Date   
Re: Second batch of uBITX shipping? #ubitx

 

9 weeks in early 1976 because of all the CB licenses the FCC was having to deal with 
Aug
AG5AT

Re: Care and Feeding of SMD Parts

Ken KM4NFQ
 

I buy SMD components in strips of 100, from Mouser. I cut them in strips of 25 and put them in a labeled envelope. I put the envelopes in a box, in order.

To use a component, I press it from the plastic side, through the paper side with tweezers, then put the freed component on the solder-pasted pads. I work over an aluminum tray covered with a cloth. I haven't lost a component yet. Of course, I have only recently started working with SMDs, so take that with a grain of salt. :)

Regards,
Ken, KM4NFQ "Not Fully Qualified"


Re: UPLOAD FIRMWARE IN RADUINO

Michael Hagen
 

I removed the Red Led on BitX Nano.    Folks running on small batteries could save a few silly Ma.  I guess you could turn it off in setup too.

Mike, WA6ISP

 

On 1/31/2018 7:33 AM, KC9SGV wrote:
And the red LED on the nano will be on.

KC9SGV


On Jan 31, 2018, at 9:25 AM, M Garza <mgarza896@...> wrote:

I always remove the power before upgrading.  The Raduino will get power from the USB connector & computer, while being programmed.

Marco - KG5PRT 

On Jan 31, 2018 9:19 AM, "Michel Dupuy" <82f1gtx@...> wrote:
Thank you qq for the procedure (I know). This is to know if the ubitx must be powered or not when transferring. Thank you

-- 
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID  "MotDog@..."
Mike@...

Re: Fixing a blown Raduino board

KC9SGV <kc9sgv@...>
 

Antenna connected.
Refurbished Raduino in place.
Allard's latest BitX40 sketch.
All necessary hardware changes for the latest sketch made.
No radio signal, but spurious noise over the band plus the 7.200 birdie hissing loudly.
What am I missing ?





On Jan 31, 2018, at 8:56 AM, David Nelson <kc2ipx@...> wrote:

I did that twice. The best investment I have made in a long
time is an 40 watt soldering iron with a built in solder sucker.
Worked really well for removing the nano I love it.
                           Dave  kc2ipx

On Wed, Jan 31, 2018 at 9:09 AM, KC9SGV <kc9sgv@...> wrote:
<IMG_2948.JPG>
Hi All,
I managed to fry my Raduino board somehow.
The board is hard to come by at the moment.
So, I ordered the parts via Ebay.
Looking good so far...


Re: Fixing a blown Raduino board

Jack Purdum
 

Allard:

Is the code for the BiX40 backwards compatible from the code for the µBITX?  Could that be an issue for this guy?

Jack, W8TEE



From: KC9SGV <kc9sgv@...>
To: BITX20@groups.io
Sent: Wednesday, January 31, 2018 12:19 PM
Subject: Re: [BITX20] Fixing a blown Raduino board

Antenna connected.
Refurbished Raduino in place.
Allard's latest BitX40 sketch.
All necessary hardware changes for the latest sketch made.
No radio signal, but spurious noise over the band plus the 7.200 birdie hissing loudly.
What am I missing ?





On Jan 31, 2018, at 8:56 AM, David Nelson <kc2ipx@...> wrote:

I did that twice. The best investment I have made in a long
time is an 40 watt soldering iron with a built in solder sucker.
Worked really well for removing the nano I love it.
                           Dave  kc2ipx

On Wed, Jan 31, 2018 at 9:09 AM, KC9SGV <kc9sgv@...> wrote:
<IMG_2948.JPG>
Hi All,
I managed to fry my Raduino board somehow.
The board is hard to come by at the moment.
So, I ordered the parts via Ebay.
Looking good so far...



Re: New case found

MVS Sarma
 


Regards
MVS Sarma
 

On Wed, Jan 31, 2018 at 9:02 PM, Bob Syristatides <bob@...> wrote:
HI MVS Sarma,

Could you point me to this case online?  I was unable to find more information about it.

Thanks,
Bob  KB1TEK


Re: Second batch of uBITX shipping? #ubitx

Clay Nicolsen
 

Well, I finally quit resisting and I've jumped in! Ordered mine the day before yesterday. 

Since the second batch is now shipping, I assume I'm in the third batch.

I'll let you when it arrives.

Clay KI7TMN

Re: Software support Request for Full QSK BITX40

Jerry Gaffke
 

Gary,

Here's some notes on a standard flyback converter:  
    https://en.wikipedia.org/wiki/Flyback_converter
Notice the diode in the secondary, though the text states that in some cases the diode is left out
and the result is just called a flyback transformer. 

The Bitx40 output stage has no diode, so the secondary winding of T7 has a balanced AC current with no DC component. 
The bottom of L8 is bypassed to ground by C153,154, so pin 6 of T7 is just a well filtered 12v DC rail.
T7 is an autotransformer where the primary winding is shared with the secondary making it a bit
harder to think about, but those windings could just as well have been kept separate.

Here's an interesting description of flyback vs forward transformers:  
      https://www.electro-tech-online.com/threads/difference-between-flyback-and-forward-transformer.109013/
#############
A flyback transformer can be thought of as an inductor with an extra winding. The energy is stored in the inductance of the primary winding during the on time of the drive circuit (similar to a switching regulator) which then is transfered to the output winding when the drive circuit is off. A flyback transformer thus has a net DC current through the windings and the core must be designed to handle this without saturating.
A normal forward transformer connection does not store energy but simply transfers the energy from the input winding to the output winding. For a typical switching converter, the transformer is driven by a push-pull driver or by alternately turning off each half of a tapped primary. There usually is no significant off time for the transformer waveform. This transformer type does not have to handle any significant DC current because of the alternating nature of the waveform.
##########

He's assuming it's a flyback converter with that diode in place when he says that the windings (plural, including the secondary) have a net DC current.
In our case, the primary winding has a DC current component, but the secondary does not.
So according to wikipedia it's a flyback transformer, but not a flyback converter.
Not that names matter, except that it helps when reading any reference material.

The output transformer of the uBitx is driven by a push-pull pair, and would be considered a forward transformer. 
Nothing flyback about it, the energy at the input is transferred immediately to the output
without being stored temporarily in the magnetic field.
Output AC voltage is determined by the input AC voltage and the turns ratio, just like a filament transformer


All half baked yet, I'm still trying to sort this out.
One major conundrum: 
When the Bitx40 IRF510 turns off and the magnetic field collapses that energy needs some place to go,
the induced emf in T7 will create voltage spikes that rise as high as it needed till it finds a load, 
perhaps arcing across the transformer.  But my LTSpice simulation of the Bitx40 final with no load
shows no such spike, the output voltage remains pretty much determined by the turns ratio
as if T7 were a straight up forward transformer.

I'll let you worry about those reflections.

Jerry, KE7ER


On Tue, Jan 30, 2018 at 11:01 pm, Jerry Gaffke wrote:
While I'm dim on transmission lines, your description of the reflection is easy enough to follow and makes good sense.
Magnetics I'm even dimmer on.
I had been assuming that T7 was primarily a forward transformer, not a flyback transformer.
Hadn't really thought about it.
But you are probably right that the source of energy when the IRF510 turns off
would be coming from the magnetics of T7, and thus it is a flyback transformer.

I once ran a simulation of the Bitx40 final with a 50 ohm load, and without any load.
The output voltage with no load increased by maybe 20%, perhaps because of lower IR losses in the IRF510.
Would be interesting to see what the output voltage does when the duty cycle at the IRF510 gate changes.
No idea what happens to your reflected wave, will have to think about that one.

These are really interesting questions, and fundamental to how this all works.
I may have to get out the scope, and maybe cut a quarter wave of coax.

Re: Care and Feeding of SMD Parts

Clark Martin
 

I’ve been working with SMDs for a few years now and have lost several.  If the get pressed right they fly off just like a tiddily wink.  They also tend to adhere to tweezers, probes and soldering irons with very little effort.  If it’s a cap or resistor I just fetch another one it’s not worth the effort of a futile search.

One thing I do to try to minimize losses is to limit the number of loose parts I have out to two.  If I need to install more than that I’ll do two at a time and tack solder them into place.


Clark Martin
KK6ISP

On Jan 31, 2018, at 8:44 AM, Ken KM4NFQ <km4nfq@...> wrote:


To use a component, I press it from the plastic side, through the paper side with tweezers, then put the freed component on the solder-pasted pads. I work over an aluminum tray covered with a cloth. I haven't lost a component yet. Of course, I have only recently started working with SMDs, so take that with a grain of salt. :)

Bitx40 USB mod

skreblins00@...
 

Hello everyone!


I want to buy bitx40 and use it as my portable station. I mostly operate digital modes and I am looking for help to add USB mod to bitx40.
I have found some information for that mod and it says to remove C91 i C92 from the board. So, I am asking is that the only thing I should do to add USB to the bitx40, or does it require some code modifications?

I apologize for opening the new topic, but I haven't really find the answer I am looking for.

Thanks in advance,

Steve, 9A3DSU
73

Nextion Display

Dr Fred Hambrecht
 

I may be late to the party, but I have just discovered the NEXTION display. I am using it on my BitX. What makes it really neat is the software that can be downloaded from the manufacturer's site. It takes all the pain out of graphics programming. I have also replaced the UNO with an STM32 as in addition to the normal stuff I have added a GPS module to display time/location/grid square data as well as using the 1PPS to do a continuous correction to the SI oscillator. The higher resolution allows calculating the SWR etc with much finer gradations.  I will be adding a filter board from a CODAN that will allow all band operation.(bought for $12.00 on EBay). Amazing what is available to the homebrewer today!

#Bitx40 Mic Pre-amp MAX9812 #bitx40

 

Thought I would share some settings on playing with a mic pre-amp with the Bitx40.

I am using a MAX9812L

So far its working ok at best I sound a bit robotish.

The audio file is from Michigan to Milford PA websdr 

I am TXing at around 20w with my amp.

I took the audio out through a 10uf dc blocking cap to the bitx40 mic in.

I powered the board from a 9v just for testing.

R136 is about 1/4. If you use a pre-amp you should adjust this lower or you will cause one heck of a noise on tx.

I am not yelling or shouting to get audio out now but not sure I like the audio in any case.


--
David

 N8DAH
Kit-Projects.com

Spare/replacement part

Michael Davis <maddmd818@...>
 

T2 on my Bitx40 is intermittent. By that I mean, if I nudge it my receiver cuts out, if I move it, it comes back on. I have re-soldered the circuit board connections and have removed T2 from an old Bitx40 board. The leads are short and before I attempt to unsolder the bad T2, I though I'd ask if there is a way to buy a spare. I am going to examine the connections more closely with my computer microscope first. Is T1 identical to T2? Any others on the board identical. Thanks

Re: Second batch of uBITX shipping? #ubitx

KK6VLV
 

Ordered uBITX on Dec 17. The order was acknowledged. No word as of yet since my order was acknowledged... ...Still waiting for shipment notice and tracking#.
--
KK6VLV

Re: Bitx40 USB mod

Jerry Gaffke
 

USB is best done on the Bitx40 by upgrading to Allard's firmware:
    https://github.com/amunters/

You need to choose between his Bitx40 and Bitx40-raduino-v2 branches.
Both take some minor hardware mods which Allard has documented extremely well.
V2 requires a slightly more extensive hardware mod, but drives the BFO from the si5351 on the Raduino
instead of using the stock analog crystal oscillator for the BFO, the si5351 makes it much more flexible

Jerry, KE7ER


On Wed, Jan 31, 2018 at 11:03 am, <skreblins00@...> wrote:
I want to buy bitx40 and use it as my portable station. I mostly operate digital modes and I am looking for help to add USB mod to bitx40.
I have found some information for that mod and it says to remove C91 i C92 from the board. So, I am asking is that the only thing I should do to add USB to the bitx40, or does it require some code modifications?

Re: Fixing a blown Raduino board

Allard PE1NWL
 

No, the BitX40 code and the related hardware mods were developed specifically for the BitX40.
The code is NOT compatible to the µBITX!

73 Allard PE1NWL

Re: Bitx40 USB mod

 

Yes to your question C91/91 will attenuate the usb signal to much so they should be removed. You do not have to change firmware or go to V2 for this to work
--
David

 N8DAH
Kit-Projects.com

Re: #Bitx40 Mic Pre-amp MAX9812 #bitx40

Charles D. Smith
 

What did the audio sound like without the pre amp?
72/73 de Chas ai4ot

Re: Fixing a blown Raduino board

KC9SGV <kc9sgv@...>
 

I use Raduino_v1.27.7 for BITX40 - Allard Munters PE1NWL
What is that ticking noise with the DDS knob stationary ?

Bernie,
KC9SGV

On Wed, Jan 31, 2018 at 11:22 AM, Jack Purdum via Groups.Io <jjpurdum@...> wrote:
Allard:

Is the code for the BiX40 backwards compatible from the code for the µBITX?  Could that be an issue for this guy?

Jack, W8TEE



From: KC9SGV <kc9sgv@...>
To: BITX20@groups.io
Sent: Wednesday, January 31, 2018 12:19 PM
Subject: Re: [BITX20] Fixing a blown Raduino board

Antenna connected.
Refurbished Raduino in place.
Allard's latest BitX40 sketch.
All necessary hardware changes for the latest sketch made.
No radio signal, but spurious noise over the band plus the 7.200 birdie hissing loudly.
What am I missing ?





On Jan 31, 2018, at 8:56 AM, David Nelson <kc2ipx@...> wrote:

I did that twice. The best investment I have made in a long
time is an 40 watt soldering iron with a built in solder sucker.
Worked really well for removing the nano I love it.
                           Dave  kc2ipx

On Wed, Jan 31, 2018 at 9:09 AM, KC9SGV <kc9sgv@...> wrote:
<IMG_2948.JPG>
Hi All,
I managed to fry my Raduino board somehow.
The board is hard to come by at the moment.
So, I ordered the parts via Ebay.
Looking good so far...




Re: Bitx40 USB mod

Jerry Gaffke
 

Umm, actually he will need to go from Farhan's stock firmwre to v1 or v2 of Allard's firmware.
Either that or hack the analog BFO such that it operates 3 or 4 khz higher than the usual ~12.998500mhz.
(Actual frequency varies depending on which freq sorted bin of crystals your rig was built with.)

Easiest is to upgrade to Allard's firmware.
He will want to do that anyways, or the tuning pot will be a wee bit unstable.


On Wed, Jan 31, 2018 at 11:38 am, N8DAH wrote:
Yes to your question C91/91 will attenuate the usb signal to much so they should be removed. You do not have to change firmware or go to V2 for this to work