Date   

Re: Stone Soup

ajparent1/KB1GMX <kb1gmx@...>
 

SM6MOJ

So I offer the challenge to those who know better than I do - please install metal shields round each individual filter and tell us what happens.

You haven't understood the issue or the cause.

Its the wiring under the relays and the way the relays are wired causing much of the grief.
There are pictures of that elsewhere in the forum.

Allison


Re: Stone Soup

Henning Weddig
 

Lev,

I am also thinking heavily on a new design!

But what has t be done beforehand is to specify what we want!  I already posted this requirement but only got minimal response. I know for EE´s to write a spec is a task which is not welcome...

So some yo Your ideas stated below can be used as a first spec. I want to include some more thoughts:

use diplexers especially on the IF port of mixers-- bandpass typ (sereis resonator + parallel resonator) with a relative low loaded Q (about 3).

I know there is an old paper "reactive loads the big mixer meanace"  published in the 70´s . Unfortunately I do not have this paper.

For the first mixer one more thought: in transmit mode the other sideband (LO + 45 MHz) which has the same amplitude as the wanted sideband is not terminated properly. So my idea is to put a lowpass - high pass diplexer the hp side to be terminated into 50 ohms on the RF port of the mixer.  

For the frist mixer: the configurattion should look like this:

RF port with LP- HP diplexer

IF port with BP diplexer but then a 90 deg hybrid with two xtal filter branches summing up into a second 90 deg hybrid. In order to get a good match both fitler branches should have equeal amplitude (S21) and transmisson phase (Phi21) characteristics.

Then a first bidi amp (low noise would preferrable) but our normal bidis with 6 dB NF could also work. We do not need a super low overall NF!  For these bidis we should use appropriiate high ft transistors as Allison already stated! 

In order to avoid  the still existing problem of the spur genratoed within the mixer I chose a IF of 70 MHz. XTAL filters were ordered.

So please have a look on my block diagrammes and total noise calc.

Before a new pcb is routed (preferrably 100 * 100 mm) the new sub modules should be characterized. I do have a good equipped home lab with spectrum analyser, signa l gerator VNA ---).

Henning Weddig

DK5LV

Am 05.09.2018 um 14:59 schrieb Lev:

So why don't we create a new design? Slightly more expensive, but a good one. My thoughts:

1. Tuned IFs
2. Filter the output of the LOs
3. Push-pull preamplifier (https://www.sv1afn.com/j310preamp.html)
4. RF transistors (BFS17P)
5. PA redesign (normal push pull design, two stage of IRF530 ) use BFQ19S for drivers
6. More filters on the output
7. Maybe change of the mixers to JFET mixers

I started to put together my own design, so I have some sketches. I can share if you interested.

On Tue, Sep 4, 2018 at 2:37 AM Warren Allgyer <allgyer@...> wrote:

Folks

I refer you to a famous story. It comes in many variations and this is just one: http://www.dltk-teach.com/fables/stonesoup/mtale.htm

I am the last person to discourage experimentation.... it is what I do, both for a living and for fun. But this is getting ridiculous.

We have here a platform that literally does nothing well. Nothing. Its only claims to fame are 1) It is inexpensive and 2) it is software configurable. The uBitx is a horrible transmitter, perhaps a worse receiver, bereft of simple operating niceties like AGC, ALC, preselection filtering, etc. As it comes out of the box it is illegal for air operations in most countries in the world. Its receiver has no front end, no filtering, miserly overall gain, and lousy audio. The transmitter cannot be put on the air legally and maintained without thousands of dollars of lab grade test equipment. Even as a core SSB generator it is 1960's technology executed badly.

And all of that would not be so bad if it were not for the fact that it IS put on the air, in the vast majority of cases, without the necessary lab equipment and testing simply because it does a lot of bands very inexpensively. This is the Twinkie offered to a starving child, the shipping container begging to become a multimillion dollar condominium,  the tricycle with dreams of winning the Indy 500. All possible..... but all ultimately futile for all but a persistent, doggedly stubborn few. And the others who try will simply add to the noise and junk that has become HF around the world.

Even the narrative that this represents employment for needy women in a third world country.... even that does not justify foisting this on amateur radio operators around the world. Producing garbage does not lift a segment out of poverty..... it just makes more garbage. It is very, very disappointing to see the hobby I have loved for 50 years be reduced to this.

If there was ever an electronic analogue for "Stone Soup", it is uBitx.

WA8TOD


Re: Stone Soup

ajparent1/KB1GMX <kb1gmx@...>
 

The idea of tunable traps is impractical. 
Another example of its simple, it will fix everything. NOT!

Unless you have a inline spec ana how do you know its properly tuned and 
adeqauate suppression????
At best its a poorly applied bandaid, at worst a bad hack.

What does work is a band pass filter as it passes what we know we want.
Another approach is suppress the trash getting into the IF and contributing 
signals we do not want.  See the posting Raj has made it goes more aggressively
down a path I tried and has a significant impact.

Allison


Re: Simple spur fix

ajparent1/KB1GMX <kb1gmx@...>
 

Farhans method...

1. Remove R27
2. Solder the 45Mhz filter two extreme ends to the pads of the resistor.
3. Solder the center lead of the filter to the nearest ground. R13 is very near with a ground via.

Sounds like something that may seriously help. I tried a low pass filter there and it
did help but not enough.  Time and other pressing things never got back to try a
band pass filter.

One I'd liked to have tried is just moving the filter to the other end of the amp.

What is the impact on RX performance?

Allison


Re: Simple spur fix

Ashhar Farhan
 

If you guys want to try out the mod, i can have some spares shipped out.
- f

On Wed, 5 Sep 2018, 19:06 Gordon Gibby, <ggibby@...> wrote:

​I ordered the pair.   Interesting and exciting development.

gordon



From: BITX20@groups.io <BITX20@groups.io> on behalf of Warren Allgyer <allgyer@...>
Sent: Wednesday, September 5, 2018 7:50 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Simple spur fix
 

Filters suitable (I believe) for this mod are available here for $5.99 for a pair: 

https://www.ebay.com/itm/Tellurian-Technologies-45MHz-Crystal-Bandpass-Filter-T45U15BG-Matched-Pair/181956516605?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

If this solves the spur problem then it is also a very positive step toward solving the overall PA filter issue. Absent the spurs, and with the board layout problems addressed, the existing four filters should be adequate. I am about to receive a prototype 4 filter board that can accept the existing components for testing. 

Very nice work!

WA8TOD


Re: stone soup ingredient list, what bands and modes are usable

Tom, wb6b
 

Hi Dave,

Gordon created a voltage divider attenuator for his dummy load so he could check harmonics with another receiver, here are the messages where he describes this. 

https://groups.io/g/BITX20/message/57979
https://groups.io/g/BITX20/message/57974

In your case you are trying to feed this into your scope rather than a receiver, so the 16K resistor may be more resistance than you want. You may want to try 5k and 50 ohms so you can still use a 1/4 watt resistor.  You don't need to put the resistors on a dummy load, you can connect the 50 ohm resistor to the ground of your antenna out and the 5k resistor to the center pin wire of your uBITX antenna output. Although if you are testing, doing so into a dummy load is a good idea. 

Looking at the spurs directly requires a spectrum analyzer or a receiver with a waterfall display. That can be a newer transceiver or a SDR dongle.

However, you will still see things like the RF waveform flattening or distorting in other ways when the TX RF out is overdriving. So, your scope should be informative and useful for monitoring your TX output. You will get the most reliable display if you first try with a single tone fed into the microphone input rather than a more complex signal like voice. But, you will get a feel for it, as you experiment. I have a little tiny scope that will at least work up to 80m and I'm planning on doing the same thing, just to see what I can see. 

Tom, wb6b


Re: Simple spur fix

Gordon Gibby <ggibby@...>
 

​I ordered the pair.   Interesting and exciting development.

gordon



From: BITX20@groups.io <BITX20@groups.io> on behalf of Warren Allgyer <allgyer@...>
Sent: Wednesday, September 5, 2018 7:50 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Simple spur fix
 

Filters suitable (I believe) for this mod are available here for $5.99 for a pair: 

https://www.ebay.com/itm/Tellurian-Technologies-45MHz-Crystal-Bandpass-Filter-T45U15BG-Matched-Pair/181956516605?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

If this solves the spur problem then it is also a very positive step toward solving the overall PA filter issue. Absent the spurs, and with the board layout problems addressed, the existing four filters should be adequate. I am about to receive a prototype 4 filter board that can accept the existing components for testing. 

Very nice work!

WA8TOD


Re: CW PTT attack time to slow #ubitx

Jim Sheldon
 

Everyone wanting better CW operation as Joop Stakenborg did and wanting to try the W0EB/W2CTX versions of the firmware.  They are located in the "Files" section of the TSW website at www.w0eb.com and I renamed the directories slightly to indicate that the programs work on original Raduino cards as well as our RadI2Cino cards.  They will also run just fine on the Raduino "Clone" card that's offered.  The programs labeled with I2C in their version# will only run on original Raduino's that have been modified to work with I2C displays or our RadI2Cino cards.  The others have slightly different CW routines in them but use the A6 and A7 lines for the Dot and Dash wires for the CW paddles.
Full PDF instruction manuals are included in each firmware version's zip file.

Jim Sheldon, W0EB
for the TSW team


Re: CW PTT attack time to slow #ubitx

Jim Sheldon
 

Super!  Thanks for the feedback.  I've mentioned this to W2CTX as well, since he did 99 percent of the programming on that version.  Looking at adding a menu item in the future that will allow the operator to set this delay.  I'll look at it myself in determining the minimum acceptable value so not to overtax the relays.

Jim Sheldon 
for the TSW team

------ Original Message ------
From: "Joop Stakenborg" <joop.stakenborg@...>
Sent: 9/5/2018 7:51:51 AM
Subject: Re: [BITX20] CW PTT attack time to slow #ubitx

I am using I2C_V4.01R. Using it on a ubitx which came preloaded with the stock 4.3 firmware.

Yes, it's okay now!


Re: Stone Soup

Lev <leventelist@...>
 

So why don't we create a new design? Slightly more expensive, but a good one. My thoughts:

1. Tuned IFs
2. Filter the output of the LOs
3. Push-pull preamplifier (https://www.sv1afn.com/j310preamp.html)
4. RF transistors (BFS17P)
5. PA redesign (normal push pull design, two stage of IRF530 ) use BFQ19S for drivers
6. More filters on the output
7. Maybe change of the mixers to JFET mixers

I started to put together my own design, so I have some sketches. I can share if you interested.


On Tue, Sep 4, 2018 at 2:37 AM Warren Allgyer <allgyer@...> wrote:

Folks

I refer you to a famous story. It comes in many variations and this is just one: http://www.dltk-teach.com/fables/stonesoup/mtale.htm

I am the last person to discourage experimentation.... it is what I do, both for a living and for fun. But this is getting ridiculous.

We have here a platform that literally does nothing well. Nothing. Its only claims to fame are 1) It is inexpensive and 2) it is software configurable. The uBitx is a horrible transmitter, perhaps a worse receiver, bereft of simple operating niceties like AGC, ALC, preselection filtering, etc. As it comes out of the box it is illegal for air operations in most countries in the world. Its receiver has no front end, no filtering, miserly overall gain, and lousy audio. The transmitter cannot be put on the air legally and maintained without thousands of dollars of lab grade test equipment. Even as a core SSB generator it is 1960's technology executed badly.

And all of that would not be so bad if it were not for the fact that it IS put on the air, in the vast majority of cases, without the necessary lab equipment and testing simply because it does a lot of bands very inexpensively. This is the Twinkie offered to a starving child, the shipping container begging to become a multimillion dollar condominium,  the tricycle with dreams of winning the Indy 500. All possible..... but all ultimately futile for all but a persistent, doggedly stubborn few. And the others who try will simply add to the noise and junk that has become HF around the world.

Even the narrative that this represents employment for needy women in a third world country.... even that does not justify foisting this on amateur radio operators around the world. Producing garbage does not lift a segment out of poverty..... it just makes more garbage. It is very, very disappointing to see the hobby I have loved for 50 years be reduced to this.

If there was ever an electronic analogue for "Stone Soup", it is uBitx.

WA8TOD


Re: CW PTT attack time to slow #ubitx

Joop Stakenborg <joop.stakenborg@...>
 

I am using I2C_V4.01R. Using it on a ubitx which came preloaded with the stock 4.3 firmware.

Yes, it's okay now!


Re: CW PTT attack time to slow #ubitx

Jim Sheldon
 

You don't say which version of our firmware.  Did 100 help you get what you wanted?  Please let us know.

Jim

------ Original Message ------
From: "Joop Stakenborg" <joop.stakenborg@...>
Sent: 9/5/2018 7:42:40 AM
Subject: Re: [BITX20] CW PTT attack time to slow #ubitx

Thanks Jim, I have set it to 100.

Regards,
Joop PG4I


Re: CW PTT attack time to slow #ubitx

Joop Stakenborg <joop.stakenborg@...>
 

Thanks Jim, I have set it to 100.

Regards,
Joop PG4I


Re: Simple spur fix

 

At 05-09-18, you wrote:

Filters suitable (I believe) for this mod are available here for $5.99 for a pair:

https://www.ebay.com/itm/Tellurian-Technologies-45MHz-Crystal-Bandpass-Filter-T45U15BG-Matched-Pair/181956516605?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

If this solves the spur problem then it is also a very positive step toward solving the overall PA filter issue. Absent the spurs, and with the board layout problems addressed, the existing four filters should be adequate. I am about to receive a prototype 4 filter board that can accept the existing components for testing.

Very nice work!

WA8TOD


Re: Grounding shematic for a Metal Chassis, which is the right way to wire up?

iz oos
 

I think the optimal solution is an entire metal case. I can talk only about what I did and my case is hybrid, it's metal except for the front and the back panels that are plastic. Why did I choose that? Simply it was nice, the right size and I had it some years taking dust. All connectors are mounted either on the front or on the back panel. I kept things as simple as possible, so the heatsinks are the originals and the board is mounted inside so I don't use the case for thermal cooling. Unless you are certain how to keep insulated the tabs of the finals (which have DC voltage if I am correct) I wouldn't mount the finals to the metal chassis. But that depends also on how you want to use the uBitx. If you use it for RTTY or digital modes, you might need a better cooling, drill holes on the chassis and/or add a vent. I mostly use SSB and CW and what I did was not optimal but adequate. In the case my finals would fail, I will spend 2 euros and half an hour to replace them.



Il 05/set/2018 12:15, "sdr freak" <sdrfreak55@...> ha scritto:
@ iz oos

ok, good to hear this, but a few more answer to the problem that i ask for was better ;D

@ WA5ZTD

i was talking about the heatsink from the IRF510, so i read it in this shematic uploaded here in forum, the v.1.9...

i have no picture or shematic for the grounding should be, that's what i ask for! my problem is that i doesn't have one! i need a couple of information about this whole things about, like grouding the metal case, what about avoid grounding loops and for important the wire up with the jacks and their sleeves in front of the grounded case.. these are my problems, when i say it shortly,... today i've tried to say it shortly

so please have anyone a few info about, please?


Re: CW PTT attack time to slow #ubitx

Jim Sheldon
 

Joop and all, yes, that is the proper value to set it.  When that software was written we didn't think that the uBITX would be used for contesting and we have now been proven wrong - LOL.  Making that number smaller shortens the transition time between TX and RX, larger lengthens the time.  You don't want to get it too short though as that will overwork the relays.  Remember, the uBITX is NOT capable of full break-in (QSK) on CW because relays are being used for T/R switching.  Get that delay too short and your relays won't last long using CW.

Jim Sheldon for the TSW team

------ Original Message ------
From: "Joop Stakenborg" <joop.stakenborg@...>
Sent: 9/5/2018 6:05:06 AM
Subject: Re: [BITX20] CW PTT attack time to slow #ubitx

Howdy,

today I have had a go at W0EB’s firmware version together with a I2C LCD display. Using the I2C bus frees up a number of digital and analog lines. A dedicated digital line is used for straight key input (I am using an external keyer). Also, using software interrupts improves keying responsiveness. I no longer have missing dits and dahs…

One thing I am missing in this firmware version: there is no way to set PTT delay, that is the time it takes to go from transmit to receiver. It is much to long, especially for contesting.

It looks like it is hardcoded:
#define CW_TIMEOUT (350l)
in ubitx.h

Regards,
Joop PG4I



Op 1 sep. 2018, om 04:10 heeft W2CTX <w2ctx@...> het volgende geschreven:

On w0eb.com webpage is NANO software that implements interrupt driven CW generation.  Also

eliminates the voltage divider scheme.  Also eliminates the need to switch between straight key 

and paddle as both are always active.


rOn




Re: Stone Soup

Ashhar Farhan
 

Warren has a point and an opinion. He has raised an issue and we are trying to fix it. His way of saying i probably rufflea some feathers, but lets do a minmal reading of how he is saying it and hear what he is saying..
It is upto each of us to fix the harmonics and spurs. 
Raj has found a way to fix the spurs. I have independently confirmed it. So, we are one down and one to go. Harmonics will be an easier fix. My parenta health issuea continue to eat into my bench time, hopefully we will be able ride this out and get back on the bench in a few days more. 

73, and get some of the awesome weather. 

- f

On Wed, 5 Sep 2018, 17:26 Praba Karan, <vu3dxr@...> wrote:
Typical colonial thinking....

On Tue, Sep 4, 2018, 6:07 AM Warren Allgyer <allgyer@...> wrote:

Folks

I refer you to a famous story. It comes in many variations and this is just one: http://www.dltk-teach.com/fables/stonesoup/mtale.htm

I am the last person to discourage experimentation.... it is what I do, both for a living and for fun. But this is getting ridiculous.

We have here a platform that literally does nothing well. Nothing. Its only claims to fame are 1) It is inexpensive and 2) it is software configurable. The uBitx is a horrible transmitter, perhaps a worse receiver, bereft of simple operating niceties like AGC, ALC, preselection filtering, etc. As it comes out of the box it is illegal for air operations in most countries in the world. Its receiver has no front end, no filtering, miserly overall gain, and lousy audio. The transmitter cannot be put on the air legally and maintained without thousands of dollars of lab grade test equipment. Even as a core SSB generator it is 1960's technology executed badly.

And all of that would not be so bad if it were not for the fact that it IS put on the air, in the vast majority of cases, without the necessary lab equipment and testing simply because it does a lot of bands very inexpensively. This is the Twinkie offered to a starving child, the shipping container begging to become a multimillion dollar condominium,  the tricycle with dreams of winning the Indy 500. All possible..... but all ultimately futile for all but a persistent, doggedly stubborn few. And the others who try will simply add to the noise and junk that has become HF around the world.

Even the narrative that this represents employment for needy women in a third world country.... even that does not justify foisting this on amateur radio operators around the world. Producing garbage does not lift a segment out of poverty..... it just makes more garbage. It is very, very disappointing to see the hobby I have loved for 50 years be reduced to this.

If there was ever an electronic analogue for "Stone Soup", it is uBitx.

WA8TOD


Re: Stone Soup

Praba Karan
 

Typical colonial thinking....


On Tue, Sep 4, 2018, 6:07 AM Warren Allgyer <allgyer@...> wrote:

Folks

I refer you to a famous story. It comes in many variations and this is just one: http://www.dltk-teach.com/fables/stonesoup/mtale.htm

I am the last person to discourage experimentation.... it is what I do, both for a living and for fun. But this is getting ridiculous.

We have here a platform that literally does nothing well. Nothing. Its only claims to fame are 1) It is inexpensive and 2) it is software configurable. The uBitx is a horrible transmitter, perhaps a worse receiver, bereft of simple operating niceties like AGC, ALC, preselection filtering, etc. As it comes out of the box it is illegal for air operations in most countries in the world. Its receiver has no front end, no filtering, miserly overall gain, and lousy audio. The transmitter cannot be put on the air legally and maintained without thousands of dollars of lab grade test equipment. Even as a core SSB generator it is 1960's technology executed badly.

And all of that would not be so bad if it were not for the fact that it IS put on the air, in the vast majority of cases, without the necessary lab equipment and testing simply because it does a lot of bands very inexpensively. This is the Twinkie offered to a starving child, the shipping container begging to become a multimillion dollar condominium,  the tricycle with dreams of winning the Indy 500. All possible..... but all ultimately futile for all but a persistent, doggedly stubborn few. And the others who try will simply add to the noise and junk that has become HF around the world.

Even the narrative that this represents employment for needy women in a third world country.... even that does not justify foisting this on amateur radio operators around the world. Producing garbage does not lift a segment out of poverty..... it just makes more garbage. It is very, very disappointing to see the hobby I have loved for 50 years be reduced to this.

If there was ever an electronic analogue for "Stone Soup", it is uBitx.

WA8TOD


Re: Simple spur fix

Warren Allgyer <allgyer@...>
 

Filters suitable (I believe) for this mod are available here for $5.99 for a pair: 

https://www.ebay.com/itm/Tellurian-Technologies-45MHz-Crystal-Bandpass-Filter-T45U15BG-Matched-Pair/181956516605?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

If this solves the spur problem then it is also a very positive step toward solving the overall PA filter issue. Absent the spurs, and with the board layout problems addressed, the existing four filters should be adequate. I am about to receive a prototype 4 filter board that can accept the existing components for testing. 

Very nice work!

WA8TOD


Re: Simple spur fix

 

Further experimentation with Farhan's method,

Instead of removing R27 47Ohms and putting the filter there. I removed C22
and soldered the filter there.

The spurs on 20 dropped even lower @5W the spurs were -55 to -60dbm!
With proper termination the results may be better!

Raj


At 05-09-18, you wrote:

This fix reduced the spurs by up to 10 db  and requires ONLY ONE part to be added.
There is big change above 10MHz in the board. There is some improvement below also.

Farhan method of the same..much simpler and CW will work.

1. Remove R27
2. Solder the 45Mhz filter two extreme ends to the pads of the resistor.
3. Solder the center lead of the filter to the nearest ground. R13 is very near with a ground via.