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Re: Spurious RF at beginning of CW transmission in the uBitx

 

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Dexter

On further examination the problem seems more insidious than just the single capacitor in the audio section.? Each bidlrectional amplifier has its owm small capacitor and apparently contributes to the problem.? It now looks like the TX ang RX power feed lines may need some conditioning.

Arv
_-_




Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: Dexter N Muir <dexy@...>
Date: 7/31/18 5:45 PM (GMT-07:00)
Subject: Re: [BITX20] Spurious RF at beginning of CW transmission in the uBitx

So for BITX40 a diode in series with R111 blocks C11 from supplying Q16 as well. Now supply that diode direct from +12, no on/off of U1 and less current through K1 pin 3. R111 can then be either reduced (to 10) or eliminated/shorted.

Re: Spurious RF at beginning of CW transmission in the uBitx

 

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BTW:

in the original BITX20 these diodes were in eacht RX and TX path leading to the individual amplifiers.

Henning Weddig

DK5LV


Am 31.07.2018 um 11:25 schrieb n1kw@...:

Hi Arv,

I have not played with the radio much on SSB but suspect that is probably the cause for the "BITX Click". Simply adding a diode in series with R66 (cathode toward C64) should fix the problem.

It is important to note that the possibility of brief oscillation could occur in both the 12 and 45 MHz bidirectional IF amplifier stages because of the back feeding of power from C52 and C64 during RX-TX and TX-RX transitions. Diodes added in series with R52 and R66 should eliminate that possibility. The values of remaining bypass capacitors (0.1 uF) in the IF amplifiers and associated discharge paths should result in extremely short time constants and should not be an issue.

Cheers and 73,
Bob N1KW
Re: Spurious RF at beginning of CW transmission in the uBitx

 

So for BITX40 a diode in series with R111 blocks C11 from supplying Q16 as well. Now supply that diode direct from +12, no on/off of U1 and less current through K1 pin 3. R111 can then be either reduced (to 10) or eliminated/shorted.
Re: End Fed antennas w/ uBITX #ubitx

 

On Wed, Aug 1, 2018 at 09:04 AM, Gordon Gibby wrote:

At any rate, it will be a huge improvement over what most of them had beforehand (NOTHING HF).? ?

I've gone this route also, Gordon.? I bought 4 uBitX units, with the intent that I will have several HF rigs for operating activities such as Field Day, and as HF rigs to loan to new hams.? For both of those use cases, a simple and efficient antenna is needed, and I've chosen to go with EFHWs using parallel-resonant matching units built around T82 toroidal inductors - T82-2 for the 40/30/20 meter units, and T82-6 for the 20/17/15/12/10 meter units.? I used magnet wire and mica compression 'trimmer' caps which I had NOS in my parts collection, so the total cost of each matching unit for me was? ~$10.? The enclosures turn out to be the most expensive part (~$2.75 each).

one year ago these hams?didn't know a resistor from a transistor.....

and that is a real WIN.
Re: End Fed antennas w/ uBITX #ubitx

Warren Allgyer
 

Iz,

According to the email trail the 800 ohm load was selected because that was the maximum the test fixture could produce.?

The 6 dB figure comes from a simulation that I did in my lab. I calibrated the spectrum analyzer/tracking generator combination to 0 with a test cable assembly. I then shunted the S/A input with a 22 ohm resistor, resulting in about a 16 ohm load for the tracking generator. This reduced the displayed power level by 6.5 dB.

What the displayed value on the source RF meter in the test setup would be determined by the output characteristics of the RF source and the probe characteristics of the power meter, neither of which I have access to. I can be assured however that the reading would be wildly inaccurate.

WA8TOD
Re: End Fed antennas w/ uBITX #ubitx

 

We need an update in QST!? Was the 800ohm load selected to test the off-frequency characteristics of the 49:1 transformer? Il the load becomes 16ohm because of the transformer, the mismatch loss should be 2db, why you say over 6db?


Il 01/ago/2018 15:18, "Russ Hines" <russ@...> ha scritto:
Noticing this thread is taking on the epic proportions of a similar thread involving baluns on another forum some years ago.? It resulted in this paper:



Gentleman and lady, write a paper.
Russ Hines
JMS & Associates, Inc.
SBE CSRE
WB8ZCC
--
Reply to: russ@...
On 8/1/2018 9:04 AM, Gordon Gibby wrote:

?Do you know why they didn't use 49*50 ohms as their termination?? ?


I didn't read the email trail (sorry, just not enough time in this world) but it seems like you could make a dummmy load for that if necessary.? ?


What I have gleaned out of all this argumentation back-and-forth is that these things can have single-digit losses if working into a resonant piece of wire.? ?And that using a tuner is preferable. [I always work for lowest losses personally.]? Some of our newer hams locally are very limited in their "radio assets".? ?We'll be building uBitx's beginning in a bout 3 weeks.? We have already built 11 knockoffs of the Buckmaster off-center fed antenna and I hope to high heaven we built baluns etc with single-digit losses!!? ?At any rate, it will be a huge improvement over what most of them had beforehand (NOTHING HF).? ? Their skills are growing and I've learned a lot from all the discussions of various "issues" on this forum.? ?


After we get the "stock units" working, hopefully with v4 factory software and setting the oscillator numbers precisely in the code itself, we will begin on some of the most important improvements, which I haven't had time to get to quite yet....one year ago these hams?didn't know a resistor from a transistor.....


cheers,


gordon



From: [email protected] <[email protected]> on behalf of Warren Allgyer <allgyer@...>
Sent: Wednesday, August 1, 2018 8:53 AM
To: [email protected]
Subject: Re: [BITX20] End Fed antennas w/ uBITX
?

I have been asked by private message what it is about the QST Review test methodology that I found invalid. I constructed this explanation of their test in response and I would like to share it with the group.

The testers used a setup that is used by the ARRL Lab to test the loss of Antenna Tuners. When testing an Antenna Tuner the tuner itself converts whatever load is presented by the "Load Box" back to 50 ohms as a termination for the RF Source. The inline HP RF Power Meter is working in its natural 50 ohm domain and should be accurate within the specification of the meter.

When testing a 49:1 transformer however, there is no way to adjust the termination to 50 ohms. So, with an 800 ohm load selected in the load box as the authors specify in the email trail, the RF Source and the source power meter are operating in a 16 ohm environment. What the actual power out of the source is, and what power is indicated on the source power meter with a 16 ohm load, are determined by the characteristics of each box. It most certainly cannot be assumed to be 10 watts. The error in this step can easily be over 6 dB.

When the test therefore shows the transformer to have a loss of 0.2 dB, the actual loss could be as much as 6.2 dB.

The two transformer back to back test that I have documented does not suffer from a load mis-match and is therefore a far more appropriate way to do this measurement.
Re: End Fed antennas w/ uBITX #ubitx

Warren Allgyer
 

Gordon, your summary is spot on.

The appropriate termination value for the 49:1 transformer would be 2450 ohms in order to present a 50 ohm load to the source. The load box used in the ARRL lab would only go as high as 800 ohms. So, in addition to the inaccuracy caused by the mis-termination of the RF Source, the transformer was also operating at a mismatch of 3:1, which would introduce an additional distortion of the results.

WA8TOD
Re: SI5351 quadrature VFO

 

Hello Miguel,
I have seen the video on you tube and you have done a remarkable job.
I am unable to find the sketch on the above link
Can you please share the link to me on my email VU3RQX@...

73

VU3RQX
Re: End Fed antennas w/ uBITX #ubitx

 

开云体育

Noticing this thread is taking on the epic proportions of a similar thread involving baluns on another forum some years ago.? It resulted in this paper:



Gentleman and lady, write a paper.
Russ Hines
JMS & Associates, Inc.
SBE CSRE
WB8ZCC
--
Reply to: russ@...
On 8/1/2018 9:04 AM, Gordon Gibby wrote:

?Do you know why they didn't use 49*50 ohms as their termination?? ?


I didn't read the email trail (sorry, just not enough time in this world) but it seems like you could make a dummmy load for that if necessary.? ?


What I have gleaned out of all this argumentation back-and-forth is that these things can have single-digit losses if working into a resonant piece of wire.? ?And that using a tuner is preferable. [I always work for lowest losses personally.]? Some of our newer hams locally are very limited in their "radio assets".? ?We'll be building uBitx's beginning in a bout 3 weeks.? We have already built 11 knockoffs of the Buckmaster off-center fed antenna and I hope to high heaven we built baluns etc with single-digit losses!!? ?At any rate, it will be a huge improvement over what most of them had beforehand (NOTHING HF).? ? Their skills are growing and I've learned a lot from all the discussions of various "issues" on this forum.? ?


After we get the "stock units" working, hopefully with v4 factory software and setting the oscillator numbers precisely in the code itself, we will begin on some of the most important improvements, which I haven't had time to get to quite yet....one year ago these hams?didn't know a resistor from a transistor.....


cheers,


gordon



From: [email protected] <[email protected]> on behalf of Warren Allgyer <allgyer@...>
Sent: Wednesday, August 1, 2018 8:53 AM
To: [email protected]
Subject: Re: [BITX20] End Fed antennas w/ uBITX
?

I have been asked by private message what it is about the QST Review test methodology that I found invalid. I constructed this explanation of their test in response and I would like to share it with the group.

The testers used a setup that is used by the ARRL Lab to test the loss of Antenna Tuners. When testing an Antenna Tuner the tuner itself converts whatever load is presented by the "Load Box" back to 50 ohms as a termination for the RF Source. The inline HP RF Power Meter is working in its natural 50 ohm domain and should be accurate within the specification of the meter.

When testing a 49:1 transformer however, there is no way to adjust the termination to 50 ohms. So, with an 800 ohm load selected in the load box as the authors specify in the email trail, the RF Source and the source power meter are operating in a 16 ohm environment. What the actual power out of the source is, and what power is indicated on the source power meter with a 16 ohm load, are determined by the characteristics of each box. It most certainly cannot be assumed to be 10 watts. The error in this step can easily be over 6 dB.

When the test therefore shows the transformer to have a loss of 0.2 dB, the actual loss could be as much as 6.2 dB.

The two transformer back to back test that I have documented does not suffer from a load mis-match and is therefore a far more appropriate way to do this measurement.
Re: End Fed antennas w/ uBITX #ubitx

Gordon Gibby
 

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?Do you know why they didn't use 49*50 ohms as their termination?? ?


I didn't read the email trail (sorry, just not enough time in this world) but it seems like you could make a dummmy load for that if necessary.? ?


What I have gleaned out of all this argumentation back-and-forth is that these things can have single-digit losses if working into a resonant piece of wire.? ?And that using a tuner is preferable. [I always work for lowest losses personally.]? Some of our newer hams locally are very limited in their "radio assets".? ?We'll be building uBitx's beginning in a bout 3 weeks.? We have already built 11 knockoffs of the Buckmaster off-center fed antenna and I hope to high heaven we built baluns etc with single-digit losses!!? ?At any rate, it will be a huge improvement over what most of them had beforehand (NOTHING HF).? ? Their skills are growing and I've learned a lot from all the discussions of various "issues" on this forum.? ?


After we get the "stock units" working, hopefully with v4 factory software and setting the oscillator numbers precisely in the code itself, we will begin on some of the most important improvements, which I haven't had time to get to quite yet....one year ago these hams?didn't know a resistor from a transistor.....


cheers,


gordon



From: [email protected] <[email protected]> on behalf of Warren Allgyer <allgyer@...>
Sent: Wednesday, August 1, 2018 8:53 AM
To: [email protected]
Subject: Re: [BITX20] End Fed antennas w/ uBITX
?

I have been asked by private message what it is about the QST Review test methodology that I found invalid. I constructed this explanation of their test in response and I would like to share it with the group.

The testers used a setup that is used by the ARRL Lab to test the loss of Antenna Tuners. When testing an Antenna Tuner the tuner itself converts whatever load is presented by the "Load Box" back to 50 ohms as a termination for the RF Source. The inline HP RF Power Meter is working in its natural 50 ohm domain and should be accurate within the specification of the meter.

When testing a 49:1 transformer however, there is no way to adjust the termination to 50 ohms. So, with an 800 ohm load selected in the load box as the authors specify in the email trail, the RF Source and the source power meter are operating in a 16 ohm environment. What the actual power out of the source is, and what power is indicated on the source power meter with a 16 ohm load, are determined by the characteristics of each box. It most certainly cannot be assumed to be 10 watts. The error in this step can easily be over 6 dB.

When the test therefore shows the transformer to have a loss of 0.2 dB, the actual loss could be as much as 6.2 dB.

The two transformer back to back test that I have documented does not suffer from a load mis-match and is therefore a far more appropriate way to do this measurement.
Re: End Fed antennas w/ uBITX #ubitx

Warren Allgyer
 

I have been asked by private message what it is about the QST Review test methodology that I found invalid. I constructed this explanation of their test in response and I would like to share it with the group.

The testers used a setup that is used by the ARRL Lab to test the loss of Antenna Tuners. When testing an Antenna Tuner the tuner itself converts whatever load is presented by the "Load Box" back to 50 ohms as a termination for the RF Source. The inline HP RF Power Meter is working in its natural 50 ohm domain and should be accurate within the specification of the meter.

When testing a 49:1 transformer however, there is no way to adjust the termination to 50 ohms. So, with an 800 ohm load selected in the load box as the authors specify in the email trail, the RF Source and the source power meter are operating in a 16 ohm environment. What the actual power out of the source is, and what power is indicated on the source power meter with a 16 ohm load, are determined by the characteristics of each box. It most certainly cannot be assumed to be 10 watts. The error in this step can easily be over 6 dB.

When the test therefore shows the transformer to have a loss of 0.2 dB, the actual loss could be as much as 6.2 dB.

The two transformer back to back test that I have documented does not suffer from a load mis-match and is therefore a far more appropriate way to do this measurement.

QST Test Methodology.pdf
QST Test Methodology.pdf

New uBITX Raduinos for sale #ubitx

 

I have 2 brand new, unused Raduinos from V4 kits of mine that I will never use.? These are the later Raduinos that have the NANO mounted on the backside to keep it from interfering with the display.

They are still wrapped in the original bubble wrap and will include the original display. They are available for $40 each shipped in the US.? International shipping costs $14 to $15 USD and would have to be added for shipping to anyone outside the US.

Interested,? please reply direct to me, not the group to minimize clutter (there's been too much of that lately).? My email address is good on my website (www.w0eb.com) there are links there to email me but it is (use standard email format) w0eb [at] cox dot net.

Jim Sheldon, W0EB
Re: Anyone with a Raduino for the uBITX version3 for sale?

 

Hi, Dennis,

Do you have a link for the VF4PLN board?

73,

Paul K2AYZ
Re: Spurious RF at beginning of CW transmission in the uBitx

 

This issue of carrier leak on PTT caused by DC flow through the product detector
seems to be absent in uBitx.

Raj

At 31-07-18, you wrote:

Raj had a nice simple fix for the carrier burst on the Bitx40,
might be applicable to the uBitx:?
??? /g/BITX20/message/33707
??? /g/BITX20/message/33742

As I recall, there were a half dozen other fixes that worked.
We've already mentioned delays in software as Allard has done for the Bitx40.
Re: Spurious RF at beginning of CW transmission in the uBitx

 

Right Jerry!

First mod I did on the ubit. now when I tune across the bands I hear the relays switching during RX.

Raj

At 30-07-18, you wrote:
I'd be fine with constantly powering the LPF relays on my rig.
And may be the best solution.
Re: Spurious RF at beginning of CW transmission in the uBitx

 

Yes, N3GO gets the credits for the good idea!!

Bob N1KW
Re: ND6T AGC and Click kit wiring notes Gerber files

 

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Thanks for the clarification. My name is Peter


Peter Paul Fox G8HAV
Mid-Cheshire Amateur Radio Society
5 Llandovery Close
Winsford
Cheshire CW7 1NA?

Group Controller
Dane Valley?RAYNET?
Tel: 01606553401 (H)
Tel: 07919315547 (M)

From: [email protected] <[email protected]> on behalf of Timothy Fidler <engstr@...>
Sent: 01 August 2018 10:12:37
To: [email protected]
Subject: Re: [BITX20] ND6T AGC and Click kit wiring notes Gerber files
?
Sorry . your name is? missing - It is hardly surprising that your software cannot import gerbers, which are simply a set of instructions for an industry standard PCB mafr process from the sixties.? Essentially it has to convert a physical layout back into a schematic.? It has no idea what the active devices were, just their footprints..Imagine a DS board with components mounted both sides. I has to convert that back to a design file at 100 percent accuracy. And some industrial PCBs are laminated up and have say 8 layers. It? would have to convert that back flawlessly.? (Just because someone wanted to reverse engineer something after losing the design file or for Industrial piracy reasons.)

Timothy E. Fidler : Engineer BE Mech(1) Auckland , NDT specialist AINDT UT /RT3 , MT2 CB #2885,?
Telephone Whangarei?? 022? 691 8405
e: Engstr@...



----- Original Message -----

To:
"[email protected]" <[email protected]>
Cc:

Sent:
Wed, 1 Aug 2018 08:30:06 +0000
Subject:
Re: [BITX20] ND6T AGC and Click kit wiring notes


Hi, I have been trying to get some software to produce the layout from a Gerber file, but I keep getting companies who will make a PCB from a .Gbr file. Is that the way to go? I use DesignSpark by RS for board design but there is no provision to import .Gbr. There is provision to export. Thanks

?

Sent from my Windows 10 device

?

From: [email protected] <[email protected]> on behalf of William R Maxwell <wrmaxwell@...>
Sent: Wednesday, August 1, 2018 12:02:27 AM
To: [email protected]
Subject: Re: [BITX20] ND6T AGC and Click kit wiring notes
?

Well done Kees and thanks. I agree the moment has come to call "Time". Having the gerbers available will enable others to have boards produced if required, including future group buys.

73

Bill, VK7MX


On 1/08/2018 1:20 AM, Kees T wrote:
A total of 864 AGC and/or Click mini-kits have been shipped so far. This is way more than i expected but that's OK .....popular circuits Don, ND6T, came up with.? Presently, I have about 20 AGC boards left from the last EasyEDA board order and about 100 Click boards left. It's been fun but it's time for me to do something else (like the SWR/Power meter as described earlier).

The new Ver 4 uBITX boards have the Click problem fixed. Therefore, after the last available AGC mini-kits have been sold/shipped, I'm going to quit and pass the torch to someone else. Order rates have dropped off some, so maybe everyone who wanted a mini-kit has one ??

The AGC board and Click board Gerbers have been uploaded to the files section under my call.

"On order" and "shipped" information is available in the "Files" section under my call.

73 Kees K5BCQ

Re: ND6T AGC and Click kit wiring notes Gerber files

Timothy Fidler
 

Sorry . your name is? missing - It is hardly surprising that your software cannot import gerbers, which are simply a set of instructions for an industry standard PCB mafr process from the sixties.? Essentially it has to convert a physical layout back into a schematic.? It has no idea what the active devices were, just their footprints..Imagine a DS board with components mounted both sides. I has to convert that back to a design file at 100 percent accuracy. And some industrial PCBs are laminated up and have say 8 layers. It? would have to convert that back flawlessly.? (Just because someone wanted to reverse engineer something after losing the design file or for Industrial piracy reasons.)

Timothy E. Fidler : Engineer BE Mech(1) Auckland , NDT specialist AINDT UT /RT3 , MT2 CB #2885,?
Telephone Whangarei?? 022? 691 8405
e: Engstr@...



----- Original Message -----

To:
"[email protected]" <[email protected]>
Cc:

Sent:
Wed, 1 Aug 2018 08:30:06 +0000
Subject:
Re: [BITX20] ND6T AGC and Click kit wiring notes


Hi, I have been trying to get some software to produce the layout from a Gerber file, but I keep getting companies who will make a PCB from a .Gbr file. Is that the way to go? I use DesignSpark by RS for board design but there is no provision to import .Gbr. There is provision to export. Thanks

?

Sent from my Windows 10 device

?

From: [email protected] <[email protected]> on behalf of William R Maxwell <wrmaxwell@...>
Sent: Wednesday, August 1, 2018 12:02:27 AM
To: [email protected]
Subject: Re: [BITX20] ND6T AGC and Click kit wiring notes
?

Well done Kees and thanks. I agree the moment has come to call "Time". Having the gerbers available will enable others to have boards produced if required, including future group buys.

73

Bill, VK7MX


On 1/08/2018 1:20 AM, Kees T wrote:
A total of 864 AGC and/or Click mini-kits have been shipped so far. This is way more than i expected but that's OK .....popular circuits Don, ND6T, came up with.? Presently, I have about 20 AGC boards left from the last EasyEDA board order and about 100 Click boards left. It's been fun but it's time for me to do something else (like the SWR/Power meter as described earlier).

The new Ver 4 uBITX boards have the Click problem fixed. Therefore, after the last available AGC mini-kits have been sold/shipped, I'm going to quit and pass the torch to someone else. Order rates have dropped off some, so maybe everyone who wanted a mini-kit has one ??

The AGC board and Click board Gerbers have been uploaded to the files section under my call.

"On order" and "shipped" information is available in the "Files" section under my call.

73 Kees K5BCQ

Re: ND6T AGC and Click kit wiring notes

 

开云体育

Hi, I have been trying to get some software to produce the layout from a Gerber file, but I keep getting companies who will make a PCB from a .Gbr file. Is that the way to go? I use DesignSpark by RS for board design but there is no provision to import .Gbr. There is provision to export. Thanks

?

Sent from my Windows 10 device

?

From: [email protected] <[email protected]> on behalf of William R Maxwell <wrmaxwell@...>
Sent: Wednesday, August 1, 2018 12:02:27 AM
To: [email protected]
Subject: Re: [BITX20] ND6T AGC and Click kit wiring notes
?

Well done Kees and thanks. I agree the moment has come to call "Time". Having the gerbers available will enable others to have boards produced if required, including future group buys.

73

Bill, VK7MX


On 1/08/2018 1:20 AM, Kees T wrote:
A total of 864 AGC and/or Click mini-kits have been shipped so far. This is way more than i expected but that's OK .....popular circuits Don, ND6T, came up with.? Presently, I have about 20 AGC boards left from the last EasyEDA board order and about 100 Click boards left. It's been fun but it's time for me to do something else (like the SWR/Power meter as described earlier).

The new Ver 4 uBITX boards have the Click problem fixed. Therefore, after the last available AGC mini-kits have been sold/shipped, I'm going to quit and pass the torch to someone else. Order rates have dropped off some, so maybe everyone who wanted a mini-kit has one ??

The AGC board and Click board Gerbers have been uploaded to the files section under my call.

"On order" and "shipped" information is available in the "Files" section under my call.

73 Kees K5BCQ

Re: experience with Sunil VU3SUA's enclosures #ubitx

Ian Reeve
 

开云体育

?

?

?

That link gives some detail, I was particularly interested in the led wiring which is shown here. I also have the connectivity for the rear panel if I can oly find it!

?

?

Trouble is

Eddie to be honest, I find so many different threads and e-mails, I get swamped and do not always conduct my computer filing in decent order.

?

I will find it and send the pic to use for Arduino to usb on the rear panel. Cant find any info on the two jack plugs or 9 pin DSub which is pretty well obsolete now anyway.

?

I dry built mine in the enclosure making sure everything fitted prior to doing any soldering.

?

Hope this helps but am always willing to assist with pictures, the only tricky bit was assembling the display spacers and getting it positioned correctly so nothing is being forced into alignment.

?

My personal e-mail is ian.radioworkshop@... and would be happy to help

?

Best 73

?

Ian M0IDR

?

Sent from for Windows 10

?

From: [email protected] <[email protected]> on behalf of Eddie Esserman <ee@...>
Sent: Wednesday, August 1, 2018 3:31:47 AM
To: [email protected]
Subject: Re: [BITX20] experience with Sunil VU3SUA's enclosures #ubitx
?
Ian,

Can you point me to the construction record you're referring to in first sentence?? Tnx.

Eddie WA4JXL

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