Date   
Re: SMD inductors for L5 and L7 replacement

Nigel G4ZAL
 

Thanks Karl.

@Peter
Paypal sent and I sent to your email address and it go returned with ... Server error: '452 ... temporary failure'

Nigel

Re: Power instead of S-Meter for CEC-software? #ubitx #smeter #arduino

Jack, W8TEE
 

Check out the map() function. It allows you to map the 1-4V read on the pin to a range of values. The voltage readings are returned as values between 0-1023. You can then map those values to whatever you need.

Jack, W8TEE

On Tuesday, February 19, 2019, 11:47:11 AM EST, anders@... <anders@...> wrote:


Hi all,
I guess it would be possible to measure power output instead of signal strength in the CEC-software, and display in the S-meter. I have copied the Elecraft K2:s RF-detector which gives me between 1 and 4V (~1-10W) that I would like to feed to arduino pin A7. What changes has to be done in the firmware to make this work? Anyone?

Re: SMD inductors for L5 and L7 replacement

Curt
 

I did notice from the v5 schematic that it still uses toroids, not shielded inductors. I am debating with myself a bit how necessary they are. In my own unit, the toroids seem to he okay, only displaying sensitivity on 40 meters, maybe mostly on CW. This has me thinking that my v4 experiences RF coupling into L5 on 7 MHz, where it then gets amplified by the BiDi amp and cancels with the excitation piped into the biased mixer (that then isn't a mixer but a resistive coupler). But why only on 7 MHz? I would guess it may be coupled from PA output. I should try same measurement of power into a dummy load for ssb, evaluating touch sensitivity of L5. My cw output dips a couple watts on 40m only, so its mostly a curiosity.  A visit to spectrum analyzer has been delayed, so no data yet to see if only adding input relays on a daughter board plus a 45 MHz LC filter is enough to cure spurious.

73 Curt

Re: Power instead of S-Meter for CEC-software? #ubitx #smeter #arduino

KE2GKB
 

On top of this you can do it right inside of the CEC firmware's Configuration software "uBITX_Manager'. You would just set it to Follow the expected Power level for each S-Meter level, Some playing with it may be required however due to how it "Labels things".
--
Tim Keller - KE2GKB
https://shop.kit-projects.com

Re: Replacement Raduino or alternative

Scot McMath
 

I to am looking foar a replacement Raduino if you have an extra and would sell it.
scotmcmath@...  WB7AVU

Re: Black rectangles - Bitx40 hardware or software problem?

rick
 

The black rectangles issue was hardware.  I replaced the display with an "Arducam 1602" and we're back in business.  Nice display too, white on blue.

As for the separate problem I had getting Windows to install the driver for the Arduino Nano, that was because I needed to download the Chinese driver.  It's quite clearly described in this forum's Wiki, under "Raduino topics > Installing the Arduino IDE".  So that problem was simply my failure to RTFM!

Thanks to all for helpful replies -

73,
Rick
N3ECZ

uBitx #ubitx

SUNIL A R
 

Hi, 
      Iam buying a ubitx ver 4.3 , its alll trifilar coil (All the RF transfomers are 8-10 trifilar turns on FT37-43) winding is not twisted. Please eplane diffrent between twisted winding and no twisted winding, 
Which is better. And one more thing u bitx frequency 1.25khz drift from actual frequency
(eg: in shortwave AM band 7.42MHz,  uBitx tune 7.418.75MHz). How can correct it ? 
kindly please give me the frequency and all other setting procedure
                                                               TU.  73
 
 
                                                                              Tu 73 

Re: uBitx #ubitx

Curt
 

Sunil

Nice to see your message. I am thinking the twisting is to make the behavior of the 3 windings more uniform (exact with each other). Hard to say exactly how much it matters, perhaps Farhan knows.

In tuning a AM signal on 40m, you are hearing the lower sideband (lsb). The passband of the v4 ubitx is nicely narrow. I would evaluate how well it is receiving ssb signals, if the BFO is not well adjusted it could make the frequency error higher. 1.25 kHz seems high that maybe bfo might be off calibration. Listen to more signals and try only small adjustments each time. Find ubitx alignment or adjustment at hfsignals website. BFO calibration is easy, frequency adjustment is a bit difficult. 

One comment, if you do CW, when perfectly calibrated the cw frequency can be 700 Hz off, because the display is shared between ssb and cw.

Be patient in working this, I enjoy using this rig.

73 Curt

Re: uBitx #ubitx

Jerry Gaffke
 

Twisting the wires on the transformers helps ensure all three wires see identical magnetic fields.
This could improve the balance of the diode mixers at T1,2,3,4,7, and thus help reject
unwanted signals from getting through the mixer.  (Google "doubly balanced mixer".)  
But so long as all three windings look equally tight and well spaced, I doubt there is an issue
with windings that are not twisted. 

I can't think of any particular reason why twisting would matter in the transformers
used for the power amp at T8,9,10,11.

Re: V5 and JackAl

Brian
 

Is that right - the filter skirts are only 30dB down?

Brian VK4BAP

Re: uBitx #ubitx

MVS Sarma
 

Hi Sunil Jee,
 Please take a close up shot of any single  trifilar wound trafo that you feel is not twisted. Your photo is not clear.

To the best of my knowledge, HF signals  did not change the policy to untwisted trifilar transformers.
regards
sarma
 vu3zmv
 


On Wed, Feb 20, 2019 at 8:27 AM Jerry Gaffke via Groups.Io <jgaffke=yahoo.com@groups.io> wrote:
Twisting the wires on the transformers helps ensure all three wires see identical magnetic fields.
This could improve the balance of the diode mixers at T1,2,3,4,7, and thus help reject
unwanted signals from getting through the mixer.  (Google "doubly balanced mixer".)  
But so long as all three windings look equally tight and well spaced, I doubt there is an issue
with windings that are not twisted. 

I can't think of any particular reason why twisting would matter in the transformers
used for the power amp at T8,9,10,11.

Re: No TX #ubitx

 

Base 3.1 and Emitter 3.4 is not alright, must be 0.6v approx.. check R80 and R81.
C80 could be leaking or bad.

Raj

At 19-02-19, you wrote:
Jim,

Unknown at this time, but I'll look when hi.e again. Havi g replaced Q90 with another SMD type 3904 and then a can-sized 2N2222a, the condition is notrepeatable.

The volt readings on the upgraded Q90 are: base 3.1v, emitter 3.4v, and colector 11.8v approx. from memory and the [b] & [e] could be reversed. Staying up way too late looking at this stuff.


Raj,

I'll take a look at L1 through L4. Thanks much.



Regards,

Ted
K3RTA

Re: No TX #ubitx

 

BASE should be higher than emitter! You will get false reading if there is RF so mic must be disconnected.

--------------------------------

Base 3.1 and Emitter 3.4 is not alright, must be 0.6v approx.. check R80 and R81.
C80 could be leaking or bad.

Raj

At 19-02-19, you wrote:
Jim,

Unknown at this time, but I'll look when hi.e again. Havi g replaced Q90 with another SMD type 3904 and then a can-sized 2N2222a, the condition is notrepeatable.

The volt readings on the upgraded Q90 are: base 3.1v, emitter 3.4v, and colector 11.8v approx. from memory and the [b] & [e] could be reversed. Staying up way too late looking at this stuff.


Raj,

I'll take a look at L1 through L4. Thanks much.



Regards,

Ted
K3RTA

Re: uBitx #ubitx

Evan Hand
 

The best way that I have found to tune the uBitx is to use a free audio spectrum analyzer software with a mic providing the input. First set the uBitx so that there is only noise on the speaker and then adjust the BFO to center the "noise" signal between 500 and 3000 hz on the analyzer.  I would then go back to a known frequency standard (Like WWV in the US) and adjust the frequency readout by zero beating to the know standard.  The way to adjust the BFO and Frequency displayed is documented on the HF Signals web site.  I just use the audio analyzer in place of a weak SSB signal, and do the BFO first.

Link to free Audio Analyzer software:
http://www.techmind.org/audio/specanaly.html

73
Evan
AC9TU

Re: uBitx #ubitx

SUNIL A R
 

Tu for the response 73...

Re: uBitx #ubitx

SUNIL A R
 

Tu for the response 73....

Re: uBitx #ubitx

SUNIL A R
 

Tu for the response 73....

Re: uBitx #ubitx

SUNIL A R
 

Tu for the response 73....

Re: uBitx #ubitx

SUNIL A R
 

Tu for the response 73....

Re: Power instead of S-Meter for CEC-software? #ubitx #smeter #arduino

anders@...
 


Thanks for input! The principles are now clear to me. I will try it out, first I will check if the so called "S-meter" on the display is available in transmit mode (anyone knows?), and then if the RF-detector produces enough current to be measured by Arduino, or if I have to apply some circuit involving LM358 or alike.

73's

Anders SM0HPL