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Re: The new uBITX boards are here

allen west
 

Ashar, have you or any other members of this group designed a pc board or kit for the new audio amplifier circuit?  I would like to build it but have no design skills.

Thanks, Al
KB4RA


On May 26, 2018, at 3:19 PM, Ashhar Farhan <farhanbox@...> wrote:

Peeps, 

HF Signals has rolled out the new (r4) version of the PCBs. Here are the changes:

1. A new, low distortion audio amplifier made from discrete transistors. This is one is optimized for head-phones and connecting to PCs for digital modes. It does work with the small speakers as well. Builders with the earlier versions can try this audio amplifier as an outboard amplifier.
2. The audio thump issue during T/R switching has been fixed.
3. At 28 Mhz, the output is about 4 watts. (this involves a single capacitor change from the earlier PCB).
4. I have included some 'jump' points to add interesting stuff like CW filters to the board. There are a large number of test points to help you debug and understand the board. 

All in all, the changes are 'backward compatible' . That is, you can hack these changes to the previous boards to get in the new functionality. I have updated the circuit diargrams on www.hfsignals.com. The earlier board's circuit diagram has moved to http://www.hfsignals.com/index.php/ubitx-r3-archived/

The bad news is that we had to bump up the price of the board by 20 dollars. We fought long and hard to keep the price down. My personal ambition was to keep the price inside (or at) $100. This is price rise has to do with three things : The recent changes in the Indian import duty and sales tax; Our own increasing costs to preorder the parts. Lastly, we also increased our payout to those who wind the coils, assemble and test the boards. They were working at the same rate for the last two years. It was about time. 

The new boards cost $129 USD with shipping. $139 USB with DHL option. 

The good news is that from now on, these boards will be available on order. The waiting queue is gone.

On a personal note, I am happy with the new audio. It is so much sweeter and cleaner on the headphones.  Far less fatigue after hours of CW work. I am also using the FT8 extensively, I have bagged almost twenty countries, testing the new firmware.

- f

Re: audio dropping out

Jack, W8TEE
 

This Forum is a general place to seek help on the Bitx40, Bitx20, and the uBITX, hence the
"Bitx20/40/u". Like they say, the art of a good answer is a clearly-stated question. Many of the regulars here are very bright people and been a huge help to thousands of owners. Another relatively new, but very helpful, resource can be found at ubitx.net.

Jack, W8TEE

On Sunday, May 27, 2018, 10:46:48 AM EDT, Dave de WS1ETI <docame12@...> wrote:


Raj,

I've seen many many references to the uBITX here. Allison is working on a mod to flatten the power curve across bands. So, I am confused what does the "u" stand for in "Bitx20/40/u"?. This is where Ashar sent me to ask questions? Was I mistaken?  

 

Thanks,
Dave WS1ETI

Re: audio dropping out

Dave de WS1ETI <docame12@...>
 

Raj,

I've seen many many references to the uBITX here. Allison is working on a mod to flatten the power curve across bands. So, I am confused what does the "u" stand for in "Bitx20/40/u"?. This is where Ashar sent me to ask questions? Was I mistaken?  

 

Thanks,
Dave WS1ETI

Re: RF power chain mods and improvements..

ajparent1/kb1gmx
 

HI Greg Its BFR106 I might have duped the R.

ITs a 5ghz low noise critter.

I'll put the datasheet in the files are under my call.

Allison

Re: The new uBITX boards are here

ajparent1/kb1gmx
 

Incremental improvement is a very good thing.  Very good Farhan.

I'm a fan of that audio circuit, Been using it and variations of it for at least 35 years and it never fails.
Saves a lot of pain over hard to find IC.


Allison

Re: Raduino 4 Line Single Sided PCB boards

K9HZ <bill@...>
 

One thing you may wish to do is put terminals/ a connector to bring out the I2C pins SDA and SCL since many people are using such devices in the uBITx.  There is a nice blank spot on the board next to the 2K2 resistors for that.

 

 

Dr. William J. Schmidt - K9HZ

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Rahul Srivastava via Groups.Io
Sent: Saturday, May 26, 2018 10:31 PM
To: BITX20@groups.io
Subject: [BITX20] Raduino 4 Line Single Sided PCB boards

 

Hi! Friends,

I have designed a homebrew friendly Single sided PCB for Raduino in a form factor of 20X4 line LCD. This board  supports 2 line display as well. I have added some minor edits to orignal Raduino schematics that is self explanatory namely few more electrolytics, separate Analog Digital ground plain, Nano module on component side to make it plugable. Largely thru hole components but SMD pads also included for coupling and decoupling caps.

All fabrication files are being made Open Source for personal and club use only. Please verify the Gerbers before making the board. Your feedback is highly appreciated for any further improvements.

Enjoy & 73

Rahul VU3WJM

 

Virus-free. www.avg.com

Re: Socketing a Nano to the other side of the Raduino

Ashhar Farhan
 

The new boards have the arduino socketed on the other sidd.
- f

On Sun, 27 May 2018, 17:46 , <davesters@...> wrote:
I socketed a nano on my bitx40. Ran the pins out of the top of the nano so it was a straight plug into the sockets coming out of the wrong side of the board. 
No big deal.

Re: The new uBITX boards are here

Ashhar Farhan
 

Nothing needs to be changed in the bias. The dc circuit remains the same.
- f

On Sun, 27 May 2018, 16:51 VE7CWS WRSeiler, <waltrseiler@...> wrote:
ASHHAR

Congratulations, you have given a great amount of inspiration to the Ham Radioand Arduino community.

A question or two
If I were to replace the C81 capacitor in my version 3 board, is it advisable to confirm the bias settings?
and what are the exact specs for the said capacitor.

Thank You!

Walt R S VE7CWS

Re: Socketing a Nano to the other side of the Raduino

_Dave_ K0MBT
 

I socketed a nano on my bitx40. Ran the pins out of the top of the nano so it was a straight plug into the sockets coming out of the wrong side of the board. 
No big deal.

Re: The new uBITX boards are here

VE7CWS WRSeiler <waltrseiler@...>
 

ASHHAR

Congratulations, you have given a great amount of inspiration to the Ham Radioand Arduino community.

A question or two
If I were to replace the C81 capacitor in my version 3 board, is it advisable to confirm the bias settings?
and what are the exact specs for the said capacitor.

Thank You!

Walt R S VE7CWS

Re: The new uBITX boards are here

Ashhar Farhan
 

Yes, the IRF510s are now without the feedback.
- f

On Sun, 27 May 2018, 15:04 Philip, <philip.g7jur@...> wrote:
Also C261, and C262. Have been removed from the PA FETs

Philip G7JUR

Re: RF power chain mods and improvements..

vk5gj@...
 

Alison, I have been following your thread with interest but this BF106 I do not know and I cannot find a datasheet
could you "wise me up" please
73 Greg VK5GJ

Re: 2 meter bitx possible?

MVS Sarma
 

On Sat, May 26, 2018 at 10:44 PM, Ashhar Farhan <farhanbox@...> wrote:
It is BFG591 transistor.
Check out hmc482 and bga612 mmics.
= f

On Sat, 26 May 2018, 19:52 David Arthur, <mumrah@...> wrote:
I'm also really curious about an inexpensive VHF/UHF MMIC. Searching around "BGA" takes me to NXP which has a wide selection of parts, but no hits for BGA591

-David

On Fri, May 25, 2018 at 3:34 PM Jerry Gaffke via Groups.Io <jgaffke=yahoo.com@groups.io> wrote:
No hits for BGA591, can you give a link?

In some other forum, I recall a conversation between Ashhar and Allison regarding low noise mmic's for a VHF receiver front end.
Can't find it anymore.  Allison had a favorite, quite cheap, extremely low noise figure.
What was that part?

Jerry

On Fri, May 25, 2018 at 11:36 am, Ashhar Farhan wrote:
As an architecture, the ubitx is quite suitable upto 432 MHz. The changes needed would be as follows:
 
1. The front-end mixer would have to be an ADE-1 or and SBL-1. The current tranformers and BAT54s would cut it.
2. We will need a good band pass filter. Above 146 Mhz, stripline/coax filters are more likely candidates.
3. The LNA and power chain will need MMICs. they are cheap and easily ordered from mouser.com. A pair of BGA591 can easily provide the obligatory 5 watts.
 
- f

--
David K4DBZ
Unofficial bitx chatroom: https://discord.gg/CrHvWFc


Re: The new uBITX boards are here

Philip
 

Also C261, and C262. Have been removed from the PA FETs

Philip G7JUR

Re: uBitX CEC LSB / USB reversal #firmware #ubitx

Tom, wb6b
 

Doing the calibration on WWB can be a bit of a challenge. First time I tried, the signal was weak and various birdies caused the real zero beat to be masked. With a strong signal that problem went away.

However, there is a subcarrier on WWV that makes it difficult to zero beat. I found during the voice announcements the sound of the voice worked well for making the adjustment. After the tones start again, you get a feel for what the signal sounds like when zero beat is obtained, and you don't need to wait for the top of the minute, for voice, after that.

One of the issues is knowing what some ballpark starting values are for the "Master Calibration" and the "USB calibration". So, here are mine after I did a calibration and set the VFO to sound good to my ear.

Reading the calibration settings from the uBITX back into the CEC uBITX Manager the "Master Calibration" ended up at 157,500 and the "USB Calibration" ended up at 11,995,655.

The master calibration number, in the CEC uBITX Manager, is the calibration number you zero beat on times 8,750. So, the Master Calibration can vary from zero to large values. In my case I zero beat at 18, so 18 x 8,750 = 157,500.

Finally, I found you need to turn the power off to the uBITX and back on after each attempt to calibrate. (If connected, be sure to disconnect the USB cable, too, to remove that source of power to the processor.) Otherwise, the calibration spirals out farther away from center each time you repeat the calibration step. 

Tom, wb6b

Re: The new uBITX boards are here

ohwenzelph
 

Ron, C81 was changed to 470pf” and R83 changed from 10 to 2.2 ohms.

Re: KD8CEC uBITX firmware 1.071 #ubitx

Tom, wb6b
 

Hi,

I upgraded to the 1.8 firmware and it seems to work fine. Although I had done my calibration when I had the 1.075 version installed.

Tom, wb6b

Re: The new uBITX boards are here

Ashhar Farhan
 

i have fixed it. i had to edit the html. my career as an html coderr is pitiful.
- f

On Sun, May 27, 2018 at 11:34 AM, Raj vu2zap <rajendrakumargg@...> wrote:
Farhan,

That link for PDF seems split into two where the left most is the new version and right most is old one!


µBITX Circuit D iagram (PDF)  | Raduino Circuit | µBITX ‘s Arduino software
^^^^^                ^^^^

At 27/05/2018, you wrote:
My bad, the new link didn't get udpated. Curse the WP! I have updated it again now.

- f


Re: The new uBITX boards are here

 

Farhan,

That link for PDF seems split into two where the left most is the new version and right most is old one!


µBITX Circuit D iagram (PDF)  | Raduino Circuit | µBITX ‘s Arduino software
^^^^^                ^^^^


At 27/05/2018, you wrote:
My bad, the new link didn't get udpated. Curse the WP! I have updated it again now.

- f

Re: The new uBITX boards are here

Ashhar Farhan
 

jerry,

yep, that's it. There are very subtle changes to the PCB layout. I have brought the audio connector in-line with the raduino connector. This will help us in the future while using a DSP enabled controller board like the JackAl.

- f

On Sun, May 27, 2018 at 11:16 AM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:
OK, changes I see are:

Everything after the audio pre-amp from the M2 relay connection on,
now with a 2n7000 at Q74 for the ptt pop and 2n3904's at Q71,72,73 to replace the TDA2822.

Cap C81 at the Q90 emitter is now 470pf instead of 0.1uF to reduce gain on the low bands
in that first stage of the transmit amp chain.

RD15/RD16's can be stuffed as an alternative to the IRF510's without having to cross the source and drain pins.

Is that it?

Jerry 


On Sat, May 26, 2018 at 10:24 pm, Ashhar Farhan wrote:
My bad, the new link didn't get udpated. Curse the WP! I have updated it again now.