Date   
PCB uBitx -working on it-

JuanCarlos
 

Hi Guys, here something my friend Heriberto-CM2KMK- is doing for the uBitx

Have a good week end

rv's


73's Jc

Re: PCB uBitx -working on it-

Roy Appleton
 

Looking good!

Roy
WA0YMH

On Mar 10, 2017 7:59 PM, "Juan Carlos Berberena Glez" <cubanqrp@...> wrote:

Hi Guys, here something my friend Heriberto-CM2KMK- is doing for the uBitx

Have a good week end

rv's


73's Jc

Re: uBITX - A reboot of the old BITX

William Londree
 

I too am interested in the UBITX and would buy if it comes up as a kit. I wonder if the BITX 40 board could be used to build one?


Bill W6SDI 

Re: PCB uBitx -working on it-

M Garza <mgarza896@...>
 

I hope it stays thru hole.  I don't have much smd experience....

Marco - KG5PRT 

On Mar 10, 2017 8:09 PM, "Roy Appleton" <twelveoclockhigh@...> wrote:
Looking good!

Roy
WA0YMH

On Mar 10, 2017 7:59 PM, "Juan Carlos Berberena Glez" <cubanqrp@...> wrote:

Hi Guys, here something my friend Heriberto-CM2KMK- is doing for the uBitx

Have a good week end

rv's


73's Jc

Re: PCB uBitx -working on it-

M Garza <mgarza896@...>
 

Good job!  Just need to know how to purchase one.....

Marco - KG5PRT 

On Mar 10, 2017 8:24 PM, "M Garza" <mgarza896@...> wrote:
I hope it stays thru hole.  I don't have much smd experience....

Marco - KG5PRT 

On Mar 10, 2017 8:09 PM, "Roy Appleton" <twelveoclockhigh@...> wrote:
Looking good!

Roy
WA0YMH

On Mar 10, 2017 7:59 PM, "Juan Carlos Berberena Glez" <cubanqrp@...> wrote:

Hi Guys, here something my friend Heriberto-CM2KMK- is doing for the uBitx

Have a good week end

rv's


73's Jc

Re: PCB uBitx -working on it-

Michael Hagen
 

Stuff now just can't stray TH.  So you have to give!

I do real well on 0603 now, and I am 71 years old.

I do not do parts 402!

Mike, WA6ISP

Re: BITX40 low output power

 

I would remove the collector R and C and connect direct to bitx. Some value changes may be needed.


At 10/03/2017, you wrote:

Hard to imagine much simpler.  I'd try to figure out how to add a component: a mike gain pot.  Maybe a 10k pot to ground between stages, keep the existing DC blocking caps before and after the pot.  R121 in the existing Bitx40 is no longer necessary with this new stage in front, but R121 would not do any harm.  R1 of the new stage might want to be 47k like R121 was in the Bitx40, since we're running from 12v, not 3v.


On Fri, Mar 10, 2017 at 06:29 am, Raj vu2zap wrote:
Looks good, It could be with less components but go for it as is and see
what you get!

Re: PCB uBitx -working on it-

Larry Przyborowski
 

Hello Jc,
That is a beautiful pcb by Heriberto!

73, Larry K3PEG


On Friday, March 10, 2017 9:26 PM, M Garza <mgarza896@...> wrote:


Good job!  Just need to know how to purchase one.....

Marco - KG5PRT 

On Mar 10, 2017 8:24 PM, "M Garza" <mgarza896@...> wrote:
I hope it stays thru hole.  I don't have much smd experience....

Marco - KG5PRT 

On Mar 10, 2017 8:09 PM, "Roy Appleton" <twelveoclockhigh@...> wrote:
Looking good!

Roy
WA0YMH

On Mar 10, 2017 7:59 PM, "Juan Carlos Berberena Glez" <cubanqrp@...> wrote:
Hi Guys, here something my friend Heriberto-CM2KMK- is doing for the uBitx
Have a good week end
rv's

73's Jc


Re: uBITX - A reboot of the old BITX

John Backo
 

The #1 criteria is to sort the crystals by frequency. Use an oscillator and an accurate frequency counter.
Be sure to measure them all exactly the same way. Choose the set of 5 which are closest in frequency, certainly within
50 Hz of each other; the closer the better. Choose the closest 4 for the filter (and a fifth for the BFO). If making a G3UUR 8 crystal filter, use the same criteria
for 8 crystals. The rest is mostly finding the proper capacitances to make the bandwidth you want. This method will produce
a perfectly good filter, though it is not nearly as rigorous as those usually suggested.

The exact frequency doesn't matter a whole lot; it will be somewhere around 12 MHz. You will choose or make a IF to match it.
But the bandwidth does matter. Really, one should make 2 filters if using SSB and CW. But I have seen good results by using varicaps
to change the bandwidth, and also changing slightly the IF by loading the BFO crystal a little differently. With a DDS, it is a relatively
simple matter to match frequencies to the filter...but the problem of wide or narrow bandwidth for SSB and CW remains. Note that
a crystal filter does not have a 50 ohm input and termination by itself (closer to 200 ohms). Usually one adapts a capacitance or transformer interface to
match the rest of the circuits.

You should measure at least 50 or so crystals to insure getting a good match. I purchased a set of 200 KDS 11.095 MHz crystals and found
at least ten good matches, to within 10 Hz. The results with smaller crystals or "generic" ones is not so good, but possible.

Mainly, match your crystals using the same oscillator conditions, and you should be ok.

Hope this helps.

john
AD5YE

Re: uBITX - A reboot of the old BITX

John Backo
 

"I wonder if the BITX 40 board could be used to build one?" [uBITX]

No.

Too many changes need to be made...primarily from the dual IF...though it would be an interesting project.
I think you would end up with an entirely different set of boards with all the different modules on them.

john
AD5YE

Re: uBITX - A reboot of the old BITX

AndyH
 

Thanks John - I think that gives me the info I need.  Thanks also for the 'paradigm shift' that occurred when you reminded me that we can match the BFO to the filter.  I've got 50 12 MHz crystals inbound and I'm drinking from the multiple fire hoses of EMRFD, W1FB's books, dishal, and various other articles.  I'll either make good filters or spontaneously combust. hi hi   µBITX or bust.

73

Andy/KG5RKB

Re: PCB uBitx -working on it-

MVS Sarma
 

 Looks  nice, Juan.
I suggest that CM2KMK could manage two versions , second one being with smd diode packs as originally proposed by Farhan.. It would great if the pcb is single sided and facilitates home-brewing.
regards
 sarma
 vu3zmv

On Sat, Mar 11, 2017 at 7:29 AM, Juan Carlos Berberena Glez <cubanqrp@...> wrote:

Hi Guys, here something my friend Heriberto-CM2KMK- is doing for the uBitx

Have a good week end

rv's


73's Jc




--
Regards
Sarma
 

Re: uBITX - A reboot of the old BITX

John Backo
 

One thing I forgot to mention...crystals age rather significantly in the first few minutes of oscillation.
What I do is leave them in the oscillator for a about an hour (and measure the frequency). Then I go on to another
and leave the first for a day or so. When I measure the same crystal again, it invariably is off the first measurement,
sometimes by a Khz or more. But Measuring them a third time a day later reveals them to be on about the same frequency.
So "age" your crystals a bit and take measurements after aging. It does make a difference and gets a better match.

Good brewing!

john
AD5YE

Re: uBITX - A reboot of the old BITX

Ashhar Farhan
 

The ubitx uses 8 crystals, not 5. they need to be within 200 Hz of each other.

- f

On Sat, Mar 11, 2017 at 10:02 AM, John Backo via Groups.Io <iam74@...> wrote:
One thing I forgot to mention...crystals age rather significantly in the first few minutes of oscillation.
What I do is leave them in the oscillator for a about an hour (and measure the frequency). Then I go on to another
and leave the first for a day or so. When I measure the same crystal again, it invariably is off the first measurement,
sometimes by a Khz or more. But Measuring them a third time a day later reveals them to be on about the same frequency.
So "age" your crystals a bit and take measurements after aging. It does make a difference and gets a better match.

Good brewing!

john
AD5YE




Re: PCB uBitx -working on it-

Ashhar Farhan
 

Nice stuff, is it single layer? I am working on a double layer layout too.

- f

On Sat, Mar 11, 2017 at 9:52 AM, Mvs Sarma <mvssarma@...> wrote:
 Looks  nice, Juan.
I suggest that CM2KMK could manage two versions , second one being with smd diode packs as originally proposed by Farhan.. It would great if the pcb is single sided and facilitates home-brewing.
regards
 sarma
 vu3zmv

On Sat, Mar 11, 2017 at 7:29 AM, Juan Carlos Berberena Glez <cubanqrp@...> wrote:

Hi Guys, here something my friend Heriberto-CM2KMK- is doing for the uBitx

Have a good week end

rv's


73's Jc




--
Regards
Sarma
 


Re: uBITX - A reboot of the old BITX

John VA7JBE
 

I plan to use a variable bandwidth digital filter from SOTABEAMS (details available here) with my uBitX, which has an adjustable bandwidth (and passband) of 200Hz-3500Hz.  This allows a lot of flexibility in regards to picking out CW signals and cleaning up SSB audio on congested parts of the spectrum. I haven't calculated the bandwidth of the crystal filter described in the schematic, but if it is very narrow I may end up retooling it and letting the audio filter do most of the grunt work. Ironically the digital filter would probably end up costing more than the uBitX itself!

Re: PCB uBitx -working on it-

Yeonghwan Jun
 

I expect It will be good product.
because I want to have it more quickly.

Thanks for it.

Re: PCB uBitx -working on it-

John VA7JBE
 

No reason that there couldn't be two versions of the PCB, one for SMD and one for through hole.

Re: uBITX - A reboot of the old BITX

Ashhar Farhan
 

There is an old but best way to do variable bandwidth. Here is how it works :

You take two crystal filters of, let's say 1 KHz bandwidth at two slightly off frequncies, let's say 12 Mhz and 11 MHz. Now place a mixer between them both, fed from a variable oscillator, in this case of 1 MHz.
Now, only when the oscillator is exactly a 1 Mhz, the the signal of 1Khz bandwidth will make it through. If you shift the frequency of the oscillator the skirts of each of the filter will move closer or away from each other. This is better than anything DSP can offer, it is completely analog too.

- f

On Sat, Mar 11, 2017 at 10:34 AM, John VA7JBE via Groups.Io <va7jbe@...> wrote:

I plan to use a variable bandwidth digital filter from SOTABEAMS (details available here) with my uBitX, which has an adjustable bandwidth (and passband) of 200Hz-3500Hz.  This allows a lot of flexibility in regards to picking out CW signals and cleaning up SSB audio on congested parts of the spectrum. I haven't calculated the bandwidth of the crystal filter described in the schematic, but if it is very narrow I may end up retooling it and letting the audio filter do most of the grunt work. Ironically the digital filter would probably end up costing more than the uBitX itself!


Re: Does this look right?

Dr Fred Hambrecht
 

Do not trim them off, they can be removed in tact with a small screwdriver or pointed object. Press it into the side while pulling gently on the wire. I found a number of uses later on, my most recent use is adding a GPS to guide the oscillator in the Si.

 

v/r

Fred W4JLE

                                                                                    

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Brian Lewis
Sent: Friday, March 10, 2017 7:20 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Does this look right?

 

Just kidding, I'm just getting started on it. Can the unused wires on the two raduino connectors be trimmed off?  Will they ever be used for anything?

.
On Mar 10, 2017, at 7:07 PM, motdog@... wrote:

Oh, What is all that?

Where does one start?