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

alans77@...
 

Don: I have Kees pop fix board in place and it works great. I have already completely disconnected the AGC board to make other changes. When transmitting with the volume control twisted pair leads and all other wires connected at the radio end only I still hear my voice through the speaker. I am going to try replacing the twisted pair with coax and wrapping it around a 120-43 core.

Alan

Re: Microscope - - new thread

 

I have this USB Microscope, https://www.dinolite.us/products/digital-microscopes/usb/am3111t I know it's kinda pricey but it works great and is designed for viewing SMD and PCB's. I think all those cheap $60.00 scopes are cheap imitations of the Dino_lite's. You get what you pay for.

Joel
N6ALT

Re: Noise Burst #bitx40

Allard PE1NWL
 

Yes, raduino_v1.27.7 fixes this problem.
Download it from https://github.com/amunters/bitx40
and install the related (minimal) mods (see instructions included).

73 Allard PE1NWL

On Tue, June 26, 2018 17:32, Jerry Gaffke via Groups.Io wrote:
Allard's fix to the Bitx40 carrier burst using a delay in the code is
described here:
    https://groups.io/g/BITX20/message/33756
    https://groups.io/g/BITX20/message/34189

There is also Raj's fix, strictly hardware, no code:
    https://groups.io/g/BITX20/message/33707
    https://groups.io/g/BITX20/message/33742

Those are all in the same thread.
The rest of the thread is worth browsing as well.

Jerry, KE7ER

On Tue, Jun 26, 2018 at 05:35 am, Michael Babineau wrote:


John et al : 

The RF burst on PTT closure, on the BITX40, has been addressed by Allard
(PE1NWL) in his Raduino Code.  

https://github.com/amunters/bitx40

His approach is to shut down the CLK output on the SI5351 for 50 mS on
PTT
closure and wait for things to settle before re-enabling it to allow
TX.  


There is also a simple hardware mod that can be used to reduce this
burst
from 50 mS to less than 20 mS so that the delay time can be reduced in
the
code.
The mod is to change C124 from 47uF to 4.7 uF. C124 is near Q12 (mic
input).  See message #29101 in this group for the original discussion
on
this. 

Cheers

Michael VE3WMB


Re: Microscope - - new thread

Ralph Mowery
 

I was looking over the specs for it and have a hard time with the working distance.  Seems that it is about 2 inches for a 20 x which is very close to the work to do any soldering.  Then there seems to be a negative distance for some magnifications.  I don't see how that could work for anything.

Did they make a mistake in the spec sheet ?  How far can you put it away from the work to get say a 20 x magnification ?

ku4pt


On Tue, Jun 26, 2018 at 12:47 PM, Joel Caulkins <caulktel@...> wrote:
I have this USB Microscope, https://www.dinolite.us/products/digital-microscopes/usb/am3111t I know it's kinda pricey but it works great and is designed for viewing SMD and PCB's. I think all those cheap $60.00 scopes are cheap imitations of the Dino_lite's. You get what you pay for.

Joel
N6ALT
_._,_._,_

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

Don, ND6T
 

Thanks Alan. This is a real mystery! There has to be something that I am missing. Just doesn't seem possible but there it is!
-Don

Re: Microscope - - new thread

 

I can get mine about 12 inches away from my work and still focus. I don't however solder with it. I use magnifier glasses for soldering and the USB Scope for inspection. If I put it right on the board I can sometimes see the layers inside the board. When soldering a si5351 recently I was able to inspect my work full screen looking only at two pins at a time. If you've ever seen a si5351, they are tiny. I could't live without it. I also have a Goose neck stand that I can put it in and move it into any position I want.

Joel
N6ALT

Re: W8TEE Power/SWR Sketch for Nano

Kees T
 

Glenn,

Looks like you are way ahead of me......you have a board assy. Ah, the magic of 4 per 100mm x 100mm panel.

On the LED bargraph version we're using a BN43-302 core and have found the two sides to interact some. That may be due to having the turns "scramble wound" and not at the far ends of the binocular core. I still prefer using the two sets of 2x T37-61 cores because of the good luck with the mWattmeter II project.   BUT, the binocular core is much easier to work with and we're not looking for 1mW granularity here.

The LM555 technique sounds interesting but I wanted digital readings and that OLED display looks great. The Teensy is a fine solution with LOTS of extra capability and Loftur does excellent work but you can't beat ~$2 for a Nano if that is all you need.  

Yes, as others have pointed out, "SWR on the fly" for SSB with this arrangement won't work well. I am making the assumption that all SWR measurements are with a CW carrier.

Jerry,

Thank you for providing a run at the firmware required. I tried writing some "C" code 10 years ago and was not very good at it.  You know what they say about "trying to teach a pig to sing".

I use the level shifters because some early OLEDs were 3.3V and you never know what you get from China. Also.... at 3.3V they may consume a little less power ? ....may RF radiate a little less ?.... etc. All good "just in case" reasons to leave $0.05 worth of parts in the design.

73 Kees K5BCQ

Transmit Voltage and Thanks

hotrod541@...
 

I just completed my uBITX and I installed the double dc inputs. One for the receiver and the second for the PA.  How high can the input for the PA be without damage to the power transistors.  I am looking for a little more output.  I also would like to know if thre are better replacements for the two power transistors . I have installed a heat sink to the rear of the radio. I would like to thank everyone who contributed to the questions that I asked on this net, it was a great help in completing the radio. The first time on power up was a qso from here in Florida to KA1GG in MA. on field day.
Buddy, KJ4ZSI

Re: Transmit Voltage and Thanks

Arvo W0VRA
 

On Tue, Jun 26, 2018 at 10:41 am, <hotrod541@...> wrote:
How high can the input for the PA be without damage to the power transistors.
And a related question, how much current will be drawn at these elevated PA supply voltages?

For example, would a 19V 3A laptop power supply be expected to work?

Thanks!

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

Michael Shreeve
 

Just starting the pop fix. Looking at your circuit and the uBITX circuit. I've enjoyed your art work BUT, I"ve never worked with art work. Occasionally a large identification pc board photo or graphic showing components locations has been available for the millions of circuit boards I've worked with over the years. But, schematic are what I usually use and I thrive with them. And before switching to communications as my specialty I would get tons of consumer grade stuff and need to draw a schematic. 

 I have a 10x17 for V3 and V4.  

What would be best for me would be a real schematic with an X where the circuit is separated (in most cases cut, nut not always, Tombstoning the caps does the same thing, freeing up the "IO" line, no cut necessary..). An "IO" would be drawn with a simple line. On the new V4 Ashhar has put a test point TP20. At least on the schematic, not sure if he had new boards made, although would be hard to put the direct coupled audio amp in the circuit without completely changing and re-doing the board. . A line would be drawn to the point "c63" ON THE SCHEMATIC with an X showing a connection that is no longer there.  Same for C50. (which can be accomplished by tombstoning)  .


 . Rx and Tx control lines seem to be self explanatory. For me, even though I like your art work, this is how I do best with circuits and circuit changes. With a true schematic featuring both the uBITX and your circuit,  I will then raise (tombstone) c=63 and c-50 the correct way. That's how I've always worked best, with an actual schematic showing the entire circuit . I may try to draw the changes in pencil and submit the graphic somewhere. But, it would be better if you did this, since its your circuit. 

Ashar, with the V4,  did something which would be harder for us to do, and what he did was insert his pop circuit (On the new schematic for V4)  in between the new direct coupled transistor audio amp, and Q70 . , a mosfet called Q74 which I'm sure you've looked at in detail, being the owner of a new V4 . Its drawn as if its a separate little board .  It relies on a timing circuit (R78, D14, and a 1uf directly on the gate of q74) to do its magic, and hopefully it does. Too bad the first V3 didn't have this simple circuit. If it works. Does It ?

I'm not using the kit,, but rather, got a bunch of nice brand new pc board material and making the pads using a Dremel with cut wheel. That's the plan. Using the three n-channel mosfet simple circuit. 

On Tue, Jun 26, 2018 at 3:48 AM, Don, ND6T via Groups.Io <nd6t_6@...> wrote:
Alan, Sorry for the relay info. I see what you are getting to now. Do you have a "pop fix" modification in place (any flavor)?
Rowland: What happens if you unplug the AGC board (everything else still connected) and transmit? Does the feedback go away? -Don




--
Michael Shreeve N6GRG

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

Michael Shreeve
 

Oh, and for some who haven't actually looked at the v3 or v4 circuit, the rx and tx do not come from the radio, but in fact pins on relay k1. On the new V4 ashar is controlling the new pop mosfet (q74) circuit with a direct voltage from the raduino, labeled T/R pin 16 on the Raduino. No relay involvement. But, with Don's circuit, there are two resistors , both 220 ohms, r52 on the V3 for RX and R66 for TX, so you won't need a wire from the relay. (you can tag onto the resistors on the correct side. The trace from the relay is the source and the correct side. If I understand the circuit correctly which I think I do. 

Wondering if users are connecting something in the TX /RX lines to the wrong point, thus making the circuit feedback. .

On Tue, Jun 26, 2018 at 11:37 AM, Michael Shreeve <shreevester@...> wrote:
Just starting the pop fix. Looking at your circuit and the uBITX circuit. I've enjoyed your art work BUT, I"ve never worked with art work. Occasionally a large identification pc board photo or graphic showing components locations has been available for the millions of circuit boards I've worked with over the years. But, schematic are what I usually use and I thrive with them. And before switching to communications as my specialty I would get tons of consumer grade stuff and need to draw a schematic. 

 I have a 10x17 for V3 and V4.  

What would be best for me would be a real schematic with an X where the circuit is separated (in most cases cut, nut not always, Tombstoning the caps does the same thing, freeing up the "IO" line, no cut necessary..). An "IO" would be drawn with a simple line. On the new V4 Ashhar has put a test point TP20. At least on the schematic, not sure if he had new boards made, although would be hard to put the direct coupled audio amp in the circuit without completely changing and re-doing the board. . A line would be drawn to the point "c63" ON THE SCHEMATIC with an X showing a connection that is no longer there.  Same for C50. (which can be accomplished by tombstoning)  .


 . Rx and Tx control lines seem to be self explanatory. For me, even though I like your art work, this is how I do best with circuits and circuit changes. With a true schematic featuring both the uBITX and your circuit,  I will then raise (tombstone) c=63 and c-50 the correct way. That's how I've always worked best, with an actual schematic showing the entire circuit . I may try to draw the changes in pencil and submit the graphic somewhere. But, it would be better if you did this, since its your circuit. 

Ashar, with the V4,  did something which would be harder for us to do, and what he did was insert his pop circuit (On the new schematic for V4)  in between the new direct coupled transistor audio amp, and Q70 . , a mosfet called Q74 which I'm sure you've looked at in detail, being the owner of a new V4 . Its drawn as if its a separate little board .  It relies on a timing circuit (R78, D14, and a 1uf directly on the gate of q74) to do its magic, and hopefully it does. Too bad the first V3 didn't have this simple circuit. If it works. Does It ?

I'm not using the kit,, but rather, got a bunch of nice brand new pc board material and making the pads using a Dremel with cut wheel. That's the plan. Using the three n-channel mosfet simple circuit. 

On Tue, Jun 26, 2018 at 3:48 AM, Don, ND6T via Groups.Io <nd6t_6@...> wrote:
Alan, Sorry for the relay info. I see what you are getting to now. Do you have a "pop fix" modification in place (any flavor)?
Rowland: What happens if you unplug the AGC board (everything else still connected) and transmit? Does the feedback go away? -Don




--
Michael Shreeve N6GRG




--
Michael Shreeve N6GRG

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

atouk
 

Not to threadjack, but a related question on RFI.

Does changing the flying leads from the board to the antenna connector, to a short piece of coax have any measurable difference in "in box" or nearby RFI?

KD8CEC Nextion - Hardware Question #ubitx

Yaya
 

Hi All,

I just ordered a display to experiment with the KD8CEC tft firmware. Looking at the pictures on his blog I can see that it has a bar for showing power output. How does this work as the stock ubitx does not have that option.

Moreover, the description on the blog says you don't need any mods for the tft display to work, it looks really great and very very professional!

73 Elia, M0ZHN

I feel I am missing something here, can someone explain this please?

I hope I can get the tft to wor

WSPR Empty Data

Bob Shaw
 

I am using uBITX 1.080 and uBITS MM 1.081 to add WSPR count and data. In MM I read from uBITX, fill in count and WSPR generated data, Write to uBITX (Write Target/Write/Match Data/OK and disconnect from uBITX.

When I select WSPR Beacon, I get message EMPTY DATA.

I am at a loss as to where the WSPR data is getting lost? Any suggestions welcomed!

de Bob VA7SU

Re: ADE-1-24

pa0jen@...
 

Hi everyone,

About the ADE-1-24,
The spec's are somewhat equal to the Data-sheet of the ADE-1
The only big difference is that the footprint of this mixer is actually a mirror image of the original ADE-24.
If you mirror over the long axel, you will actually swap pin 1 with 6, 2 with 5,  3 with 4.

Just compare this mixer to pictures on google of the original ADE-1: https://commons.wikimedia.org/wiki/File:Frequency_mixer_Mini_Circuits_ADE-1_macro.png

I tested this mixer with the Bitx-20.
Also with two signal generators and a spectrum-analyzer and it worked like it should be.

As far as I am concerned, I am happy with this ADE1-24 mixer.

Regards,
Han
PA0JEN

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

Don, ND6T
 

Mike,

This thread is about the AGC and a possible RF feedback issue. The ClickFix is does not seem to be involved. In answer to your question: I just fired up the V4 board and Farhan's circuit fixes that click very nicely, a much more elegant approach. With that issue behind us, I don't feel that re-drafting the uBITX schematic is necessary on my part.
73,
Don

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

Michael Shreeve
 

I began to see that his problem seemed to be AGC related, being somewhat thick headed this am. Oh well. 

On Tue, Jun 26, 2018 at 2:51 PM, Don, ND6T via Groups.Io <nd6t_6@...> wrote:
Mike,

This thread is about the AGC and a possible RF feedback issue. The ClickFix is does not seem to be involved. In answer to your question: I just fired up the V4 board and Farhan's circuit fixes that click very nicely, a much more elegant approach. With that issue behind us, I don't feel that re-drafting the uBITX schematic is necessary on my part.
73,
Don




--
Michael Shreeve N6GRG

Re: SSM2167 wiring.

Nick VK4PP
 

Re: Transmit Voltage and Thanks

ajparent1/KB1GMX
 

The IRF510 can tolerate up to about 30V if the SWR is reasonable.  I've run the same pair at
28V for years.  Expect a lot more power and watch the heatsink temps.  More power more
cooling required.

As to current draw it depends on the band and what the drivers will give at that band.
Stay under 4A.

Better replacements.  THe RD16HHF is at 10$ for a pair and do not exceed 16V with those.
I could list some other RF stuff at maybe 50-100$ a pair. You are limited in the amount of
drive the driver stage can do and the traces on the board will likely go away at more than 4A.

Allison

Re: WSPR Empty Data

Lowell Haney NE4EB
 

If you power cycle the arduino then read it with MM, are the fields still filled in?