re: Tell me your favorite uBitx mods
I think it was posted (if I recalling right) that you can narrow the filter to 500Hz / etc by increasing the 5 capacitors at C217-C221.? However, if the teensy3.2 audio DSP mod (as suggested by Gerry) is any good, it might be able to provide an additional CW filtering, though it is post-fact really.
I'm unsure what causes that tuning, it's like it's got a slow speed and a fast speed, it does drive me bonkers too.? But then, I haven't used it that much.
I have a bunch of RD16HHF1's in my parts bin.? I should try that out.? Would also change how you do the heatsinking too... they're common source, so no need to insulate them on a common grounded heatsink.
On Mon, Jan 1, 2018 at 8:03 PM, Dave Bottom <ars.kd6az@...> wrote: 3 Days getting familiar with the MicroBITX...
CW Keying as is - isn't really usable.? Critical on the fix it list. It misses the first dit or even dah and the faster you send with the paddle, and the longer you send the worse it gets.
10 WPM is barely usable with errors and 25 to 30 WPM (typical CW speeds) it is completely unusable.
Whether this is RF riding on the paddle inputs or code changes necessary I don't think has been resolved.?? A little more time with these to sort this out - time will tell if anything external needs to be dealt with.
Narrow 500/600 Hz CW Filter?- The bands are crowed here... May really only be a PCB layout change for a later rev? with optional component loading??? I think important. I'm guessing 50% QRP's are CW Ops.
SSB Modulation -?I no longer think a Mic pre-amp is needed except for typical HF Electret Mics like ICOM etc. have much lower output, but they easily drive KX2's & KX3's. The supplied Mic drives the stage with LOUD voice and my SmartPhone/Tablet?PC headset drives almost identically (except the headset has an exceptional noise cancelling aviation Electret Mic) Maybe just adjust the Audio Stage Gain with a Set and Forget Pot on PCB - This I can try while monitoring for distortion. Power however is --- 80M is 15W CW, 12W PEP, 40M is 3W PEP unless yelling into the Mic so look then below...
Output Power vs Frequency - I see now the main issue is rapid fall off of output power w/freq.
Power drops from 80M 15W to 40M 7.5W to 20M 3W and so on down to 0.4W on 10M (all CW) Filter shapes look good with flat output across the bands! Maybe a shift to Mitsubishi RD16HHF-1 MOSFET is worth a try. Need to check proper BIAS for idle current on the Mitsu parts and watch on the Spectrum Analyzer while tweaking.?? I wonder if Ashhar Farhan has tried these?? They are everywhere from $5 each here in the US to US $0.85 (China) in lots of 10.
Erratic Tuning - Erratic Operator? Tuning seems a bit erratic and I don't know if a better operator or a better quality encoder would help.? LOL It can start stepping at 200 to 400 KHz to MHz when moving across an Amateur Band at what seems like steady tuning speed? This really shows up when moving from CW portion to Phone portion of the band (e.g. 7.025 to 7.280).
Overall a stunningly well done Kit.? - Thanks to the whole team! I'm really impressed that the only assembly issue was the Wire-Up schematic with Yellow and Orange leads reversed to the Volume control.? Please correct and post the correct wiring diagram.? - Pictures of course tell the truth (if you look.) . RTFM LOL
The radio came up the first time playing well and all alignment was spot on.? I only adjusted the BFO - 11.996.5 seems about the best listening, but I haven't looked where that is on the skirt yet? (20dB down) vs TX Audio. Initially I was suspecting that might account for the weak PEP figures on SSB vs CW before I saw the rapid drop in power vs Freq..?
Happy New Year everyone.??
Those waiting, you're going to have fun with your new radio when it arrives.
Dave WI6R
-- Martin Held - AE7EU
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?
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Re: Tell me your favorite uBitx mods
As far as alignment is concerned, if the new board has holes over the locations of the Pots on the uBitX board then that at least can be done without service cables or board removal.
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On Jan 1, 2018, at 6:56 PM, Jerry Gaffke via Groups.Io < jgaffke@...> wrote:
This new board will hide all the parts on the uBitx, servicing will require a cable set to split the boards.
Might be better to flip over the uBitx.
Alternately, mount the new board under the uBitx with any surface mount components facing down.
?
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I like to take a bit mapped image of something and paste it into my drawing program. ?Then I use it as a guide to drawing the object. ?Now I have a vector image of it which can be scaled up indefinitely.
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i draw them in inkscape. they are simple symbols to make. if you use the same thickness of lines eveeywhere, then they look consistent.the other thing to do is to scrap them off arrl handbook'a pdfs.
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Re: Tell me your favorite uBitx mods
At first I had some erratic keying. The contacts of my vibroplex paddle
had to be cleaned as the contacts were
showing a few 100 ohms and this was freaking out the Raduino. The keying
is done by the resistance across the
input.
I agree with erratic tuning. Sudden jumps is annoying and is waiting to
be tackled at my bench.
Raj
At 02-01-2018, you wrote:
toggle quoted message
Show quoted text
3 Days getting familiar with
the MicroBITX...
CW Keying as is - isn't really usable.?? Critical on the fix it
list.
It misses the first dit or even dah and the faster you send with the
paddle, and the longer you send the worse it gets.
10 WPM is barely usable with errors and 25 to 30 WPM (typical CW speeds)
it is completely unusable.
Whether this is RF riding on the paddle inputs or code changes necessary
I don't think has been resolved.? ?
A little more time with these to sort this out - time will tell if
anything external needs to be dealt with.
Erratic Tuning - Erratic Operator?
Tuning seems a bit erratic and I don't know if a better operator or a
better quality encoder would help.?? LOL
It can start stepping at 200 to 400 KHz to MHz when moving across an
Amateur Band at what seems like steady tuning speed?
This really shows up when moving from CW portion to Phone portion of the
band (e.g. 7.025 to 7.280).
|
i draw them in inkscape. they are simple symbols to make. if you use the same thickness of lines eveeywhere, then they look consistent. the other thing to do is to scrap them off arrl handbook'a pdfs. - f
On 2 Jan 2018 2:04 am, "Jeffrey Peters" < dek9jp@...> wrote: Hello Ray,
Great question. I just googled symbols for each morse code key, headphone, and microphone. The Google images webpages had lots of symbols for each.? Now, to see if there is a better place to find them. HNY, Jeff K9JP
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Re: Tell me your favorite uBitx mods
3 Days getting familiar with the MicroBITX...
CW Keying as is - isn't really usable.? Critical on the fix it list. It misses the first dit or even dah and the faster you send with the paddle, and the longer you send the worse it gets.
10 WPM is barely usable with errors and 25 to 30 WPM (typical CW speeds) it is completely unusable.
Whether this is RF riding on the paddle inputs or code changes necessary I don't think has been resolved.?? A little more time with these to sort this out - time will tell if anything external needs to be dealt with.
Narrow 500/600 Hz CW Filter?- The bands are crowed here... May really only be a PCB layout change for a later rev? with optional component loading??? I think important. I'm guessing 50% QRP's are CW Ops.
SSB Modulation -?I no longer think a Mic pre-amp is needed except for typical HF Electret Mics like ICOM etc. have much lower output, but they easily drive KX2's & KX3's. The supplied Mic drives the stage with LOUD voice and my SmartPhone/Tablet?PC headset drives almost identically (except the headset has an exceptional noise cancelling aviation Electret Mic) Maybe just adjust the Audio Stage Gain with a Set and Forget Pot on PCB - This I can try while monitoring for distortion. Power however is --- 80M is 15W CW, 12W PEP, 40M is 3W PEP unless yelling into the Mic so look then below...
Output Power vs Frequency - I see now the main issue is rapid fall off of output power w/freq.
Power drops from 80M 15W to 40M 7.5W to 20M 3W and so on down to 0.4W on 10M (all CW) Filter shapes look good with flat output across the bands! Maybe a shift to Mitsubishi RD16HHF-1 MOSFET is worth a try. Need to check proper BIAS for idle current on the Mitsu parts and watch on the Spectrum Analyzer while tweaking.?? I wonder if Ashhar Farhan has tried these?? They are everywhere from $5 each here in the US to US $0.85 (China) in lots of 10.
Erratic Tuning - Erratic Operator? Tuning seems a bit erratic and I don't know if a better operator or a better quality encoder would help.? LOL It can start stepping at 200 to 400 KHz to MHz when moving across an Amateur Band at what seems like steady tuning speed? This really shows up when moving from CW portion to Phone portion of the band (e.g. 7.025 to 7.280).
Overall a stunningly well done Kit.? - Thanks to the whole team! I'm really impressed that the only assembly issue was the Wire-Up schematic with Yellow and Orange leads reversed to the Volume control.? Please correct and post the correct wiring diagram.? - Pictures of course tell the truth (if you look.) . RTFM LOL
The radio came up the first time playing well and all alignment was spot on.? I only adjusted the BFO - 11.996.5 seems about the best listening, but I haven't looked where that is on the skirt yet? (20dB down) vs TX Audio. Initially I was suspecting that might account for the weak PEP figures on SSB vs CW before I saw the rapid drop in power vs Freq..?
Happy New Year everyone.??
Those waiting, you're going to have fun with your new radio when it arrives.
Dave WI6R
On Mon, Jan 1, 2018 at 1:27 PM, Diver Martin <diver.martin@...> wrote: Not sure how I could do CW filter mods without significant mods.? What I'd like for most of the mods is one-wire in, one wire out.? Narrower CW filtering can be achieved by changing the cap values on the Bitx, so that's not one I'd probably aim for. When you say clean keying for CW, I assume it's clicky, and has sharp edges?? Could be doable with a keyshaper on the output of the CW Tone.? I'll consider it. QSK:? Pretty significant modification, one I'm not going to attempt with this pass I think. Digital mode audio/PTT:? PTT in the works, digital mode would just require isolated transformers, no? AGC: In the works :) SWR Gauge:? In the works :) ATU:? In the works :) CAT Control:? In the works :)
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Does it receive ?
Shake all trifilar toroids and any shorts may show up.
Check all the yellow toroids for bad solder.. check continuity with multimeter in beep mode..
Raj
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At 02-01-2018, you wrote: Finally got around to putting my ubitx into a box, and I'm having trouble getting measurable output. I followed the bias tuneup procedure but when I got to the part where you HAAALLLLOWW into the mic and watch for deflection on the ammeter, I got none. I also didn't see any movement on the power meter/swr/dummy load. So I hooked up a cw key and confirmed: no measurable output when keyed down.
Where ought I to start troubleshooting?
Thanks much and 73
Joe KD9JLV
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Re: Variable power control
Take a look at this,?
I am trying to figure out a way to use this inline with the PA power supply to be able to control the output power from software. Just brainstorming, but if you had a spare pwm pin and buffered its output with some capacitors into a transistor controlling the power rail, it might be doable. But I am really new to all this and am just looking at projects to try when my kit comes in.
Someone feel free to poke a hole in this and save me from wasting an afternoon if this isn't on the right track for a software controlled solution...
--
----------
N5WLF, Greggory (or my nickname, Ghericoan)
General Class, Digital Radio Hobbyist
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Re: Tell me your favorite uBitx mods
The only things requiring a cable/wire are the AGC mods.? All the rest interface with the existing headers and would just plug in.? Noted though... could make it a cable that's easy to remove.
On Mon, Jan 1, 2018 at 6:56 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote: This new board will hide all the parts on the uBitx, servicing will require a cable set to split the boards.
Might be better to flip over the uBitx.
Alternately, mount the new board under the uBitx with any surface mount components facing down.
?
-- Martin Held - AE7EU
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?
|
Re: Tell me your favorite uBitx mods
This new board will hide all the parts on the uBitx, servicing will require a cable set to split the boards.
Might be better to flip over the uBitx.
Alternately, mount the new board under the uBitx with any surface mount components facing down.
?
|
This has been very useful to me so I'll share it in case it is useful to others.
I have written an Arduino sketch that provides a simple command-line console (serial) to control most features of an Si5351/A.? This provides a very generic tool that can be used during the early phases of home-brew rig development when you just want to get the RF/IF chain up and running in a minimal way without fooling around with displays, encoders, Arduino coding, etc.? Just load up this sketch, connect the I2C pins to the Si5351/A, open he Serial Monitor (or other terminal program) and you're ready to start tuning.
There are some handy features that make it easy to deal with superhet math and filter pass-band tweaking. The details are here:?.
I'm doing a scratch-build of the BITX-40 with some modifications so I've been using this sketch a lot.? For my BITX I use CLK0 for the VFO, CLK2 for the BFO, and CLK1 as an RF signal injector/tester.? Here is a video of the receive side up and running:?
Happy New Year and 73s,
Bruce KC1FSZ?
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Happy 2018 for everyone in everywhere.
Here something I am doing before to test the board for a 'modular rig"
This is the Qrp PA (100 x 33 mm)from the Bitx40v3 schematic with small change in the toroid winding.
I used a IRFZ44 and the Qso with Cuba from Cape Coral, FL is excellent in the morning around 9:30am (EST)
I made a Qso last Sunday, Dec 31st and today.
I am very happy with AllPcb, they charge $5.000(plus$0.45 Pay Pal fee) for 10 board with free delivery to USA for free, fast and inexpensive for test.
I have found JLCpcb with $2.00 for the same area with DHL free delivery, I will coment here after I use it.
Tomorrow I will to get the other board with the exciter (100 x 100 mm) to use with this PA, all inside a DVD recycled metal box enclosure.
You can find more inf here in my FB wall
https://www.facebook.com/groups/QrpCuba
or email to wj6c
Have a good night
Qrv's
73's Jc
?
?
?
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Re: #ubitx Power output on 40 / 80 m with high current levels
#ubitx
Layout is important, as John has said.? I'd suggest a very short source lead soldered directly to the ground plane,
keep the drain lead well separated from the other two (Allison suggests clipping the drain lead off and soldering to the tab),
and try adding a 10 ohm resistor in series with the gate.
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On Mon, Jan 1, 2018 at 05:26 pm, John Backo wrote:
So it is likely that you are seeing VHF oscillation drawing the extra current.
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Re: #ubitx Re: Ubitx only on preorder now
#ubitx
Correct, a custom clearance fee but there should not be any taxes.
On Mon, Jan 1, 2018 at 8:56 PM, Michael Babineau <mbabineau.ve3wmb@...> wrote: DHL will charge a customs clearance fee and ?HST will be applied to the value of the goods on top of that.?
For the BITX40 the extra charges were around $Can 30, so it will be more for the uBITX.
Michael VE3WMB?
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Jeff
Raj vu2zap
Ghericoan
JuanCarlos Berberena Gonzalez
