Date   
BITX QSO Afternoon/Evening, Sunday, June 17, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

John P
 

BITX QSO Afternoon/Evening, Sunday, June 17, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

Join us as we make contacts with our BitX-40s or uBitXs or anything else on 7.277 MHz in 40 meters!

This is a worldwide event for BitX40 (and other QRP) stations starting at 3PM and 7pm in each time zone. To participate, call CQ BitX on Sunday, starting at 3PM and/or 7PM your local time. The BitX QSO Night continues through the evening and conditions usually improve after sunset, so it is worthwhile to participate later in the evening.

Suggested Best Operating Practices:

Work at QRP power levels unless conditions require more power.
Call and listen for CQ BITX on the hour and every quarter hour.
It is helpful if you call CQ BITX with your callsign, name and location. 
Repeat your callsign a number of times during your CQ BITX and during QSO's.
Start a QSO by confirming the callsign, location, name and signal report of the other operator.
Say the callsign, name and location of the other operator so others can hear.
If the frequency is busy, avoid long conversations.
After your initial QSO is complete, ask if there are any other stations who would like to contact.

Report your QSO's, discuss propagation, noise, signal reports, audio reports, antenna type, etc. in this thread.

This is an undirected, scheduled event.  The BITX QSO Night relies on you to call CQ BITX to initiate contacts with other stations, so warm up that final and transmit a few calls on Sunday evening.  Talk to you then!
--
John - WA2FZW

Re: Can't get my uBitX to transmit CW on the Dial frequency

Jerry Gaffke
 

I'm not sure what you mean about shifting the BFO.
The BFO has nothing to do with transmit.
On receive, it can remain exactly where it was for SSB operation.

And no idea what all the other software releases out there are doing.
Mine is rigged as follows

On transmit the dial shows the frequency of the CW carrier (of course).

On receive (if RIT is not enabled) it still shows the same operating frequency in the LCD.
However, the VFO is tuned up in frequency by however many hertz the cw sidetone is set up to be
if operating in LowerSideBand mode, and down in frequency by that many hertz if UpperSideBand mode.

Since I worked for years with not terribly selective receivers (no crystal filter) I prefer to tune in a CW carrier
by going for a zero beat in the audio.  In this mode, the BFO is moved to the center of the 12mhz
crystal filter passband, halfway between USB and LSB mode.  I call it ZSB. 
Then once tuned in, flip back to LSB or USB mode to operate CW.
This ZSB mode is also handy when calibrating the the 25mhz si5351 reference oscillator as per post 35235.

Jerry, KE7ER


On Thu, Jun 14, 2018 at 07:57 pm, Tim Gorman wrote:
It would actually make the most sense to me if *both* the TX and RX
frequency stayed the same, only the BFO would be shifted. If you are
working CW on 7030 the both the TX and RX should show 7030! If you
change from CWL to CWU only the BFO should move. Otherwise you wind up
continually having to do math in your head to determine what frequency
you are actually listening to!It's far easier and quicker to make the
rig do that!

Re: VOM Advice?

Jerry Gaffke
 

I'm not sure I would recommend trying to replicate all the ACV/DCV/Ohms/Amps/mAmps ranges 
of a $1 Centek DVM from Harbor Freight.
But instead of spending the extra $11 bucks on a DVM with a capacitance range, it might be worth
building this capacitance meter into your Raduino:
    http://wordpress.codewrite.co.uk/pic/2014/01/21/cap-meter-with-arduino-uno/

Select it with a menu option.

Jerry



On Thu, Jun 14, 2018 at 07:25 pm, Arv Evans wrote:
It is relatively easy to build up an Arduino with LCD display to display voltages that are
presented to one, or more, of the ADC inputs.  This gives you a basic 5V range that can
be increased with dividers. 

Re: Can't get my uBitX to transmit CW on the Dial frequency

Tom, wb6b
 

On the CEC firmware, and the original factory firmware when you use the PTT for SSB the transmit frequency is what is shown on the display. When you key the transmitter with the CW key the firmware changes the transmit frequency to be lower than what is on the display by the same amount as the "sidetone" frequency setting. 

For someone hearing a CW station that they would like to respond to, then, if they tuned the other station at the same tone as the sidetone they hear when transmitting, everything is great. If you were wanting to initiate an exchange at a specific frequency (like inside the lower edge of amateur band) the unexpected offset kind of sucks. 

If the display at least switched to showing the actual transmit frequency, when transmitting CW, at least people would not be kept in the dark about what the radio is doing. Basic user interface feedback. Pretty much people assume the displayed frequency is the frequency they are transmitting on, and this shift from the display is unexpected behavior.

Tom, wb6b

Re: VOM Advice?

Jerry Gaffke
 

That's the same Centech brand as the red rectangular cheapies form Harbor Freight.
Pretty much the same functionality.  And I'd guess the same stuff inside.
The primary differences I see is that this ebay job has a continuity beeper  and a backlight. 

Jerry



On Thu, Jun 14, 2018 at 08:11 pm, Tim Gorman wrote:
For most anything you'll do with the ubitx you don't need an expensive
desk meter.

this one:
www.ebay.com/itm/Digital-Voltmeter-Ammeter-Ohmmeter-Multimeter-Volt-AC-DC-Tester-Meter-US-Seller/271496690158?hash=item3f3676b9ee:g:qgUAAOSwHnFVkYPk

is representative of one that has lots of functions. It's a lot like
the one I use much of the time. PLEASE don't hook the test leads up the
way it is shown, it won't work!

There is a huge gap in its current measuring scales, from 200ma to
10amp in one big jump, but that will probably get you by.

tim ab0wr

Re: Can't get my uBitX to transmit CW on the Dial frequency

Jerry Gaffke
 

My code is different than most others in that there is an explicit CW mode that you select within the menu.

Without an explicit CW mode (just hit the key to send CW, hit the PTT to send SSB), the receiver must always
display the the frequency of what is normally the suppressed carrier of the SSB signal since this is 
primarily an SSB transceiver.   To hear a CW signal (which is just a carrier, in this case not suppressed),
you must tune a few hundred hz to one side somehow.  That's the source of the confusion.

The solution is an explicit CW mode as per post 44349
This also allows the PTT switch to be used as a straight key, freeing up A6 in the stock code.

Jerry
 


On Thu, Jun 14, 2018 at 08:57 pm, Jerry Gaffke wrote:
On receive (if RIT is not enabled) it still shows the same operating frequency in the LCD.
However, the VFO is tuned up in frequency by however many hertz the cw sidetone is set up to be
if operating in LowerSideBand mode, and down in frequency by that many hertz if UpperSideBand mode.

Re: SI5351 quadrature VFO

Hans Summers
 




Hi Jerry 

> I'm curious, have you measured the increase in jitter when going to a 
> fractional output msynth on the si5351?
> Not clear to me whether or not this is a significant consideration for the uBitx.

No, I have not measured it. In my opinion it is not likely to be a problem. As you mention, SiLabs do various tricks in the silicon that reduce jitter. I agree that the difference between the two modes may be a factor of 2 or less. Both of them are surely fine and better than the LC VFOs everyone was happy with for a century. Elecraft use the Si5351A as the VFO in the KX2, I'd like to hope that also confirms it can't be bad :-)

But still I prefer the use of the even integer divisor, and I have always used it this way. And it allows the quadrature mode if that is desired. 

> Another issue, the uBitx uses all three clocks out of the si5351, and with only 
> two PLL's available in the si5351 it's at least bothersome if not impractical to keep all three 
> output msynth's in integer mode. I agree that you must be in integer mode to use the phase 
> shift feature to get quadrature clocks, but that is not a requirement on the uBitx. 

Yes that's a very good point that I had forgotten. Not just bothersome or impractical; but in the general case impossible... there are three outputs (with three MultiSynth dividers) but only two PLLs. So if you want to use three outputs all on different frequencies, then the third MUST use fractional MultiSynth division. Unless you are lucky enough that your third frequency is somehow related to one of the others, such that it can use an integer division too. 

I do use the fractional division mode in my ProgRock kit http://qrp-labs.com/progrock which supports three independent frequency outputs. So I use even integer on two outputs and MultiSynth fractional division on the third. 

One other comment... 

Use of floating point arithmetic greatly increases the code size. And execution time - but generally I have found the execution time is not usually a constraint, neither is RAM or EEPROM... the biggest constraint I run into is the Flash program memory size. 64-bit arithmetic increases the code size even worse than floating point. Accordingly I use only 32-bit unsigned integer arithmetic in my Si5351A configuration routines in my firmware. It is possible to do all the calculations in 32-bit arithmetic without losing any precision (Floating point loses precision, 64-bit increases the code size too much). The result is compact code and accurate. 

73 Hans G0UPL

Went Dead

Bill Watkins
 

Was in middle of wspr transmission. Radio went dark. Power source checks out good. When cycle off and on, display just slightly flashes. Display and raduino work fine with usb to computer.

What happened? Where do I start?

Bill

Re: Went Dead

Ashhar Farhan
 

Something has shorted. take out the PA power line and check?

- f

On Fri, Jun 15, 2018 at 11:54 AM, Bill Watkins <kf7yxs@...> wrote:
Was in middle of wspr transmission. Radio went dark. Power source checks out good. When cycle off and on, display just slightly flashes. Display and raduino work fine with usb to computer.

What happened?  Where do I start?

Bill




Nextion Displays >> warning

Glenn
 

I purchased what appeared to be a Nextion display according to the description, off ebay recently. Cost was $12.  It arrived ok but does not work. The Nextion editor warns that displays with the prefix "TJC" are not compatible. On ebay they are being sold as Nextion displays but appear to be some sort of copy. (Hardly unusual) ( Genuine Nextion displays start at more like $18-20.)

The Nextion editor does not allow them to be uploaded with files.  Apparently there was supposed to be a way, with some previous versions of the Nextion Editor which I found and also tried, but to no avail.

So a warning about using 'Nextion" displays, but actually shown as TJC types, they should not be purchased.  Unfortunately ebay (as usual) sellers do not tell us this. Some don't even show the part number on the back in a picture.

glenn

Re: Nextion Displays >> warning

John
 

I just ordered one and the model number starts with NX paid 16.22 with 1.99 shipping. Comes from China so have to be a bit patient to if it will work or not. About 2-3 weeks of patience ;)

John
KG5WJQ

Re: Nextion Displays >> warning

Ian Lee
 

Thank you for important information.

I made the same mistake.
Nextion comes with a USB Pin board in the box.
I was able to find $ 14 including shipping costs in Aliexpress.

Ian KD8CEC



2018-06-15 16:37 GMT+09:00 Glenn <glennp@...>:

I purchased what appeared to be a Nextion display according to the description, off ebay recently. Cost was $12.  It arrived ok but does not work. The Nextion editor warns that displays with the prefix "TJC" are not compatible. On ebay they are being sold as Nextion displays but appear to be some sort of copy. (Hardly unusual) ( Genuine Nextion displays start at more like $18-20.)

The Nextion editor does not allow them to be uploaded with files.  Apparently there was supposed to be a way, with some previous versions of the Nextion Editor which I found and also tried, but to no avail.

So a warning about using 'Nextion" displays, but actually shown as TJC types, they should not be purchased.  Unfortunately ebay (as usual) sellers do not tell us this. Some don't even show the part number on the back in a picture.

glenn



--
Best 73
KD8CEC / Ph.D ian lee
kd8cec@...
www.hamskey.com (my blog)

Re: VOM Advice?

Jack, W8TEE
 

One feature I find really useful is the ability for the unit to "beep" when doing continuity checks. Without that feature, I seem to lose my test points when I go to look at the meter's display. With the beep feature, it can keep the leads where they belong rather than slipping off the part under test and releasing the magic white smoke from the most expensive part on the board.

Jack, W8TEE

On Thursday, June 14, 2018, 11:11:52 PM EDT, Tim Gorman <tgorman2@...> wrote:


For most anything you'll do with the ubitx you don't need an expensive
desk meter.

this one:
www.ebay.com/itm/Digital-Voltmeter-Ammeter-Ohmmeter-Multimeter-Volt-AC-DC-Tester-Meter-US-Seller/271496690158?hash=item3f3676b9ee:g:qgUAAOSwHnFVkYPk

is representative of one that has lots of functions. It's a lot like
the one I use much of the time. PLEASE don't hook the test leads up the
way it is shown, it won't work!

There is a huge gap in its current measuring scales, from 200ma to
10amp in one big jump, but that will probably get you by.

tim ab0wr

On Thu, 14 Jun 2018 19:11:08 -0700
"Mark M" <junquemaile@...> wrote:

> Sorry if this is a bit off topic but it is related to uBitX hacking...
>
> My ancient, el-cheapo VOMs (Radio Shack/Harbor Freight freebies) all
> have pretty much ceased working so I'm looking for some suggestions
> about suitable replacement units. I'm not looking for lab quality,
> just something for a hobbiest/amateur hardware hacker (like for
> modifying the uBitx). I'd like to find something that's reliable and
> reasonably accurate for a few 10's of dollars. I see many units on
> Amazon for around that but don't know which ones would be good buys.
> So, any advice from y'all?
>
> Thanks & 73....     Mark    AA7TA
>
>
>



Re: Transmitter Mods

Sajid Rahum
 

Hi Rob

Doing these mods this evening.  Much appreciated Howard's parts.

For the tee pee - let me know how you did it.

I am going to gently put the solder iron on right side and try to lift it as soon as solder start to give.  Any suggestions will be appreciated.

Re: Can't get my uBitX to transmit CW on the Dial frequency

 

As Tom, WB6B suggests, an important reason for displaying the TX frequency in CW modes is that you need to know that when you
hit that key that you are transmitting in-band. It is more important to know your TX frequency than your RX frequency and this is also 
the convention used on most commercial HF rigs. 

I only had the original uBITX code installed for a day but I do seem to recall that there was no explicit CW mode.  
The CEC code does have explicit CWU and CWL and as I stated, once you have a station properly tuned you should be able to toggle
back and forth between the two CW modes and still have the received station in the filter passband. There may be a slight shift in received tone
(nothing is perfect) but it should be very close.  

I also believe that what Tim AB0WR suggests regarding changing the BFO frequency is correct.
If you haven't moved the VFO the frequency it's frequency shouldn't change except to apply a +/- offset equal to the sidetone frequency on RX (the TX carrier frequency stays the same and should be the dial frequency as stated above). Switching back and forth  from CWU to CWL should change the BFO frequency (which only affects RX) to allow the switching of the selected sideband. The change in BFO frequency plus the application of the RX offset with the correct sign to the VFO determines the change in RX frequency on the CW mode change. 

If you must display the actual RX frequency as the dial frequency then it has to change when you change from CWU to CWL. Changing the TX frequency
as it currently does is incorrect.  Also I would suggest that if the dial frequency remains the RX frequency, then the display should change on TX  to show the
TX frequency (i.e. carrier frequency) and then back again on RX. 

As Allard, PE1NWL stated in an earlier posting on this same topic ... we went through pretty much the same discussion on the operation of the BITX40
and came to the conclusion that the display frequency on both CWU and CWL should be the TX (carrier frequency) and that is what Allard implemented in
his Bitx40 code. 

Cheers 

Michael VE3WMB 

Re: VOM Advice?

bobolink
 

For the complex digital mode signals you might be interested in a “true rms” voltmeter. I paid a little extra for that (about $12) from banggood.
I haven’t tested it against my Fluke. That would be an interesting comparison.
true-rms

Re: Can't get my uBitX to transmit CW on the Dial frequency

 

One more thing ...

Just to simplify the discussion, what we have here are two issues :

1)  switching from CWU to CWL on CEC V1.08 incorrectly changes the TX frequency (it should remain fixed) wheres it should be the RX frequency
that moves due to the change in sign of the applied RX offset and the change to the BFO frequency to match the selected sideband. 

This is a bug. 

2) The issue of what frequency should be displayed. (Currently it is the RX frequency).

   Options are :
   
   1) Display Tx frequency - will not change on display when moving between CWU/CWL. Will not change on TX vs RX. (Recommended) 

    2) Display Rx Frequency - must change when switching CW sidebands to be accurate.
        Recommend it change to TX frequency and back when switching between TX and RX so operator knows what actual carrier TX frequency is. 

Cheers

Michael VE3WMB 


 

Re: VOM Advice?

Karl Heinz Kremer, K5KHK
 

Jack is right, it should beep, and it should also beep right away, without any delay: I have to meters, one (actually a relatively cheap true RMS pocket meter from Banggood) beeps right away, my more expensive one has a small delay, and when you are testing for conductivity, you will wait until it beeps, but if you are testing for non-conductivity, the instant feedback is much better than to decide if you've waited long enough :) 
--
Karl Heinz - K5KHK

Re: Transmitter Mods

Rob Snow
 

Sajid,

The teepee was the hardest part for me.  My first thought was to heat one side and try to lift it, but that didn't work as the other side still held tough.  Next I wicked both ends and then tried the same thing again and got some movement.  Finally, I just applied pressure to the side and heat and slid it off the pad completely and started the tee pee fresh.  My inductor is a squat little thing so I soldered it down as a tower on one pad and then re-applied the resistor as a bridge.

My biggest concern was either a) destroying the resistor with heat, or b) flicking it off and sending it into the ether while trying to desolder.  I have a SMD resistor sampler pack and I think I read it as being a 102 (1k ohm), so I had that as a fallback and maybe made me a bit braver on my application of heat and force.


On Fri, Jun 15, 2018 at 7:24 AM, Sajid Rahum via Groups.Io <zs735@...> wrote:
Hi Rob

Doing these mods this evening.  Much appreciated Howard's parts.

For the tee pee - let me know how you did it.

I am going to gently put the solder iron on right side and try to lift it as soon as solder start to give.  Any suggestions will be appreciated.


Re: VOM Advice?

n5ib_2
 

An interesting tale about one of those inexpensive Harbor Freight DMMs...

A few years back I was working on a GPS tracker for our high altitude balloon project. It was outdoors on a bright sunny day. I was measuring the DC supply to the GPS and noticed the voltage reading bouncing around for no apparent reason. After a few minutes of bafflement I noticed that when I leaned over to read the meter, it was in my shadow, and the reading changed. Curiosity piqued, the meter (one of the early yellow ones) was promptly disassembled for inspection.

Turns out the chip that controls the whole thing was, as in most low-cost mass-produced stuff, not encapsulated in a package, but just die bonded to the PCB with a resin overcoating. The ground plane beneath the die was etched away on the other side of the PCB. The chip was located right underneath the LCD display. Strong sunlight would filter through the display, through the translucent PCB material, and fall on the silicon substrate of the chip. Can you say "phototransistor" ?! A bit of strategically placed black tape solved the problem. I've taken apart some later versions of that DMM and see that there now is an opaque strip underneath the display.

N5IB