Re: Schematic . . . What Schematic . . mine?

William Cullison

i think I need to start a notebook. I'll order parts quite often from Chaina and by the time I have my parts I can't remember what they were ordered. At least I'm collecting a good supply of parts.

73 Bill WA8VIH/4

On Mon, Jun 25, 2018 at 11:14 PM, Vince Vielhaber <vev@...> wrote:
I do the same thing.  Mainly because I figure I won't remember it tomorrow!


On 06/25/2018 11:00 PM, Ashhar Farhan wrote:
I always work with a lab notebook. Each time something is finished (as a
module or rig), i pull out the notebook, draw out the circuit and note
the readings and the performance. Then, move on. It is a habit worth
cultivating. In six month time you will forget what you built and why.
Building without a log book is filling a leaky bucket.

- f

On Tue, Jun 26, 2018 at 8:14 AM, <russkg0bk@...
<mailto:russkg0bk@...>> wrote:

    Ty Jon. That's about what I was saying.
    I'm I retired Broadcast Engineer an never kept a notepad (except hidden)
    Job security I guess. hi hi
    Just wanted those that were making mods to know.
    When some quits working. . . how do i get through this rats net to
    fond it.
    AGN TY

  Michigan VHF Corp.

Re: Keypad for Raduino...?

Felix Lopez

I want do something similar with the raspberry pi3 and it's own touch screen. Can use code segments from another project to do this maybe i2c? Any help would be appreciated.  Thanks.

Re: Understanding Spurious Emissions



The math is simple but the LO is not a direct contributor yet required.  I considered 2if-LO as possible
as well as aboth follow the spur. Usually 2if spurs only show up when we hit the 1db compression
point of the mixer and then they stat to grow.  This spur is there even when the mixer input (45mhz)
is -30dbm.

Changing the LO does not help.  The spur is 45mhz (IF)  minus output frequency (dial frequency)= spur

So for 45mhz and 28mhz out  the spur is 17mhz.  Change to a low side LO to 45-17mhz(new lo)=28 plus spur plus 
mixer leakage and the IF-dial frequency spur.   Measured isolation for the mixer was about 40db varied about 1 db
from that with frequencies so the mixer is very good but not perfect.

Remember your line and mine, DBM is a conundrum [headaches] in three ports.  Any of the ports are an
input AND output so even if we assume the RF port is the signal out its also a signal in.  So the LO generates
28mhz if its 73mhz or 17mhz and the spur will be the IF always 45mhz minus the output frequency and the
lo is required but what frequency is only dependent on creating the output frequency.  Happens with
commercial mixers too. 

It works up to 20mhz as the spur frequency is more than the lowest low pass.  The spur being an image
spur goes down with increasing frequency. So at some point a low pass filter cannot stop it.  

Nyquist sampling theory forecasts it.  At 22.5mhz is the alias point the spur overlaps the
generated frequency.  So does Spurtune[program].   Higher IF greater than 60mhz would
work.  Or the traditional solution band pass filters above 20mhz and low pass filter below that.   

Also the assumption is when not talking there is no spur (false) as you sill have carrier
leakage so 45mhz is always there.

It does not appear for CW as the mixer has bias on it to make it a switch and the LO is at signal frequency
without any significant mixing action and nothing else to mix with.


Re: #ubitx safely putting on tight tuning knob #ubitx

Latham, Chip

I think there is something wrong (possibly) with the encoder switch. Mine is not that hard to push maybe 10 ounces of force.
You can get another encoder or what I would do and am planing is to do is just not use that switch and simply replace it with a panel switch. I end up changing frequency when pushing mine and its making me nutz. N5FJK Chip

#ubitx safely putting on tight tuning knob #ubitx

JOHN CRONHELM <johncronhelm@...>

The knob without set screw is very difficult to push on the encoder.i am worried about pushing too hard in case I damage the encoder. Can anyone give me advice.
Many thanks,
John Vo1jcc.

Re: KD8CEC - Nextion Display - IAN questions

Lowell Haney NE4EB

"Je ne suis pas habitué au lignes de commande."

Neither was I, but I am learning.

Bon chance.

Re: Noise Burst #bitx40


Here is full description (from message #27395) of what is happening : 

"When the radio goes into TX, that cap has to charge up via R127 -- which takes a LONG time.  During that time, Q12 is also powering up and C122 has been sitting at zero volts, so it starts charging as well.  This is the response of the Microphone Amplifier to the rising edge of the TX signal -- and the net result is that the Balanced Mixer (T4/D15/D16) is knocked out of balance until the amplifier stabilizes.  The result of that is a spurious RF transmission that looks like the one I have attached as a file.  The RF rises almost immediately to about 5-8 watts, within 5 ms drops down to about 3 watts, builds back up to 5-8 watts in another 5 ms, then slowly decays over a period of 60 ms decays down to close to zero.  (All of this observed with the PTT line held)."

The thread starts with message #27393.


Michael VE3WMB 

Re: Microscope - - new thread

Terry Morris

Thanks Don. I will try Cheese. The article in QQ was over 1 year too late. I ordered the toy in March 2017 after reading some other ham's alleged success with it. I have returned to using Optical headband lenses and other magnifiers that clip on to my reading spectacles.

Terry - KB8AMZ
Brimfield Twp, OH  USA
Linux User# 412308, Ubuntu User# 34905, PCARS#78, NAQCC#6668, QRP-ARCI#8855, SKCC#14195

On Tue, Jun 26, 2018 at 8:25 AM Don, ND6T via Groups.Io <> wrote:
Terry, on Linux try Cheese. My Celestron (which is very similar in appearance) and my 10 meter endoscope work with that program. No, aside from documentation photos, it is just a toy. -Don

Re: Noise Burst #bitx40


John et al : 

The RF burst on PTT closure, on the BITX40, has been addressed by Allard (PE1NWL) in his Raduino Code.

His approach is to shut down the CLK output on the SI5351 for 50 mS on PTT closure and wait for things to settle before re-enabling it to allow TX.  

There is also a simple hardware mod that can be used to reduce this burst from 50 mS to less than 20 mS so that the delay time can be reduced in the code.
The mod is to change C124 from 47uF to 4.7 uF. C124 is near Q12 (mic input).  See message #29101 in this group for the original discussion on this. 


Michael VE3WMB 

Re: Microscope - - new thread

Don, ND6T

Terry, on Linux try Cheese. My Celestron (which is very similar in appearance) and my 10 meter endoscope work with that program. No, aside from documentation photos, it is just a toy. -Don

Re: amp for ubitx4

Stephanus K6NG

do you connect this amp to the speaker wires from the uBitx or do you take the audio from before the audio amp on the uBitx board?


Re: Output power

Terry Morris

I have a 5 watt dummy load consisting of 5-1 watt carbon resistors, gold band, soldered into a PL-259 connector circa 1970's. It was given to me from an elderly ham, now SK. He learned I was starting the hobby with a QRP kit built HW-9. He told me he tried QRP once but it was too difficult making contacts. Thought I would like the low power heater. I do.

Terry - KB8AMZ
Brimfield Twp, OH  USA
Linux User# 412308, Ubuntu User# 34905

On Wed, Jun 20, 2018 at 7:13 PM brad martin <emclinux@...> wrote:
Thank you all for the replies. Unfortunately my idea on paper does not look like it’s going to work out based on my experiments last night. My idea was that I have a cb type swr meter and I was going to make it into a digital swr and power meter and well being that it’s not for Hf the output voltage of the meter didn’t line up with output power. .6v on 80, 1v on 40 and 30 and 1.5v on 20. So oh well on that one. I have Arduinos all over the place so using a mega for this is not a loss for me. I almost use them as coasters at this point. I would see a deal on them and get them over the last few years and as far as time goes I always try to make time for my hobbies because life is short right :).

I have seen the dummy load with a cap and diode before and have been planning on adding that to my dummy load as well. When choosing the diode what properties are you looking for?

I have a goal most people would probably say I’m crazy for doing. The plan is that my first HF contact will be done using things I have made, built, or repaired. So far everything I have (power supply, uBITX, antenna, CW paddle, dummy load, and other random stuff) and the swr meter is the only thing I have left that has not has been modified.

On Wed, Jun 20, 2018 at 3:39 PM Jerry Gaffke via Groups.Io <> wrote:
The BAV21 is not a bad choice for the dummy load dectector.
Very cheap, which is of course my primary criteria.

Forward voltage drop appears to be around 0.5v at 0.1ma from their graphs,
the detector would have a much smaller current going through it.
So should still be able to measure 10mW into the dummy load,
though factoring in that drop to the calculations becomes more important than with the 1n5711. 

I'd still use the 1n5711 for the diode RF probe.


On Wed, Jun 20, 2018 at 12:27 pm, Jack Purdum wrote:
We use a BAV21 diode in our design, which is rated at 250V.

Re: Keypad for Raduino...?

Dennis Zabawa

Here are a number of hardware devices that are applicable to uBITX operator interface designs:
 Operator Interface (Keypad):
     PDN1144  Four Row by Four Column Keypad Interface IC     pdn1144.pdf
     PDN1188 Eight Row by Eight Column Keypad Interface IC     pdn1188.pdf
Operator Interface (Text LCD)
     PDN702 Character LCD Controller IC     pdn702.pdf
Operator Interface (7-Segment LED)
     PDN707 Hex Display 7-Segment LED Driver     pdn707.pdf
     PDN747 Eight Digit Seven-Segment LED Controller/Counter     pdn747.pdf
Mechanical Pushbutton Interface
     PDN2008 Eight Channel Contact Debouncer     pdn2008.pdf
     PDN2108A One-of_Eight Latching (one output active)     pdn2108.pdf
     PDN2108D One-of-Eight Latching (one or zero outputs active)     pdn2108.pdf
     PDN2208 Eight Channel Toggle     pdn2208.pdf

Re: Microscope - - new thread

Terry Morris

This is what I bought for $29 plus shipping, There were no comments whether it was compatible with Linux. For less than $30 I can tell you that it is not compatible with Linux. Its a cute toy but for the $29 I could bought a nice meal for my canine and I. LOL

Terry - KB8AMZ
Brimfield Twp, OH  USA
Linux User# 412308, Ubuntu User# 34905

On Fri, Jun 22, 2018 at 7:30 PM Don, ND6T via Groups.Io <> wrote:
The little microscope with the screen looks like fun! Trouble is, though, a stereoscopic microscope helps a bunch. Nothing like a bit of depth perception to help guide your hot soldering iron to its destination. Same goes with trying to pick up something. Trying to do that with one eye gets old fast. Although I like the dental loupes at times, they don't have the amplification and since they are mounted on my head the focus wanders as I move and my neck starts to feel it after a while. K9AC's SolderScope gives a better, more stable view. Yes, it takes some DIY innovation but check out his wooden stand that he made from scrap. Until somebody gives me a Mantis Elite I prefer the SolderScope. It's smaller, too. 73, Don

Re: Bitx40 75KHz Spurious, How to solve it. #bitx40



That is the marker M 7.049 , its very low in level and not seen.


At 26-06-18, you wrote:
It shows scanning from 7.029Mhz to 7.049Mhz. That's only a 20khz
scan, not 50khz. And certainly not 50khz per division on the screen.

The funny thing is that those unknowns are *increasing* in amplitude as
you move away from the carrier instead of decreasing. I'm not sure what
would generate this.

Could these be products from overdriving the spectrum analyzer?

tim ab0wr

Re: KD8CEC - Nextion Display - IAN questions

Michel Dupuy

Je vais essayer .
Ce n est pas grave si cela ne fonctionne pas.
Je ne suis pas habitué au lignes de commande.
J utiliserai IDE Raduino lorsque on aura le fichier source.
De toutes façon j ai aussi un PC et là pas de problèmes.

Re: Keypad for Raduino...?



Well, thank you for that information about the TTP229.
The code I found did the job for an HDSDR controller project that was eventually abandoned
even although it worked as planned. The ergonomics just didn't work for me.

Having also built a Nextion controller my preference is to complemented the touch inputs
with knobs and buttons for tuning and certain other most frequently used controls.

I agree 100% with your comment about adding an external S-meter with the Nextion display.

73 Bob GM4CID

Re: RFI from uBitx TX after AGC and other mods installed

Don, ND6T

Alan, Sorry for the relay info. I see what you are getting to now. Do you have a "pop fix" modification in place (any flavor)?
Rowland: What happens if you unplug the AGC board (everything else still connected) and transmit? Does the feedback go away? -Don

Re: Keypad for Raduino...?

Mike Woods

This is not quite correct.  This sketch is a hack that would work but the TTP229 is a true i2c device.  See the following use case that deploys the wire library:

This is an easy add to the uBITx for somebody wanting a keypad ... but why not use a Nextion display with KD8CEC firmware?  It already has firmware built to provide touchpad frequency entry in the UI!

It is a bit the same as building an analogue S-meter when KD8CEC firmware and Nextion already feature a classy digital S-meter that can be calibrated easily...

There are always different ways of doing things, but some ways are easier than others!



On Tue, 26 Jun 2018 at 3:38 AM, Robert McClements <gm4cid@...> wrote:

The TTP229 capacitive  keyboard has two pins labelled SCL and SDO but unfortunately they are not I2C.

The way that they work is SCL is clocked frequently up to 16 times and during each clock cycle SDO is
checked. If a key is pressed SDO will return a Low, the count stops and the clock count equates to
the key number. Hope that makes sense, not easy to put into words.

So this device will require the use of two digital pins.



Sample code below :-

 // Routine to read if a key is pressed and return its value
byte Read_Keypad(void)
   byte Count;
   byte  Key_State = 0;
   for(Count = 1; Count <= 16; Count++) // Pulse the clock pin up to 16 times and read the state of the data pin on each pulse
      digitalWrite(Clock_PIN, LOW);
      if  (! digitalRead (Data_PIN)) // data pin low store the current key number
         Key_State = Count;
      digitalWrite(Clock_PIN, HIGH);
   return Key_State;

Re: KD8CEC - Nextion Display - IAN questions

Lowell Haney NE4EB


If you have the Arduino IDE, there is a command line utility built into the package. it is called "AVRDude" and can be executed from a terminal window. Here is the command line that works with my setup.

avrdude -pm328p -carduino -P/dev/ttyUSB0 -b57600 -Uflash:w:ubitx_CEC1.01.hex:i

The filename you want to load  (.hex file) is just after the 'w:'  I execute this line after navigating to the file location directory/file in the terminal program. The help function for avrdude explains all the switches that can be invoked.

Hope this helps.