Date   
Re: Mic Preamp install, bias resistors #ubitx

Arvo W0VRA
 

Cool, Nick!  I've got a couple of SSM2167 boards, too.

Can you draw up a schematic?  I think I follow what you did, but I want to make sure.

I plan to replace both R1 and R2 with pots.  I'm also going to try to use C3 as part of a HPF by putting another pot between pin 6 and ground.  The goal is to keep everything <300 Hz out of the signal chain.

Re: Ubitx case

Jeffrey Benedict
 

Here's a link to the "Cases and Enclosures" on US eBay:

https://www.ebay.com/b/Electrical-Boxes-Enclosures/42886/bn_7717992

 

Go nuts.

Re: uBitX PA Drivers

K9HZ <bill@...>
 

Those are excellent low power RF amplifiers… will work above the 432 band…

 

 

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

 

 

email:  bill@...

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Mike
Sent: Tuesday, January 23, 2018 3:56 AM
To: BITX20@groups.io
Subject: Re: [BITX20] uBitX PA Drivers

 

On Mon, Jan 22, 2018 at 09:00 pm, M Garza wrote:

2SC1973

Re: Mic Preamp install, bias resistors #ubitx

chris gress <Chrisg0wfh@...>
 

Got 3x max4466 mic amps with mic for £1,98 each just need my ubix and case chris

On 23 Jan 2018 01:44, <nickpullen@...> wrote:
Hi.
I have completed this as per above. Seems to work.
I have also replaced the default R1 15K resistor with a 50k pot for easy adjustment.
Did some testing last night, But I really need to get a setup where I can hear myself.

Ill try some more QSO test tonight.

73 VK4PLN


Re: Mica Cap replacements for WA2EBY Filter?

MVS Sarma
 

After long soaking, we need to request the paper  slowpealing by pressure and labor.
 All these could be avoided by the Yellow papers with silicon coating solde by ebay, aliexpress  very cheao and also on amazon.com.
after transfer wait for pcb cool to 50%down. just peel off . I have been comfortably using this.
 
Though costly American made Press and peel papers with starch coating , just fload off few seconds after dip in wrm water.
 But only few could afford.
I also admire their green TRF coating foil that protects pcb from etchant attack at unwanted   microscopic holes . I used to get dam nice resilts from the   P$P papers.


Regards
MVS Sarma
 

On Tue, Jan 23, 2018 at 3:49 PM, Lawrence Galea <9h1avlaw@...> wrote:
Hi Mark
I've used photo paper with no problems at all.
You have to leave the pcb in the water to soak quite well before trying to remove the paper backing.
Regards
Lawrence


On Tue, Jan 23, 2018 at 5:38 AM, Mark Baldridge <marktbaldridge@...> wrote:
Lawrence, I've tried a bunch of different paper. Either the toner would stick to the paper and not transfer (plenty of heat and pressure here) or the paper would stick to the copper and just tear when I'd try to pull it off. That stuff I linked to was what it took for me. Although I'd certainly like to not have to buy something else.

On Mon, Jan 22, 2018 at 3:44 AM, Lawrence Galea <9h1avlaw@...> wrote:
You can use glossy photo paper and other glossy paper.
When you use the clothes iron just press it on the paper.
If it does not cover the whole pcb lift it up and place place it on the part that was not covered.
If you move it as if you are pressing clothes you may smudge the traces.
If when you remove the paper with water you see that part of the traces did not stick (because the toner will still be attached to the paper) just press it again with the iron.
You have to strike a balance between having good toner transfer and smudging thin lines because if you leave it too long the toner will spread which also results in a thinner coating the etchant eating away part of the trace.
Regards
Lawrence

On Sun, Jan 21, 2018 at 10:33 PM, Mark Baldridge <marktbaldridge@...> wrote:
I used this paper. https://www.amazon.com/Circuit-Board-Thermal-Transfer-Special/dp/B01CGRL2G0/ 

You print the image in reverse to scale on that stuff, iron it to the copper clad, and then soak in ferric chloride. Getting a good etching mask is where all the trickiness is. I think lots of iron pressure and heat really help.

On Sat, Jan 20, 2018 at 8:03 AM, Jack Purdum via Groups.Io <jjpurdum@...> wrote:
The date etching shows how good the etch was. What did you end up using, from method to etchant?

Jack, W8TEE



From: Mark Baldridge <marktbaldridge@...>
To: BITX20@groups.io
Sent: Saturday, January 20, 2018 1:21 AM
Subject: Re: [BITX20] Mica Cap replacements for WA2EBY Filter?

I just etched the filter board! Not a perfect toner transfer, but not too bad. The traces are solid and pass the beep test. :)



On Fri, Jan 19, 2018 at 10:18 PM, Mvs Sarma <mvssarma@...> wrote:
Jstin, If you make PCB, it could have facity for both throhiole for silver mca and for smd too.

Regards
MVS Sarma
 

On Sat, Jan 20, 2018 at 3:04 AM, Mark Baldridge <marktbaldridge@...> wrote:
This will be great. I plan to order the SMT parts as they are cheap, and then "upgrade" to the mica caps if I need to.

On Thu, Jan 18, 2018 at 9:15 AM, <freefuel@...> wrote:
Hi Mark, I have started to build up two filter boards for this amp, one with mica caps I was lucky enough to find at a local surplus outlet, and another with SMT parts. I'll post the results as soon as I test them. 

-Justin N2TOH 



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Re: BITX-40 just built it #bitx40

Vic WA4THR
 

Very nice. Can you tell us more about the laminated paper and front plate design software you used for the front panel? I have the same case on a slow boat coming "someday".

=Vic=

Re: help

Perrouin pierre andre
 

Brian

Many thanks for advice,work nicely.

73 f6fjh

-----Message d'origine-----
De : BITX20@groups.io [mailto:BITX20@groups.io] De la part de B C
Envoyé : mardi 23 janvier 2018 04:53
À : BITX20@groups.io
Objet : Re: [BITX20] help

yep..been there done that...you need to use the zipped library...you have some big html version of the file..I will send you the zip file then use the arduino IDE to add it to your project.
Brian K9WIS

---- Perrouin pierre andre <pa.perrouin@...> wrote:
Hello



Why when i want upload in my arduino the Sketch Raduino_v1.27.7 for BITX40 –
i can’t compile ,i have error stray ‘#’ in program.



Thanks for help.



Pierre-André

F6FJH






Re: Mica Cap replacements for WA2EBY Filter?

Lawrence Galea
 

Hi Mark
I've used photo paper with no problems at all.
You have to leave the pcb in the water to soak quite well before trying to remove the paper backing.
Regards
Lawrence


On Tue, Jan 23, 2018 at 5:38 AM, Mark Baldridge <marktbaldridge@...> wrote:
Lawrence, I've tried a bunch of different paper. Either the toner would stick to the paper and not transfer (plenty of heat and pressure here) or the paper would stick to the copper and just tear when I'd try to pull it off. That stuff I linked to was what it took for me. Although I'd certainly like to not have to buy something else.

On Mon, Jan 22, 2018 at 3:44 AM, Lawrence Galea <9h1avlaw@...> wrote:
You can use glossy photo paper and other glossy paper.
When you use the clothes iron just press it on the paper.
If it does not cover the whole pcb lift it up and place place it on the part that was not covered.
If you move it as if you are pressing clothes you may smudge the traces.
If when you remove the paper with water you see that part of the traces did not stick (because the toner will still be attached to the paper) just press it again with the iron.
You have to strike a balance between having good toner transfer and smudging thin lines because if you leave it too long the toner will spread which also results in a thinner coating the etchant eating away part of the trace.
Regards
Lawrence

On Sun, Jan 21, 2018 at 10:33 PM, Mark Baldridge <marktbaldridge@...> wrote:
I used this paper. https://www.amazon.com/Circuit-Board-Thermal-Transfer-Special/dp/B01CGRL2G0/ 

You print the image in reverse to scale on that stuff, iron it to the copper clad, and then soak in ferric chloride. Getting a good etching mask is where all the trickiness is. I think lots of iron pressure and heat really help.

On Sat, Jan 20, 2018 at 8:03 AM, Jack Purdum via Groups.Io <jjpurdum@...> wrote:
The date etching shows how good the etch was. What did you end up using, from method to etchant?

Jack, W8TEE



From: Mark Baldridge <marktbaldridge@...>
To: BITX20@groups.io
Sent: Saturday, January 20, 2018 1:21 AM
Subject: Re: [BITX20] Mica Cap replacements for WA2EBY Filter?

I just etched the filter board! Not a perfect toner transfer, but not too bad. The traces are solid and pass the beep test. :)



On Fri, Jan 19, 2018 at 10:18 PM, Mvs Sarma <mvssarma@...> wrote:
Jstin, If you make PCB, it could have facity for both throhiole for silver mca and for smd too.

Regards
MVS Sarma
 

On Sat, Jan 20, 2018 at 3:04 AM, Mark Baldridge <marktbaldridge@...> wrote:
This will be great. I plan to order the SMT parts as they are cheap, and then "upgrade" to the mica caps if I need to.

On Thu, Jan 18, 2018 at 9:15 AM, <freefuel@...> wrote:
Hi Mark, I have started to build up two filter boards for this amp, one with mica caps I was lucky enough to find at a local surplus outlet, and another with SMT parts. I'll post the results as soon as I test them. 

-Justin N2TOH 



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Re: uBitX PA Drivers

Mike
 

Thanks . . . for the value of single emitter resistor (to replace the 22ohm pairs), would I use 11 ohm?

Re: uBitX PA Drivers

Mike
 

On Mon, Jan 22, 2018 at 09:00 pm, M Garza wrote:
2SC1973

Re: uBitX PA Drivers

M Garza <mgarza896@...>
 

If you have some 2SC1973s lying around, you could sub those in.  They would produce about 2 watts or so in a push-pull circuit.  They are rated for 1 watt each.

Remember, this was made to be something easily repairable.  I don't think 2N3904s will be going obsolete anytime soon.

Marco - KG5PRT 



On Jan 22, 2018 10:44 PM, "Mike" <msmith@...> wrote:
I presume the driver pairs Q92,Q93/Q96,Q97 are in parallel to increase current handling . . . any recommendations to replace with just a single pair, something rated a little heftier?

uBitX PA Drivers

Mike
 

I presume the driver pairs Q92,Q93/Q96,Q97 are in parallel to increase current handling . . . any recommendations to replace with just a single pair, something rated a little heftier?

Re: Mica Cap replacements for WA2EBY Filter?

Mark Baldridge
 

Lawrence, I've tried a bunch of different paper. Either the toner would stick to the paper and not transfer (plenty of heat and pressure here) or the paper would stick to the copper and just tear when I'd try to pull it off. That stuff I linked to was what it took for me. Although I'd certainly like to not have to buy something else.

On Mon, Jan 22, 2018 at 3:44 AM, Lawrence Galea <9h1avlaw@...> wrote:
You can use glossy photo paper and other glossy paper.
When you use the clothes iron just press it on the paper.
If it does not cover the whole pcb lift it up and place place it on the part that was not covered.
If you move it as if you are pressing clothes you may smudge the traces.
If when you remove the paper with water you see that part of the traces did not stick (because the toner will still be attached to the paper) just press it again with the iron.
You have to strike a balance between having good toner transfer and smudging thin lines because if you leave it too long the toner will spread which also results in a thinner coating the etchant eating away part of the trace.
Regards
Lawrence

On Sun, Jan 21, 2018 at 10:33 PM, Mark Baldridge <marktbaldridge@...> wrote:
I used this paper. https://www.amazon.com/Circuit-Board-Thermal-Transfer-Special/dp/B01CGRL2G0/ 

You print the image in reverse to scale on that stuff, iron it to the copper clad, and then soak in ferric chloride. Getting a good etching mask is where all the trickiness is. I think lots of iron pressure and heat really help.

On Sat, Jan 20, 2018 at 8:03 AM, Jack Purdum via Groups.Io <jjpurdum@...> wrote:
The date etching shows how good the etch was. What did you end up using, from method to etchant?

Jack, W8TEE



From: Mark Baldridge <marktbaldridge@...>
To: BITX20@groups.io
Sent: Saturday, January 20, 2018 1:21 AM
Subject: Re: [BITX20] Mica Cap replacements for WA2EBY Filter?

I just etched the filter board! Not a perfect toner transfer, but not too bad. The traces are solid and pass the beep test. :)



On Fri, Jan 19, 2018 at 10:18 PM, Mvs Sarma <mvssarma@...> wrote:
Jstin, If you make PCB, it could have facity for both throhiole for silver mca and for smd too.

Regards
MVS Sarma
 

On Sat, Jan 20, 2018 at 3:04 AM, Mark Baldridge <marktbaldridge@...> wrote:
This will be great. I plan to order the SMT parts as they are cheap, and then "upgrade" to the mica caps if I need to.

On Thu, Jan 18, 2018 at 9:15 AM, <freefuel@...> wrote:
Hi Mark, I have started to build up two filter boards for this amp, one with mica caps I was lucky enough to find at a local surplus outlet, and another with SMT parts. I'll post the results as soon as I test them. 

-Justin N2TOH 



--




--



Virus-free. www.avast.com




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Mark Baldridge
608.561.3853

Re: help

K9WIS
 

yep..been there done that...you need to use the zipped library...you have some big html version of the file..I will send you the zip file then use the arduino IDE to add it to your project.
Brian K9WIS

---- Perrouin pierre andre <pa.perrouin@...> wrote:

Hello



Why when i want upload in my arduino the Sketch Raduino_v1.27.7 for BITX40 –
i can’t compile ,i have error stray ‘#’ in program.



Thanks for help.



Pierre-André

F6FJH






Re: #ubitx and 6 meters #ubitx

Tom Christian
 

Thanks, Jerry!  Will check out the Murata PX1002.
Tom
AB7WT

Re: #ubitx and 6 meters #ubitx

Tom Christian
 

Thanks Ashhar!  I'll follow up while I wait for my ubitx to arrive.  I've been reading like crazy in the meantime.  I just received Wes Hayward's Introduction to RF Design book and have been relearning some basics.....:)
Tom
AB7WT

Re: while Im impatiently waiting

K9WIS
 

hmmm..never thought of that....I was just going to dabble with raduino..but now you've rally got me thinking...I could use a good antenna analyzer..

---- Arv Evans <arvid.evans@...> wrote:

Brian K9WIS

Now you are ready to make lots of computerized tools:

- Digital voltmeter
- Digital SWR bridge
- Digital LCR meter

- Period counter
- Frequency counter

- Audio signal source
- Digital signal source

- Scalar Network Analyzer
- Swept Frequency Signal Generator
- Swept voltage component analyzer

and so on. Once you have NANOs and a compiler the whole world opens up.

Arv
_._



On Mon, Jan 22, 2018 at 4:27 PM, B C <k9wis@...> wrote:

Bought some Nano's from ebay, 3 for $10, and a5351a breakout board from
adafruit for $7.95, and an old lcd display from the junk box..Downloaded
the bitx40 code from github..Got it to compile and load...let the fun begin.

Still waiting
Brian K9WIS



Re: Ubitx case

Art Howard
 

Too many holes for my taste

On 22 Jan 2018 3:05 pm, "philip yates" <phil@...> wrote:
Looks like the same case available from R.S.Components. 754-5979 - next on my list.
Am very interested as to how much room you have front to back for the mounting of the µBitx.

Phil - G7BZD

On Mon, Jan 22, 2018 at 8:53 PM, N8DAH <Dherron@...> wrote:

I made a post a little after the Ubitx was announced about this case.

The case came today and thought I would share that the quality of the packing and the case is top notch.

Looks great can't wait to get the ubitx that it belongs to!

I will be buying from this seller again when I need a case.
--
David

 N8DAH
Kit-Projects.com


Re: I2C display up and running on my uBITX

John Backo
 

Good information, Jerry.

That is a good price on the sunrom FTDI cable, if it is genuine.

They were about $US20.00 a short time ago.

Admittedly, though, it is old technology by now with the advent of the CH3xx
and AD2102 chips, but still useful.

john
AD5YE

Re: I2C display up and running on my uBITX

Jim Sheldon
 

100 percent agree Jerry and thanks for the excellent explanation.  Cleared up a lot of mud in my mind.  I actually went back, carefully removed the +5 wiring I had on pins 2 and 15 of the display, put the pins back in place from 2 and 15 of the I2C controller and rewired my pickoff interface on the back of the Raduino to put +5 instead of 3.3 volts to the I2C controller.  I HAD removed the 4.7K pullups to Vcc on that controller before I even used it on 3.3v.  With +5 on the controller, I have excellent display contrast and it runs just fine in the uBITX.  

I still have no noise or tuning artifacts in the receiver from the I2C interface.  I DO have a good DC supply coming to the radio - its an MFJ 40 amp (quiet) switcher that I use to power the main station (K3S, P3 and KAT500 tuner on the 13.8 supply) KPA500 amp running on 220V.

BTW I just worked PV8ADI on 40 meter CW with the uBITX just after I finished putting the I2C display back the way it should have been in the first place.

Jim - W0EB

------ Original Message ------
From: "Jerry Gaffke via Groups.Io" <jgaffke@...>
Sent: 1/22/2018 8:54:55 PM
Subject: Re: [BITX20] I2C display up and running on my uBITX

I looked a bit further into this, it's not as trivial a problem as it first seems.
I believe removing the two pullup resistors from the i2c backpack is the best solution if using a 5v i2c display
along with the Raduino's 3.3v si5351, powering the i2c backpack and the display from 5v.
The 3.3v SDA and SCL signals into the 5v powered chip on the backpack is not enough
to be guaranteed to work, though good enough for our purposes.

If you want guarantees, best to go to an i2c level shifter such as  this one previously referenced:
     https://www.adafruit.com/product/757 
There are similar i2c displays designed to operate from 3.3v, not 5v.
That is also a good solution, though will require a new 3.3v regulator to power the display
as the 3.3v rail from the Nano can't supply much current.

Here's a schematic of the backpack:  https://www.sunrom.com/p/i2c-lcd-backpack-pcf8574
and a datasheet for the PCF8574 chip it uses:   http://www.ti.com/lit/ds/symlink/pcf8574.pdf

Datasheet says the default i2c write address with no resistors is 0x4E.
the LSB of that address is 0 for write and 1 for read,  so the i2c read address is 0x4F.
In binary, the write address = 0x4E =  0100-1110
Some i2c documentation figure that to be 7 bits of address = 0100-111 = 0x27  plus a R/W bit in the LSB.
Your scanner apparently uses this 7 bit address convention when reporting addresses.
A short across the A0,A1,A2 resistor pads (a piece of wire will do) can change the write address to any of
the eight addresses between 0x27 and 0x20 as described in the TI datasheet referenced above.

It says on this webpage:  https://tronixlabs.com.au/news/tutorial-serial-i2c-backpack-for-hd44780compatible-lcd-modules-with-arduino/

"We may send you one of two versions of this device - the difference is the controller IC. If you have the PCF8574T. the default I2C bus address is 0x27. If you have the PCF8574AT the default I2C bus address is 0x3F."

The datasheet for the PCF8574 says it will work fine on anything between 2.5v and 6.0v,
so your powering the i2c backpack from 3.3v is perfectly legal (assuming the Nano's wimpy little regulator can supply it).
Likewise, the HD44780 that is likely on your LCD is good from 2.7v to 5.5v:   https://www.sparkfun.com/datasheets/LCD/HD44780.pdf
However, on page 48 of the HD44780 datasheet is says that the input high voltage must be a minimum of 0.7Vcc = 0.7*5v = 3.5v,
your i2c backpack powered from 3.3v will not be able to meet that spec when the HD44780 is running on 5v.
(Though you have found it to work anyway).

On page 4 of the PCF8574 datasheet, it says input high voltage for this chip should be a minimum of 0.7Vcc as well.
So removing the two 5v pullup resistors from the i2c backpack means SDA and SCL into the PCF8574 won't meet spec,
as they get a max of 3.3v using the Raduino's R13 and R14:  http://www.hfsignals.com/wp-content/uploads/2017/12/raduino.pdf
But seems to work, and this is probably the easiest mod to get this i2c display to talk on the same bus as the 3.3v si5351.

Going back to this webpage:  https://www.sunrom.com/p/i2c-lcd-backpack-pcf8574
the resistors we want to remove are the 4.7k resistors at R8 and R9, probably marked as "472" (so 47 plus 2 zeros worth of ohms)
There is a third 4.7k that feeds Q1 to turn on the LED, no need to mess with that.
From the photo, I believe the two 4.7k resistors to be removed are in the middle row, nearest the PCF8574 chip.
You should measure 0 ohms between the SDA pin on the 4 pin header to one of the resistors, and 0 ohms from SCL to the other resistor.
I would use two soldering irons, one on each end of the resistor, to pick them off the board, though many here
just use one iron and figure out how to touch both ends simultaneously.

Jerry, KE7ER


On Mon, Jan 22, 2018 at 04:35 pm, Jim Sheldon wrote:
Thanks Jerry,
That cleared up a lot of stuff We were unable to find regarding the controllers and caused a bit of worry regarding possible damage to the Si5351A by running the backpack on 5 volts even with the pullups on SDA & SCL removed.  Now I won't worry about it and will run the next one on 5V and just remove the 2 pullup resistors.
 
As to addressing, some of these (with all 3 address pads open) have a base address of 0x3F and some have a base of 0x27 and no documentation comes with them, hence the need to run "Scanner" on them.
 
Thanks again, 
W0EB