Need information about blank PCB filter mod

[F1SSF]

Hi,
I have received my blank PCB filter modulator V2 (my order), and there are some différents between bill of materials and schematics with the wiki pages.
So when I look , I can see RBTVMOD 3.0 on top side. Is it an old or new design ?
Best 73 Franck F1SSF

[g8gtz]

Franck,

It looks like I have made an error in the shop and ordered some version 1 blank PCBs.

The information for these is found here https://wiki.batc.org.uk/Filter_Modulat ... ifications

If the board is built and modified (just 4 component changes) the performance is exactly the same as the version 2 PCB - the first batch of 50 boards we sold are modified version 1 boards and there have been no problems at all with them.

I will be ordering more version 2 PCBs today and happy to replace your board when they arrive in 10 days time - if not you can go ahead and build the board you have but just make sure you use the parts list found on the version 1 wiki page listed above.

Apologies for the error.

73
Noel - G8GTZ

[F1SSF]

Hi Noel,
No worries, the important thing is to understand.
We are big boys, we should get away ......
all the best
Franck

[VK5BI]

Thanks for the info Noel, i received one of these boards the other day as well.

Wayne VK5BI

[g8gtz]

Hi Wayne,

Apologies - happy to send you a replacement board if needed when they arrive.

73 Noel

[VK5BI]

That's ok Noel. It has been over 40 degrees celcius here, too hot to do anything outside so I had already started soldering as I already had the parts from the V2 parts list so I will take the modification approach.

Wayne VK5BI

[g8gtz]

Ha - same logic applied here yesterday to stay in the shack all day - except it was wet and windy and 5 degrees C

[F1SSF]

Hi alls,
Just rapid information, when I check schematics, there is an other mod difficult to apply on this PCB .
In RBTV it's the same 5V on it , in V2 , 5V IQ is powered across 4,7uH.
Noel, do you have feedback about it? necessary or not ?
Best 73 Franck F1SSF

[G8GKQ]

Hi Franck

Apologies, that it not very clear on the Wiki. The 4.7uH are not required in in the PCB that you have. They were included in the Version 2 PCBs as good practice, but made very little difference to the transmitted signal. So they were not included in the details for the V1A modification.

For testing, a board built to V1 standard will work, but there will be some unwanted sidebands due to filter clock breakthrough at symbol rates of 500 KS or less. The V1A mods simply reduce these sidebands and equalise the modulation levels between low and high symbol rates.

I use a V1A board in one of my transmitters and a V2 board in another - there is very little difference.

Dave

[F1SSF]

Ok Dave, thank you for return.
I think to run first test the last week.
73 Franck