Date   

Re: BITX40 Pop Fix

Evan Hand
 

Ted,
Based on what you have described so far, I believe that you do have a BITX40 with the Raduino board in place of the VFO.  That version does not use the Nano for any of the rig control EXCEPT for the frequency.  What that means to you is if you want to remove the pops, then either the circuit that Paul provided or Allison's circuit on ubitx.net with the 2N7000 inverter in front of it.  This adds another 2n7000 and a 1 meg resistor to the parts list.  You would connect the gate of the inverter MOSFET to the PTT line and the output of the inverter to the diode to the gate of the second MOSFET.  The TX line is connected to the diode with the resistor across it.

Again I must warn that I have not tested this, as I do not have a BITX 40 to experiment with.
Good Luck in protecting your ears!
73
Evan
AC9TU


Re: UBITX V4 for sale #v4

WD8WV
 

Mike,

if you still have it email me at my email address on QRZ.com.  
--
Judd, WD8WV


Re: BITX40 Pop Fix

BevTed Stanier
 

Hi Evan

Probably obvious I don’t know what I have. Don’t know difference between Arduino Raduino Nano etc.

The main board has BITX 40 v3 on it.

There is a LD display board. Plugged into this board is a board with mini USB jack and xtal oscillator and a 5v regulator. On this board (Raduino?) is a small board labeled Nano. This small board has a 30 pin connection. Pins 16 and 17 of this connector are labeled TXD0 and RXD1 respectively as per the schematic I found on the internet. There is nothing labeled “TX/RX”. It is a single band SSB only rig.

It appears to match the November cct description from-

Https://hfsignals.com/index.php/2017/11/23/bitx40-circuit-desription/

 

Page 3. Published in 2017.

I thought TXD0 meant it was a data o/p pin and not a 5v logic pin?

If true will assume I have to find a different mod or listen to the pops.

73

Ted VA7CTA

 

 

 

 

 

Sent from Mail for Windows 10

 

From: Evan Hand
Sent: Saturday, July 25, 2020 3:54 PM
To: BITX20@groups.io
Subject: Re: [BITX20] BITX40 Pop Fix

 

Ted,
I do not have any experience with the single band versions of the BITX transceivers.  The best help that I can provide is a link to the ubitx.net pages on Pop Fix:
http://ubitx.net/category/hardware/audio-pop-mod/

I believe that you will need to adapt what is there, as almost all are for the multiband uBITX series.  The good thing that I see is most of the terminal descriptors are the same.  The not so good part is that with the original BITX series, there is not a Raduino with the Nano and 5volt level control signals.  As the fix from Allison uses the 5volt level to turn the transistor on before power to the transmitter stages through the relay, you will need to come up with the equivalent.  If you do not have the Raduino and the Nano, then you would need to build an inverter from the PTT signal to drive the gate of "Q74" high when the PTT signal goes low.  I would use a second 2n7000 as an inverter:
http://www.learningaboutelectronics.com/Articles/Transistor-inverter-circuit.php

Again, these are suggestions that I have NOT verified as I do not have a rig to do the testing.

Hopefully, someone on this board has the first-hand experience and can set us straight.
73
Evan
AC9TU

 


Re: BITX40 Pop Fix

BevTed Stanier
 

Thanks Paul. It is obvious I don’t know what I have. More later.

 

Ted VA7TA

 

Sent from Mail for Windows 10

 

From: Paul KL7FLR
Sent: Saturday, July 25, 2020 4:03 PM
To: BITX20@groups.io
Subject: Re: [BITX20] BITX40 Pop Fix

 

This this the original fix for the Bitx40.
http://www.nd6t.com/bitx/40click.htm

works too..
regards,
Paul
KL7FLR

 


Re: BITX40 Pop Fix

Paul KL7FLR
 

This this the original fix for the Bitx40.
http://www.nd6t.com/bitx/40click.htm

works too..
regards,
Paul
KL7FLR


Re: BITX40 Pop Fix

Evan Hand
 

Ted,
I do not have any experience with the single band versions of the BITX transceivers.  The best help that I can provide is a link to the ubitx.net pages on Pop Fix:
http://ubitx.net/category/hardware/audio-pop-mod/

I believe that you will need to adapt what is there, as almost all are for the multiband uBITX series.  The good thing that I see is most of the terminal descriptors are the same.  The not so good part is that with the original BITX series, there is not a Raduino with the Nano and 5volt level control signals.  As the fix from Allison uses the 5volt level to turn the transistor on before power to the transmitter stages through the relay, you will need to come up with the equivalent.  If you do not have the Raduino and the Nano, then you would need to build an inverter from the PTT signal to drive the gate of "Q74" high when the PTT signal goes low.  I would use a second 2n7000 as an inverter:
http://www.learningaboutelectronics.com/Articles/Transistor-inverter-circuit.php

Again, these are suggestions that I have NOT verified as I do not have a rig to do the testing.

Hopefully, someone on this board has the first-hand experience and can set us straight.
73
Evan
AC9TU


UBITX V4, bitx40 misc boards for sale

Mike Short <ai4ns.mike.spam@...>
 

I have for sale:
uBITX V4 $80
bitx40 and  amateurradiokits case $60
Two K5BCQ AGC boards $5 each
External Relay Board $10
External connection boards $2
VK4PLN CW filter boards and breakout boards. $1 each

or make an offer. 

mike AI4NS 



Re: BITX40 Pop Fix

BevTed Stanier
 

Thanks for the reply Evan.

I seem to be having trouble matching the right BITX board to the right schematic to the right version of the Pop Fix mod etc.

I have a BIXT40 V3 old board that was passed on to me with no documentation. It is now working okay but wanted to do the PopFix mod.

You are right the BITX 40 that I have does not have a Q47 Mosfet. The schematic and parts list that I found on the net for this mod uses a Mosfet designated Q74 as well as a diode, resistor and a couple of caps. The drain of Q74 goes to flag M2 or the Vol H of the volume control and the source to Gnd. It shows the gate being fed by “TX/RX” but my Arduino wiring diagram does not show a signal called this “TX/RX”. Is this signal only on the uBITX  and this mod cannot be used on a BITX 40. The signal that controls the K1 relay is a 12v supply from the PTT sw. and not a 5v signal. I seem to be confused between BITX40 and uBITX 40 and trying to find the right mod for Popfix.

Any thoughts are welome.

Ted

VA7CTA

 

Sent from Mail for Windows 10

 

From: Evan Hand
Sent: Saturday, July 25, 2020 12:36 PM
To: BITX20@groups.io
Subject: Re: [BITX20] BITX40 Pop Fix

 

Not sure that I understand what you are asking for the BITX40, as there is not a Q74 in that rig.  If your question is for the uBITX (any version), the T/R signal that controls the gate of Q74 is a 5 volt signal direct from the Raduino board.  It is labeled T/R, not TX/RX.  It is also connected to Q15 that then drives the K1 relay.

73
Evan
AC9TU

 


Re: UBITX V4 for sale #v4

Mike Short <ai4ns.mike.spam@...>
 

I have the case also

I also started the Allard mods. How about $60?

On Sat, Jul 25, 2020 at 06:18 WD8WV <juddie.d.burgess@...> wrote:
How much for the Bitx 40?
--
Judd, WD8WV


Re: BITX40 Pop Fix

Evan Hand
 

Not sure that I understand what you are asking for the BITX40, as there is not a Q74 in that rig.  If your question is for the uBITX (any version), the T/R signal that controls the gate of Q74 is a 5 volt signal direct from the Raduino board.  It is labeled T/R, not TX/RX.  It is also connected to Q15 that then drives the K1 relay.

73
Evan
AC9TU


Re: kit-projects AGC, with G4HUP buffer + audio buffer; AGC not very effective

 

Rob,

 It sounds like you might have a bit much loading down the IF and Audio. I would try and tap the Vol-H for the AGC from R70 and see how it goes. The Vol-H signal provides the bias that runs the AGC not the RF signal. If its being loaded down and not providing enough juice so to speak then the AGC will not work as intended.
--
David

 N8DAH
https://kit-projects.com/

Shop is open!


BITX40 Pop Fix

BevTed Stanier <bevtedstan@...>
 

The schematic for the Q74 gate shows an input signal called TX/RX. I see only a TX or RX flag on the schematic that I have for an old BITX40 v3. Where do I get “TR/TX” from or is “TX” or “RX” from the PTT relay the signal to use?

Help appreciated.

Ted

 

Sent from Mail for Windows 10

 


Re: UBITX V4 for sale #v4

WD8WV
 

How much for the Bitx 40?
--
Judd, WD8WV


Re: UBITX V4 for sale #v4

Mike Short <ai4ns.mike.spam@...>
 

I found it. I also have a bitx 40

On Tue, Jul 14, 2020 at 17:03 Mike Short via groups.io <ai4ns.mike.spam=gmail.com@groups.io> wrote:
Now I can’t find it. If I do, yes I will ship to AU. 

On Tue, Jul 14, 2020 at 03:27 Paul <sthcsttkd@...> wrote:
Would you ship to Australia? 
73

Paul
VK2FPAD

On Tue, 14 Jul. 2020, 4:13 am Mike Short, <ai4ns.mike.spam@...> wrote:
V4 with mods to add JackAl board. All parts that come with it, and W0EB Raduino clone.

$80 OBO 

mike
AI4NS


Re: Installed a 2.8 basic Nextion, but . . .

Evan Hand
 

The way that I set the calibration settings using the CEC software is by clicking on the encoder bringing up the yellow box menu.  That is the same as the stock v4 menu with some added settings.  Like in the original v4, you need to rotate the encoder until you get to the setup selection where you press the encoder again to turn on the setup settings.  This will clear the screen of the yellow box, so you need to press the encoder yet again to bring it back up.  Now when you scroll through the selections you will find the calibration and BFO tuning choices.  Follow the process outlined in the v6 video, instead of selecting the BFO and Calibrations from a menu page, you will need to select them through the yellow box that pops up on the screen.  The process is:
1 - Tune the BFO towards the low end to ensure the best accuracy when zero beating an AM station like WWV
2 - Calibrate the frequency by first setting the frequency of the AM station on the dial, entering calibration mode, then zero beating against a known frequency AM station.  I use WWV at 10MHz
3 - Tune the BFO centering the audio "plateau" between 300 and 3000 Hz.

For the CEC software, you need to press the PTT button to save the values, wait 10 seconds then turn the rig off then on again.  This ensures that the values are saved.

Here is the v6 video from Fahran:
https://www.youtube.com/watch?v=t6LGXhS4_O8

Hope this helps, and yes, the receiver will need calibration if you are not getting good received signals.
73
Evan
AC9TU


Re: tinySA now available at alibaba and aliexpress

Reed N
 

Given that the source code is literally forked from the nanoVNA, I guess it's not too surprising that it physically resembles and has a UI that resembles the nanoVNA. Too bad it's not open-source hardware too.



Reed


tinySA now available at alibaba and aliexpress

Doug W
 

I know this is off topic but I figured it would be of interest to enough that it was worth posting.  Shipping, at least to the US, is less on Aliexpress.

https://tinysa.org/wiki/
https://groups.io/g/tinysa/topics

https://www.aliexpress.com/item/4001274404758.html
https://www.alibaba.com/product-detail/Hand-held-tiny-Spectrum-analyzer-TinySA_1600085564565.html

Specification

User interface:

* Display resolution 320*240 pixels
* Screen diagonal 2.8"
* 16 bits per RGB pixels
* Resistive touch control
* Jog switch control
* USB serial port control
* Optional TTL USART port (SW not yet implemented) on the internal PCB
* Linear power supply to avoid switching noise.

The input/output specification of the tinySA is split over the 4 modes

Low input mode spec:

* Input frequency range from 100kHz to 350MHz
* Input impedance 50 ohm when input attenuation set to 10dB or more.
* Selectable manual and automatic input attenuation between 0dB and 31dB in 1 dB steps
* Absolute maximum input level without attenuation of +10dBm
* Absolute maximum input power with 30dB attenuation of +20dBm for short period
* Input Intercept Point of third order modulation products (IIP3) with 0dB attenuation of +15dBm
* 1dB compression point at +2dBm with 0dB attenuation
* Power detector resolution of 0.5dB and linearity versus frequency of +/-1dB
* Absolute power level accuracy after power level calibration of +/- 1dB
* Lowest discernible signal using a resolution bandwidth of 30kHz of -102dBm
* Frequency accuracy equal to the selected resolution bandwidth
* Phase noise of -90dB/Hz at 100kHz offset and -115dB/Hz at 1MHz offset
* Spur free dynamic range when using a 30kHz resolution bandwidth of 70dB
* Manually selectable resolution filters of 3, 10, 30, 100, 300, 600kHz. Automatic selection of one of the 57 resolution filters.
* On screen resolution of 145 or 290 measurement points.
* Scanning speed of over 1000 points/second using largest resolution filters.
* Automatic optimization of actual scanning points to ensure coverage of the whole scan range regardless of the chosen resolution bandwidth
* Spur suppression option for assessing if certain signals are internally generated or actually present in the input signal

High input mode spec:

* Input frequency range from 240MHz to 960MHz
* As there is no input bandfilter strong signals outside the 240MHz to 960MHz range can cause distortion of the in band signals
* Absolute maximum input level without attenuation of +10dBm
* Input Intercept Point of third order modulation products (IIP3) of -5dBm
* 1dB compression point at -6dBm with 0dB attenuation
* Power detector resolution of 0.5dB and linearity versus frequency of +/-1dB
* Absolute power level accuracy after power level calibration of +/- 1dB
* Lowest discernible signal using a resolution bandwidth of 30kHz of -115dBm
* Frequency accuracy equal to the selected resolution bandwidth
* Spur free dynamic range when using a 30kHz resolution bandwidth of 50dB
* Selectable (automatic and manual) resolution filters of 3, 10, 30, 100, 300 and 600kHz
* Optional 25dB to 40dB frequency dependent input attenuator. The power level error with this attenuator activated increases to +/- 15dB
* On screen resolution of 145 or 290 measurement points.
* Scanning speed of over 1000 points/second using largest resolution filters.
* Automatic optimization of actual scanning points to ensure coverage of the whole scan range regardless of the chosen resolution bandwidth

Low output mode spec:

* Sinus output with harmonics below -40dB of fundamental
* Output frequency range from 100kHz to 350MHz
* Output level selectable in 1dB steps between -76dBm and -6dBm
* Optional AM, narrow FM and wide FM modulation or slow sweep over selectable frequency span

High output mode spec:

* Square wave output
* Output frequency range from 240MHz to 960MHz
* Output level selectable in variable increments between -38dBm and +13dBm
* Optional narrow FM and wide FM modulation or slow sweep over selectable frequency span

Reference generator spec:

* Optional square wave output with fundamental at -25dBm connected to high input/output
* Frequency can be set to 1MHz, 2MHz, 4MHz, 10MHz, 15MHz or 30MHz.

Battery spec:

* Charging time max 1 hour on 500mA minimum USB port or USB charger
* Operation on fully charged battery for at least 2 hours



www.bitxmap.com


Re: Installed a 2.8 basic Nextion, but . . .

Grover Cleveland
 

Now that the correct  UBITXV5_CEC_V1.200_NX  installed, I find that the receiver seems dead.
I'm hoping this is just a calibration issue but if it is, I can't find how to get to the calibration settings.

Grover


Re: S-Meter #v6

Evan Hand
 

There is not a built-in S meter.  There are multiple ways to add either as hardware kits with a meter or via software and a hardware mod.  A lot depends on which version of uBITX that you have.

73
Evan
AC9TU


Re: Installed a 2.8 basic Nextion, but . . .

Evan Hand
 

Do not feel alone. You would be surprised at the number of times this has come up. 


Enjoy your upgraded rig!
73
Evan
AC9TU