Date   
Narrow filter for CW #ubitxcw

_Dave_ K0MBT
 

Hello
I am teaching myself CW and find that the receive filters are too wide even when in cwl or cwu. Many times I hear 3 or 4 signals and it becomes confusing to my new CW ears and older brain.

Has any on designed an IF filter that would be suitable for cw?

I have a v3 and v4 uBITX's Running kd8cec firmware and Nextion displays.

Thanks
Dave
k0mbt

Re: Antuino now available for purchase

Ashhar Farhan
 

Mike, we calibrate it using a reference 10 mhz by zero beating it. The calibration may slip. It is best to calibrate it with WWV.


On Mon 12 Aug, 2019, 5:16 PM Mike Short, <ai4ns.mike.spam@...> wrote:
One other question. Can the 10 MHz output be used as a frequency source for calibration purposes?

What is the current version board? I have been away from the forum for awhile

Tech Guy
 

Any new features or bug fixes?

Re: Zero beating / calibration using old Drake method

Don--AE4DW
 

I found this interesting: http://novicehistory.slafetra.org/1971-75/index.html 

I remember a lot of those milestones in the 70s..getting a WD call as a novice (WD8QXM), as opposed to a WN call was still kind of a new thing.

Re: AGC Circuit for uBITX Featured in July 2019 QST Magazine

Jakobus van der Merwe
 

All caps have a rated voltage. That is the max voltage you apply to it. If you exceed this voltage the insulation between the "plates" of the cap will break down and the magical smoke will be released out of it. It will blow. Alliminium  caps are very sensitive to this max voltage. Therefore the max voltages are printed on them so you are can be aware of it. And the circuit designer also jods it down on the cct diagram. If your supply voltage is say 12V, it is safe to use a 16V rated cap. You do then have a safety margin for 'n slight mishap in the supply voltage if it occur. The cap will only charge up to the supply voltage. So using a higher voltage rated cap will make no difference. The cap can not generate a higher voltage than what is supplied to it. Your safety margin will just be greater. Using a 50V cap in a 12V system ? So what. The capacitance of the cap is worth watching and to adhere to. Also the voltage rating of the cap determines its fiscall  dimensions. 

J van der Merwe

On Mon, 12 Aug 2019, 12:21 David Wilcox via Groups.Io <Djwilcox01=yahoo.com@groups.io> wrote:
Can someone explain the reasons for certain voltages listed on any schematic for the electrolytic caps, AND what problems could arise if one used a cap with a larger voltage rating? How much higher a voltage cap could be substituted without causing a problem?

Dave K8WPE 

David J. Wilcox K8WPE’s iPad

On Aug 12, 2019, at 2:18 AM, MadRadioModder <madradiomodder@...> wrote:

Since the entire circuit set is 12V or less, your 16V caps should work just fine.

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Rob French (KC4UPR)
Sent: Monday, August 12, 2019 12:40 AM
To: BITX20@groups.io
Subject: Re: [BITX20] AGC Circuit for uBITX Featured in July 2019 QST Magazine

 

Thanks.  Any thoughts on voltage rating for the capacitors, especially the "big" electrolytic ones?  (10uF, 100uF, 470uF... I'm assuming they're electrolytics.)  I looked at the Hycas schematic, and that calls out 50v for all the caps, but I don't have many of those... got lots of 16v though!


Virus-free. www.avg.com

--

…_. _._

Re: Antuino now available for purchase

Mike Short
 

One other question. Can the 10 MHz output be used as a frequency source for calibration purposes?

Re: Antuino now available for purchase

Mike Short
 

Thanks. I had already ordered it and saw the video of it not in a case. Now I can sell my MFJ-259. 

Re: Antuino now available for purchase

Ashhar Farhan
 

It is a fully tested unit in the all metal case. It has an internal battery case for 6 AA cells. Two SMA connectors.


On Mon 12 Aug, 2019, 5:00 PM Mike Short, <ai4ns.mike.spam@...> wrote:
Does it come with the case?

Re: Antuino now available for purchase

Mike Short
 

Does it come with the case?

Re: AGC Circuit for uBITX Featured in July 2019 QST Magazine

Ian Reeve
 

The voltage rating on the capacitor is the maximum the component can “deal with”. It works absolutely fine at lower voltages of course and it is best to give some headroom for example on a 12v rail,use 16v capacitors.

There is no problem going up to say 25 or higher voltage rating,just expect a physically larger component which might not fit in the desired space.

Electrolytics are happiest when run at 50%  and above of their stated voltage, they tend to deteriorate if say a 100v component is used on a 12v rail. The low voltage in comparison to their rating does not properly keep the component and its chemicals in proper balance.

 

This is why equipment not used for some considerable time needs careful powering up because of the deterioration of electrolytics deprived of polarising voltage.

 

For a 12v DC  rail use 16v or 25v components.

 

Hope this helps

 

Ian M0IDR

 

Sent from Mail for Windows 10

 


From: BITX20@groups.io <BITX20@groups.io> on behalf of David Wilcox via Groups.Io <Djwilcox01@...>
Sent: Monday, August 12, 2019 11:21:17 AM
To: BITX20@groups.io <BITX20@groups.io>
Subject: Re: [BITX20] AGC Circuit for uBITX Featured in July 2019 QST Magazine
 
Can someone explain the reasons for certain voltages listed on any schematic for the electrolytic caps, AND what problems could arise if one used a cap with a larger voltage rating? How much higher a voltage cap could be substituted without causing a problem?

Dave K8WPE 

David J. Wilcox K8WPE’s iPad

On Aug 12, 2019, at 2:18 AM, MadRadioModder <madradiomodder@...> wrote:

Since the entire circuit set is 12V or less, your 16V caps should work just fine.

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Rob French (KC4UPR)
Sent: Monday, August 12, 2019 12:40 AM
To: BITX20@groups.io
Subject: Re: [BITX20] AGC Circuit for uBITX Featured in July 2019 QST Magazine

 

Thanks.  Any thoughts on voltage rating for the capacitors, especially the "big" electrolytic ones?  (10uF, 100uF, 470uF... I'm assuming they're electrolytics.)  I looked at the Hycas schematic, and that calls out 50v for all the caps, but I don't have many of those... got lots of 16v though!


Virus-free. www.avg.com

--

…_. _._

Re: AGC Circuit for uBITX Featured in July 2019 QST Magazine

David Wilcox
 

Can someone explain the reasons for certain voltages listed on any schematic for the electrolytic caps, AND what problems could arise if one used a cap with a larger voltage rating? How much higher a voltage cap could be substituted without causing a problem?

Dave K8WPE 

David J. Wilcox K8WPE’s iPad

On Aug 12, 2019, at 2:18 AM, MadRadioModder <madradiomodder@...> wrote:

Since the entire circuit set is 12V or less, your 16V caps should work just fine.

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Rob French (KC4UPR)
Sent: Monday, August 12, 2019 12:40 AM
To: BITX20@groups.io
Subject: Re: [BITX20] AGC Circuit for uBITX Featured in July 2019 QST Magazine

 

Thanks.  Any thoughts on voltage rating for the capacitors, especially the "big" electrolytic ones?  (10uF, 100uF, 470uF... I'm assuming they're electrolytics.)  I looked at the Hycas schematic, and that calls out 50v for all the caps, but I don't have many of those... got lots of 16v though!


Virus-free. www.avg.com

--

…_. _._

Re: Antuino now available for purchase

Ashhar Farhan
 

Can you guys wait for me to say it? 
(Grin)

On Mon 12 Aug, 2019, 2:22 PM Jim, <Jscook@...> wrote:
Good news. Everyone has been waiting. Thank you.



Re: Antuino now available for purchase

Jim
 

Good news. Everyone has been waiting. Thank you.

Antuino now available for purchase

Gerry Kavanagh
 

Good work Ashar!
http://www.hfsignals.com/index.php/antuino/

Re: AGC Circuit for uBITX Featured in July 2019 QST Magazine

MadRadioModder
 

Since the entire circuit set is 12V or less, your 16V caps should work just fine.

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Rob French (KC4UPR)
Sent: Monday, August 12, 2019 12:40 AM
To: BITX20@groups.io
Subject: Re: [BITX20] AGC Circuit for uBITX Featured in July 2019 QST Magazine

 

Thanks.  Any thoughts on voltage rating for the capacitors, especially the "big" electrolytic ones?  (10uF, 100uF, 470uF... I'm assuming they're electrolytics.)  I looked at the Hycas schematic, and that calls out 50v for all the caps, but I don't have many of those... got lots of 16v though!


Virus-free. www.avg.com

--

…_. _._

Re: AGC Circuit for uBITX Featured in July 2019 QST Magazine

Rob French (KC4UPR)
 

Thanks.  Any thoughts on voltage rating for the capacitors, especially the "big" electrolytic ones?  (10uF, 100uF, 470uF... I'm assuming they're electrolytics.)  I looked at the Hycas schematic, and that calls out 50v for all the caps, but I don't have many of those... got lots of 16v though!

Re: AGC Circuit for uBITX Featured in July 2019 QST Magazine

MadRadioModder
 

As I recall, the JackAl AGC circuit is just the Hycas AGC circuit lifted from QST December 2007.  Al added a couple of things like a switch to turn it off.  The FETs are nothing special.  A 201 and a 102 will work fine.

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Rob French (KC4UPR)
Sent: Sunday, August 11, 2019 10:57 PM
To: BITX20@groups.io
Subject: Re: [BITX20] AGC Circuit for uBITX Featured in July 2019 QST Magazine

 

I'm looking at possibly lifting just the AGC circuit out of the JackAl design, and seeing if I can stock it out of my junk box.  But... the only JFET's I have are MPF102, J201, 2N5486, and 2N4393... will any of those work?  Other than the MPF102, the rest were all originally purchased for audio work, so I can totally imagine them not being suitable.

Thanks!
-Rob


Virus-free. www.avg.com

--

…_. _._

Re: uBitx and QCX review in QST August 2019

Donald
 

I agree: the video was nice, but lacking. Many very basic facts were left out. Seemed to be aimed at hams who already knew about the uBitx and just wanted to see one.
-- Donald, KB5PWL

Re: AGC Circuit for uBITX Featured in July 2019 QST Magazine

Rob French (KC4UPR)
 

I'm looking at possibly lifting just the AGC circuit out of the JackAl design, and seeing if I can stock it out of my junk box.  But... the only JFET's I have are MPF102, J201, 2N5486, and 2N4393... will any of those work?  Other than the MPF102, the rest were all originally purchased for audio work, so I can totally imagine them not being suitable.

Thanks!
-Rob

Re: Calibration success #ubitx #calibration

Jerry Gaffke
 

For transmitting CW, clk2 drives mixer d1/d2 at the transmit frequency.  The modulator, 2 crystal filters, and 2 IF amps are not used. 

When transmitting SSB, all of that stuff must work.

Jerry, KE7ER


On Sun, Aug 11, 2019 at 08:56 AM, Evan Hand wrote:

Dan's suggestion on CW as a test is the correct course.  It will verify if you have an RF or Audio issue.