Date   
Re: R141

 

The transistor Q14 is probably bad. Check R142 and 143 if both are ok then replace Q14.

I have observed on a FLIR thermal imager that R143 gets real hot and heats up the whole
area on the PCB. This probably degrades other parts around it.

Raj


At 25/01/2018, you wrote:
Replace it with a 1/2 watt.  Also make sure the transistor is not bad.
There have been many discussions about this resistor.  The original part is a 1/4 watt but should be higher.

Hope this helps,

Marco - KG5PRTÂ

On Jan 24, 2018 6:53 PM, "Michael Davis" <maddmd818@...> wrote:
Well, after doing many tests and staring at the tiny components for much too long, I finally noticed, with help from this forum, that R141 was in fact burned open. I believe that I must have transmitted into a non resonant load and smoked it, or set bias or drive too high. What are the wattage values of SMD resistors? I'll replaced it with an axial 1/8 watt 10 ohm. It to started to smoke. One step forward and 2 steps back...but getting there. Is anyone using a QRP tuner? Are you doing this to protect the Bitx PA? 73

Sent from Mike's iPad WA1MAD

Re: Software support Request for Full QSK BITX40

Gordon Gibby <ggibby@...>
 

​Are those ONE microfarad capacitors in the input and output of the series mosfet doing the T/R switching?   Seems sorta large....or is there a decimal point that I can't see and they are really supposed to be 0.1 microfarad????


Thanks....


gordon gibby



From: BITX20@groups.io <BITX20@groups.io> on behalf of Gary O'Neil <n3go@...>
Sent: Wednesday, January 24, 2018 9:27 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Software support Request for Full QSK BITX40
 
... that are masked by the Purging Switch in previous post...   

Thank Apple for the #%~? discontinuity in this post.

With the caveats above, and others to be discovered, proceed at your own risk/reward comfort level. Attached are the remaining mods... requires removal of K1 & K2, and some jumpers at K2 to short pins 3 & 5, and pins 12, 14, & 16. 

All 3 circuits interface to the K1 pads. Any layout volunteers interested in doing a layout of a daughter board that plugs into a 16 Pin DIP header at K1 for this? It doesn’t look like I’m going to learn Kicad this vacation trip. :-(

72/73

Gary, N3GO

P.S.  My apologies for the slow response time and bungled posts. I’ve been barely dangling from the grid this trip.  dit dit !!!

Re: BitX40 voltage booster implementation

AA9GG
 

Specs say the part runs at a fixed 100khz.  The LM2587 seems to be a nice part.  Mouser wants $8 a piece, so module is a sweet deal!

On Wed, Jan 24, 2018 at 6:46 PM, Michael Davis <maddmd818@...> wrote:
In my experience, the boosters are very noisy. They are sort of inverters.

Sent from Mike's iPad WA1MAD









--
Paul Mateer, AA9GG
Elan Engineering Corp.
www.elanengr.com
NAQCC 3123, SKCC 4628

Re: AE7EU Top Level PCB Mod

Diver Martin <diver.martin@...>
 

Geoff, I'm not sure Farhan wants to.  If he wants to, I'm sure he'd approach people with respect to that.  But I've gotten the indication that they're more about encouraging others to set up their own shops for manufacturing.  I won't put words in his mouth, but he may have discovered how time and soul consuming it is to sell a product like this :)

On Wed, Jan 24, 2018 at 6:04 PM, Geoff Lowe <gdlemail@...> wrote:
Aren't we missing the obvious solution for manufacture? Don't we already know someone who is all set up to do this? I'm thinking this might be a nice add-on for Farhan's group to do. They do SMT soldering, torpid winding, etc. Maybe he would be willing to add this to his manufacturing group? Just thinking out loud here . . . 




--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?

Re: Software support Request for Full QSK BITX40

Gary O'Neil
 

... that are masked by the Purging Switch in previous post...   

Thank Apple for the #%~? discontinuity in this post.

With the caveats above, and others to be discovered, proceed at your own risk/reward comfort level. Attached are the remaining mods... requires removal of K1 & K2, and some jumpers at K2 to short pins 3 & 5, and pins 12, 14, & 16. 

All 3 circuits interface to the K1 pads. Any layout volunteers interested in doing a layout of a daughter board that plugs into a 16 Pin DIP header at K1 for this? It doesn’t look like I’m going to learn Kicad this vacation trip. :-(

72/73

Gary, N3GO

P.S.  My apologies for the slow response time and bungled posts. I’ve been barely dangling from the grid this trip.  dit dit !!!

Re: SMD Group Build

 

This is how I DIY SMT....
https://hackaday.io/project/7938-pcb-smt-maker-lab-home
--
AncelB, MIT EE6002

Re: SMD Group Build

Clark Martin
 


Clark Martin
KK6ISP

On Jan 24, 2018, at 5:56 PM, Diver Martin <diver.martin@...> wrote:

Mouser & Digikey are my go-to for SMT parts.  They carry just about everything.  If you have other oddball SMT stuff, and either one are out, head to findchips.com.  There are alternate suppliers, but those two always have what I need, either in the exact specified part number, or an equivalent.  Other places will source 1206's and stuff, but might only sell by the full reel (which I have yet to need, except maybe 0.01uF caps or 0.1uF caps across multiple, multiple projects).

SMD resistors/caps (0603, 5% in my case) are usually cheap enough that I buy them in 1000-piece quantity, because $2 of parts for life or $0.5 for the parts I need for the project, and to always have them on hand, is easy.


I’ve only bought from Digikey a few times but I use Mouser all the time.  Also there are Newark and Allied for such supplies.

I bought a set of 0805 resistors (from 0 ohm through several Mohms) and a set of 0805 caps (10s of pF through 1µF).  They came on cards that fit a day planner binder.  There are between 1 and four strips of 25 each for each value (depending on expected usage levels).  I have little trouble working with 0805 parts and they  fit nicely on .1” grid perfboard (with plated through holes).  

When I use up a strip I buy a new strip of 25 at a local electronics shop (Silicon Valley still has a few).

I haven’t done any PCB fabricating yet but that is in the plans.

SMD diodes and transistors of most any size are easily soldered to perfboard.

I’ve also soldered up to 8 pin SOICss buy putting alternate pins on the perfboard pads and tack soldering leads to the other pins.

It definitely makes for smaller boards.

R141 fried

Michael Davis <maddmd818@...>
 

Well, after months of trouble free, fairly infrequent operating, I did something to burn out R141. After replacing it with a small axial resistor, it worked into a QRP dummy load, but when I connected it to my ground mounted vertical antenna, I smoked the axial too. Stinky smoke. My dummy load is the Elecraft copy so I can read voltage on the graph they publish and convert it to power. I did this while using my cell phone audio frequency app against the mic. 11 volts is about 6 watts. Of course, a steady audio tone may be too much power for the final to handle. I guess I should use my tuner, or use my QRP, 40 meter antenna and no others. What mismatch can the Bitx40 handle? Should I reduce power out by lowering the drive by adjusting r136? Any other thoughts? Thanks

Re: AE7EU Top Level PCB Mod

Geoff Lowe
 

Aren't we missing the obvious solution for manufacture? Don't we already know someone who is all set up to do this? I'm thinking this might be a nice add-on for Farhan's group to do. They do SMT soldering, torpid winding, etc. Maybe he would be willing to add this to his manufacturing group? Just thinking out loud here . . . 

Re: Software support Request for Full QSK BITX40

Gary O'Neil
 

The attached circuits replace K1 and eliminates K2 to achieve Full QSK on BITX40. Also requires M1 to M2 jumper (220 ohms used in prototype.

QSK to >50 WPM in simulation, with prototype in close agreement but unverified. Not yet supported in SW, but impact (TBD) should be zero to minimal.
I anticipate receiver recovery time to bound QSK limit due to overdamped power supply bypassing, and/or audio interstage coupling, much of which is contributing to the current T/R switching noise problems that are masked by 

Re: SMD Group Build

Clark Martin
 

On Jan 24, 2018, at 5:27 PM, Jack Purdum via Groups.Io <jjpurdum@...> wrote:

All:

We have a small group of local hams who enjoy building stuff, yet most are scared to death of SMD parts. Our last build had 29 do the build which is about half of our group. What I'd like to do is put together a small SMD project and have 30 or so boards made. (I have no idea what a good starter project would be.) If anyone has done this, are the board costs less than thru-holes boards? Also, are Mouser and Digikey the likely source for large (e.g., 1206) parts or do you know of a better source.

Re: SMD Group Build

Diver Martin <diver.martin@...>
 

Hi Jack,

SMT board is the same as Through hole, no cost difference.  Some PCB manufactures will put a limit on the hole density, but it's usually gotta be something pretty high like 1000 holes/sqin (think perfboard).  As an example, OSHPark charges $5/sqin.  It doesn't matter if it's all SMT + vias, no vias no drills, or TH.  2 layers, $5/sqin as big as you want to go.  

Mouser & Digikey are my go-to for SMT parts.  They carry just about everything.  If you have other oddball SMT stuff, and either one are out, head to findchips.com.  There are alternate suppliers, but those two always have what I need, either in the exact specified part number, or an equivalent.  Other places will source 1206's and stuff, but might only sell by the full reel (which I have yet to need, except maybe 0.01uF caps or 0.1uF caps across multiple, multiple projects).

SMD resistors/caps (0603, 5% in my case) are usually cheap enough that I buy them in 1000-piece quantity, because $2 of parts for life or $0.5 for the parts I need for the project, and to always have them on hand, is easy.

On Wed, Jan 24, 2018 at 5:27 PM, Jack Purdum via Groups.Io <jjpurdum@...> wrote:
All:

We have a small group of local hams who enjoy building stuff, yet most are scared to death of SMD parts. Our last build had 29 do the build which is about half of our group. What I'd like to do is put together a small SMD project and have 30 or so boards made. (I have no idea what a good starter project would be.) If anyone has done this, are the board costs less than thru-holes boards? Also, are Mouser and Digikey the likely source for large (e.g., 1206) parts or do you know of a better source.

Thanks!

Jack, W8TEE




--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?

Re: ant tuner

 

I'll second the vote for the Elecraft  T1. This is a great little tuner, runs off of a 9v battery. I have used it for 
doublets, end-fed wires, loops and various other antennas both at home and in the field. 

Cheers

Michael VE3WMB 

SMD Group Build

Jack, W8TEE
 

All:

We have a small group of local hams who enjoy building stuff, yet most are scared to death of SMD parts. Our last build had 29 do the build which is about half of our group. What I'd like to do is put together a small SMD project and have 30 or so boards made. (I have no idea what a good starter project would be.) If anyone has done this, are the board costs less than thru-holes boards? Also, are Mouser and Digikey the likely source for large (e.g., 1206) parts or do you know of a better source.

Thanks!

Jack, W8TEE

Re: Updates to later batches ubitx

Jerry Gaffke
 

No mention of any changes for the uBitx in this forum, so I'd expect none.
The Bitx40 with Raduino started shipping a year ago, no changes since.

Once a prototype works, Farhan turns the design over to hfsignals.
It's up to us to develop these kits any further than that.
The intent is to provide a radio that encourages experimentation,
not a fully polished product.

Jerry


On Wed, Jan 24, 2018 at 04:48 pm, Dennis Yancey wrote:
Are the later batches incorporating changes, upgrades, bug fixes? If so, are these documented somewhere?

Re: Software support Request for Full QSK BITX40

Gary O'Neil
 

Take 2...  This is the circuit (required for Full QSK) that also mitigates the Tx and Rx pop/thump noises in SSB mode. Should work fine with relays and with or without other mods, but not yet verified. Volunteers?

See previous posts for how it works. Fast and reliable with Full QSK prototype, but not yet optimized.

72

Gary, N3GO


On Sun, Jan 21, 2018 at 12:45 pm, Gary O'Neil wrote:
It appears my dwg failed to post. Will attempt ago when I settle in at campground.

Gary, N3GO 

Re: #ubitx Power Supply For uBitx? #ubitx

Jim
 

Vince
i ordered a ten amp like that. I don’t have ubitx yet but I measured the voltage coming from the supply and it was 12.18 volts without a load
Jim
wb4ctx

Re: R141

M Garza <mgarza896@...>
 

Replace it with a 1/2 watt.  Also make sure the transistor is not bad.
There have been many discussions about this resistor.  The original part is a 1/4 watt but should be higher.

Hope this helps,

Marco - KG5PRT 

On Jan 24, 2018 6:53 PM, "Michael Davis" <maddmd818@...> wrote:
Well, after doing many tests and staring at the tiny components for much too long, I finally noticed, with help from this forum, that R141 was in fact burned open. I believe that I must have transmitted into a non resonant load and smoked it, or set bias or drive too high. What are the wattage values of SMD resistors? I'll replaced it with an axial 1/8 watt 10 ohm. It to started to smoke. One step forward and 2 steps back...but getting there. Is anyone using a QRP tuner? Are you doing this to protect the Bitx PA? 73

Sent from Mike's iPad WA1MAD








R141

Michael Davis <maddmd818@...>
 

Well, after doing many tests and staring at the tiny components for much too long, I finally noticed, with help from this forum, that R141 was in fact burned open. I believe that I must have transmitted into a non resonant load and smoked it, or set bias or drive too high. What are the wattage values of SMD resistors? I'll replaced it with an axial 1/8 watt 10 ohm. It to started to smoke. One step forward and 2 steps back...but getting there. Is anyone using a QRP tuner? Are you doing this to protect the Bitx PA? 73

Sent from Mike's iPad WA1MAD

Updates to later batches ubitx

Dennis Yancey <bigbluedry@...>
 

Are the later batches incorporating changes, upgrades, bug fixes? If so, are these documented somewhere?