|
Hi Farhan, ? Studying your circuit I have stumbled upon a query, how the antenna connected to your RF tag in the schematic. ? Is there anything missing in this section ? ? 
? regards charudatt – VU2UPX
|
C4 goes to RF Tag.
On 02/08/2022 2:06 PM, Charudatt Uplap
wrote:
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Show quoted text
Hi
Farhan,
?
Studying
your circuit I have stumbled upon a query, how the antenna
connected to your RF tag in the schematic.
?
Is
there anything missing in this section ?
?
?
regards
charudatt
– VU2UPX
|
The circuit is a direct plot from the production circuit layout. Charu, can you tell me where exactly is the problem? - f
C4 goes to RF Tag.
On 02/08/2022 2:06 PM, Charudatt Uplap
wrote:
Hi
Farhan,
?
Studying
your circuit I have stumbled upon a query, how the antenna
connected to your RF tag in the schematic.
?
Is
there anything missing in this section ?
?
?
regards
charudatt
– VU2UPX
|
Hi Raj,?
Yes, the C4 goes to RF Tag, the wire from Pin 4 (U3) seems to be a remnant of some link unless it is meant to go to a specific location?? Looking a bit further, The Antenna route goes from the Antenna jack via the LPF (not energised) then via pin 7? to U3, so it would therefore seem that the RF would reach the two RF tags is when the LPF relay is energised, and then from there on to the 30MHz LPF.
Apologies, if I'm missing something, thought I would chip in.
Kind regards
Ravi/M0RVI
C4 goes to RF Tag.
On 02/08/2022 2:06 PM, Charudatt Uplap
wrote:
Hi
Farhan,
?
Studying
your circuit I have stumbled upon a query, how the antenna
connected to your RF tag in the schematic.
?
Is
there anything missing in this section ?
?
?
regards
charudatt
– VU2UPX
-- I'm here to add more value to the world than I'm using up.
|
see here Ravi, attached circuits -
On 02/08/2022 4:14 PM, Ravi Miranda
wrote:
toggle quoted message
Show quoted text
Hi Raj,?
Yes, the C4 goes to RF Tag, the wire from Pin 4 (U3) seems
to be a remnant of some link unless it is meant to go to a
specific location??
Looking a bit further, The Antenna route goes from the
Antenna jack via the LPF (not energised) then via pin 7? to
U3, so it would therefore seem that the RF would reach the two
RF tags is when the LPF relay is energised, and then from
there on to the 30MHz LPF.
Apologies, if I'm missing something, thought I would chip
in.
Kind regards
Ravi/M0RVI
C4 goes to RF Tag.
On 02/08/2022 2:06 PM, Charudatt Uplap wrote:
Hi
Farhan,
?
Studying
your circuit I have stumbled upon a query, how the
antenna connected to your RF tag in the schematic.
?
Is
there anything missing in this section ?
?
?
regards
charudatt
– VU2UPX
--
I'm here to add more value
to the world than I'm using up.
|
Hi Raj,?
Thank you for this information, at first glance this is different to the one posted here:?
Anyway, will read the new one now.?
Cheers,
Best 73,
Ravi/M0RVI
see here Ravi, attached circuits -
On 02/08/2022 4:14 PM, Ravi Miranda
wrote:
Hi Raj,?
Yes, the C4 goes to RF Tag, the wire from Pin 4 (U3) seems
to be a remnant of some link unless it is meant to go to a
specific location??
Looking a bit further, The Antenna route goes from the
Antenna jack via the LPF (not energised) then via pin 7? to
U3, so it would therefore seem that the RF would reach the two
RF tags is when the LPF relay is energised, and then from
there on to the 30MHz LPF.
Apologies, if I'm missing something, thought I would chip
in.
Kind regards
Ravi/M0RVI
C4 goes to RF Tag.
On 02/08/2022 2:06 PM, Charudatt Uplap wrote:
Hi
Farhan,
?
Studying
your circuit I have stumbled upon a query, how the
antenna connected to your RF tag in the schematic.
?
Is
there anything missing in this section ?
?
?
regards
charudatt
– VU2UPX
--
I'm here to add more value
to the world than I'm using up.
-- I'm here to add more value to the world than I'm using up.
|
So Ravi, ? This updated schematic now makes a lot of sense. I guess Farhan should also update his schematic on github. ? Thanks Raj, you really made me sound like a dumb guy when you answered with the C4 comment. Nevertheless thanks ? regards charudatt – vu2upx ?
toggle quoted message
Show quoted text
From: [email protected] <[email protected]> On Behalf Of Raj vu2zap
Sent: 02 August 2022 16:30
To: [email protected]
Subject: Re: [BITX20] sBitx doubt? see here Ravi, attached circuits - On 02/08/2022 4:14 PM, Ravi Miranda wrote: Hi Raj,? Yes, the C4 goes to RF Tag, the wire from Pin 4 (U3) seems to be a remnant of some link unless it is meant to go to a specific location?? Looking a bit further, The Antenna route goes from the Antenna jack via the LPF (not energised) then via pin 7? to U3, so it would therefore seem that the RF would reach the two RF tags is when the LPF relay is energised, and then from there on to the 30MHz LPF. Apologies, if I'm missing something, thought I would chip in. ? C4 goes to RF Tag. On 02/08/2022 2:06 PM, Charudatt Uplap wrote: Hi Farhan, ? Studying your circuit I have stumbled upon a query, how the antenna connected to your RF tag in the schematic. ? Is there anything missing in this section ? ? 
? regards charudatt – VU2UPX
-- I'm here to add more value to the world than I'm using up.
|
Charu, Thanks for pointing this out. I will update it- f
So Ravi, ? This updated schematic now makes a lot of sense. I guess Farhan should also update his schematic on github. ? Thanks Raj, you really made me sound like a dumb guy when you answered with the C4 comment. Nevertheless thanks ? regards charudatt – vu2upx ? ? see here Ravi, attached circuits - On 02/08/2022 4:14 PM, Ravi Miranda wrote: Hi Raj,? Yes, the C4 goes to RF Tag, the wire from Pin 4 (U3) seems to be a remnant of some link unless it is meant to go to a specific location?? Looking a bit further, The Antenna route goes from the Antenna jack via the LPF (not energised) then via pin 7? to U3, so it would therefore seem that the RF would reach the two RF tags is when the LPF relay is energised, and then from there on to the 30MHz LPF. Apologies, if I'm missing something, thought I would chip in. ? C4 goes to RF Tag. On 02/08/2022 2:06 PM, Charudatt Uplap wrote: Hi Farhan, ? Studying your circuit I have stumbled upon a query, how the antenna connected to your RF tag in the schematic. ? Is there anything missing in this section ? ?
? regards charudatt – VU2UPX
-- I'm here to add more value to the world than I'm using up.
|
Hi Farhan, ? Well this schematic is not up-to-date. ? Well one of your pledgers shared the updated schematic and made a things clear ? Can you please explain why did you use U3 instead of a simple DPDT relay for Antenna for Rx/Tx Cycle. ? Also if you may , explain the use of a Zener Diode for FSA switch supply ? ? Are there any heat issues with U7 , connecting 12V directly to it ? ? I ask you , since I am designing it at my end ? regards charudatt – VU2UPX ?
toggle quoted message
Show quoted text
From: [email protected] <[email protected]> On Behalf Of Ashhar Farhan
Sent: 02 August 2022 15:18
To: [email protected]
Subject: Re: [BITX20] sBitx doubt ? The circuit is a direct plot from the production circuit layout. Charu, can you tell me where exactly is the problem? ? C4 goes to RF Tag. On 02/08/2022 2:06 PM, Charudatt Uplap wrote: Hi Farhan, ? Studying your circuit I have stumbled upon a query, how the antenna connected to your RF tag in the schematic. ? Is there anything missing in this section ? ?
? regards charudatt – VU2UPX
|
Welcome Charu,
I am under the sBitx's spell for the last week!
73, Raj
On 02/08/2022 4:51 PM, Charudatt Uplap
wrote:
toggle quoted message
Show quoted text
So
Ravi,
?
This
updated schematic now makes a lot of sense. I guess Farhan
should also update his schematic on github.
?
Thanks
Raj, you really made me sound like a dumb guy when you
answered with the C4 comment. Nevertheless thanks
?
regards
charudatt
– vu2upx
?
?
see here Ravi, attached circuits -
On 02/08/2022 4:14 PM, Ravi Miranda
wrote:
Hi Raj,?
Yes, the C4 goes to RF Tag, the wire
from Pin 4 (U3) seems to be a remnant of some link
unless it is meant to go to a specific location??
Looking a bit further, The Antenna
route goes from the Antenna jack via the LPF (not
energised) then via pin 7? to U3, so it would therefore
seem that the RF would reach the two RF tags is when the
LPF relay is energised, and then from there on to the
30MHz LPF.
Apologies, if I'm missing something,
thought I would chip in.
|
Hi Charu Looking forward to see your design, must be very interesting by rolling your own.
- What’s ?the catch between the schematic from GitHub (1rst mixer to antenna via LPF) and the updated from Raj (1rst mixer to antenna bypassing LPF)?
- Do we need a band pass filter for the 1st RX mixer or a single 30MHz LPF is good enough?
- Has any one successfully booted an RPI 400 (identical to RPI4 without EEPROM) or it’s not compatible?
73 Pascal
|
Actually , Farhan had forgotten to update the Schematic on his GithHub page, as a result of which I was searching for a route from the Antenna Connector to the RF port he used. ? But some pledger privileges came to the rescue and I found the right schematic. ? I hope the schematic on the Github is updated. ? I am building a very limited portion of the design. The Exciter and the RPi HAT. ? I attach herewith my version of the schematic for all reference. This is going to be a TH version of the project, with 1/8W resistors ? regards charudatt – VU2UPX ?
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Show quoted text
From: [email protected] <[email protected]> On Behalf Of Pascal Nguyen
Sent: 03 August 2022 01:09
To: [email protected]
Subject: Re: [BITX20] sBitx doubt ? Hi Charu
Looking forward to see your design, must be very interesting by rolling your own. - What’s ?the catch between the schematic from GitHub (1rst mixer to antenna via LPF) and the updated from Raj (1rst mixer to antenna bypassing LPF)?
- Do we need a band pass filter for the 1st RX mixer or a single 30MHz LPF is good enough?
- Has any one successfully booted an RPI 400 (identical to RPI4 without EEPROM) or it’s not compatible?
73 Pascal
|
Very nice schematic, easy to read! Thanks Charu.
- Your Logic input Vi pin 6 / U4 FST3157 is DC isolated from CLK2 and is DC biased by RV1.
I would have a direct Vi input from U3 SI5351 with 3.3V logic which satisfy ViHigh / ViLow, please share your reason.
- I would use 7862 to have 6.2V for pin 5 and use RV1 to bias the V+ from 2.5 to 3.5V for best IMD3 figure.
73 Pascal
|
Raj vu2zap
