Date   
Re: Adjustments using uBITx Memory Manager

Vic WA4THR
 

Did you set yours just like the picture I included, Martin? Be sure that the "CW Freq Adjust Value is" remains at zero as that is a separate setting at the top of the Memory manager. The "CW Side tone" is where this is controlled and a value in the CW Freq Adjust area can confuse the results. Also, I think you need to reboot the uBitX for these changes to take effect.


=Vic=

Re: Express Receiver Audio stage for uBitx

Tom, wb6b
 

Hi,

If you don't need all those audio buffer stages and are OK with the audio output to the speaker, maybe something like this chip to directly replace the volume control pot of the uBitx.

https://www.digikey.com/product-detail/en/maxim-integrated/DS3501U/DS3501U-ND/1642373

This part cost a dollar rather than six dollars. It has the zero crossing detector that the specification sheet says eliminates the "zipper effect" when changing the volume level.

If you don't want to do the logarithmic calculation in software there are logarithmic versions for about two dollars. 

This one, with no "extra" features for only 53 cents.

https://www.digikey.com/product-detail/en/microchip-technology/MCP4018T-103E-LT/MCP4018T-103E-LTCT-ND/2060161

These chips seem to only rate the analog voltage to -0.6 volts below ground. So, assuming they work with negative going analog signals, they need to be in a low level signal portion of the circuit. 

The data sheets are a little weak in their specifications and example circuits, but the Express Receiver looks like it is running the audio through its digital potentiometer as A.C. referenced to ground.

Tom, wb6b

Re: Express Receiver Audio stage for uBitx

Ashhar Farhan
 

I too was reading up on it the other day. It would be easy to just take  the output from the 3db rf attenuator pad into the audio preamp of the express receiver.

- f

On Sun 6 Oct, 2019, 4:31 AM John Scherer, <jrsphoto@...> wrote:
This is the audio output stage I was referring too:

http://www.expressreceiver.com/wp-content/uploads/2015/05/2016-Prod-Det-BFO-Audio-Amp-Page-2.bmp

Re: Express Receiver Audio stage for uBitx

John Scherer
 

This is the audio output stage I was referring too:

http://www.expressreceiver.com/wp-content/uploads/2015/05/2016-Prod-Det-BFO-Audio-Amp-Page-2.bmp

Re: cw when I tune #ubitx-help

KG5YUO
 

I moved the resister there and presto!  


 Thanks 
Bruce KG5YUO

Re: Adjustments using uBITx Memory Manager

hickmodawg@...
 

Hi Vic:
Thank you for your reply.
I tried the change you suggested, using uBITx Manager to upload it to my new Nano in my radio, but it didn't change anything...
I appreciate help, though.
I'm open to any other suggestions.
I'm really frustrated
Martin

Express Receiver Audio stage for uBitx

John Scherer
 

I've been reading through the build of the Express Receiver lately.  What a lovely and detailed project!  One aspect that really caught my attention was its audio output stage with the DS1807 digital audio taper pot.  How would one go about adding this (including the NE5532 amps) to a uBitx with the  kit-projects uBitx AGC?
--
John - N0CTL - Fulltime RV in a 40' motorhome

Re: Redy for smoke test but Bitx 42

mtngentleman@...
 

I checked the resistance across the power connector and get a direct short.  It is open when I unplug the two two pin PS connectors.  Any ideas


Tks

Re: Smoke test prep

MVS Sarma
 

Most possibly the pa  fet irf510 might be   culprit.  You may remove 3 pin power plug connevt power using only black and  red pins tgat go for balance board. You can startcRx signals. 


On Sat, 5 Oct 2019, 8:04 pm , <mtngentleman@...> wrote:
I've checked and rechecked and my my Bitz 40 shows a direct short across the power connector.  Any clues?

Also notice instructions don't mention hook up of master switch and fuse??

Tks Shep

Re: How to delete a bad .tft file from display

MVS Sarma
 

Finally you Did. Congrats.


On Sat, 5 Oct 2019, 5:11 pm KN4SMO via Groups.Io, <dtb2greenville=ymail.com@groups.io> wrote:
"Bet you write the file using a Mac. Macs writes extra files to the sd card.  Believe it has a “.” Prefix but  has the “.tft”  suffix. That is what is causing the multiple tft file error."

OK Fellas, My Mac could properly format my SD card but wrote extra files to the card.  My PC could not properly format my card but could load the single .tft file. The little Nextion tells you the issues when I would try to load a file , smart little thing. With your help I was able to load the proper screen size on the Nextion. This gives me hope I can build the radio.  

Thanks so much for the direction for this issue! 

Scott, KN4SMO

Re: cw when I tune #ubitx-help

KG5YUO
 

Thank you. I guess the fatigue had set in last night as this morning I looked at the schematic and it is obvious. (DUH) Thanks for helping a noob.


 Bruce KG5YUO

RE Smoke test prep more

mtngentleman@...
 

when I remove both  the 2, 2 conductor plugs (supply points) no short. So gues it is something downstream?

S

Re: uBITX + Teensy audio interface - ground loops (?), RX/TX audio bleed? #teensy #ubitx

Martin Potter
 

In general transformers are used to isolate one circuit from another, as well as to transform the impedance, etc etc. So it is quite possible, and sometimes desirable, to have different ground circuits on each side of the transformer. You could try rearranging your ground connections to take advantage of the isolation provided by the transformer.
Very 73,
... Martin VE3OAT

Smoke test prep

mtngentleman@...
 

I've checked and rechecked and my my Bitz 40 shows a direct short across the power connector.  Any clues?

Also notice instructions don't mention hook up of master switch and fuse??

Tks Shep

Re: Redy for smoke test but Bitx 42

mtngentleman@...
 

many thanks!

Re: How to delete a bad .tft file from display

KN4SMO
 

"Bet you write the file using a Mac. Macs writes extra files to the sd card.  Believe it has a “.” Prefix but  has the “.tft”  suffix. That is what is causing the multiple tft file error."

OK Fellas, My Mac could properly format my SD card but wrote extra files to the card.  My PC could not properly format my card but could load the single .tft file. The little Nextion tells you the issues when I would try to load a file , smart little thing. With your help I was able to load the proper screen size on the Nextion. This gives me hope I can build the radio.  

Thanks so much for the direction for this issue! 

Scott, KN4SMO

Re: How to delete a bad .tft file from display

MVS Sarma
 

Lo l, I am no expert. I use win7. Yes mac is popular. . Is it possible to rename file extention of unwanted file to serve your cause


On Sat, 5 Oct 2019, 9:43 am Mark Hatch, <mark2382@...> wrote:
Bet you write the file using a Mac. Macs writes extra files to the sd card.  Believe it has a “.” Prefix but  has the “.tft”  suffix. That is what is causing the multiple tft file error. 

Been there...

mark

Re: Redy for smoke test but Bitx 42

Dexter N Muir
 

Wrong, Curt.  Presence of that Tuning connector defines your board as BITX40 - and yes, Shep, that extra 3-pin connector on board was for the potentiometer to control the voltage of a varicap diode in the early analog oscillator. If you have the Raduino, that is redundant: the Raduino replaces that oscillator. The inductor for that oscillator was a toroid: there should be a blank component outline in that area for that(L4), and C91. Refer to the circuit diagram at http://www.hfsignals.com/index.php/2017/11/23/bitx40-circuit-description/

That 4.7k resistor is only needed for proper operation of the uBITX.

Re: cw when I tune #ubitx-help

MVS Sarma
 


On Sat, 5 Oct 2019, 9:45 am Mvs Sarma, <mvssarma@...> wrote:
Econd phto is here. The resistor faced other sude. Hence you see white background.
You can silder normal 1/4w resistor across those leads.

On Sat, 5 Oct 2019, 9:37 am MVS Sarma via Groups.Io, <mvssarma=gmail.com@groups.io> wrote:
You can see the 8 pin connector marked"P1"
Place resistor between pins 2 and 3 as counted from end of 16pin lcd connector. I placed smd 0805  , that too at a vertical angle. Let me show it. 

Obviously 2nd pin goes to ket socket ,  other wire being Gnd.  The battery wire at pin3 need not go up to key socket.

All the best.

On Sat, 5 Oct 2019, 8:13 am KG5YUO, <wtxrcdog@...> wrote:
Hello 
I just got my U-bitx together. I used the Amateur radio kits case kit. I had trouble with my encoder wiring so I cut the wires off of the plugs that came with the kit and soldered them directly to the encoder. This took out the resister that keeps the transmitter from keying cw. Where in the line do I put the resister?

 Thanks for the help 
Bruce KG5YUO
--
"A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort."

Re: cw when I tune #ubitx-help

MVS Sarma
 

Econd phto is here. The resistor faced other sude. Hence you see white background.
You can silder normal 1/4w resistor across those leads.

On Sat, 5 Oct 2019, 9:37 am MVS Sarma via Groups.Io, <mvssarma=gmail.com@groups.io> wrote:
You can see the 8 pin connector marked"P1"
Place resistor between pins 2 and 3 as counted from end of 16pin lcd connector. I placed smd 0805  , that too at a vertical angle. Let me show it. 

Obviously 2nd pin goes to ket socket ,  other wire being Gnd.  The battery wire at pin3 need not go up to key socket.

All the best.

On Sat, 5 Oct 2019, 8:13 am KG5YUO, <wtxrcdog@...> wrote:
Hello 
I just got my U-bitx together. I used the Amateur radio kits case kit. I had trouble with my encoder wiring so I cut the wires off of the plugs that came with the kit and soldered them directly to the encoder. This took out the resister that keeps the transmitter from keying cw. Where in the line do I put the resister?

 Thanks for the help 
Bruce KG5YUO
--
"A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort."