Date   
Re: boosting the power on 28 MHz #ubitx

Daniel Conklin
 

Please let us know how well it works for you.
Dan, W2DLC

Anyone working With Nextion HMI LCD Touch Displays and UBITX?

Joe
 

Hi,
I have been working with the regular LCD and TFT Touch displays and was wondering if anyone in our group had ventured into the Nextion Touch Displays?

They appear to be an excellent alternate to the regular TFT touch displays and are nearly the same price.
The big thing i see is it has a full micro-controller on board so virtually no load on the Arduino micro-controller and only 2 wires required to exchange data.

With the current nano as the processor it does not take much to bog it down so using Nextion  Touch displays would provide much improved visual enhancements

Free software is available  to build your graphic display, and emulate functions before uploading to the Display...

Just throwing this out to the group for feedback.

Joe
VE1BWV

Re: Anyone working With Nextion HMI LCD Touch Displays and UBITX?

Doug W
 

There was a thread a few months back...
https://groups.io/g/BITX20/topic/9607885

Re: Anyone working With Nextion HMI LCD Touch Displays and UBITX?

Joe
 

Thanks!



Joe
VE1BWV

On Mon, May 21, 2018 at 10:35 PM, Doug W <dougwilner@...> wrote:
There was a thread a few months back...
https://groups.io/g/BITX20/topic/9607885


Re: Nextion Display

Joe
 

I was wondering if you would share your hmi file.  I am thinking of trying the Nextion display and would appreciate a starting place for the display.
What model are you using?
I was thinking  of either the 3.5 or 5 inch

Thanks
joe
VE1BWV

Re: RF power chain mods and improvements..

ajparent1/KB1GMX <kb1gmx@...>
 

Here is where i'm at...

This is experiments 101, interim progress.

While waiting for parts, used whats on hand:
Made Q90 a 2n2369A smt part, Better gain bandwith product (ft) gain maintains at higher frequency (also lowered bias)
I installed 6 2n2222A in the predriver and driver.  (HFE hold up at high current(
Put 470 pf across R82 ( gain increases with frequency.
Placed 390pf cap from top of RV1 to the wiper  (only works if your not maxed out!)
   The trick here is couple more rf through RV1 with increasing frequency.  If it is all the
   way up its hard to get more vis this path.
Put 3.3uH inductor in series with R86 (allows decreasing feedback with frequency)

Turned up the bias on the IRF510s. I'm running at 210ma per device!  
Doing this really helped the output power at 20M and up.
Key down at 10W is 2A.

Power set to 10W at 12.0 V 3.6mhz
40m    10.3w
30M    6W  ???  output low pass filter??
20m     9.8w
17M     7.5w ???  low pass filter again??
15M      8w
12M      8.5W
10M      8W         

This is still interim testing and I have many more things to try.
It does confirm that the performance can be more uniform.

I'm perplexed that 30M and 17M is so low, it may be the low pass filter in use.

The only problem I see with 210ma per device is the no-modulation standing current is .8A
which is not battery friendly but maybe what we need.  They do not seen to heat much. 
It suggests T11 is less than optimum.

I need to try improved output transformer both 1:1 (2t:2t) and 1:2 (2t:3T) on
bn43-6802 (and bn61-6802).  I may also try a different configuration driver
transformer.

This IS NOT FINAL, net even close. I need to see what it looks like with spectrum analyzer. 
The final result will be put up with pictures and explanation of what, where, and how.
Patience please.


Allison

Socketing a Nano to the other side of the Raduino

Jerry Gaffke
 

We would like to socket the Nano, but then the standard display doesn't fit,
If we extend the pins to make it fit, then we may have to redo our enclosure
to give the display some extra room.

Here's a possible solution:

Remove Nano from the Raduino, add socket strips to the other side of the Raduino,
Get a Nano with the pins not yet installed:
    https://www.amazon.com/Elegoo-Arduino-ATmega328P-without-compatible/dp/B0713XK923
Solder them pins to the top side of the Nano.
Plug and play.

Bad news is that the Nano is now sitting right above the RF part of the uBitx,
no longer shielded by the Raduino's ground plane.
So the audio tone issue could be the next issue to solve.

Fortunately, the CH340 is now easy to remove/disable, use a USB-to-UART cable assembly instead.

Perhaps hang caps on the 16mhz resonator to bring it down in frequency,
or replace it with a non-16mhz crystal?  Drive it from the BFO?

Or tinfoil and duct tape?

Jerry, KE7ER

Re: Anyone working With Nextion HMI LCD Touch Displays and UBITX?

ajparent1/KB1GMX <kb1gmx@...>
 

Haven't tried that specific one but I have an Rpi with a 7" TFT with touch.  Power required i
s about that of the Rpi.  But it looks good and is really nice to use.

However using it with a Raduino is likely a bit tough as its compute intensive and IO too.
STMF4 or Cypress CY8CKit-049-42xx.

The Cypress family is handy as its PSoC peripherals allow some programable CLBs for
custom interfaces.  That and 32 bit ARM at 40Mhz 32k falsh and 4K ram (plus ADC,
serial, lots of IO) makes a nice step up.

Allison

Re: Transmitter Mods

Howard Fidel
 

Just to let those know that sent me prepaid envelopes, I was away for the last 2 weeks, and will send out the parts tomorrow for the requests that I received during my absence.

Howard


On 4/17/2018 11:25 AM, Howard Fidel wrote:

I got my uBitx last week. I was surprised to get it, since it was sent 3 days before and I paid for India Post shipment, but it came by DHL, which was a nice surprise. I have assembled it, and started testing and am doing a number of modifications in my lab before moving it to its home in the shack.

Today I modified the transmitter to improve the output power at the higher frequencies. The power out in the original state is about 3 watts at 28 MHz. My modification brings the power at 28 MHz up to 7 watts on both the 15 and 10 meter bands. On my board at least, there is not enough range in VR1 to increase the power to anywhere near this level without this modification. The other bands remain unchanged in output, which I measured at 11 watts.  The output stage could be modified as others have done by changing the FETs and transformer to improve it more, but I am happy with this for now. I plan on adding a power amplifier later, something between 50 and 100 watts.

My fix is simply to add 3 passive parts. I added:
33 uH inductor in series with R86. I lifted the resistor mounting it on one pad standing up, and teepeeing the inductor between the top of the resistor and the other pad.

Add a 270 pF capacitor across both R87 and R88.

The values are not very critical, I calculated that I needed 27 uH and 220 pF, but the values I tried were in the lab.

If anyone wants to try the fix and needs the parts, I have a full reel of each, so just send me a stamped self addressed envelope, and I will send it to you by return mail. The offer is good until I run out of parts.

Next up is adding an AGC and S meter.

I also measured the receiver sensitivity and can confirm that it meets specifications. 

Howard

WB2VXW



Re: Socketing a Nano to the other side of the Raduino

ajparent1/KB1GMX <kb1gmx@...>
 

Why not remote it some from the mainboard and put a box around the back of it
with the wires sneaking out of  it.  The front of the box is the front panel and the
Raduino is tinned up.  Take care with the signal leads (use SHORT twisted pairs).
Used those tricks for old style counter circuits that radiated digital noise like mad.

In my case the height of the board when mounted is a problem.  Solution is change
the board connector into a right angle and then relocate the display with wires.
That lowers the profile.   Both boards can easily then have a cover over them
made of soldered up PCB, hobby brass, or copper screening.  Control pins will
exit though the screen box via 1000pf feedthroughs.  I try to keep noise in
the box so to speak.

Allison

Re: boosting the power on 28 MHz #ubitx

ajparent1/KB1GMX <kb1gmx@...>
 

yes and other mods as well.  For now its at best a partial fix.

FYI the IRF510s will deliver 10W and then some at 10M!


Allison

Re: Socketing a Nano to the other side of the Raduino

Kees T
 

You could actually have different Nanos for different overall functions and just swap them out since it would be pluggable.

73 Kees K5BCQ

Re: Socketing a Nano to the other side of the Raduino

Jerry Gaffke
 

Cuz sheet metal work is not as much fun as burning solder.

Shielding various sections of the radio from each other is not a bad idea.
And the Raduino/display is a good place to start.

Allowing the Si5351 clocks out of the box while disallowing
everything else might be problematic.
Simple solution: move the Si5351 to the uBitx, filter the i2c bus to a few hundred khz and less.

Though I do think that running the processor from the BFO and kicking 
the USB-to-UART out entirely would pretty well solve most interference
from the Raduino.  

Jerry



On Mon, May 21, 2018 at 07:23 pm, ajparent1/KB1GMX wrote:
Why not remote it some from the mainboard and put a box around the back of it
with the wires sneaking out of  it.  The front of the box is the front panel and the
Raduino is tinned up.  Take care with the signal leads (use SHORT twisted pairs).
Used those tricks for old style counter circuits that radiated digital noise like mad.

Re: W8TEE vft/tft questions

Jack, W8TEE
 

Tom:

If we are talking about the VFO/TFT board, look for the place where we read the encoder. If this is the BITX code, look for the symbolic constant ENCODERTUNING around line 1720. At line 1729, you should see some scaffolding code:

#ifdef DEBUG          
Serial.print("Examine Fast Tune: Start = ");        // May be useful for setting Fast Tune rate
Serial.print(fasttuneStart);
Serial.print("   end = ");
Serial.print(fasttuneEnd);
Serial.print("  diff = ");
Serial.println(fasttuneEnd - fasttuneStart);
#endif   
      

If DEBUG is defined (see line 36) it will print the info out. (If it's commented out with "//", remove those.) This should tell you if the encoder is working and if the Fasttune parts are working.

Jack, W8TEE

On Monday, May 21, 2018, 5:09:08 PM EDT, tom.mccobb@... <tom.mccobb@...> wrote:


I completed  a build of Jack's board a few months ago, and it was working fine. I even made some mods to his code, adding a 4th button press destination from which I could set tuner increments to 50Hz, 100Hz, 1KHz.  (I never had much luck with the encoder speed routines)

All was fine until just recently.  Now when I rotate the encoder, It will pretty much stay in the the same 2KHz range.  If I spin it furiously, I can get it to move erratically up and down the band, but I have obviously broken something.

Which isn't a complete surprise given how many times I have dismantled the unit to change my front panel layout, swap in a SO-359 for the standard antenna jack, replaced the power connector on the W8TEE board to a screw terminal, etc.  I suspect I laid the VFO down on the metal case with some pins touching where they shouldn't have.

So the  question is where to look.  I have checked and verified voltages.  I backed out my modified sketch and reinstalled the original.  I have swapped in several different encoders (I got a bunch of them).  No joy.  The behavior is the same whether it is driven by the USB power connector when disconnected from the Bit40, or the Bit40 power.  (I am feeding it 12v, btw, as the schematic specifies, not the 7-9v in the assembly guide. Is that a problem?).  In all other respects it appears to work - I think - see below.  I have a spare Mega 2560, and as soon as can get headers on it I will swap that in.  

While troubleshooting, I put the outputs on a scope.  The buffered output looks to be about 2.5-3v , and is a nice clean sine wave at about 60 Hz - and it does not change when the encoder is rotated.  The un-buffered output is about the same frequency, but voltage is several orders of magnitude smaller.  And the square wave output is just noise, or at best a very noisy triangle wave.  Does this indicate a problem with the A9850?  (Yes, it could indicate that I don't know what I am doing with the scope, a Tek 2235).

Any pointers?  It is kind of fun troubleshooting, but I would like to get it working again before the end of the decade.

Thanks.

Re: boosting the power on 28 MHz #ubitx

Jerry Gaffke
 

I just want to say that I'm very happy to see you take this on!
Jerry


On Mon, May 21, 2018 at 07:30 pm, ajparent1/KB1GMX wrote:
yes and other mods as well.  For now its at best a partial fix.

FYI the IRF510s will deliver 10W and then some at 10M!

Re: #ubitx #ubitx-help #ubitx-help #ubitx

WA9PWR
 

Generally silicon diodes will fail with a short circuit, protecting the hardware.

Re: #ubitx #ubitx-help #ubitx-help #ubitx

Jerry Gaffke
 

This reference suggests silicon diodes generally fail with a short when subjected to over-voltage.
And generally fail with an open when subjected to too much current.
    https://electronics.stackexchange.com/questions/77712/can-a-diode-fail-to-open-position

The uBitx reverse protection diode would likely blow open due to excessive current (and heat)
if the power supply is not fused properly.

Jerry


On Mon, May 21, 2018 at 08:50 pm, WA9PWR wrote:
Generally silicon diodes will fail with a short circuit, protecting the hardware.

Knob adapter sleeve (6mm ID, 1/4 inch OD)

Jonathan
 

I got a bit frustrated finding a knob to fit the 6mm knobs on the uBitx.  Fortunately I found these adapter sleeves to bring the shaft OD up to 1/4 inch so I can use standard American 1/4 shaft knobs!    I received them today and they work.  You do have to be careful to pull them out slightly before you tighten the set screws so the knob has enough clearance to be pushed in for the switch to work.

https://www.ebay.com/itm/222983860788

-Jonathan

Re: Mic doesn't work in bitx40 #bitx40

qonita.salimah@...
 

Thanks for your reply..

I've already swap the leads of the electret mic. But the same thing is happened. What voltage suppose the capacitor showed exactly?
is there any limitation on how big the voltage is to make the mic work?

thank you very much

Re: #ubitx #ubitx-help #ubitx-help #ubitx

WA9PWR
 

Tell that to varidur.  Reverse protection diodes are cheap insurance.