Date   
Re: Tell me your favorite uBitx mods

Clark Martin
 

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.

Clark Martin
KK6ISP

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.
 

Re: Tell me your favorite uBitx mods

Diver Martin <diver.martin@...>
 

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


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 :)

On Mon, Jan 1, 2018 at 8:14 AM, KD8CGH <rkayakr@...> wrote:
Narrower audio filters for CW
Clean keying for CW
Pop elimination
QSK
Digital mode audio interface + PTT
AGC
SWR gauge
Auto Tuner
CAT control




--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?




--
73 Dave WI6R




--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?

Re: Tell me your favorite uBitx mods

Diver Martin <diver.martin@...>
 

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.

Clark Martin
KK6ISP

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
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?

Re: Variable power control

Clark Martin
 

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.

Clark Martin
KK6ISP

On Jan 1, 2018, at 7:27 PM, Ghericoan <boakawizkid@...> wrote:

Take a look at this, http://www.toptechboy.com/arduino/lesson-8-writing-analog-voltages-in-arduino/

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...


Re: Tell me your favorite uBitx mods

Clark Martin
 

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.


Clark Martin
KK6ISP

On Jan 1, 2018, at 8:43 PM, Diver Martin <diver.martin@...> wrote:

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.


Re: Tuner? Well Sure!

Jeff
 

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.

Re: Tell me your favorite uBitx mods

Dave Bottom <ars.kd6az@...>
 

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. Â
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).




--
73 Dave WI6R

Re: Tell me your favorite uBitx mods

Jerry Gaffke
 

Careful with those $0.85 RD16HHF-1's
Often some random switcher FET with fresh paint.
Google "fake RD16HHF"


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.

Re: Tell me your favorite uBitx mods

 

I have been reading about the CW keying here and in another post. Would it be possible to just make it a "to gnd"  trigger? and take out the current keying function. I would rather add a cheap 10-20$ keyer than argue with the raduino. I had planned to wire it for straight key use with a qrpguys keyer, any thoughts?

 

73

  David

Antenna tuner for uBitx

 

Hi Gang!

I am using a LDG 100Z-100plus along with the uBitx. The tuner is much smaller than the bitx. It can easily be bolted together
with bitx or the board can be removed and installed inside your bitx. Almost takes no power as it uses latching relays.
Any voltage from 7 upwards works. The unit can work with a 9V battery too. Very flexible and neat.

Take a look at the LDG Z-100Plus.

Happy new year!

--
Raj, vu2zap
Bengaluru, South India.

Re: Tell me your favorite uBitx mods

Diver Martin <diver.martin@...>
 

I would think that easily doable.  Just a matter of code really I would think.  The fact that it's using the analog input samping instead of just an I/O makes things probably more interesting.  I'm not familiar with the raduino code so I can't say as much about it.

On Mon, Jan 1, 2018 at 9:24 PM, N8DAH <Dherron@...> wrote:

I have been reading about the CW keying here and in another post. Would it be possible to just make it a "to gnd"  trigger? and take out the current keying function. I would rather add a cheap 10-20$ keyer than argue with the raduino. I had planned to wire it for straight key use with a qrpguys keyer, any thoughts?

 

73

  David




--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?

Re: Tell me your favorite uBitx mods

 

Dave,

RF may be getting into your key line. Try a bypass cap across the key jack pins.

There should be 3 resistors, two for the dit and dah and one permanently across +5 to key line.

Raj


At 02-01-2018, you wrote:
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.  LOLÂ

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. Â
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. Â
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.Â

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. Â
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).




--
73 Dave WI6R

Re: Tell me your favorite uBitx mods

John Backo
 

"Careful with those $0.85 RD16HHF-1's"

Yes! The Mitsubishi part is under patent and has not (as far as I know)
been sublet to anyone. The cheap RDxx devices are automatic fakes.
Remember an authentic device is going to cost about $US5.00 for some time
to come...

john
AD5YE

Re: Variable power control

Diver Martin <diver.martin@...>
 

If I need a true DAC output, I'll sometimes throw on a $2 MCP4921.  Depends on if you need i2c or SPI though.  There's a bajillion single chip / single output DAC's out there in the wild.

On Mon, Jan 1, 2018 at 8:50 PM, Clark Martin <kk6isp@...> wrote:
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.

Clark Martin
KK6ISP

On Jan 1, 2018, at 7:27 PM, Ghericoan <boakawizkid@...> wrote:

Take a look at this, http://www.toptechboy.com/arduino/lesson-8-writing-analog-voltages-in-arduino/

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...





--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?

Wiring encoder

ekelley
 

A word of caution when wiring the encoder. The schematic on page one
has the encoder wiring reversed. Don't wire it up by the schematic
use the picture, you will see that the red and yellow wires are reversed
and the black and brown are reversed. I made the mistake of wiring everything
up using the schematic. When tuning my frequency goes down with clockwise
rotation of encoder. Goes up with counter-clockwise rotation.
Ed

Re: uBitx IRF510 to IRF510 physical measurement

Prathap Naidu
 

Hi Bill

centre pin to centre pin is 34.5mm

best 73

Pop

VU2POP

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of bill richardson
Sent: Sunday, December 31, 2017 10:20 PM
To: BITX20@groups.io
Subject: [BITX20] uBitx IRF510 to IRF510 physical measurement

 

looking to buy a large heatsink to use on my uBitx when it arrives. Can someone (that has a uBitx) measure on center to on center from one irf510 to the other.

looking at using this one:

Aluminum Heat Sink Heatsink Module Cooler Fin for High Power Amplifier Transistor Semiconductor Devices with Dense 24 pcs Fins 5.9"(L) x 2.3"(W) x 0.98"(H) 1pc/ 150 mm (L) x 59mm (W) x 25mm (H)

https://www.amazon.com/dp/B073VDVVP5/ref=cm_sw_r_cp_tai_xsrsAb5YJE73T

Thank you

Bill ng1p

Re: uBitx IRF510 to IRF510 physical measurement

John Backo
 

Bill:

That's a good heat-sink for the IRF510 pair. Just be wary of shorting the devices to ground.
Also note that pc board and plastics are a very poor conductor of heat -- if you are building a case from non-metallic
materials, be sure that the IRF510's are connected DIRECTLY to the metal, and not through
the wall of the enclosure. Also, ground the metal. Hi.

I have bought this kind of heat-sink as surplus. They are used on voltage converters and inverters,
especially in solar installations.

john
AD5YE

BITX20 Ver3C SBL VFO

Kevin Luxford
 

Building Sunil's kit. VFO completed. Lo freq = 3.957 MHz. Hi freq = 4.477 MHz. Range is a bit wider than I would like.  Will look at ways of restricting the range.  However the FLL makes it absolutely rock steady.  LED extinguishes in less than a second. Wound L4 with a slightly heavier guage wire that solders through the coating.  Had to wind the last few turns back over the earlier ones.  This will probably add a bit of capacitance in parallel to the inductance, but it seems to work OK.  Using RG316 which I have on hand instead of the RG174 supplied because longer interconnections seemed advantageous when testing and fiddling about. On to the next stage!

Re: No TX #ubitx

joe kallo <quietglow@...>
 

It does indeed receive. 

I'll check out the toroids, thanks. It's funny you mention that as they looked a little flattened when I opened the kit.

Joe

Re: No TX #ubitx

 

Joe,

This means that you can ignore L1-L4 & T1 to T7 - these are common to TX and RX

Check T8 onwards.

Check TX on all the bands, the problem may be band specific.

Raj

At 02-01-2018, you wrote:
It does indeed receive.

I'll check out the toroids, thanks. It's funny you mention that as they looked a little flattened when I opened the kit.

Joe