Differentiated band switching frequencies > 23cm?

Discussion about this major DATV Project. See https://wiki.batc.org.uk/The_Portsdown_Transmitter
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DL5BCA
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Differentiated band switching frequencies > 23cm?

Post by DL5BCA » Thu Jun 17, 2021 5:34 pm

Hello,

is it not possible to do a differentiated band switch (for LNA and/or PA) with frequencies > 23cm with the Portsdown, like Langstone?
73 Thomas
DL5BCA

G8GKQ
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Re: Differentiated band switching frequencies > 23cm?

Post by G8GKQ » Thu Jun 17, 2021 6:54 pm


DL5BCA
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Re: Differentiated band switching frequencies > 23cm?

Post by DL5BCA » Thu Jun 17, 2021 7:14 pm

Hello Dave,

Thank you for the answer

automatic only 4 status, by output MSB LSB.

I think i have to use a MCP23017.

I will test at next weekend.
73 Thomas
DL5BCA

DL5BCA
Posts: 109
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Re: Differentiated band switching frequencies > 23cm?

Post by DL5BCA » Fri Jun 18, 2021 11:03 am

Do I have to activate it in portsdown to control the MCP23017?

It works at the Langstone.
73 Thomas
DL5BCA

radiogareth
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Re: Differentiated band switching frequencies > 23cm?

Post by radiogareth » Fri Jun 18, 2021 12:46 pm

From memory, I think I had to do it from the RPI dashboard via SSH....
I got it working and tested, but I have not used it so far and the card has been rebuilt since. Not sure if its retained in the RPi or on the card...
Gareth.

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Re: Differentiated band switching frequencies > 23cm?

Post by G8GKQ » Fri Jun 18, 2021 9:14 pm

Hi Robert

There are 3 switching lines (the transverter line is used as the 3rd), so 8 combinations are available. I am working on increasing this to 4 lines for 16 combinations.

Control of the MCP23017 is not supported by Portsdown.

Dave

DL5BCA
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Re: Differentiated band switching frequencies > 23cm?

Post by DL5BCA » Sat Jun 19, 2021 7:57 am

Hi Dave,

MCP23017: Then I misunderstood that. I understood it that way, because only 3 lines are available, an I2c expander was chosen as an alternative.

Now a good 8 possibilities are enough.
Can I set the signals myself, or are they fixed?
73 Thomas
DL5BCA

G8GKQ
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Re: Differentiated band switching frequencies > 23cm?

Post by G8GKQ » Sat Jun 19, 2021 10:40 am

Hi Thomas

You can force the 3 outputs to your own settings by setting them in [Menu 3], [Band Settings], [Desired Band], [Express and Lime Port Settings] to numbers above 16:

Code: Select all

16: 000
17: 001
...
23: 111
The script that does this is here: https://github.com/davecrump/portsdown4 ... er.sh#L139

I am currently revising all of the band switching so this will change soon, but there will be some backwards comapatibility.

Dave

DL5BCA
Posts: 109
Joined: Tue Jun 30, 2020 11:59 am

Re: Differentiated band switching frequencies > 23cm?

Post by DL5BCA » Sat Jun 19, 2021 4:30 pm

Thank you for the information Dave.
73 Thomas
DL5BCA

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