Portsdown 4 Software Update

Discussion about this major DATV Project. See https://wiki.batc.org.uk/The_Portsdown_Transmitter
G8GKQ
Site Admin
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Re: Portsdown 4 Software Update

Post by G8GKQ » Fri Mar 12, 2021 10:38 am

Hi Ken

Just wired up a PE43703 attenuator to my Portsdown 4 and found that it does work with the LimeSDR, but not with the Pluto or the Signal Generator.

It is not the easiest beast to test, because changes entered on the keyboard do not take effect until you select transmit or change band. So for testing, I suggest that you set different attenuation levels on 146 and 437 (they are stored "per-band") and switch between the 2 frequencies. You should then be able to see the attenuation change as you change frequency.

I'll add making it work with the Pluto and the Signal Generator to my to-do list. What setup are you trying to use? I can prioritise that.

Dave

m0ijs
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Joined: Tue Sep 01, 2020 9:40 pm

Re: Portsdown 4 Software Update

Post by m0ijs » Sun Mar 28, 2021 11:37 am

I had a problem also with the attenuator on Portsdown4. Worked fine from the command line, but not when called from the menu into TX.
I think the problem is that the ctlfilter.sh script wants to run the application as root. I modified it to run without elevation and it seems fine.

Tested using PE4302 on Portsdown4 Buster 202102250.

Command line testing done with the platform in TX. Changes on the fly without issue.
Attachments
Edits to ctlfilter.sh
Edits to ctlfilter.sh
Portsdown4 attenuator ctlfilter.sh.png (26.44 KiB) Viewed 1911 times
Testing at the command line
Testing at the command line
Portsdown4 attenuator command line.png (11.53 KiB) Viewed 1911 times
Ian M0IJS

M0YDH
Posts: 264
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Re: Portsdown 4 Software Update

Post by M0YDH » Thu May 27, 2021 5:45 pm

Hello
I can't get the Pluto and attenuator combination working.
I've a PE43703 which has seen Portsdown action before. Solder blobs J4 and J7 are open circuit. J3 is soldered. I did find that I'd cross connected LE and CLK - now corrected. But that hasn't brought the device into control. In 437MHz 333KS Pluto 0, I have 577uW out of the 2 way and 8 way switches. Adding the attenuator card lowers this to 458uW so -1dB instead of anticipated -2. Altering the attenuation value on the screen to e.g. -3 makes no change to power output. During Tx, I'm measuring 0V at the card's connector block of DAT, CLK and LE to ground. These lines all measure 1Kohm terminal block to block.
Software is Buster 202104250.
Can anyone spot an obvious problem or suggest a course of action please? Is the attenuator a dead 'un? I have crude control using Pluto output [-10 here makes it 54uW output]. 2 PE4302 cards are on order and may arrive in late June.

73
David M0YDH
Attachments
P4 GPIO Breakout board and the attenuator. CLK and DAT are cross connected if you're eagle eyed - now corrected.
P4 GPIO Breakout board and the attenuator. CLK and DAT are cross connected if you're eagle eyed - now corrected.
PhotoPictureResizer_210524_182836421_copy_567x1008.jpg (261.85 KiB) Viewed 1629 times

G8GKQ
Site Admin
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Re: Portsdown 4 Software Update

Post by G8GKQ » Thu May 27, 2021 9:07 pm

David

Do you see any data on the data line when you change the filter settings?

Pluto Power should give you control of Pluto output in 1 dB steps. Do you need the attenuator?

Dave

g4hiz
Posts: 91
Joined: Thu Oct 18, 2018 6:40 am

Re: Portsdown 4 Software Update

Post by g4hiz » Fri May 28, 2021 6:52 am

David,

Does the attenuator work in parallel addressing mode (using the DIP switches) ? If so, then it may not be technically 'dead'. However, I had one of these that simply would not work in serial mode, even though I checked everything, but it worked in parallel mode. Not much use as a 'programmable' attenuator, but it's in the junk box in case I need an adjustable attenuator.

73
Jen

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