Date   
Re: Board won’t power up.

 

Send me a photo preferably by whatsapp, email will take more response time.

At 11-03-18, you wrote:
I have checked twice that the sacrificial diode is installed correctly.

Re: Board won’t power up.

 

Bruce,

Check the voltages with your -ve probe on the mother board. In case there is a ground fault in P1 or wire!

Raj

At 11-03-18, you wrote:
I think my microBitx main board may be defective. When powered up (without the raduino attached), according to the wiring instructions, it only draws 60-80 micro amps, rather than 90-110 mA the instructions specify. I have checked twice that the sacrificial diode is installed correctly.

Any ideas how to proceed?

Thanks,

Bruce W1BWA

Re: Final implemented version of audio fix

_Dave_ AD0B
 

My ubitx is still in production but I like your idea.

I wonder if the supply voltage could be limited with a resistor maybe a pot. At high power it would limit the voltage more also giving it a quasi AGC. 

Re: ubitx mount question regarding lcd display and bezel

Bert N8NN
 

Tom -- Very nice tuning knob!  Can you provide the part number and source?

Thanks, Bert N8NN

Re: [uBiTx] last frequency memory?

sulu82@...
 

I have the same problem.Mine defaults at 7.350.

Re: Board won’t power up.

 

Bruce,

Check on the uBitx board if you get the 12V power. Start first just below the power jack P1.
Sometimes these wires are crimped well and may not be making contact.

It is almost impossible to see uA unless something drastic wrong with P1 or your measurement! This has happened before.

Raj

At 11-03-18, you wrote:
I think my microBitx main board may be defective. When powered up (without the raduino attached), according to the wiring instructions, it only draws 60-80 micro amps, rather than 90-110 mA the instructions specify. I have checked twice that the sacrificial diode is installed correctly.

Any ideas how to proceed?

Thanks,

Bruce W1BWA

Board won’t power up.

Bruce Anderson
 

I think my microBitx main board may be defective. When powered up (without the raduino attached), according to the wiring instructions, it only draws 60-80 micro amps, rather than 90-110 mA the instructions specify. I have checked twice that the sacrificial diode is installed correctly. 

Any ideas how to proceed?

Thanks,

Bruce W1BWA

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

Philip
 

Hello Ian.

Is the WSPR frequency calculator in uBITX manager working correctly. Or is the uBITX transmitting on the wrong side band ?.
I would like test the update when you have done it.

Philip G7JUR

[uBiTx] last frequency memory?

Mike Hoddy
 

Hi all

When turning on the uBiTx it always defaults to 6.785 mHz irrespective of what frequency I was tuned to when turning off.  I'm guessing this is normal and if so is there a way of keeping the Raduino powered to default to the last frequency used?  So far I've built the BiTx40 and Ive two uBiTx to play with so plenty of scope!

73 de Mike, G0JXX

Re: RD16HHF1 power curve flattening...some

Glenn
 

Plenty of MPSH10's on eBay.

I used 0.25mm wire  on the toroids. Just what i had basically.

glenn
vk3pe

Re: RD16HHF1 power curve flattening...some

John Backo
 

Dan's has MPSH10's/ 12/$US3.00.

I have found he has generally good transistors,
mostly old stuff. These are Fairchild pieces.

I think BGMicro has some a while back...but they
are no longer advertising them, so they are out.


john
AD5YE

Re: #uBITX Firmware KD8CEC - IF-Shift etc. #ubitx

Jerry Gaffke
 

I think Gerald's complaint about USB sounding different than LSB winds up being due to
a USB signal going through the 45mhz filter a few khz away from where an LSB signal does. 
Gerald was using Ian's code which I have not yet looked over.
I assume Ian borrowed numbers from the original uBitx code.
Here's my argument:

The original uBitx code has the BFO at
    #define INIT_USB_FREQ   (11996500l)
and uses these frequencies for clk1:
    #define SECOND_OSC_USB (56995000l)
    #define SECOND_OSC_LSB (32995000l)

The 12mhz filter is passing audio between roughly 500 and 2500 hz in its upper sideband,
so the 12mhz filter is probably centered around 11996500 + (500+2500)/2 = 1199800 hz.

With a clk1 for USB of 56995000 hz, the center of that upper sideband in the 45mhz filter
would be 56995000-11998000 = 44997000 hz
With clk1 for LSB of 32995000 hz, the center of that lower sideband in the 45mhz filter
would be 32995000+11998000 = 44993000 hz.

That's a 4khz difference in where the center of the sideband of interest got placed
within the 45mhz crystal filter passband. 

Assuming the the 45mhz crystal filter is truly centered at 44.995mhz as the notes in the code suggest,
then I figure that values of 56993000 hz and 32997000 hz should be optimal for clk1.

If the 45mhz crystal filter sweeps out to be somewhere else, then add the difference to those two figures.
For example, if the center is found to be at 44.997mhz (so 2khz higher) then the two figures for clk1
should be 56995000 hz and 32999000 hz.


Regarding Tim's writup:

> When you are talking about adjusting the BFO I assume you are talking about adjusting CLK1.

No, we are talking about adjusting the BFO.
When adjusting the BFO, we should move the VFO to get us back to the displayed frequency.
The display shows the frequency of the suppressed carrier, always easy enough to compute:
    For USB, it's   VFO-(clk1-BFO)
    For LSB, it's   VFO+(clk1-BFO) 
where VFO is clk2, and BFO is clk0.

RIT allows a different VFO setting on receive than transmit.
This IF-Shift thing apparently allows a different BFO setting (with attendant VFO correction) on receive than transmit.

So IF-Shift will change what part of the sideband the 12mhz filter will capture (and thus capture a different range of audio frequencies) 
but does not change the frequency of the suppressed carrier that we are tuned to.

CW is a bit different, but easy enough.

Jerry, KE7ER 

Re: Dirt cheap uBitx case #ubitx

John Backo
 

Looks good.

It is always a challenge to fit a rig into a small space.

As Bill Schmidt says, watch out for stray RF. You may have to mount some
shielding (which is true of almost any ham and any rig). Hi. The easiest solution
is usually coax cable with included shielding. That probably should be
used for the three RF signals from the Raduino to the board anyway. Ground
the coax on the Raduino side, but NOT on the motherboard side. The cable
to the display can be wrapped with aluminum foil -- that is usually adequate.
Ground the foil on the Raduino side.

A good cable, if you can find it, is RG-48 with teflon insulation and 100%
shielding. It works well every time, and it is a bit smaller than regular RG-48.
It is a natural for smd connectors and GPS.

I wonder about the heat sinks. Perhaps you should drill 2 small holes
and tighten them against the case with long 4-40 screws. As long as the
IRF510's are isolated, the heat sink should be at ground, and the case is a
good place to anchor them. Every little bit helps. They can be tapped to
accommodate the screws so no nuts are needed...But nuts can be used as well.
Alternately, you could place a larger heat sink on the outside of the case
a la the method of Graham, VE3WGW. That kind of heat sink is easily found
as it is usually used in power inverters and voltage converters, especially
solar power units.

john
AD5YE

Re: The issues of the TDA2822

Ashhar Farhan
 

sajid,
i am working on an audio amp. i am testing it live. i always personally use circuits in the air before recommending them. i hope that my tuesday i will have something you can use. in the meantime, just about 100 out of 4000 boards have had this problem. and about less than 20 of them have reported the blow out.
- f

On 11 Mar 2018 5:46 am, "Sajid Rahum via Groups.Io" <zs735=yahoo.com@groups.io> wrote:
Farhan

Where can one order the good replacement TDA2822?  There are all sorts of makers but unsure where to get replacement.

My ubitx was sent 2 weeks back; most likely with the older TDA.

Thanks
Sajid/va3qy.

Re: RD16HHF1 power curve flattening...some

M Garza <mgarza896@...>
 

Nice Work, Glenn.

It looks like the MPSH10 is obsolete.  Doing some searching and comparing, the KSP10 is an exact replacement.   
It is in stock at Tayda, Mouser, and Digikey.  I only checked these three vendors.

What size wire did you use for your toroids?

Thanks.

Marco- KG5PRT



On Sat, Mar 10, 2018 at 8:52 PM, Glenn <glennp@...> wrote:
Hi Bill, yes  a bit more work should get the 2dB back also. Just needs 'time'. I didn't know what spec toroids were used in the original, but had the FT37-43 on hand. The MPSH10 was on hand also, a better FT than the 2N3904's.  I did very briefly play with the bias also but  no real gains there.

Once it's all flattened out it would simplify fitting of some sort of power control immensely.

glenn


OT: RE: out of specification operation with Si4721 for use on 4 Meters #parts

freefuel@...
 

I found this data sheet while reading up on the Silicon Labs SI4721 FM Broadcast transceiver chip, I have to ask if it can be tuned outside of it's specified range into maybe the 4 Meters band or maybe even up into the 2 meters band as well. the data sheet indicates that the stereo pilot and inputs can be disabled along with an easy way to specify the deviation of the transmitter. so far this looks like a nice little part to build a Handie Talkie around for fun. https://cdn-shop.adafruit.com/datasheets/SiLabs+Programming+guide+AN332.pdf

-Justin N2TOH 

Re: My uBitX build.

Skip Davis
 

Good idea Graham on the heat sink source, I have a few here I’ll have to check them out.

Skip Davis, NC9O

Re: Endian issues...final chapter

Ashhar Farhan
 

ietf solved this by insisting that internet protocos SHOULD be in plain text. it makes debuggera out our eyeballs and prevents testing of friendships.

On 11 Mar 2018 12:27 am, "Michael Hagen" <motdog@...> wrote:

If Push comes to Stack, who wins Big Injun or Little Injun?


On 3/10/2018 10:48 AM, Jerry Gaffke via Groups.Io wrote:
We agree that  "Endianness is a problem when a binary file created on a computer is read on another computer with different endianness."

Where we seem to disagree is that I am convinced this code will always prints a value of "4"
regardless of whether the machine is big or little endian:

  long data32;    int  data8;
  data32 = 0x04030201;
  data8 = data32>>24;
  printf("%d \n", data8);

From this, we can create the endian agnostic code at the top of post 44018.  
Arv is correct, this is not something most of you need to worry about.
I'm totally done here.
Unless you want to talk about Gulliver's Travels.

Jerry


On Sat, Mar 10, 2018 at 08:42 am, Jack Purdum wrote:
   Endianness is a problem when a binary file created on a computer is read on another computer with different endianness.
 

-- 
Mike Hagen, WA6ISP
10917 Bryant Street
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(909) 918-0058
PayPal ID  "MotDog@..."
Mike@...

Re: Dirt cheap uBitx case #ubitx

K9HZ <bill@...>
 

You are gonna want to keep those leads as short as possible since they carry RF (the oscillator frequencies) to the motherboard…

 

 

Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ

 

Owner - Operator

Big Signal Ranch – K9ZC

Staunton, Illinois

 

Owner – Operator

Villa Grand Piton – J68HZ

Soufriere, St. Lucia W.I.

Rent it: www.VillaGrandPiton.com

Like us on Facebook! facebook icon

 

Moderator – North American QRO Yahoo Group.

 

email:  bill@...

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of KB1JPW
Sent: Saturday, March 10, 2018 10:56 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Dirt cheap uBitx case #ubitx

 

Things are getting tight in the case. Holding off on the RJ45 jack until I can make sure it's all working happily. I've removed the 16 pin connector and will be soldering leads directly to the board due to space constraints.


Virus-free. www.avg.com

LCD Bumper

Ben Piecora
 

Hello, I’m working on building my uBITX, but my cutout for my LCD in my metal case is a little rough. I know a while back someone had 3D printed a little bumper that went around it to cover up the cutout. Does anyone have the STL?

K2CPU
--
Ben
K2CPU