Date   
Re: Variable power control

John Seager <jseager2009@...>
 

Arv, a) Happy New Year. b) Aside from using an attenuator, drive is controlled by
the preset RV1. This could be replaced by a variable pot., perhaps on the back panel. 
However I think it was Farhan who pointed out a long time ago that the only problem
with this is the temptation to keep turning it up!  73,  John  G0UCP



On Monday, 1 January 2018, 17:05, Arv Evans <arvid.evans@...> wrote:



On Mon, Jan 1, 2018 at 9:19 AM, <ad4xx@...> wrote:
I'd love it if I could add a variable control to adjust output power on the uBitx.  After looking for solutions, I understand now that it's not a simple add of a potentiometer.  Anyone done this yet?




Virus-free. www.avast.com

Re: elves are at it

Leland Lannoye
 

Sounds like many experiences I have heard both in and out of the confessional.  Would a bigger salary habe enhanced any thing of real importance?



Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: B C <k9wis@...>
Date: 1/1/18 14:30 (GMT-05:00)
To: BITX20@groups.io
Subject: Re: [BITX20] elves are at it

If I ever run across the guidance couselor that told me electronics was the wave of the future when I was in high school 50 years ago I would punch him in the nose...hi hi..I learned that it takes years of education and training to become an electronics engineer, but no training what so ever to be an electronics engineer's boss. so after 40 years of below average wages I retired. so it looks like we had similar experiences.
My boss whose mission was to keep wages down and 'evaluate performance' even though he had no experience at it, made twice as much as I did.
hi hi..But Im  not bitter...
Brian K9WIS



Re: Variable power control

Jerry Gaffke
 

Farhan did, using RV1.
Alternately, build a new mike preamp with audio gain control, though that solution will not affect CW power level.


On Mon, Jan 1, 2018 at 08:19 am, <ad4xx@...> wrote:
I'd love it if I could add a variable control to adjust output power on the uBitx.  After looking for solutions, I understand now that it's not a simple add of a potentiometer.  Anyone done this yet?

Re: Selecting the correct BFO frequency

Jerry Gaffke
 

I assume this is a single conversion receiver, like the Bitx40.
With the BFO set above the crystal filter, you get a lower sideband signal at around 10mhz.

Assume you wish to transmit at 7mhz.
You could put the VFO at 3mhz,  stuff at 10mhz would get converted to 10-3 = 7.0mhz,
and stuff at 9.999mhz would get converted to 9.999 - 3 = 6.999mhz.
This has the advantage of a low frequency VFO which is likely to be more stable.
But you need the BFO on the high side of the crystal filter.

Or you could put the VFO at 17mhz, stuff at 10mhz would get converted to 17-10 = 7,.0mhz,
and stuff at 9.999mhz would get converted to 17-9.999 = 7.001mhz, so now an upper sideband signal.
To compensate, you want the BFO on the low side of the crystal filter go generate 10mhz USB
which gets flipped to 7mhz LSB.  The advantage is fewer birdies because mixer products
of the VFO haromonics are all well above the operating frequency, but the VFO won't be so stable.

VFO stability is not such an issue if you go to the $1 si5351 instead of building a traditional VFO
using analog techniques.
 
Jerry, KE7ER


On Mon, Jan 1, 2018 at 11:00 am, Kerr Smith wrote:
From what I have read I think the current BFO frequency is a little low and it should be around (9.998887MHz + 2.5kHz) so 10.001387MHz.
Would it also work if I set the frequency to (9.998887 - 2.5kHz) so 9.996387MHz, I think it may be easier to lower the BFO frequency rather than raise it.

SYMBOLS

rf200655
 

Where do you get symbols ike headphone, key , mic  ?
Have decal paper so far no luck finding symbols .
Thanks Ray
KC4DYM

Re: SYMBOLS

Jeffrey Peters <dek9jp@...>
 

Hello Ray,

Great question. I just googled symbols for each morse code key, headphone, and microphone.
The Google images webpages had lots of symbols for each.  Now, to see if there is a better
place to find them.

HNY, Jeff K9JP

On Mon, Jan 1, 2018 at 3:27 PM, rf200655 <crf2@...> wrote:
Where do you get symbols ike headphone, key , mic  ?
Have decal paper so far no luck finding symbols .
Thanks Ray
KC4DYM




--
Not all of me will die - - - The good I do will live forever.  <><

New file uploaded to BITX20@groups.io

BITX20@groups.io Notification <BITX20+notification@...>
 

Hello,

This email message is a notification to let you know that a file has been uploaded to the Files area of the BITX20@groups.io group.

File: ubitx_chassis_122617.pdf

Uploaded By: Ken wa4mnt

Description:
Fabricated PCB uBITX case

You can access this file at the URL:
https://groups.io/g/BITX20/files/ubitx_chassis_122617.pdf

Cheers,
The Groups.io Team

Re: Variable power control

Clark Martin
 

That’s easy enough to fix.  You put a power control pot (2 terminals only) between the +5V and the bias pot(s).  You set the power control to maximum and adjust each bias pot(s) for for the proper current draw.  Now you can turn down the bias / power, as you please.  But you can’t turn it up past “full”.

Clark Martin
KK6ISP

On Jan 1, 2018, at 11:54 AM, John Seager <jseager2009@...> wrote:

Arv, a) Happy New Year. b) Aside from using an attenuator, drive is controlled by
the preset RV1. This could be replaced by a variable pot., perhaps on the back panel. 
However I think it was Farhan who pointed out a long time ago that the only problem
with this is the temptation to keep turning it up!  73,  John  G0UCP



Re: Tell me your favorite uBitx mods

Diver Martin <diver.martin@...>
 

Not sure how I could do CW filter mods without significant mods.  What I'd like for most of the mods is one-wire in, one wire out.  Narrower CW filtering can be achieved by changing the cap values on the Bitx, so that's not one I'd probably aim for.
When you say clean keying for CW, I assume it's clicky, and has sharp edges?  Could be doable with a keyshaper on the output of the CW Tone.  I'll consider it.
QSK:  Pretty significant modification, one I'm not going to attempt with this pass I think.
Digital mode audio/PTT:  PTT in the works, digital mode would just require isolated transformers, no?
AGC: In the works :)
SWR Gauge:  In the works :)
ATU:  In the works :)
CAT Control:  In the works :)

On Mon, Jan 1, 2018 at 8:14 AM, KD8CGH <rkayakr@...> wrote:
Narrower audio filters for CW
Clean keying for CW
Pop elimination
QSK
Digital mode audio interface + PTT
AGC
SWR gauge
Auto Tuner
CAT control




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

Re: Tell me your favorite uBitx mods

Diver Martin <diver.martin@...>
 

The Teensy3.2 is a great little uC, I've used it in a lot of other projects.  Removing the leonardo and replacing with a Teensy would yield a price delta of about ~+$15, as the ATMega32U4 is about $4, popcorn components another $1, and the teensy3.2 is $20.  The downside to a teensy3.2 in this case is that it'll have to require some level shifting for the display and a few other things I think maybe, as it's a 3.3V output IO. (Unless the display and other things can tolerate 3.3V, which I haven't looked into)

On Mon, Jan 1, 2018 at 3:21 AM, gerrykav via Groups.Io <gerrykav@...> wrote:
I am planning on adding this audio filter/DSP project to mine... when I get it.

https://gi1mic.github.io/

/ Gerry




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

Re: Variable power control

Daniel Isaza
 

Just a tought...

what happens if we reduce the voltage to the electret mic with a simple pot? distortion? variable power?

Dan

On Mon, Jan 1, 2018 at 4:09 PM, Clark Martin <kk6isp@...> wrote:
That’s easy enough to fix.  You put a power control pot (2 terminals only) between the +5V and the bias pot(s).  You set the power control to maximum and adjust each bias pot(s) for for the proper current draw.  Now you can turn down the bias / power, as you please.  But you can’t turn it up past “full”.

Clark Martin
KK6ISP

On Jan 1, 2018, at 11:54 AM, John Seager <jseager2009@...> wrote:

Arv, a) Happy New Year. b) Aside from using an attenuator, drive is controlled by
the preset RV1. This could be replaced by a variable pot., perhaps on the back panel. 
However I think it was Farhan who pointed out a long time ago that the only problem
with this is the temptation to keep turning it up!  73,  John  G0UCP




Re: Variable power control

Arv Evans
 

John  G0UCP

Agreed.  Some just can't have enough knobs and some percentage of those "must have
them turned to the right-most position". 

There is also the problem of change in operating parameters when power levels are changed
without a good idea of what the effect might be. 

Attenuators for QRP power levels are inexpensive and easy to build.  Add a switch or relay
and they allow the exciter to run at design specifications and still have controllable output. 

Using an attenuator on the input of a power booster helps insure that the impedances are
matched (maybe!) between exciter and linear amp.

HAPPY NEW YEAR! 

Arv  K7HKL
_._


On Mon, Jan 1, 2018 at 12:54 PM, John Seager <jseager2009@...> wrote:
Arv, a) Happy New Year. b) Aside from using an attenuator, drive is controlled by
the preset RV1. This could be replaced by a variable pot., perhaps on the back panel. 
However I think it was Farhan who pointed out a long time ago that the only problem
with this is the temptation to keep turning it up!  73,  John  G0UCP



On Monday, 1 January 2018, 17:05, Arv Evans <arvid.evans@...> wrote:



On Mon, Jan 1, 2018 at 9:19 AM, <ad4xx@...> wrote:
I'd love it if I could add a variable control to adjust output power on the uBitx.  After looking for solutions, I understand now that it's not a simple add of a potentiometer.  Anyone done this yet?




Virus-free. www.avast.com


Re: elves are at it

Dexter N Muir
 

> Would a bigger salary habe enhanced any thing of real importance?

Yes, Leland. It would have given (me anyway) more resources to do more and learn more, and more leisure to THINK.
73 de ZL2DEX

No TX #ubitx

joe kallo <quietglow@...>
 

Finally got around to putting my ubitx into a box, and I'm having trouble getting measurable output. I followed the bias tuneup procedure but when I got to the part where you HAAALLLLOWW into the mic and watch for deflection on the ammeter, I got none. I also didn't see any movement on the power meter/swr/dummy load. So I hooked up a cw key and confirmed: no measurable output when keyed down.

Where ought I to start troubleshooting?

Thanks much and 73

Joe KD9JLV

Re: No TX #ubitx

joe kallo <quietglow@...>
 

Should have noted: the radio does go into tx mode when the PTT is pressed and when the key is down. 

Re: Variable power control

Art Howard
 

I agree, attenuator would be the best/simplest option

On 1 Jan 2018 3:51 pm, "Daniel Isaza" <hk4dei@...> wrote:
Just a tought...

what happens if we reduce the voltage to the electret mic with a simple pot? distortion? variable power?

Dan

On Mon, Jan 1, 2018 at 4:09 PM, Clark Martin <kk6isp@...> wrote:
That’s easy enough to fix.  You put a power control pot (2 terminals only) between the +5V and the bias pot(s).  You set the power control to maximum and adjust each bias pot(s) for for the proper current draw.  Now you can turn down the bias / power, as you please.  But you can’t turn it up past “full”.

Clark Martin
KK6ISP

On Jan 1, 2018, at 11:54 AM, John Seager <jseager2009@...> wrote:

Arv, a) Happy New Year. b) Aside from using an attenuator, drive is controlled by
the preset RV1. This could be replaced by a variable pot., perhaps on the back panel. 
However I think it was Farhan who pointed out a long time ago that the only problem
with this is the temptation to keep turning it up!  73,  John  G0UCP




Re: #ubitx Re: Ubitx only on preorder now #ubitx

Art Howard
 

109 ground shipping ?

On 1 Jan 2018 1:51 pm, "chris gress" <Chrisg0wfh@...> wrote:
I ordered mine last night and got the HF signals email today I an on pre order got it for the 109 dollar price so I am happy 
Chris G0WFH 

On 1 Jan 2018 19:16, "B C" <k9wis@...> wrote:
Just got an email from hf signals acknowledging my order and payment on Dec 14th, two weeks ago...No indication of when they will ship..
Brian K9WIS



Re: Selecting the correct BFO frequency

Kerr Smith
 

Thanks for the replies - will adjust the BFO so it sits at 20dB down the edge of the filter - I will try lowering its frequency first and see how it goes, I tried changing the capacitance in series with the crystal as a quick test and this did alter its frequency so I will look in to this more tomorrow.

The circuit for the BFO I am using is the one shown in figure 18 of the following site:

http://www.nutsvolts.com/magazine/article/bipolar_transistor_cookbook_part_5

This receiver is planned to be a completely handmade version - my last creation was a Bitx20 using a si5351 and this works very well, it has a display screen, rotary encoder tuning as well as memory - I spent far longer on writing the software than in making the actual circuit (every time I thought I was finished I had another idea for an extra feature).

For this receiver I am trying to design it as much as possible by hand so I can learn more about how to do this. I only have a few bits left such as the second mixer, another RF amplifier and the audio amplifier - I already have working versions of the mixer and tuned RF amplifier so these just need duplicating.

Just to clarify - will it matter if I decide to put the BFO above or below the center frequency of the crystal filter - this is just going to be a receiver for 40m, there will be no transmitting circuits?

Re: #ubitx Re: Ubitx only on preorder now #ubitx

Andrew Farkas <afarkas@...>
 

I ordered mine on the 12th of December and it's due here in VA3 land on Jan 3rd. I ordered it and had it sent DHL for Christmas and later on found out they were previously sold out. 
If I'd known they were sold out I would've just had it sent India Post since I'll probably get dinged for the duty coming into Canada. I'll take the hit though for this uBitx. I was going to buy an FT817ND last year. I figure I'm saving myself at least $700 to $1000 Canadian.
Works for me! 
Thank you Mr. Ashar Farhan!

On Jan 1, 2018 2:51 PM, chris gress <Chrisg0wfh@...> wrote:
I ordered mine last night and got the HF signals email today I an on pre order got it for the 109 dollar price so I am happy 
Chris G0WFH 

On 1 Jan 2018 19:16, "B C" <k9wis@...> wrote:
Just got an email from hf signals acknowledging my order and payment on Dec 14th, two weeks ago...No indication of when they will ship..
Brian K9WIS




Re: Tell me your favorite uBitx mods

K5ESS
 

There are many 3.3v 16 X 2 displays advertised on Ebay.  Practically giving this one away.

https://www.ebay.com/itm/DC-3-3V-HD44780-1602-LCD-Display-Module-16x2-Character-LCM-Blue-Blacklight-NEW-/162222360139?hash=item25c534c64b

Mike

K5ESS

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Diver Martin
Sent: Monday, January 1, 2018 3:33 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Tell me your favorite uBitx mods

 

The Teensy3.2 is a great little uC, I've used it in a lot of other projects.  Removing the leonardo and replacing with a Teensy would yield a price delta of about ~+$15, as the ATMega32U4 is about $4, popcorn components another $1, and the teensy3.2 is $20.  The downside to a teensy3.2 in this case is that it'll have to require some level shifting for the display and a few other things I think maybe, as it's a 3.3V output IO. (Unless the display and other things can tolerate 3.3V, which I haven't looked into)

 

On Mon, Jan 1, 2018 at 3:21 AM, gerrykav via Groups.Io <gerrykav@...> wrote:

I am planning on adding this audio filter/DSP project to mine... when I get it.

https://gi1mic.github.io/

/ Gerry



 

--

Martin Held - AE7EU

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