Date   
si5351a CLK drive levels in uBITX #ubitx

 

I noticed that in both Ashar and Ian's uBITX code that the CLK outputs of the si5351a are being set to 4ma.

uint8_t  si5351bx_drive[3] = {1, 1, 1};  // 0=2ma 1=4ma 2=6ma 3=8ma for CLK 0,1,2

My understanding is that this translates to an output signal level of about 6dBm. 

What I have previously read is that most passive Double Balanced Diode ring mixers need a LO signal of 
7dBm or greater for optimal performance. 

Has anyone tried increasing one or more CLK output levels to 6mA to see what effect this has on receiver performance ?
A 6mA setting would translate to about 8dBm.

This would be an interesting experiment for someone with the necessary test equipment to verify whether this would be a positive
or a negative change. 

Cheers

Michael VE3WMB 

Re: Mike element

Jerry Gaffke
 

You might need a bigger hole.

There's significant variation on transmit gain between different uBitx's.
I'd guess much of this is in the 45mhz IF, but could be any of a dozen different places.
On some, a Baofeng mike just works.
You can tweak the mike preamp if you need more gain per post  https://groups.io/g/BITX20/message/40742
Or add an external preamp.
Though be aware that this may aggravate Allison's spur when operating above 20m
if your gain issue is not in the mike or mike pre-amp.

Jerry




On Tue, Jul 24, 2018 at 06:52 AM, Ken Held KF7DUR wrote:
Jerry

I have 3 or 4 of the Baofeng mics from different sources, as well as a variety of mic elements.  When I was trying to get them to sound good on the Baofeng radio I concluded that the housing caused them to sound bad. The mics sounded good out of the housing but got muffled when the housing was closed up.
The Baofeng mics did have a hole over the element, I even drilled it out a bit to see if that would help the sound quality. I never did get the mics to sound good.
The -24dB element I used for my uBitX mic is the larger size element but it fits snugly in the housing. I think that may take care of the sound quality issue I had.

Re: miss alignment

W2CTX
 

AGAIN!  If you don't tell us whose firmware and version you are running people


can only guess at a solution to your problem.


rOn


On July 24, 2018 at 11:17 AM David Posthuma <davep@...> wrote:

I have version 4 of mBitx. I have it completed, but the frequencies seem to be off by 2.4kh. The setup instructions online no longer match my menu functions. Can I please get some updated configuration instructions?

 

Thanks,

 

David A Posthuma, WD8PUO

 


 

 

Re: uBITX HF transceiver and blue MBITX metal case.

David McGaw
 

Most simple USB interfaces are in fact RS-232 serial ports internally.  If there is a DE9 or DB25 RS-232 serial port on a device, use a USB to Serial adapter.  NBD.

David N1HAC


On 7/24/18 11:24 AM, Jerry Gaffke via Groups.Io wrote:
Being a product of the previous millenium myself, I have no problem with equipment that has a UART.
There are variations, but this paragraph on "data framing" is most of what you need to know:
    https://en.wikipedia.org/wiki/Universal_asynchronous_receiver-transmitter#Data_framing

If you really want to understand USB then be my guest, it can take years:
    http://www.usb.org/developers/docs/

The solution for punters like me happy to get by with 115.2 kBaud are chips such as the CH340 used
on the Nano, the FTDI chips on the original Arduinos, and the CP2102 from Silicon Labs. 
This CP2102 item just works on my Ubuntu box, no drivers needed:
    http://www.oddwires.com/cp2102-serial-adapter-module-usb-to-rs232-with-jumper-wires/
First tie the UART's TX and RX lines together, run a loopback test from the host to prove the USB-to-UART device is working.
If it doesn't magically work, then move on to a different device driver, USB port, USB-to-UART device, host OS, or host computer.
Once you get that going, it's easy enough to get the UART to talk to the microcontroller of your choice.

Given some random USB device, if you happen to have appropriate software for your host computer
then it can just work when you plug in that USB cable.  If it doesn't, good luck.
I'd much prefer to debug a UART connection.

Jerry, KE7ER


On Tue, Jul 24, 2018 at 06:51 AM, Jim Strohm wrote:
In my last field of professional endeavor (product documentation for microcontrollers and industrial equipment) a lot of the "next to new" equipment like endpoint sensors and plasma generators used proprietary, one-off serial interfaces at baud rates from the last millennium.  Documenting them and getting them to work was always a challenge.

Re: NEXTION 4.3" Basic & Enhanced now Supported

Joe
 

The 3.2 has been available since last month



Joe
VE1BWV


On Mon, Jul 23, 2018 at 11:31 AM Joel Caulkins <caulktel@...> wrote:
I would love to see a 3.2 inch version of this.

Joel
N6ALT

Re: uBITX HF transceiver and blue MBITX metal case.

Arv Evans
 

Jerry

And...DB9 and DB25 connectors are relatively cheap, robust, and readily available as salvage
from old modems and PCs.  One does not have to use them for RS-232.  They can be re-purposed
as connectors for other protocols and other uses. 

Arv
_._


On Tue, Jul 24, 2018 at 9:40 AM David McGaw <david.g.mcgaw@...> wrote:
Most simple USB interfaces are in fact RS-232 serial ports internally.  If there is a DE9 or DB25 RS-232 serial port on a device, use a USB to Serial adapter.  NBD.

David N1HAC


On 7/24/18 11:24 AM, Jerry Gaffke via Groups.Io wrote:
Being a product of the previous millenium myself, I have no problem with equipment that has a UART.
There are variations, but this paragraph on "data framing" is most of what you need to know:
    https://en.wikipedia.org/wiki/Universal_asynchronous_receiver-transmitter#Data_framing

If you really want to understand USB then be my guest, it can take years:
    http://www.usb.org/developers/docs/

The solution for punters like me happy to get by with 115.2 kBaud are chips such as the CH340 used
on the Nano, the FTDI chips on the original Arduinos, and the CP2102 from Silicon Labs. 
This CP2102 item just works on my Ubuntu box, no drivers needed:
    http://www.oddwires.com/cp2102-serial-adapter-module-usb-to-rs232-with-jumper-wires/
First tie the UART's TX and RX lines together, run a loopback test from the host to prove the USB-to-UART device is working.
If it doesn't magically work, then move on to a different device driver, USB port, USB-to-UART device, host OS, or host computer.
Once you get that going, it's easy enough to get the UART to talk to the microcontroller of your choice.

Given some random USB device, if you happen to have appropriate software for your host computer
then it can just work when you plug in that USB cable.  If it doesn't, good luck.
I'd much prefer to debug a UART connection.

Jerry, KE7ER


On Tue, Jul 24, 2018 at 06:51 AM, Jim Strohm wrote:
In my last field of professional endeavor (product documentation for microcontrollers and industrial equipment) a lot of the "next to new" equipment like endpoint sensors and plasma generators used proprietary, one-off serial interfaces at baud rates from the last millennium.  Documenting them and getting them to work was always a challenge.

Re: PCB Artwork hint

Jon Titus, KZ1G <tituskz1g@...>
 

Un-centered traces between evenly spaced pins such as those on ICs and connectors offends my sense of artistic perfection.  Just the way my mind works (or doesn't). ;-)
--
Jon Titus, KZ1G
Herriman, UT USA

Re: NEXTION 4.3" Basic & Enhanced now Supported

 

Joe,

Not with, "It is a mix of KD8CEC/KN4UD and my PD5DJ
Menu's and all screens are redone, cleaned up and aligned" I have the 3.2 inch release and it doesn't look anything like this one.

Joel
N6ALT

Re: NEXTION 4.3" Basic & Enhanced now Supported

Joe
 

Sorry, guess I am not looking at the same files...
The 4.3 are only the non editable compiled tft versions. So not able to load into the editor.. to see

I have the 5.0 and 7 inch re-done and both editable and compiled files released files released... these use enhanced graphics, extra menu etc...

Joe
VE1BWV

On Tue, Jul 24, 2018 at 1:37 PM Joel Caulkins <caulktel@...> wrote:
Joe,

Not with, "It is a mix of KD8CEC/KN4UD and my PD5DJ
Menu's and all screens are redone, cleaned up and aligned" I have the 3.2 inch release and it doesn't look anything like this one.

Joel
N6ALT

Re: si5351a CLK drive levels in uBITX #ubitx

Jim Sheldon
 

Michael and all,
I set my signal generator to .5 microvolt @ 7.000 MHz and listened to the sound of it (no accurate S meter here yet).  Compiled my own group's software, Version 6.00R (for the BITeensio card we sell) at 6 and 8 ma.  6 ma gave an increase in sensitivity by a noticeable amount (not a lot but noticeable) and 8 ma brought it up again by a quite small amount but I noticed a marked increase in extra signal artifacts in the RX Audio.  There were a few added artifiacts @ 6 ma also, but not nearly as pronounced as with the drive set to 8 ma.  

This may very well be different for each different uBITX due to the variable nature of the transistors and mixer diode arrays used in the rig.  Not a scientific measurement but I did see some RX gain from setting it to 8 ma.  I left mine at that setting for now and will run it for a while to see what happens.  Might have to get the adapter out and see what it did on TX to the spurious and harmonic output.  I don't TX with this particular uBITX except into a dummy load so may let someone with better test equipment check the TX spurs & harmonics @ 8 ma clock drive.

Jim Sheldon, W0EB

------ Original Message ------
From: "Michael Babineau" <mbabineau.ve3wmb@...>
Sent: 7/24/2018 10:27:01 AM
Subject: [BITX20] si5351a CLK drive levels in uBITX #ubitx

I noticed that in both Ashar and Ian's uBITX code that the CLK outputs of the si5351a are being set to 4ma.

uint8_t  si5351bx_drive[3] = {1, 1, 1};  // 0=2ma 1=4ma 2=6ma 3=8ma for CLK 0,1,2

My understanding is that this translates to an output signal level of about 6dBm. 

What I have previously read is that most passive Double Balanced Diode ring mixers need a LO signal of 
7dBm or greater for optimal performance. 

Has anyone tried increasing one or more CLK output levels to 6mA to see what effect this has on receiver performance ?
A 6mA setting would translate to about 8dBm.

This would be an interesting experiment for someone with the necessary test equipment to verify whether this would be a positive
or a negative change. 

Cheers

Michael VE3WMB 

Re: miss alignment

 

I am currently using the stock firmware that comes with version 4. I am simply seeking updated direction on realignment of the transceiver. The current directions posted on the HF Signals website do not match the firmware’s menu options nor process.

 

David A Posthuma, WD8PUO

 

From: BITX20@groups.io <BITX20@groups.io> On Behalf Of W2CTX
Sent: Tuesday, July 24, 2018 11:38 AM
To: BITX20@groups.io
Subject: Re: [BITX20] miss alignment

 

AGAIN!  If you don't tell us whose firmware and version you are running people

 

can only guess at a solution to your problem.

 

rOn



On July 24, 2018 at 11:17 AM David Posthuma <davep@...> wrote:

I have version 4 of mBitx. I have it completed, but the frequencies seem to be off by 2.4kh. The setup instructions online no longer match my menu functions. Can I please get some updated configuration instructions?

 

Thanks,

 

David A Posthuma, WD8PUO

 


 


 

Re: si5351a CLK drive levels in uBITX #ubitx

ajparent1/KB1GMX
 

Actually 5 to 10dbm the performance is about the same...

However!  There are attenuators before each of the mixers so there is
what the 5351 puts out and what actually gets delivered which is 3 to 6 db less.

Myself, 4ma into a 50 ohm load does not translate to 6dbm.  Math says maybe -1dbm.
My scope and Spec analyzer both agree within about 1db.

To hit +7Dbm in a 50 ohm system you need 1.41V PP or about 28ma PP.


Allison

Re: ND6T AGC S Meter Calibration

Kees T
 

When you connect the S-meter to J1, don't forget that you still have to add a jumper to set the AGC "hold" time by "loading" C4. I expect the S-meter analog input to be a very small load

You might try a little different load on C4 by installing a different resistor jumpers on J2,J3,J4,or J5.  What effect does that have on the readings ? J5 has the highest 1.9M load and therefore the longest "hold" time.

73 Kees K5BCQ 

Re: si5351a CLK drive levels in uBITX #ubitx

ajparent1/KB1GMX
 

I haven't looked at spurs or harmonics related to this save for it makes sense.
The drive is way too low and the sensitivity increase is consistent with drive increase.

If the drive is increased the spurs due to mixer overload should improve, harmonics
may stay the same.

The problem is even at 8ma drive your barely at 5dbm out out and most of the
mixers have 6db attenuators ahead of them.... So drive is -1dbm.  The mixers
are running starved.

Allison

Re: NEXTION 4.3" Basic & Enhanced now Supported

Björn Pasteuning
 

Hi all,

I seem to forgot adding the HMI files, my apologies for that :-)

With the same download link, you should be able to get the TFT + HMI files.

 

@Rob PA0RBL
I have ordered the nextion's from Banggood

--
73' Björn de PD5DJ
www.pd5dj.nl

Re: PCB Artwork hint

AA9GG
 

and my OCD......LOL

Re: si5351a CLK drive levels in uBITX #ubitx

Jim Sheldon
 

Sort of what I thought Allison I'm going to try it at max for a while and see just what transpires.  I have the SA on and will run rig into a dummy load with the SA pickoff in the line - we'll see what I find as far as harmonics.  Unfortunately my SA is an old GW Instek and I can't get enough span at the normal HF frequencies involved to see all the harmonics at once.  I have to carefully increase the center frequency to see 'em all.  Makes it sort of unscientifice and I'm not sure how well calibrated this thing is. 

Wish I could have afforded a RIGOL or Sigilent but I got this one off ITT Tech when they close a NJ branch for just under $400.  Better than no SA at all - LOL - but sometimes the readings (even though it had a recent calibration sticker on it when I got it) can be suspect.

OK, before sending this, I hooked up the SA and ran a harmonic / garbage scan on it.  Set the TX freq first at 3.5 MHz, output 5 watts (where I normally run it).  Set the Spectrum Analyzer input sensitivity to put the signal from the pick-off so that the fundamental was at 0 dBm on the screen and started looking.  2nd Harmonic 55 dB down, 3rd harmonic 62 dB down and all the others were each slightly better than that so I think everything is still OK.  

With the transmitter keyed at 5 watts out, I ran the analyzer through the freq range up into the VHF range and I didn't see any garbage that wasn't at least 60 + dB down from the fundamental.  Remember though this was with the fundamental at 3.5 MHz.  I'm out of time for right now, but will try and run scans with the TX on the higher bands and look for the "spurs" as well.  

I am pleased though that with the clock drive set to the max available in the software, the sensitivity of the RX has increased enough to make it worthwhile and the Harmonics/Spurs are still within FCC boundaries.  (At least on this particular V4 uBITX).

Jim Sheldon, W0EB



------ Original Message ------
From: "ajparent1/KB1GMX" <kb1gmx@...>
Sent: 7/24/2018 12:30:38 PM
Subject: Re: [BITX20] si5351a CLK drive levels in uBITX #ubitx

I haven't looked at spurs or harmonics related to this save for it makes sense.
The drive is way too low and the sensitivity increase is consistent with drive increase.

If the drive is increased the spurs due to mixer overload should improve, harmonics
may stay the same.

The problem is even at 8ma drive your barely at 5dbm out out and most of the
mixers have 6db attenuators ahead of them.... So drive is -1dbm.  The mixers
are running starved.

Allison

Re: #ubitx #ubitx-help Not able to set up extension switches using CEC firmware #ubitx #ubitx-help

Daniel Conklin
 

When no button is pressed it is 255, and when the encoder is pressed it is 3, the same as when I press the first switch. The second switch gives me 6 and the third gives me 7.  I verified the resistors with an ohm meter.  Thanks for helping me work through this.
Dan, W2DLC
 

Re: si5351a CLK drive levels in uBITX #ubitx

Don, ND6T
 

I'd never really considered running it other than full output. Since I run my own firmware all of the time, I never bothered to try it at lower levels and have had great results. Measuring with my old HP power meter I get between +3.2 dBm to +3.8 dBm from 3 MHz to 150 MHz. The slight dip near 52 MHz I attribute to the blocking capacitor that I use. The spectrum analyzer shows it as +3.17 dBm on 10 MHz where my power meter shows +3.8 dBm. That pretty much coincides, since the SA is looking at narrow-band energy and the old bolometer power meter is looking at overall energy (including all the harmonics).
This is using just the Si5351 in a signal generator project.
The mixer depends upon the peak voltage to switch those diodes so I wouldn't think that there would be much of a performance change unless the output was dropped appreciably. I see no reason to run the synthesizer at any level other than full throttle. Did anyone find a measurable increase in either receive or transmit birdies?
-Don

End Fed antennas w/ uBITX #ubitx

 

Not trying to start a "antenna war", but I noticed several people on this forum use "End Fed antennas".(Like Allison KB1GMX).  I have also used them with good success.  I feed them with 33' of coax and a 1:64 unun (PD7MAA design).  I have one with a trap (again PD7MAA blog) doing multiple bands.
On QRZ, everytime a End Fed topic is brought up, there is a bunch of nay sayers that always chime in. What are you experiences with them and QRP?  I'd like to know, being limited by an HOA, for antenna structures.
Thanks,
Jim W0CHL