Date   
Re: Spurious RF at beginning of CW transmission in the uBitx

 

This is the first I have heard of this issue on the uBITX.  

There was a similar issue with the BITX40 and Allard, PE1NWL implemented a code workaround to suppress it by temporarily shutting down the Si5351 CL2 for about 50ms after PTT closure, to let things settle down before allowing the rig into TX. 

Michael VE3WMB 

Re: uBitx for sale

K4LXY
 

Item is sold.  Thanks for all your interest.
Howard

Re: uBitx for sale

Gwen Patton
 

I just received one of those CW filter kits. I'm building it outboard, so I can use it on some other radios. I've got a Small Wonder Labs 20m, an Elecraft K2 (which doesn't really need it) and the nice little modular 40m rig Jack Purdum had in QST that might benefit from it.

I've also got a couple of little squeakers like Pixies and a Tixie 80m cw 3-watter (Pixie II with an integral Tick keyer chip) that it might work on, too.

Gwen NG3P

Re: Nextion TFT

pat griffin
 

I have had good results with robotshop and zero problems with returning a defective 7" display.  They make the return process easy.

73, Pat AA4PG

Pat Griffin
http://www.cahabatechnology.com/aa4pg.html


From: BITX20@groups.io <BITX20@groups.io> on behalf of Al Duncan VE3RRD <ve3rrd@...>
Sent: Sunday, July 29, 2018 9:14:21 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Nextion TFT
 
I got my 2.8 inch Nextion from robotshop.ca https://www.robotshop.com/ca/en/28-nextion-hmi-lcd-touch-display.html
they also have the 3.2 inch https://www.robotshop.com/ca/en/nextion-enhanced-32-hmi-touch-display.html 
Only took 2 days for it to arrive.
AL  VE3RRD

Re: NEXTION UPDATES FOR 7 AND 5 INCH - --ADAPTED FOR KD8CEC VER 1.095

Bo Barry
 

Joe,  Is there any chance of getting the USB icon changing when LSB is chosen?  What a radio! WWV signal is equal to my Icom 7300!  Bo W4GHV

Re: End Fed antennas w/ uBITX #ubitx

ajparent1/KB1GMX
 

Jack,

I kind of figured that I was hearing QRP and crappy antenna too. ;)
Some this I can make suggestions on but social engineering in not a 
forte I can claim I do well.

Maybe this helps, When I had an 18ft pole with a 2 element for 6 I envied the
guys that had a 40ft tower and a 7 element.  Then their broke and I could
easily still fix mine.  I realized envy is not practical.  So people envy my
30ft tower and I do what I can to help them achieve that for themselves.
For the guy with a 80ft tower and a broken antenna I realize that I don't
have to pay someone to climb it because I would never. My puny 30ft
has a lowering mechanism I put effort into to avoid that case.  So that
tower gets my VHF and UHF antennas as they need the height.  The
HF gets wires and other things to amuse me.    The experimentation
is everything and satisfying.  Its something I can do for a lot more
years.  That everyone can do.

So most of the time Its QRP and crappy antenna for me too.  Only
mine a LNR EF-QUAD.  But I enjoy being on and to me contacts are 
good be they down the block or rare DX.  And still my favorite sport is
breaking the pileups at qrp SSB as its a challenge, If I can hear them
I try patiently and persistently, even Navassa!    All I can do is encourage
people to try as they can be successful as well.

Allison

Re: NEXTION UPDATES FOR 7 AND 5 INCH - --ADAPTED FOR KD8CEC VER 1.095

Joe
 

Not sure I follow.
Let me check the mode button.

Joe 

On Sun, Jul 29, 2018, 11:47 PM Bo Barry <bobarr@...> wrote:
Joe,  Is there any chance of getting the USB icon changing when LSB is chosen?  What a radio! WWV signal is equal to my Icom 7300!  Bo W4GHV

Re: uBitX SSB transmit oscillations on 20m only #ubitx

 

Bruce,

In uBitx the audio amplifier stage is disconnected by K3 via M1 and M2. So there cannot
be audio leak unless K3 is defective.

The only other way is RF leak into the audio.

Are you using any add on mods?

Raj

At 29/07/2018, you wrote:

Thanks, Raj. I have tried most of those. It seems like I have audio feedback not induced RF. In transmit I hear low volume audio from the speaker or headphones on all bands but especially above 14MHz. It is odd that an apparent audio "leak" is sensitive to the transmit frequency, that it is strongest on 20m.

I have read that the BitX designs use the audio stages in a unique way. My problem acts like the audio from the microphone goes into the receiver audio stream, that the receiver is not shut down -muted - when the T/R relay goes into transmit as it is on all transceivers I have worked on.

Although I have an oscilloscope I have not yet figured out where to probe in that dense board to try to find the problem.

Re: Spurious RF at beginning of CW transmission in the uBitx

Warren Allgyer <allgyer@...>
 

Good info Tom. I still have the Pacific and most of the US between me and my lab but looking forward to getting into it in 24-36 hours. 

WA8TOD

Gamma-matching antenna tuner

hirosmb <hirosmb@...>
 

Hi, all.

 

I am getting interested in a Gamma-Matching antenna tuner (manual one) for suppressing spurious in order to observe Japans new spurious regulation.

 

BPF will be fine but I need to make number of coils, right?

 

Then, can anyone point me out where I find some schematics of the Gamma-Matching tuner, or kit of it is very much appreciated.

 

Thanks in advance.

 

// hiro, JJ1FXF

#uBITX #ubitx

SM6MOJ
 

The July 17 news shows a build with a CEC keypad on the front. I would
like to know where the constructor got his keypad from.
Andrew SM6MOJ

Re: Gamma-matching antenna tuner

Timothy Fidler
 

Hiro,  suggest you look at  ARRL antenna HB . You should be able to find some PDF on line .....copyright breach and all. (this was supposed to be a  PM But what the Heck)

Gamma match generally used only on 2m and above. ONe side of your coax goes directly to the driven ele dipole side A.

Other side goes to  a rod that lines away from the side b but  paralled to  it. THis can be a  solid rod or of the same round stock as the driven element.

There are two PE or PP plastic elements holding the rod away from the B side driven element.  The rod can be slid back and forth along the B element  to get the best possible coupling.

THe exact stand off  distance and rod length  are a black art .  You never try to test or tune up this stuff except at low power or reduced V on finals.

THe coupling into the B side is capacitive and inductive  and distributed.  Hence black art.  It is hellish unlikely you will get this to work with anything other than a Yagi antenna.

Do you have a 1:1 balun in line as in current balun. If you have harmonics in your transmitted signal this will help the issue of return down the outside of your coax  and that will help keep any harmonics forced into the antenna where since they are not resonant , will be somewhat suppressed.   Voltage baluns can be work of the devil and for VHF accept nothing less than type 61 material in the balun core. Above 150 Mhz you cannot even have type 61 because it is getting very lossy but only your tests with a FSMeter will show what the difference is.

cheers New member -
A and B sides are whatever you define them to be - as above.

 

Timothy E. Fidler : Engineer BE Mech(1) Auckland , NDT specialist AINDT UT /RT3 , MT2 CB #2885, 
Telephone Whangarei   022  691 8405
e: Engstr@...



----- Original Message -----
From:
BITX20@groups.io

To:
<BITX20@groups.io>
Cc:

Sent:
Sun, 29 Jul 2018 23:57:39 -0700
Subject:
[BITX20] Gamma-matching antenna tuner


Hi, all.

 

I am getting interested in a Gamma-Matching antenna tuner (manual one) for suppressing spurious in order to observe Japans new spurious regulation.

 

BPF will be fine but I need to make number of coils, right?

 

Then, can anyone point me out where I find some schematics of the Gamma-Matching tuner, or kit of it is very much appreciated.

 

Thanks in advance.

 

// hiro, JJ1FXF

Re: Spurious RF at beginning of CW transmission in the uBitx

n1kw@...
 

That seems unlikely as the Si5351 itself is very fast. As the data sheet indicates, it has "glitchless frequency changes" in the microsecond range. That is why I suspect an issue with the firmware.

73, Bob N1KW

Re: BITX40 #bitx40help #radiuno need a new board #bitx40help #radiuno

19835@...
 

Re: BITX40 #bitx40help #radiuno need a new board #bitx40help #radiuno

Philip
 

Thats the correct one
Philip

Re: Accidental Calibrate #ubitx #calibration

 

Amen

 

David A Posthuma, WD8PUO

 

From: BITX20@groups.io <BITX20@groups.io> On Behalf Of EI_Frank
Sent: Saturday, July 28, 2018 11:07 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Accidental Calibrate #ubitx #calibration

 

Hi Guys, just a short update on my Tune-up problems.
It seems that the main issue I have here is that the instructions provided by HF Signals do not align with the actual menu on the uBitx.
Part 2 of the Tune-Up instructions are for aligning the Master Clock. It advises to go to an AM broadcast signal of known frequency. If NOT zero beat then click on encoder button again  and a new option "Set Calibration" will be displayed. This is a photo of what's displayed.


When I click to enter this option it does not give me the option of adjusting to Zero Beat, but instructs me to go to Exactly 10Mhz. per the photo here.
When I press the PTT, it TX's on 10Mhz and displays this on LCD.
When I rotate the encoder it increments the 0 digit on the top right corner. But its a blind adjustment, no feedback on adjustment until you back out of the Calibration and back to a known frequency.
It is not possible to realistically and accurately adjust the clock with this method. 
What am I missing? This is extremely frustrating. 

Re: Nextion TFT

Al Duncan VE3RRD
 

Hi Ken, our little builder group in Barrie has been focusing on the uBitx and the amazing firmware from Ian KD8CEC http://www.hamskey.com/ . A number of us also have the Bitx40 which works very well with the Allard PE1NWL firmware https://github.com/amunters/bitx40 .
73, AL  VE3RRD


On Sun, Jul 29, 2018 at 08:09 PM, Ken wrote:
Thanks all for the input.
 
Al Duncan, we're thinking of a transceiver for the next buildathon. Last Wednesday's meeting we asked for ideas. Transceiver sounds like what people want. I suggested the Nextion display for something a little fancier.
 
73
 
Ken VA3ABN

Re: Gamma-matching antenna tuner

hirosmb <hirosmb@...>
 

Timothy,

Many thanks for your detailed explanation.

But I was wrong.

What I needed to know was “pi-match antenna tuner”.

Am I right that this type of antenna tuner suppress much spurious?

Again, thanks for your kind comments, Timothy.

// hiro, JJ1FXF



2018/07/30 16:52、Timothy Fidler <engstr@...>のメール:

Hiro,  suggest you look at  ARRL antenna HB . You should be able to find some PDF on line .....copyright breach and all. (this was supposed to be a  PM But what the Heck)

Gamma match generally used only on 2m and above. ONe side of your coax goes directly to the driven ele dipole side A.

Other side goes to  a rod that lines away from the side b but  paralled to  it. THis can be a  solid rod or of the same round stock as the driven element.

There are two PE or PP plastic elements holding the rod away from the B side driven element.  The rod can be slid back and forth along the B element  to get the best possible coupling.

THe exact stand off  distance and rod length  are a black art .  You never try to test or tune up this stuff except at low power or reduced V on finals.

THe coupling into the B side is capacitive and inductive  and distributed.  Hence black art.  It is hellish unlikely you will get this to work with anything other than a Yagi antenna.

Do you have a 1:1 balun in line as in current balun. If you have harmonics in your transmitted signal this will help the issue of return down the outside of your coax  and that will help keep any harmonics forced into the antenna where since they are not resonant , will be somewhat suppressed.   Voltage baluns can be work of the devil and for VHF accept nothing less than type 61 material in the balun core. Above 150 Mhz you cannot even have type 61 because it is getting very lossy but only your tests with a FSMeter will show what the difference is.

cheers New member -
A and B sides are whatever you define them to be - as above.

 

Timothy E. Fidler : Engineer BE Mech(1) Auckland , NDT specialist AINDT UT /RT3 , MT2 CB #2885, 
Telephone Whangarei   022  691 8405
e: Engstr@...



----- Original Message -----

To:
<BITX20@groups.io>
Cc:

Sent:
Sun, 29 Jul 2018 23:57:39 -0700
Subject:
[BITX20] Gamma-matching antenna tuner


Hi, all.

 

I am getting interested in a Gamma-Matching antenna tuner (manual one) for suppressing spurious in order to observe Japans new spurious regulation.

 

BPF will be fine but I need to make number of coils, right?

 

Then, can anyone point me out where I find some schematics of the Gamma-Matching tuner, or kit of it is very much appreciated.

 

Thanks in advance.

 

// hiro, JJ1FXF

Re: Spurious RF at beginning of CW transmission in the uBitx

Jerry Gaffke
 

The "glitchless frequency changes" thing means that when clocking digital logic you don't get a runt clock pulse.
As it turns out, for small frequency changes it's a smooth transition, and a vfo sweep using an si5351 
sounds about as good as an analog vfo.  Large frequency changes will be very abrupt. 
When transitioning to CW transmit,  clk2 is jumping  from 45mhz + operating_frequency to operating_frequency.
The si5351's internal vco remains at a constant 875mhz when using the si5351bx routines
since si5351bx_setfreq() is only messing with the output dividers.
I'd expect the output divider ratio change to be instantaneous. 

However, it does take a couple milliseconds to load all those i2c registers at 100khz for each clock.
So if the transmitter is getting turned on and then the call to si5351bx_setfreq(clk2, operating_freq) is made,
you will have an initial burst of energy for a few milliseconds at 45mhz + operating_frequency.

Here's the original firmware for the uBitx as it was shipped from hfsignals.
Note that the transmitter gets turned on with  digitalWrite(TX_RX, 1);
before any calls to si5351bx_setfreq() get made.  That's clearly wrong.
 

void startTx(byte txMode){
  unsigned long tx_freq = 0;
  digitalWrite(TX_RX, 1);
  inTx = 1;
 
  if (ritOn){
    //save the current as the rx frequency
    ritRxFrequency = frequency;
    setFrequency(ritTxFrequency);
  }
 
  if (txMode == TX_CW){
    //turn off the second local oscillator and the bfo
    si5351bx_setfreq(0, 0);
    si5351bx_setfreq(1, 0);
 
    //shif the first oscillator to the tx frequency directly
    //the key up and key down will toggle the carrier unbalancing
    //the exact cw frequency is the tuned frequency + sidetone
    if (isUSB)
      si5351bx_setfreq(2, frequency + sideTone);
    else
      si5351bx_setfreq(2, frequency - sideTone);
  }
  updateDisplay();
}
 

The calls to turn off clk0 and clk1 should happen pretty quick because with a frequency of 0
the only i2c register write that happens is this:  
    i2cWrite(3, si5351bx_clken); // Enable/disable clock
On returning to receive mode we could restore clk0 and clk1 by again only writing to the clken register,
but the extra few ms of delay incurred by writing to all those i2c registers doesn't really matter then.

Clearly, we should turn the transmitter off with
      digitalWrite(TX_RX, 0);
before restoring the clocks for receive mode.

So I think the extra delay incurred by turning on the transmitter after clk2 has moved 
will be on the order of 2ms.   At 40 WPM, a dot takes 33ms.

I have no idea what the other firmware releases are doing,
but a good chance they are doing the same thing.
 
Jerry, KE7ER



On Mon, Jul 30, 2018 at 01:59 AM, <n1kw@...> wrote:
That seems unlikely as the Si5351 itself is very fast. As the data sheet indicates, it has "glitchless frequency changes" in the microsecond range. That is why I suspect an issue with the firmware.

BITX40 relay K1 AND q13

Denis
 

By rewiring K1 contact 12 as common and contact 14 to K2 contact 14 for receive. For transmit K1 contact 12 common to K1 contact 16 to Q13.
Would this work to protect Q13 from strong receive signals, if relay K1 was rewired to open the path to Q13 during receive?
Thank you.
Denis, WB8SKP