Date   
Re: uBitxr4 audio distortion fix

lkorahul
 

Diz has one on his site for historical reference. Maybe for topics like these.





73

Rahul VU3WJM

Re: uBitxr4 audio distortion fix

lkorahul
 

Re: Ubitx receive intermittent

M0CLS
 

I fixed the low power issue. It was down to the thick wire I had going from the Neg terminal of the power plug to the rear chassis bolt?? Anyway I removed this and power jumped back up.

The audio is a separate issue. As I said, I believe it is audio and not signal related as when it drops out I still receive signals only much quieter. My board is a later v3 with socketed audio chip. I wonder if I tap off the back of the volume control to a separate amplifier? 

Carl.

Re: Ubitx receive intermittent

John Wulf
 

I had a similar problem where w1aw at 10 over would fade out to the point where I could no longer copy them on cw. Worked fine with headphones plugged. Replaced the 2 inch speaker and ok now.
73 John K4FT 

Re: TX frequency? of uBitx at CWL and CWU mode #ubitxcw

iz oos
 

I usually use a Softrock Ensemble as the receiver for the Ubitx and other rigs. The CW TX in the Ubitx is 700hz off the actual frequency. I believe it was done by purpose although I would have rather preferred it indicated the actual frequency.


Il 01/lug/2018 07:43, <jj1epe@...> ha scritto:
Hi!

I would like to know whether the behavior of TX frequency of uBitx at CWL and CWU mode I experienced is normal on CECFW v1.08.

For instance,
When there is the CQ station on 7.0100MHz on my ICOM transceiver,  uBitx at CWL mode shows 7.0085MHz as RX frequency.
Then I transmit CW carrier on ubitx at the exact same RX frequency of uBitx.
CW carrier is observed not at 7.0100MHz but 7.0085MHz on my ICOM transceiver as RX frequency.

When there is the CQ station on 7.0100MHz on my ICOM transceiver,  uBitx at CWU mode shows 7.0100MHz as RX frequency.
Then I transmit CW carrier on ubitx at the exact same RX frequency of uBitx.
CW carrier is observed not at 7.0115MHz but 7.0100MHz on my ICOM transceiver as RX frequency.

This means that TX frequency is lower 1.5KHz at CWL mode and higher 1.5KHz at CWU mode than actual frequency.

Your comment would be much appreciated.

Akira,
JJ1EPE



Re: TX frequency? of uBitx at CWL and CWU mode #ubitxcw

iz oos
 

The firmware is still the original for the ver. 3 Ubitx


Il 01/lug/2018 13:25, "iz oos" <and2oosiz2@...> ha scritto:

I usually use a Softrock Ensemble as the receiver for the Ubitx and other rigs. The CW TX in the Ubitx is 700hz off the actual frequency. I believe it was done by purpose although I would have rather preferred it indicated the actual frequency.


Il 01/lug/2018 07:43, <jj1epe@...> ha scritto:
Hi!

I would like to know whether the behavior of TX frequency of uBitx at CWL and CWU mode I experienced is normal on CECFW v1.08.

For instance,
When there is the CQ station on 7.0100MHz on my ICOM transceiver,  uBitx at CWL mode shows 7.0085MHz as RX frequency.
Then I transmit CW carrier on ubitx at the exact same RX frequency of uBitx.
CW carrier is observed not at 7.0100MHz but 7.0085MHz on my ICOM transceiver as RX frequency.

When there is the CQ station on 7.0100MHz on my ICOM transceiver,  uBitx at CWU mode shows 7.0100MHz as RX frequency.
Then I transmit CW carrier on ubitx at the exact same RX frequency of uBitx.
CW carrier is observed not at 7.0115MHz but 7.0100MHz on my ICOM transceiver as RX frequency.

This means that TX frequency is lower 1.5KHz at CWL mode and higher 1.5KHz at CWU mode than actual frequency.

Your comment would be much appreciated.

Akira,
JJ1EPE



Re: Bitx (40) agc and muting

Derrick Young <deyoung10@...>
 

Yes, more info please.

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

John KC9OJV
 

Don,
I spent part of yesterday applying ferrites to this and that to little success. I also tried wrapping the 5v line around the twisted pair coming from the volume pot and that did some good. This morning I was thinking about fixing a 7805 to the metal base of my case, drilling a hole in the ground plane and routing a wire through that hole to feed the AGC board. It could be driven off the 12v relay (K1?). Has anyone else had any ideas/success?

John
KC9OJV

Re: Bitx (40) agc and muting

Elmar Völler <dl2qa@...>
 

Hello Derrick,
here is more info.
please look at the picture .
hope it is visible.
if you have any question --give me a  shout.
 
 
Gesendet: Sonntag, 01. Juli 2018 um 13:52 Uhr
Von: "Derrick Young" <deyoung10@...>
An: BITX20@groups.io
Betreff: Re: [BITX20] Bitx (40) agc and muting
Yes, more info please.

Re: Bitx (40) agc and muting

4Z1NT
 

When you say solder 1n4148 t0 +12v not RX, which one are we talking about?

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

Rick Price
 

John, Don, others,
Yesterday I attached a 78L05 (TO220) directly to the back of the AGC board that is mounted to the RF gain control on the front panel. Bypassed all power leads and ran a separate power lead to the 12V regulator that powers my uBitx. In other words the AGC board had its own isolated(?) power source. Stll heard the audio when transmitting.  Beginning to think that radiated power is being absorbed by the AGC board and then recitifed and then coupled into the audio system. I also have the pop click board installed and not sure if this was a problem before it was installed. My AGC board is one I fabricated using Don's technique of cutting pcb with an x-acto knife.  I also have a AGC board made on perf board using through hole parts.  May sub that in and see if there are any changes. I eventually plan on installing the JackAl mod when it becomes available so this problem should go away for me but its beginning to become a challenge to fix.
 
Rick KN4AIE



From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of John KC9OJV
Sent: Sunday, July 01, 2018 8:05 AM
To: BITX20@groups.io
Subject: Re: [BITX20] RFI from uBitx TX after AGC and other mods installed

Don,
I spent part of yesterday applying ferrites to this and that to little success. I also tried wrapping the 5v line around the twisted pair coming from the volume pot and that did some good. This morning I was thinking about fixing a 7805 to the metal base of my case, drilling a hole in the ground plane and routing a wire through that hole to feed the AGC board. It could be driven off the 12v relay (K1?). Has anyone else had any ideas/success?

John
KC9OJV

Re: Bitx (40) agc and muting

Elmar Völler <dl2qa@...>
 

from junction r111/r113 solder a 1n4148 diode direct to the 12volt rail
(LM368 is now alltime connected with 12volt)
73 elmar-dl2qa
 
Gesendet: Sonntag, 01. Juli 2018 um 14:15 Uhr
Von: 4Z1NT <menashedovid@...>
An: BITX20@groups.io
Betreff: Re: [BITX20] Bitx (40) agc and muting
When you say solder 1n4148 t0 +12v not RX, which one are we talking about?

Re: Anyone seen an SSB xmit causing the menu to pop up?

MVS Sarma
 

learnt a point Farhan jee.


Regards
MVS Sarma
 

On Sun, Jul 1, 2018 at 12:06 PM, Ashhar Farhan <farhanbox@...> wrote:
check if your supply voltage is dropping on 'hellow'.

- f

On Sun, Jul 1, 2018 at 11:43 AM, Mvs Sarma <mvssarma@...> wrote:
Perhaps local radtion due to left over mismatch.
 It might be wiser to shield loose wires to/from audio amp /agc  by shielded wires and shield grounded on one side.
Also the power reaching to raduino could be passed thro a diode say 1N5401 and filtered by 100uF parallel 100nF.

All the best

Regards
MVS Sarma
 vu3zmv

On Sun, Jul 1, 2018 at 10:05 AM, brad martin <emclinux@...> wrote:
I too have seen this. I have yet to sort mine out and usually for me happens on an antenna and not the dummy load.

Brad
On Sun, Jul 1, 2018 at 12:34 AM Gwen Patton <ardrhi@...> wrote:
I was testing into a dummy load and noticed that when I whistled into the mike, or even spoke into it on higher frequencies, would cause the rig to react as if I had pressed the button on the encoder. It showed "Band Select >", and receive stopped. Pressing the encoder twice exited the menu normally. Is this RF getting into the switching transistor the encoder switch trips? How can I prevent this?

Gwen NG3P




Re: TX frequency? of uBitx at CWL and CWU mode #ubitxcw

 

Akira-san : 

The uBITX display frequency in CWU/CWL is the RX frequency not the TX frequency. The norm in CW on most commercial rigs is to always display the TX frequency.
You can however set the RX offset. It seems that yours must be 1.5 Khz which is a lot. Typically it would be something in the range of 500 to 800 Hz. 

There is a related issue which I have reported and that is that changing CW modes is "broken". When switching back and 
forth between CWU/CWL modes the TX frequency changes and the RX frequency does not which is wrong. This means that 
if you properly tune in a CW station (RX tone matches your offset) on CWU and switch to CWL the other station is no longer audible and 
he can't hear you. It should be possible to switch back and forth between CWU and CWL and still maintain contact.

See message #51983 for more details.

Cheers

Michael VE3WMB 

Re: Nextion Display programming, extension cable

Allen Merrell
 

That looks neat..
--
Allen  Merrell

Re: uBITX Version 4 first attempt #ubitx-help #ubitx

Andy V. Borisenko
 

Richard, good afternoon!
note, there are many people here who consider themselves radio engineers. but no one gives you advice on calibration.
I'll try with my bad English to tell you how to properly calibrate.
for this, it is tedious to measure and record the true value of the BFO frequency in the file.
for this you need: a commercial transceiver (I have FT-2000), an Android smartphone and an installed program Audio Frequency Counter ( or any similar), piece of wire.
the transceivers warm up for 30 minutes.
in the commercial transceiver we set 25.000.00 and usb.
Instead of the antenna, we connect a piece of wire and bring it close to the raduino. a commercial transceiver we find a raduino tone. for example: i have 25.003 50. next the smartphone will measure the frequency of AUDIO speaker. 
for example: freq in transceiver 25.003.500, audio freq 902 Hz. 25.003.500+902=25.004.402 this is the true frequency BFO you uBitx!!! 
this frequency must be written in the firmware file name ubitx_si5351.ino
for example: here are my changes      #define SI5351BX_XTAL 25004402          // Crystal freq in Hz 
this should be done with the help of the program arduino ide. 
how to do it (and it's very simple) let him tell someone from the engineers who speak English better than me.
After that, the tuning and calibration of the transceiver will take several minutes.
good luck!
 

Re: uBITX Version 4 first attempt #ubitx-help #ubitx

Andy V. Borisenko
 

let someone from the competent radio engineers check my method and tell here for everyone if it works.

Ubitx and QRP Guys Multi Z Tuner #ubitx-help

davedt1e@...
 

Hope this is an appropriate topic for the board.

Just built he QRP Guys Multi Z tuner and hooked it up to the Ubitx.  The Ubitx goes straight into TX on power up.  I was very careful in building the tuner and don't think I made any errors.

The antenna is a horizontal loop cut a bit over 40 meters and fed with ladder line.

The Ubitx behaves normally when using a dummy load or with loop hooked up for receive.

No balun is currently attached.

Any ideas as to what's happening?

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

John KC9OJV
 

Rick, If it's the PCB what about putting it below the ground plane in the same relative position as the suggested spot next to the RF relays?

John
KC9OJV

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

 

Akira,

I just put my uBitxr4 on the spectrum analyzer and found nothing +-250 Khz. That is 500 Khz BW.

I think your measurements are being affected by switch mode power supply in one of the items.

Raj

At 25-06-18, you wrote:
Hi!

I built Bitx40 about 2 weeks ago.

I measured the spurious of Bitx40 by using the spectrum analyzer.
The level of spurious of harmonics were under 50db. So this is fine.
But the spurious at 75KHz was observed.
The spurious might be the multiple of 25KHz.
It would be much appreciated if you could advise me the cause and solution of this spurious of Bitx40.

In Japan, we must prove to the authority that the spurious of the transceiver meets the criteria to obtain the certification of the transceiver from the authority.
So if i could not resolve this spurious, I will not be able to use Bitx40 in Japan.

Thanks in advance,
Akira
JJ1EPE