¿ªÔÆÌåÓý

  1. BITX20
  2. Messages
Expanded Topics Messages Polls
Date
Re: Spurious RF at beginning of CW transmission in the uBitx

 

Generally 10-20MS is fast for a relay.

Keep in mind for 80M, 5 relays have to switch so you always plan for the slowest
which in the case of this is a cascade of two.

To go to transmit The Raduino activates K1, TX+ is its output and that activates the remaining?
3 band pas filter relays as needed and K3 always.

So RX to TX switching is the sum of K1 and K3 switching time.? 20mS would be optimistic.

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

 

A possible firmware fix for the LPF relay delay would be to add a pipeline delay
to all CW code elements, not just the starting edge of the transmission.
The sidetone could happen immediately, so the operator would not notice a difference.

Jerry


On Mon, Jul 30, 2018 at 11:17 AM, Jerry Gaffke wrote:
At 20 wpm, a dot is around 60 ms.
Would be interesting to measure how long it takes the LPF relays to turn on
after TX_RX is driven true.? There are two levels of relays involved there,
first the T/R relay has to supply power to the TX rail.? Maybe 20ms total?
And need additional delay to add a margin of safety.
So getting iffy.
Re: End Fed antennas w/ uBITX #ubitx

 

The inductance meter reads 97uH to antenna, and 38uH to ground. The first one I bought that looks like this model and is a 1:1 balun has shielded cable to the toroid and shrink wrapped magnet wire wrapped around it, and looks professional. The inductance readings on the 1:1 balun are 49 and 53uH. This 9:1 unun looks like the typical knock off crap made in the back of a Shenzhen market stall with white shmoo hiding the lies. Are these inductance readings something you expected to see, or way off?
Re: End Fed antennas w/ uBITX #ubitx

 

IT is likely a verbatim copy of THe EARC design copy enclosed.

Endfed6_40.pdf
Endfed6_40.pdf

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

 

I'd be fine with constantly powering the LPF relays on my rig.
And may be the best solution.

Though does raise power requirements a bit during receive,
an issue for those running from a battery.?
Those few that care could go to latching relays.

Also, we apparently have several thousand uBitx's out in the field now.
We need a firmware fix to not be messing with the clocks while transmitting.
If that fix can also deal with these other issues, then it's a win
for those hesitant to take a knife to their precious uBitx.
Especially since most users won't be sending CW at 20 wpm.

At 20 wpm, a dot is around 60 ms.
Would be interesting to measure how long it takes the LPF relays to turn on
after TX_RX is driven true.? There are two levels of relays involved there,
first the T/R relay has to supply power to the TX rail.? Maybe 20ms total?
And need additional delay to add a margin of safety.
So getting iffy.

Jerry, KE7ER



On Mon, Jul 30, 2018 at 10:29 AM, ajparent1/KB1GMX wrote:
Jerry,

There is a simple mod for that.? Rather than a delay in the code that might mess with the first CW character
just apply DC to the relays.

It requires an etch cut between kt3 and K3 and a wire jumper from 12V(power in) and kt1 +Vpin.
Sorry I have no pictures of that just my notes.

What this does is keep power for KT1 though 3 on and separates it from the TX/RX function.
There is no TX RX delays for band pass and in some cases it prevents hot switching of RF
before the contacts are made (more likely with SSB).

Allison
Re: Gamma-matching antenna tuner

 

There are a great many articles available on-line for Gama Match Antenna.
Do a Google search for "" to see what is available.?

Arv? K7HKL
_._


On Mon, Jul 30, 2018 at 2:08 AM Timothy Fidler <engstr@...> wrote:
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:
<[email protected]>
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 Japan¡¯s 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: BITX40 #bitx40help #radiuno need a new board #bitx40help #radiuno

 

Thanks a lot, that will help !!

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

 

Jerry,

There is a simple mod for that.? Rather than a delay in the code that might mess with the first CW character
just apply DC to the relays.

It requires an etch cut between kt3 and K3 and a wire jumper from 12V(power in) and kt1 +Vpin.
Sorry I have no pictures of that just my notes.

What this does is keep power for KT1 though 3 on and separates it from the TX/RX function.
There is no TX RX delays for band pass and in some cases it prevents hot switching of RF
before the contacts are made (more likely with SSB).

Allison
Re: End Fed antennas w/ uBITX #ubitx

 

Okay you got a trasformer. If you have an LC meter, which inductance values do you read across the SO239 and across the two terminals for the antenna and the ground?


Il 30/lug/2018 18:18, "John Smith via Groups.Io" <johnlinux77=[email protected]> ha scritto:
I just received my 1:9 unun today and opened it up and saw white silicone trying to hide insulated CAT5e cable wires, colored stripes and all wrapped around the toroid, can't even see how it was wound. I bet this is going to add some frustration and disappointment to an already challenging new antenna design for me to learn how to use. Here is the link to it on ebay, it's gone down in price since the last sucker bought one---?

Re: Accidental Calibrate #ubitx #calibration

Kevin Rea
 

it happened to me, i just turned the unit off and back on, and it was fine.

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

 

The LPF relays only get powered when TX_RX is asserted, which puts 12 on the TX rail.
So there should be a delay in there between when TX_RX is asserted?
and the first time that CW_KEY is asserted.? This addresses Tom's concern of post? ?55339

Jerry, KE7ER



On Mon, Jul 30, 2018 at 09:12 AM, Jerry Gaffke wrote:
Not quite as simple as post? 55338? suggested, but I do think the fix is to?
mess with the clocks first, and only then assert TX_RX.
Re: NEXTION UPDATES FOR 7 AND 5 INCH - --ADAPTED FOR KD8CEC VER 1.095

Bo Barry
 

The earlier versions changed the USB to LSB when tapped.
Re: End Fed antennas w/ uBITX #ubitx

 

I just received my 1:9 unun today and opened it up and saw white silicone trying to hide insulated CAT5e cable wires, colored stripes and all wrapped around the toroid, can't even see how it was wound. I bet this is going to add some frustration and disappointment to an already challenging new antenna design for me to learn how to use. Here is the link to it on ebay, it's gone down in price since the last sucker bought one---?https://www.ebay.com/itm/1-9-BALUN-miniature-barron-YY-100-M/171852292305?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
Re: Spurious RF at beginning of CW transmission in the uBitx

 

Not quite as simple as post? 55338? suggested, but I do think the fix is to?
mess with the clocks first, and only then assert TX_RX.


Here's the sequence of events at the start of a CW transmission:

main loop continuously calls cwKeyer(), if the paddle was press then
? ? cwKeyer calls startTX()
? ? ? ? which turns on the TX_RX bit to supply power to the transmit circuits
? ? ? ? calls setFrequency(), which calls setTXFilters(),? and then sets the VFO up for SSB transmit
? ? ? ? shuts down clk0 and clk1, then sets the VFO (which is clk2) at the operating_frequency for CW transmit
? ? cwKeyer then asserts CW_KEY to actually start transmitting.

So the mixer should not get unbalanced by CW_KEY till the very last thing, good.
And the filters get set up several milliseconds before CW_KEY is asserted since it takes awhile
to do all the i2c writes out to the si5351 when setting clk2 to the operating_frequency.
However, note that the first thing done is to assert TX_RX, so any audio at the mike will
go out over the air as if it were a normal SSB transmission.
This happens before setting up the filters.
And before we start messing with all those clocks.



Here's the pertinent code for the stock uBitx v3 firmware as installed by hfsignals:


:In file ubitx_20.ino:
?
void setFrequency(unsigned long f){
? uint64_t osc_f;
?
? setTXFilters(f);
?
? if (isUSB){
? ? si5351bx_setfreq(2, SECOND_OSC_USB - usbCarrier + f);
? ? si5351bx_setfreq(1, SECOND_OSC_USB);
? }
? else{
? ? si5351bx_setfreq(2, SECOND_OSC_LSB + usbCarrier + f);
? ? si5351bx_setfreq(1, SECOND_OSC_LSB);
? }
?
? frequency = f;
}
?
?
.....
?
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 transmit filter relays are powered up only during the tx so they dont
// draw any current during rx.
void setFrequency(unsigned long f){
? uint64_t osc_f;
?
? setTXFilters(f);
?
? if (isUSB){
? ? si5351bx_setfreq(2, SECOND_OSC_USB - usbCarrier + f);
? ? si5351bx_setfreq(1, SECOND_OSC_USB);
? }
? else{
? ? si5351bx_setfreq(2, SECOND_OSC_LSB + usbCarrier + f);
? ? si5351bx_setfreq(1, SECOND_OSC_LSB);
? }
?
? frequency = f;
}
?
....
?
?
?
?
In file ubitx_20.keyer:
?
void cwKeyer(){
....
? ? // if we are here, it is only because the key or the paddle is pressed
? ? if (!inTx){
? ? ? keyDown = 0;
? ? ? cwTimeout = millis() + CW_TIMEOUT;
? ? ? startTx(TX_CW);
? ? ? updateDisplay();
? ? }
? ??
? ? // star the transmission)
? ? // we store the transmitted character in the lastPaddle
? ? cwKeydown();
....
?
?
void cwKeydown(){
? keyDown = 1;? ? ? ? ? ? ? ? ? //tracks the CW_KEY
? tone(CW_TONE, (int)sideTone);?
? digitalWrite(CW_KEY, 1);? ? ?
? cwTimeout = millis() + CW_TIMEOUT;
}
?

Jerry, KE7ER


On Mon, Jul 30, 2018 at 08:36 AM, Jerry Gaffke wrote:
The code is a bit convoluted (as is pretty much all unfamiliar code),
still trying to figure out what happens when here.
Re: Spurious RF at beginning of CW transmission in the uBitx

 

Hmm, the LPF's should knock out my? ? 45mhz + operating_frequency? burp
at the start of a CW transmission, regardless of which filter is selected.
Though the filters aren't perfect.

Also, in an addendum to my previous post, we aren't actually transmitting
until CW_KEY is asserted to unbalance that mixer.
The code is a bit convoluted (as is pretty much all unfamiliar code),
still trying to figure out what happens when here.

Jerry, KE7ER


On Mon, Jul 30, 2018 at 07:37 AM, Tom Cooper wrote:
I noticed this jump in reflected power on CW also. ?There appears to be no corresponding increase on forward power, so I am guessing it is due to the LPF relays. ?When the first CW character starts the relays are just closing, so there is some unfiltered RF that is out of band and that is not matched by the tuner.?
Re: Gamma-matching antenna tuner

 

Hiro san,

A pi type tuner is generally in the same form as Low pass filters.? As such it can help with harmonics
but lower frequency spurious outputs it will be less helpful.

What you likely want is a transmitting band pass filter then an antenna matcher after that.
Two sites that may be more helpful.??





Allison
Re: Nextion TFT

 

Hi Al

A few of us have the ubitx and bitx40.
We had quite few people at the meeting, which is odd for the summer months.
Anyways we have a few teens joining and decided we could do something they could use. In the next month we'll be coming with a plan and we do have a resident software guy.

Next buildathon news to come.

73 Ken

On Mon, Jul 30, 2018, 9:36 AM Al Duncan VE3RRD <ve3rrd@...> wrote:
Hi Ken, our little builder group in Barrie has been focusing on the uBitx and the amazing firmware from Ian KD8CEC . A number of us also have the Bitx40 which works very well with the Allard PE1NWL firmware .
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: Spurious RF at beginning of CW transmission in the uBitx

 

I noticed this jump in reflected power on CW also. ?There appears to be no corresponding increase on forward power, so I am guessing it is due to the LPF relays. ?When the first CW character starts the relays are just closing, so there is some unfiltered RF that is out of band and that is not matched by the tuner.?

73,

Tom ?W1EAT
Re: BITX40 #bitx40help #radiuno need a new board #bitx40help #radiuno

 

That Nano clone looks fine to me.

Note that on the new raduino boards that come with the v4 uBitx from hfsignals
the Nano gets mounted on the other side of the main raduino board as per this post:
? ??/g/BITX20/message/50027

So the header pins must be soldered to the "wrong" side of the Nano.
And this means you should avoid buying a Nano that already has header pins soldered in place.

If I were replacing a Nano on a raduino from a v3 uBitx,
I would definitely socket the Nano using the technique described above.

Jerry, KE7ER


On Mon, Jul 30, 2018 at 03:24 AM, <19835@...> wrote:
I?m searching for a new raduiono Board,
my question is this the right ?
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
61841 - 61860 of 116849