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And that is exactly what you need to do with the BITX concept.

Look at the circuit, think it over with your ideas (and what you have laying around) and modify the design.

Just try out your thoughts, it will be interesting to read about your results here.

?

That¡¯s the way my 6 mtr version is ¡®developed¡¯ ( )

?

Chris PA3CRX

Hello Ashhar,
I quickly browsed through the bitx23 design.?
I really like that there is now a 2m transceiver design.?
I alsi like usage of a Pico as controller, as this is readily available and nowadays cheaper than a Nano and I also like usage of MMICs, but might use other ones, that I have in my junk box (BGA-614).?
For the input stage I would prefer an MMIC like the PGA-103+ due to the low noise figure of <1dB vs 3dB of the AG-303.

BTW: There seems to be a typo for the PA transistor. I guess it is a 2N5109 and not a 2N5901 (PNP Germanium). Why did you pick the 2N5109, as this is obsolete and the ones offered on Aliexpress and eBay are either extremely expensive (>€10 with shipping) or most probably fakes? Would a BFQ19 (€0.70 @Mouser) be an alternative, if a bipolar transistor shall be used? I would prefer something like a RD01MUS2/RD15HVF1 or an AFT05MS004 (€2.62 @Mouser, >10000 avaliable).

What do you think?
--
73, Joerg - DB2OO

ALC is designed not to overdrive the final stage.
In the forum topic where the publication was made, it is described what you should do next.
A link is provided where the description of what to do is found.
This should definitely be done. It's not enough to just do part of it. But it is also written there.

If you haven't already checked the screws that attach the FETs to the heatsink, do it now.
It happens that during the transport these have become loose and therefore they are not clamped to the cooling fin.
So, if you have a good and solid hardware, you can modify the firmware and load the device.
You charge the device with this setting, but there was a delivery in between.
Even though the manufacturer has tested this, it may change by the time it reaches you.
--
Gyula HA3HZ

MicroSD card manufacturers exclude defective cells from use during production.
For this reason, a card called 32GB may not be usable, because, for example, Farhan wrote the image on a high-quality one, and whoever copies it has a card that is a few bits smaller. That's why you can't write on it, even though it's called 32GB.
At the end of formatting, you will get an information window.
There you can see how big the card is and compare it with the size of the image.
At that point, it is already clear whether it will be writable.
Those who use Linux have the option to modify this under Linux and make it a little smaller, which can already be written.
--
Gyula HA3HZ

Probably the mechanical designer thought it would be sturdy. 2mm is just not enough for pressing.
A longer pressed part is worth more, with a longer pressing. By the way, the aluminum heatsink here is a very soft material.
Electrically, I can imagine that the FETs can't transfer the heat, which is why there will be a distorted radio frequency output over time.
--
Gyula HA3HZ

If you use the new firmware, you have to calibrate because of the ALC, just like the v2 ones.
--
Gyula HA3HZ

Hi loopMasta
It does indeed sound similar to my problem but I can't see any noise floor at all. Only this odd chirping noise shown in my second picture.
Connecting/disconnecting the antenna also does nothing for me, no audible change in noise nor visual on the waterfall. Just very strong stations show up (and are barely audible with audio gain turned up high) as described in my initial message.
If I find something I'll be happy let you know. I hope to get some guidance here to what I can try.
73, Nanak

Hi Evan,

I'm using a SanDisk Extreme Plus.? A little bit of web searching shows that essentially all "32G" report 29.8.



I can get a 64 tomorrow and try again.

73,
Dean
KK4DAS

Hi Dean,

When burning the image to a Micro Center 32GB card, I encountered the same issue.? Those cards do not have 31.9GB free.? To not waste more money on another card that is not larger than 31.9 GB, I bought a 64gb card and used it.? 64GB will work, as will any card larger than 32 GB.

It would have been nice if Ashhar Farhan had made the image smaller than 30GB so it could be burned to any 32GB card.? The space used on the card is much less than 30GB.

73
Evan
AC9TU

Jb weld will work just make sure not to get it in threads. Clean with alcohol before applying. Put screw in threaded insert before pressing in then take screw out after inserting and let dry. That should keep most of it out of the threads.?

These inserts are never a good option in my opinion.?

Will I need to calibrate the power output levels, or will I be good to key up?

Yes, the Raspberry Pi immature version 1.7.4. And I just successfully installed the default pi image with no problem.? ?For your image, I used the "other" image menu and selected the file that was extracted from thr RAR file that you posted.? Your file had no extension so I added a . IMG extension to the end so it would find it.

73,Dean

Hi Farhan,

It is a brand new 32G card.

Dean

He did indeed.

Hi Farhan -

There may be something wrong with the image file.? ?I extracted the image file from the rar file and tried to use the Raspberry Pi imager "use custom" option to install it on a 32G card.? ?I got a message "Storage capacity is not large enough.? Needs to be at least 31.9 GB"

73,
Dean
KK4DAS

?

Evan,

Thank you for the update
73,

Robert
AG6LK