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I have a problem with the original bitx20 version #bitx20help #bitx20


dries breughe
 

i built the bitx20 original version in 2012 but it functioned very badly
I built it clean with a PCB board (not the ugly style)

But the reception was rather deaf. except from unwanted beep tones. I suspect unwanted mixing products.
transmitting did not function
I made some modifications based on version 3 and i used a computer controlled vfo
the noise is louder and the beep signals are still there
does anyone have an idea how to solve this problem


Bob Lunsford <nocrud222@...>
 

I'm not trying to be funny but... If it were me, I'd get a V6 and look at that original version as some replacement parts. I know you are determined to make that work but consider the operating time you lose by "re-engineering" that rig.

Bob — KK5R

On Sunday, July 5, 2020, 1:37:06 PM EDT, dries breughe <driesbreughe@...> wrote:


i built the bitx20 original version in 2012 but it functioned very badly
I built it clean with a PCB board (not the ugly style)

But the reception was rather deaf. except from unwanted beep tones. I suspect unwanted mixing products.
transmitting did not function
I made some modifications based on version 3 and i used a computer controlled vfo
the noise is louder and the beep signals are still there
does anyone have an idea how to solve this problem


Arv Evans <arvid.evans@...>
 

Possibly one of the mixer diodes is in backwards. 

The original BITX20 had a very sensitive receiver, which allowed 
spurious signals to be heard if there was no RF input and if the 
volume was turned up way too high.  

What is your MDS (Minimum Discernable Signal) in microvolts?
MDS should be in the 0.2 to 0.4 microvolt range.
If you do not have capability to insert a clean 0.2 to 1.5 microvolt 
signal then ignore that test.   

Like all superhet receivers the BFO frequency needs to be adjusted 
to between 10 and 12 db down the side of the crystal filter passband.
Setting it above the filter passband will give you LSB and setting it 
below the filter passband will give you USB reception.  Setting the 
BFO within the filter passband will give you DSB reception.  If you 
set the BFO too far outside the filter passband your received audio 
will be distorted.  where you adjust the BFO relative to the filter 
passband will affect the amount of highs or lows in your received 
signal, and in your transmitted signal.  

Arv  K7HKL
_._


On Sun, Jul 5, 2020 at 11:37 AM dries breughe <driesbreughe@...> wrote:
i built the bitx20 original version in 2012 but it functioned very badly
I built it clean with a PCB board (not the ugly style)

But the reception was rather deaf. except from unwanted beep tones. I suspect unwanted mixing products.
transmitting did not function
I made some modifications based on version 3 and i used a computer controlled vfo
the noise is louder and the beep signals are still there
does anyone have an idea how to solve this problem


Doug W
 

On Sun, Jul 5, 2020 at 04:46 PM,  wrote:
If it were me, I'd get a V6
The original poster is asking about his BITX20, not the µBITX.  Farhan released the µBITX design in early 2017.  It was first available commercially through HF Signals at the end of 2017.  His BITX design, originally in 20m thus the BITX20, was made public around 2003.  HF Signals started selling a BITX40 populated board in what I think was 2016.  Other have also sold pcb's and/or kits over the years with Farhan's blessing and there are lots of home brewed rigs out there as well.  This list goes all the way back to 2004 as it started around the original BITX20.
 
--
www.bitxmap.com


Ashhar Farhan
 

there are some creaky bones like us who are stull puffing the ol bitx20. this way before this city came up here. we'd hunt 'em nylon tap washers and cook 20 meters on nights of 2009 cycle.
- f

On Mon, Jul 6, 2020 at 7:26 PM Doug W <dougwilner@...> wrote:
On Sun, Jul 5, 2020 at 04:46 PM,  wrote:
If it were me, I'd get a V6
The original poster is asking about his BITX20, not the µBITX.  Farhan released the µBITX design in early 2017.  It was first available commercially through HF Signals at the end of 2017.  His BITX design, originally in 20m thus the BITX20, was made public around 2003.  HF Signals started selling a BITX40 populated board in what I think was 2016.  Other have also sold pcb's and/or kits over the years with Farhan's blessing and there are lots of home brewed rigs out there as well.  This list goes all the way back to 2004 as it started around the original BITX20.
 
--
www.bitxmap.com