Date   
BITX QSO Afternoon/Night, Sunday, March 11, 3PM/7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere

John P
 

BITX QSO Afternoon/Evening, Sunday, March 11, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

Join us as we make contacts from BITX40 to BITX40 on 7.277 MHz in 40 meters!

This is a worldwide event for BITX40 stations starting at 7pm in each time zone. To participate, call CQ BITX on Sunday, starting at 3PM and/or 7PM your local time. The BITX QSO Night continues through the evening and conditions usually improve after sunset, so it is worthwhile to participate later in the evening.

Suggested Best Operating Practices:

Work at QRP power levels unless conditions require more power.
Call and listen for CQ BITX on the hour and every quarter hour.
It is helpful if you call CQ BITX with your callsign, name and location. 
Repeat your callsign a number of times during your CQ BITX and during QSO's.
Start a QSO by confirming the callsign, location, name and signal report of the other operator.
Say the callsign, name and location of the other operator so others can hear.
If the frequency is busy, avoid long conversations.
After your initial QSO is complete, ask if there are any other stations who would like to contact.

Report your QSO's, discuss propagation, noise, signal reports, audio reports, antenna type, etc. in this thread.

This is an undirected, scheduled event.  The BITX QSO Night relies on you to call CQ BITX to initiate contacts with other stations, so warm up that final and transmit a few calls on Sunday evening.  Talk to you then!
--
John - WA2FZW

Re: The issues of the TDA2822

Skip Davis
 

Raj, when you use the TDA 2822 in other designs what voltage are you running them at? Is it at the 9 volt dc via a voltage regulator?

Skip Davis, NC9O

Re: uBITX Firmware CEC Version Added WSPR function, I am looking for a beta tester. #ubitx

Philip
 

Hi Ian.
I would like to be a beta tester for the WSPR firmware. Just been playing with V1.05W, noticed a couple of problems.
For the uBITX to TX in WSPR mode the band your going to TX in needs to be selected first, maybe in WSPR mode the BPF selection is incorrect.
The other one is to do with the TX frequency. the display shows 14.097100 MHz which is the frequency I selected in uBITX manager, but the RF being transmitted is in fact 14.099330 MHz.. 
I have attached my BTX file from uBITX manager.
Best 73 Philip g7jur.

Re: The issues of the TDA2822

 

Skip,

For me obsessed in experimenting with receivers, the audio parts graduated from LM380 then smaller 386 and then someone
mentioned the TDA2822.. I always had a soft corner for National Semi but switched to TDA. I always worked on 12V and
the TDA in bridge mode. Compared to 386 the 2822 sounded warm and nice lows with 2W out.

Vaguely I remember blowing one to reverse polarity supply. One TDA melted my solderless bread board but survived. I now realise
that it IS designed for 9V or lower although it can take 15V max.

Raj

At 09-03-18, you wrote:
Raj, when you use the TDA 2822 in other designs what voltage are you running them at? Is it at the 9 volt dc via a voltage regulator?

Skip Davis, NC9O

Re: Dirt cheap uBitx case #ubitx

N1AFF - formerly KB1JPW
 

I'll be uploading a few more pics as I go along. The display is a tad bit too forward for the front panel so I'm flipping the header pins from the back to the front of that board that the LCD plugs into. That will give additional clearance.  I'd not recommend reusing the headers and to definitely use new ones instead. It wasn't worth the hassle and the ugly result.  The heatsinks on the finals also needed to be flipped upside down and slightly angled inwards towards the center of the board to avoid touching the case. I'll add a few strips of kapton tape where they are located to avoid any bumps to the case moving them. I'm still seeing conflicting information on the heatsinks making contact with the case, does anyone have definitive information about the tabs being at ground voltage level?  I'll be added a RJ45 jack for microphone/speaker/up/down (with the related component changes needed for dynamic mics) and a 2A fuse holder adjacent to the power input.  I'll use the provided power jack but will have a short tail to powerpole connectors. That's the extent at the moment I'll be deviating from the original design. 

Thanks to Mike Woods - ZL1AXG for tossing my post up on his page here http://ubitx.net/category/cases/   It was a surprise to see that while looking for additional ubitx hacks a few hours after I posted.  
@Joe - I'll be probably freeing some pins up by going with a I2C display later on
@John - They've got plenty more sitting there on the shelf for the same prices.  The place is a goldmine and has been in operation since 1971 - http://www.esssurplus.com/ They also sell through ebay.  

Re: Raduino oscilators. 33mhz and 57mhz. Documentation says one thinng, but this is what I measured.

Jack, W8TEE
 

Nicely done...

Jack, W8TEE



From: Lawrence Galea <9h1avlaw@...>
To: BITX20@groups.io
Sent: Friday, March 9, 2018 7:03 AM
Subject: Re: [BITX20] Raduino oscilators. 33mhz and 57mhz. Documentation says one thinng, but this is what I measured.

Sorry for the incomplete email. 
Pushed the wrong button on the keyboard while still compiling this draft before any corrections..

OK.
Let's see if I can make it easy.

Lets say that we have a 12 MHz carrier and we want to convert it to transmit to the 28 MHz band.
We could either mix the 12 MHz carrier with a 16 MHz signal (12 MHz + 16 MHz = 28 MHz) or a 40 MHz (40 MHz - 12 MHz = 28 MHz).
In the case of mixing the 12 MHz carrier with the 40 MHz signal we will also get 52 MHz which we do not require and which we will filter out.

Let's say that now we have a 12 MHz filter which passes the lower side-band and we want to mix the filter output signal to transmit on the 28 MHz band.
Let's say that the carrier frequency is exactly 12 MHz and we modulate the carrier with a 1 kHz audio tone.
In a normal AM transmitter, we end up with the carrier and two side bands, one which is 12 MHz + 1 kHz = 12,001,000 MHz which is the Upper Side Band (USB) and the other 12 Mhz - 1 kHz = 11.999,000 MHz which is the lower side band 

Now let's take the same example as above but the signals are passed through a filter which passes the lower side-band (LSB) (11,999,000 MHz in the example) and filters out the Upper Side-band (USB) (12,001,000 MHz).

The carrier is also attenuated somewhat by the filter as it is placed down the slope of the filter curve to cut the lower voice frequencies as we are not after generating a hi-fi signal and are not really required for intelligibility apart from other considerations while the carrier is further heavily attenuated in the balanced modulator. Theoretically, if the balanced modulator was perfectly balanced and everything screened, the carrier attenuation will be infinite, but practically it is attenuated to a very very low level as to be considered as being suppressed.

Now let's say that the carrier was not suppressed but the lower side-band was passed by the filter and we mix them with a 40 MHx oscillator. (Remember that the upper side-band was suppressed by the filter and theoretically is not present, leaving us with the 12 mHz carrier and the 11.999,000 MHz signals)

The output of the mixer will contain the 40 MHz oscillator, the 12 MHz carrier and the 11.999.000 MHz lower side-band including other mixer products which for the present purpose we shall ignore.

By using a balanced mixer as used in the 12 MHz side-band generator the 40 MHz signal can be cancelled (attenuated to a very low level) and we will have an output signal from the mixer of 40 MHz + 12 MHz = 52 MHz and 40 MHz - 12 MHz = 28.000,000 MHz and also 40 MHz + 11.999,000 MHz = 51.999,000 MHz and 40 MHz - 11.999,000 = 28.001,000 MHz.

However, since we used a balanced modulator at 12 MHz, the 12 MHz carrier was suppressed and only the lower side band was allowed to pass through, which simplifies the matter as when we mix the lower side band from the filter with the 40 MHz oscillator will will only get  40 MHz + 11.999,000 MHz = 51.999,000 MHz and 40 MHz - 11.999,000 = 28.001,000 MHz.

At the output of the mixer we put a filter to select our wanted 28 MHz signal and strip the unwanted 52 MHz signal.

This clearly shows how the lower side-band from the filter (11.999,000 MHz) in relation to the original carrier frequency of 12 MHz has been turned into an upper side-band by the mixer when we used an oscillator frequency for mixing higher then the output frequency required.

Now if we take the lower side band which is 11.999.000 Mhz and mix it with a 40 MHz oscillator, we can also get on the 50 MHz band, but in this case it is easy to see that we will still end up with a side-band transmission if you work out the simple mathematics.

Now let's say that instead of mixing our crystal filter output with 40 MHz, we mix it with 16 MHz to get on the 28 MHz band (16 MHz + 12 MHz = 28 MHz).
But since we have suppressed the carrier and we only have an 11.999,000 MHz signal, 16 MHz + 11,999,000 = 27.999,000 signal which in this case will be outside the 28 MHz band but serves to illustrate our purpose.
16 MHz - 11.999,000 Mhz will also give us 4,001.000 MHz which we can easily filter out.

If our side-band filter passed the upper side-band, the opposite will be true

As you can see it is simple mathematics but may be difficult to understand without some numbers.

Hope this explained the difficulty.

Regards
Lawrece


On Fri, Mar 9, 2018 at 12:39 PM, Lawrence Galea <9h1avlaw@...> wrote:
OK.
Let's see if I can make it easy.

Lets say that we have a 12 MHz carrier and we want to convert it to transmit to the 28 MHz band.
We could either mix the 12 MHz carrier with a 16 MHz signal (12 MHz + 16 MHz = 28 MHz) or a 40 MHz (40 MHz - 12 MHz = 28 MHz).

Let's say that now we have a 12 MHz filter which passes the lower side band and want to mix the filter output signal to transmit on the 28 MHz band.
Let's say that the carrier frequency is exactly 12 MHz and we modulate the carrier with a 1 kHz audio tone.
In a normal AM transmitter, we end up with the carrier and two side bands, one which is 12 MHz + 1 kHz = 12,001,000 MHz which is the Upper Side Band (USB) and the other 12 Mhz - 1 kHz = 11.999,000 MHz which is the lower side band

Now let's take the same example as above but the signals therough a filter which passes the lower sideband (LSB) (11,999,000 MHz in the example) and filters out the Upper Sideband (USB) (12,001,000 MHz) in this example.

The carrier is also attenuated somewhat by the filter as it is placed down the slope of the filter curve to cut the lower voice frequencies which are not re and further heavily attenuated in the balanced modulator. Theoretically, if the balanced modulator was perfectly balanced and everything screened, the carrier attenuation will be infinite, but practically it is attenuated to a very very low level as to be considered as being suppressed.
Now let's say that the carrier was not suppressed but the lower sideband was still passed by the filter and the upper sideband was rejected we mix them with a 40 MHx oscillator. 
The output of the mixer will contain the 40 MHz oscillator, the 12 MHz carrier and the 11.999.000 MHz lower sideband including other mixer products which for the present purpose we shall ignore.
However, by using a balanced mixer as used in the 12 MHz sideband generator the 40MHz signal can be cancelled (attenuated to a very low level) and we will have an output signal from the mixer of 40 MHz + 12 MHz = 52 MHz and 40 MHz - 12 MHz = 28.000,000 MHz and also 40 MHz + 11.999,000 MHz = 51.999,000 MHz and 40 MHz - 11.999,000 = 28.001,000 MHz.
However, since we used a balanced modulator at 12 MHz, the 12 MHz carrier was suppressed and only the lower side band was allowed to pass through, which simplifies the matter as when we mix the lower side band from the filter with the 40 MHz oscillator will will only get  40 MHz + 11.999,000 MHz = 51.999,000 MHz and 40 MHz - 11.999,000 = 28.001,000 MHz.
At the output of the mixer we put a filter to select our wanted 28 MHz signal and strip the unwanted 52 MHz signal.
This clearly shows how the lower sideband from the filter has been turned into an upper sideband by the mixer when we used an oscillator frequency for mixing higher then the output frequency required..
Now if we take the lower side band which is 11.999.000 Mhz and mix it with a 40 MHz oscillator, we can get 

On Wed, Mar 7, 2018 at 10:13 PM, Michael Shreeve <shreevester@...> wrote:
Ok, checked out the BITX40 explanation, and clearly the uBITX is a completely different giraffe and requires different math. If someone even wanted to try to do that I'd be grateful. I guess I might be able to wrap my head around it.





Virus-free. www.avast.com

Re: Variable power control

Walter
 

On Wed, Feb 21, 2018 at 06:23 pm, LKNDAVE wrote:
i did the hokie pokie and this jpg came out

Based on this design I built this attached circuit.

It controls voltage nicely.  Really helps limit output power while working digital.

However the TIP 142 really generates some heat.  I have a heat sink on it but it will need to be much larger.  it is only drawing about .5 amp (1/2 amp) while transmitting.

Does that seem normal?  it the heat something I should be concerned about?  Or just provide a better heat sink and run it?

Thanks for the circuit idea and plan.
 
--
73, W9KJO
Walter

Re: Wiring of the CW jack

Michael Monteith
 

Can tags be added to posts once they are posted?  It would be nice to differentiate which one it's for.   I had to come back here to read the original to make sure which one it's for.   I like the picture.  I just needed to keep it straight which one it's for.

73, Michael
KM4OLT

Re: uBITX Firmware CEC Version Added WSPR function, I am looking for a beta tester. #ubitx

Ian Lee
 

Philip

Thank you very much
Your feedback is a great help to me because I am not in an environment where I can test now.
I will update the program within a day or two and upload it again and announce it through the group.
Note that the BPF selection uses some tricks as a constraint on program memory.
I will check that again.
Once again, I sincerely appreciate your test.

Ian KD8CEC

2018-03-09 22:36 GMT+09:00 Philip <philip.g7jur@...>:

Hi Ian.
I would like to be a beta tester for the WSPR firmware. Just been playing with V1.05W, noticed a couple of problems.
For the uBITX to TX in WSPR mode the band your going to TX in needs to be selected first, maybe in WSPR mode the BPF selection is incorrect.
The other one is to do with the TX frequency. the display shows 14.097100 MHz which is the frequency I selected in uBITX manager, but the RF being transmitted is in fact 14.099330 MHz.. 
I have attached my BTX file from uBITX manager.
Best 73 Philip g7jur.



--
Best 73
KD8CEC / Ph.D ian lee
kd8cec@...
www.hamskey.com (my blog)

Re: cheap logic analyzer

Ian Lee
 

Rod

I happened to talk about that logic analyzer some time ago. 
Of the cheap instruments I bought, the logic analyzer was my favorite instrument.
That is very simple, small and easy use.
I abandoned the big logic analyzer that I used.

However, it is only a logic analyzer. Only the logic analyzer was the most useful instrument among the cheapest instruments.
To connect Wsjt-X for Linux to Nano, I recommend keeping Reset Pin high.

Ian KD8CEC


2018-03-09 20:33 GMT+09:00 Rod Self <km6sn@...>:

In the previous email, I am not sure why the PULSEVIEW screen looks fuzzy- however, on the actual PC screen, it is quite sharp and clear,
and the pic I posted was sharp and clear.

Something got fuzzy in the posting process.

Rod KM6SN






--
Best 73
KD8CEC / Ph.D ian lee
kd8cec@...
www.hamskey.com (my blog)

Re: uBITX Firmware CEC Version Added WSPR function, I am looking for a beta tester. #ubitx

Philip
 

Hi Ian.

The frequency error is down to the way uBITX manager calculates the RF frequency. If I enter into the Band 2 box 14094850 Hz, then the audio comes out of my radio at 1.5 KHz, when it is tuned to 14.09560 MHz.
Now my WSPR is going all around the world.
I do find that I get a bit confused by all the calculations, when trying to work out all this stuff.
Anyway thanks for putting WSPR in to the uBITX, a great bonus.

Philip G7JUR 

Re: Dynamic mic on ubitx

Walter
 

On Wed, Mar 7, 2018 at 01:07 am, Walter wrote:
I solved my Dynamic mic problem by installing the 5 Band Mic Processor by UR8QW.  I mounted the potentiometers on the front panel so that I now have a mic processor with compression, mic level and output level.  Works beautifully with my dynamic mic.

My solution might cost a little more then many are willing to spend but it gives me the ability to fully adjust my mic and audio.

I am very pleased with my solution, so far.  I have just installed it so operation over a number of coming days will be revealing.

A couple of more mods ought to have my UBITX completed.

--
73, W9KJO
Walter
Update.  It appeared to put out about the rating of the ubitx.  But I have to talk very loud and it does not sound right.  When I get the new mic cord from China I will install the mic that came with the unit.  Since I cannot alter this mic as it does not belong to me.  I have given up on the dynamic mic idea.  LOL.

I am giving this update to keep folk from thinking this mod worked for dynamic mics.  It does not work well.
 
--
73, W9KJO
Walter

Re: uBITX Mic Wireup

Tim Gorman
 

Shaun,

I am using an old CB microphone. Inside of it is a multi-pole switch.
Most communication mics have the same. I have wired mine so the
positive side of the mic goes through one switch pole to the microphone
connector. The mic is only actually connected when the PTT switch is
pushed. The negative side of the mic goes to the shield of the mic
cord. The PTT lead from the mic connecotor goes through another switch
pole and is connected to the shield via the switch when the PTT is
pushed.

This is why I recommend using a communications mike instead of a
standalone mic with a separate PTT switch. You can get old CB mics off
of ebay pretty cheap. You can probably find one for almost nothing at
garage sales this summer.

tim ab0wr

On Thu, 8 Mar 2018 21:54:42 -0600
"Shaun" <slong682000@...> wrote:

Does anybody have a diagram or description of the mic wire up for the
uBITX? I am looking for the mic itself, not the mic jack on the
transceiver. Most of the mic's I have dealt with have the MIC+ going
to one side of the electret and MIC- or ground routing through the
PTT switch when it is closed, completing the circuit. Looking at the
uBITX schematic and a mic wireup for an older version of BITX from
several years ago on the forum, what I think I am seeing is that the
sleeve is providing a constant ground to both the MIC- side of the
electret and one side of the PTT switch. The tip connects a constant
output to the other side of the PTT switch and the ring is providing
a constant output to the MIC+ side of the electret. It almost looks
like the electret is an "always on" state but the output is not
utilized until the separate PTT circuit is completed. Any help would
be appreciated.

Shaun
KEØNLN

Shipping notice today, ordered Jan 12 #ubitx

Xcott Craver
 

I know people are tracking the shipping dates, so I offer this as a data point.   Hooray!

Thanks, Xcott K2CAJ

Re: cheap logic analyzer, clear picture

Rod Davis
 

Hi  All,

Attached is a clear photo of PULSEVIEW looking at a UART serial link.

Rod KM6SN

Re: uBITX Mic Wireup

Jerry Gaffke
 

How is this an advantage?


On Fri, Mar 9, 2018 at 07:23 am, Tim Gorman wrote:
The mic is only actually connected when the PTT switch is pushed. ....   This is why I recommend using a communications mike instead of a standalone mic with a separate PTT switch.

Re: Shipping Update

Gary Shriver
 

Ordered on January 13th.  Received shipping notice via PayPal today.  Estimated delivery is Tuesday 3/13 via DHL.   
WoooooHooooo!


On Mar 9, 2018, at 7:28 AM, Xcott Craver <xcottcraver@...> wrote:

I know people are tracking the shipping dates, so I offer this as a data point.   Hooray!

Thanks, Xcott K2CAJ

Re: Fw: uBitx delivery

Nelson
 

Hoowdy All,

I ordered my uBITX on January 11th, 2018 and was notified by PayPal that my order shipped today (March 9th, 2018).  I had it shipped by India Post so expect another month for it to arrive...

Nelson

On Thu, Mar 8, 2018 at 1:38 PM, John KG9DK <jab3739@...> wrote:
Nick,
I ordered mine on Jan. 8th,got a heads up from PayPal yesterday that it has been shipped.  Based on that I would say about 2 months from the day you order to ship date.  

john kg9dk




--
I always thought the Universe was a wonderfully strange place until I studied Particle Physics - I now know the Universe is, in fact, profoundly odd in nature

Re: Fw: uBitx delivery

Noel f6bgc
 

Hi uBITX group,

who knows if March 9th delivery batch has good or tested  TDA 2822 ?

73 - noel f6bgc

2018-03-09 17:47 GMT+01:00 Nelson <ngtdlt@...>:

Hoowdy All,

I ordered my uBITX on January 11th, 2018 and was notified by PayPal that my order shipped today (March 9th, 2018).  I had it shipped by India Post so expect another month for it to arrive...

Nelson

On Thu, Mar 8, 2018 at 1:38 PM, John KG9DK <jab3739@...> wrote:
Nick,
I ordered mine on Jan. 8th,got a heads up from PayPal yesterday that it has been shipped.  Based on that I would say about 2 months from the day you order to ship date.  

john kg9dk




--
I always thought the Universe was a wonderfully strange place until I studied Particle Physics - I now know the Universe is, in fact, profoundly odd in nature


Re: Raduino oscilators. 33mhz and 57mhz " . Documentation says one thing, but this is what I measured.

Michael Shreeve
 

Yes, I'll need to hook a scope to hear the 3 or 4 hz flutter when your spot on. Thanks Jerry. Hopefully doing more today, as its raining here finally.

On Thu, Mar 8, 2018 at 8:32 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:
That's an excellent method to measure the frequency of the 25mhz oscillator.
If the receiver has sufficient low frequency audio response, you could monitor the speaker wires with a scope
and get sub hz accuracy when zero-beating.

I'll check my uBitx (tomorrow?), see how much warmup drift I can detect.
The 2.3khz drift (at 25mhz) you reported seems too large by a couple orders of magnitude. 

Jerry




On Thu, Mar 8, 2018 at 07:55 pm, Michael Shreeve wrote:
I don't know if I responded to this. I thought I explained but then maybe not. What I have always done when there is no buffered output is 1 use a receiver and an "antenna" if you will, one that is near the raduino but not touching anything. 2 turn on a somewhat stable generator and, in my case right now, measure the generator frequency directly with a counter. I can hear that generator in the same receiver.. Zero beat the generator , which is being measured, with the 25 MHz signal emanating from the raduino. Turns out it did change as I indicated, merely from heating up. No direct coupling at all for this measurement. At least to the raduino. If I had a communications monitor I wouldn't need to measure the freq of the generator. Or some other stable generator source. Also, I need to try to determine just how accurate my counter is. 
 




--
Michael Shreeve N6GRG