Category: uBITX

Carpentry and Socketry for the uBITX

Yesterday I decided to spend some time at the bench — I wanted to get the uBITX boxed up. My basswood box had arrived from Amazon on Friday. It was time for what George Dobbs G3RJV called “socketry.”

First, the back. I figured I would need five connectors back there. Connectors for 12V DC, speaker, and antenna would be needed right away (it is my preference to have the speaker connector on the back of the BITX). Looking ahead, I might want to also have a jack for T/R control of my linear amplifier, and a jack for 24 VDC if I want to go wild and put more voltage on the drains of the IRF510s. So I put two extra holes in there.
Basswood is SO easy to cut. I put the LCD in the center of the front panel, and opted to put the board close to the front of the board. This avoids the need for jumpers to connect the Raduino to the LCD, and it keeps the lines to the front panel controls and connectors very short. I mounted the board on the spacers that came with the BITX, drilling holes the bottom of the basswood box. It all fit quite nicely.
I would need to put two jacks on the front panels: key jack and mic jack. And I’d need two controls: main tuning and AF gain. I used hole saws to cut holes big enough to accommodate the four items.
The controls and jacks were then placed on two small pieces of copper clad board. These then went on the front panel.

Wiring up the uBITX was easy. I just followed Farhan’s instructions. I did the wiring AFTER placing the boards and controls in the box — this helped me keep all the wires at their optimum length (not too long, and more important — not too short!). If you do it this way, put a cloth over the boards so you don’t drop solder blobs on the uBITX.

Farhan’s uBITX fired up nicely as soon as I applied power. The receiver really sounds nice. I hope to make some contacts with it today.

Three cheers for Farhan!

Boxing up my uBITX — Question for the Group

Our friend Rogier and I are involved in an East Coast — West Coast uBITX launch project — we plan to assemble our uBITXs together (more or less, via Skype) and then get them on the air.

As has been my recent practice, I have opted to put my uBITX in the same kind of wooden box that I used for my three scratch-built BITX projects. See above.

Now, due to Farhan’s wizardry the uBITX is considerably smaller than the box. This is, of course, a good thing. It leaves room in the box for many bells and whistles.

But here is my first box design question


 Should I put the uBITX board to the front of the box so that the LCD can be connected to the board DIRECTLY via the connector on the Raduino board (no jumpers needed), or should I put the uBITX board to the back of the box so that I can stick the PA heat sinks out the back? In the later case I’d have to use 4 inch jumper cables to connect the LCD to the Raduino. This use of jumpers seems to increase the possibility of noise from the display.

What say the Knack Wizards? Back of the box with LCD jumpers, or front of the box with no jumpers but heat sinks inside the box?

SolderSmoke Podcast #203 Winter, Transceivers, Antennas, DC RX, uBITX, Mixers, ‘fests, MAILBAG

N6QW in 1959. Building an SSB transceiver

SolderSmoke Pocast #203 is (FINALLY!) available:

http://soldersmoke.com/soldersmoke203.mp3

 24 March 2018

 –The reasons for our delay.
Winter, Computers, College, Family Trees, Lawyers….

 — Winterfest 2018
— Pete launches 2018 THE YEAR OF THE TRANSCEIVER
http://n6qw.blogspot.com/
— SDR – Satan’s Digital Radio?
— Direct Conversion Receiver Projects
— Mixer Musings
— A Thailand Troubleshoot
— Nor’Easter knocks out Bill’s Moxon — An appliance replacement?
— Homebrew Electret Mics. Seriously.
— uBITX Build with Rogier
— Civilized Crystal Testing
— Baofeng!
— DRAGNET

 — MAILBAG
KD4PBJ’s REGEN
N6ORS’s SDR rig
Mike Rainey’s DX-100

Termination Insensitive Amp Boards from VU3ZMV — Eagle Files

Bill:


Here are the eagle file data for the TIA, that I love to use as incorporated in Farhan’s ubitx.

 The TIA , I tried to realise two such on a double sided pcb measuring less than an inch.

It mounts one TIA on each side. I suppose one could simply homebrew.

It has provision for 5 pin berg (male right angle) and would be easy to plug into the main board. We may not need PTH except the connector. We can use bare pins soldering on either side.

Here are the eagle files I created.

Termination Insensitive Amp Boards from VU3ZMV — Eagle Files

Bill:


Here are the eagle file data for the TIA, that I love to use as incorporated in Farhan’s ubitx.

 The TIA , I tried to realise two such on a double sided pcb measuring less than an inch.

It mounts one TIA on each side. I suppose one could simply homebrew.

It has provision for 5 pin berg (male right angle) and would be easy to plug into the main board. We may not need PTH except the connector. We can use bare pins soldering on either side.

Here are the eagle files I created.

Modular BITX Boards

International Brotherhood and the BITX Rigs

Bore and Heriberto’s uBITX board

Nowhere is the International Brotherhood of Electronic Wizards more evident than in the work on the rigs designed by Farhan. With the BITXs we see rigs designed in India that are now being built and modified all over the planet. Here are just a few examples of the global collaboration currently underway:

In Italy, Giuseppe is putting a BTX40 on 20 meters and making it a dual bander:

Hi everyone, I just completed some tests on a Bitx40 running in 20 meters band. I addes the 20 as secondary band activate when needed. I apply some mods to switch to secondary QRPLab BPF filter centered to 20 meters and removed the C91 and C92 caps to work in USB. I done some RX tests in the weekend of iaru hf contest to listen some stations Active.
Here the issues registered:
1) the 20 RX sensitivity was a bit weak compared to 40 meters. I need to increase volume. ( To receive the 20 meters the vfo run to 26 MHZ, mybe some stage suffers of poor performance in this High frequency?)
I also tryed to increase the vfo over maximum allowed by raduino, using external buffer, but no results.
Please read the issues as: work but could work better!
2) the RX was not very clean: voice acceptable, but RX of Digital mode not very stable ( probably the cause could be the vfo shift for poor tuning control. I need to add lock function in firmware …) Or interferences for free wire of connection.
3) Sometimes when switch on or change vfo to other band or mode, the bf amplifier start a self oscillation …Resulting in my wife’s screaming (the tests were also performed during the night!)
No tests was performed at the moment in TX because i need to install the LPF for the new band.
The firmware to make the test was a modified version of 1.17.1, few temporary mods to preset the vfo b to 14 MHz USB and correct the freq. Display.
These my tests.
Giuseppe Callipo IK8YFW.
Pavel is a young fellow in Cuba who is doing great things with the Raduino software:

My Photo

 Hi to all.
The code was updated, the change log is this:
v1.4Update to catch up with the features added in the Raduino v1.17.1 from Allard’s code (CW SPOT and bug fixes)
  • Upgraded the operations instructions
    • More user friendly version with embedded images.
    • Add instructions for the S-meter, AGC and TX-power mods details and tricks.
  • Moved all images to its own folder “images”.

As usual tips/bugs/comments/suggestions are welcomed, you can reach the code here: https://github.com/pavelmc/bitx40/

There is a inoffensive bug in the calibrate process, in which the actual calibrate value is not correctly showed in the LCD until you move the pot to adjust it, I’m working on it.
I’m slowly working in this direction now:
  • Bug removal in the calibrate function.
  • Finish the upgrade of the Si5351mcu lib with some improvements.
  • Adding CAT support via ft857d lib (https://github.com/pavelmc/ft857d):
    • Full compliance needs get rid of all the blocking delay() sentences and that need a structural/paradigm code change and a lot of testing (I have Fldigi/MixW/Hamlib to test, I think if that 3 works the rest will do it)
    • Moving to a library (yatuli: https://github.com/pavelmc/yatuli) for the pot usage, that will ease the process of implementing the CAT as almost all delay() calls are related to pot/clicks, so I’m on it.
    • Maybe implement a multiclick lib to optimize the code and make it more easy to understand.
Any thoughts or whishes related to that?

I plan to make the CAT operation optional via a #define declaration as not all of us will/want-to use that.
73 Pavel CO7WT


Here we see Bore in Montenegro working on a uBITX designed in Cuba by OM Heriberto

Hi Colleagues
Bore Lezaic from Montenegro is working on the uBitx PCB designed by Heriberto -CM2KMK- from Havana, Cuba
Here some pictures he(Bore Lezaic) have posted in my FB wall.
Any question regarding uBitx PCB please send to Heriberto Gonzalez Mendoza at cl2kmk@frcuba.cu (please take care with the email address it is slight different to his actual call sign).
Qrv’s
73’s Jc

Bore and Heriberto’s Board

Hidehiko in Japan was struggling with some LCD noise in his experimental BITX40. I passed along the active filter circuit that I’d first seen in Roy Lewallen’s Optimized QRP rig.

To
BITX20@groups.io Jul 29 2017 at 4:22 AM I’ve finished the Bitx40 experimental project today. I added the AF-AGC and LM386 POP limitter with raduino v1.20.1 (Thanks Allard). And I also added the DuinoVOX for Digital Mode operation. It’s a great radio but the problem is only the “LCD noise” when increasing the AF volume. hi… Can I reduce this noise? Or I have to use the analog VFO? Any suggestions welcome.
ja9mat Hidehiko
To Hidehiko JA9MAT:
Very simple. Just three parts. NPN transistor (like a 2N3904) and a 47k resistor (collector to base) 100 uF cap (base to ground). Vcc the collector. Emitter goes to the DC power input of the AF amplifier. You can see my use of this circuit in the schematic in this blog post:
Look in the lower right, near the LM386 AF amplifier. Click on the schematic to enlarge. 73 Bill N2CQR
Thanks Bill,
Well I added “3-parts”(2N3904+47kohm+100uF) between the D18(1N4148) and the junction of R111(100ohm) and R1113(220ohm). The noise has absolutely gone!
ja9mat Hidehiko.

_._,_._,_

SolderSmoke Podcast #195: (We need some help!) BITX, 60, SSB History, Tribal Socketry

SENDING IT BACK


 SolderSmoke Podcast #195 is available. Link appears below (scroll down)

 We’ve got a problem: Pete Juliano and the QRP Hall of Fame 🙁 PLEASE HELP!


BENCH REPORTS
Pete Releases Smoke (wiring harness)
Pete’s DifX on 60
Architecture and Dual Conversion (uBITX: uses ALL THREE clocks on the Si5351)
The Big Kahuna
ON HACKADAY with Philco SB100 SEE! QRP!!!!!
BITX60
Cap Stack Hack mod (with leads)
Let the smoke out of an Si5351 (shorted output) Several actually.
(Same day delivery zone for Amazon — but no drones or parachutes yet.)
Installed scanning switch
Observations on 60. All the weird bands have a 6 in them: 160, 60, 6
The good: 100 watt limit, wire antennas
The bad: Kind of cliquish– like 75, not much of a CQ band. Channels. Not much activity.
Met Josh KE8CPD on 40. BITX 40!
TRIBAL KNOWLEDGE:
Socketry: How to keep BNC jacks from spinning loose?
Do you heat shrink?
Feel Tech Sig Gen might not have blocking cap at the output.
Speaking of which, when I spoke of the Ne602, I mostly meant blocking caps, not bypass caps.
How come they don’t have a cable TV channel devoted to radios? They have HGTV? Why not HBTV?
REPORT FROM WINTERFEST
Bad weather. Tailgaters wimped out!
Combined forces with Armand WA1UQO.
Met up with Charles AI4OT.
Acquisitions: 1/4 phono jacks, carbon mic, vero board, disc caps, weather radio,
LARGE collection of Electric Radios from Armand. Wow.
Electric Radio notes: 1st Fifty Years of Sideband 1991 articles by Jim Musgrove K5BZH
Why LSB on 75? — so AMers couldn’t follow to top of band
W2, W6, W8s liked phasing, W3, W4, W0 more into filter rigs.
Early SSB guys turning on carrier and talking AM hams into SSB RX.
Kelvinator Refrigerator rigs.
A reading on the homebrewing of SSB rigs.
Tony Fishpool on QSO Today! Pete mentioned prominently.
Good Hacks from ND6T on BITXHacks, Stockton Bridge
MAILBAG

LINK: http://soldersmoke.com/soldersmoke195.mp3

SolderSmoke Podcast 194 – Approaching the Digital-Analog Singularity

SolderSmoke 194 is available (scroll down for link)
March 4, 2017

BIG NEWS: uBITX from Farhan
BENCH REPORTS
Pete: Recycling Old Boards
Working on Arduinos and advanced displays
Bill: SDR Adventures and Misadventures.
RTL-SDR is fun. Built HB front end.
HDSDR under Windows is fun and easy.
Thought about Raspi3, 7 inch touch screen, Linux, software YUCK.
Followed advice of Ken G4IIB and got a 50 buck tablet with Google Play.
Who needs tiny OLEDs? Use a 7 inch tablet as your display!
Building a Ceramic Resonator for the HRO 455 kc filter
The value of doing something different.
Boxed up my NE602 OLED rig.
OLED noise and ACTIVE decoupling.
NE602 and MOSFET tips
LEXICON:
OTD Obsessive Tinkering Disorder G6LBQ
“A Thing of Beauty”
Source of Tombstoning term: Don ND6T.
Ken G4IIB’s extremely smooth audio.
ON THE AIR:
On AM on 75 and 40. Fun. Old Military Radio Net and “The Lonely Guy Net” on 75 Saturday morning.
Good old 17 meters. Open at mid-day
HB2HB on 40 with W0PWE.
Listening on 60
Hambrew magazines disappeared, but are back now.
EMRFD Classic Edition available
New Posts to BITX HACKS
MAILBAG:
Gloves follow-up. Not a good idea.
VK3YE’s QRP by the Bay event and a new book!
Colin M1BUU achieves Mountaingoat status
Martin A65DC JoO MMM in the UAE
Tom NY2RF Editorial with mention of JoO!
Lots of Al Fresco rigs: W8LM BITX on a board, Brad WA8WDQ DC RX, KA4KXX Al Fresco OZ DSB
ON6UU DSB from Spain via Belguim
Hugh ZL1UEM SMALL Si5351 OLED
Cookie Tin rigs VK2EMU’s Biscuit Tin DC RX, WA7HRG’s Popcorn rig
VK4FFAB FB LTSPICE intro
Ken G4IIB’s BITX adventure (with VERY smooth audio. How smooth? We can’t say.)
VU2XE’s BITX with a CAD box
G0ETP’s shockingly beautiful SDR receiver
Alan W2AEW on the mend with broken ankle. His videos are a treasure trove of tribal knowledge.