PE43703 Attenuator & Lime o/p Issues

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PE43703 Attenuator & Lime o/p Issues

Post by G6MNJ » Sun Sep 08, 2019 1:00 pm

I have 2 issues, probably separate.

1) Connecting power measuring equipment to the output of the Lime mini with its gain set to 88 often the first few times I ask it to transmit I only get -40dBm of power then eventually it rises to around 0dBm where it should be. Then randomly it will drop to -40dBm even though no parameters have changed.

2) Accepting the above is unstable makes the second issue hard to debug but I am sure the PE43703 attenuator is simply not accepting commands from the Pi to reduce the power levels it stubbornly sits at 0.25dB loss. I have added the wiring of the Pi to the PE43703 which for clarity is using a Willow GPIO board where:-

PE43703 Wire Colour Willow board GPIO Pin on 40 pin header
DATA Yellow 6 31
CLK White 5 29
LE Grey 15 10

The leads between Pi and PE43703 for LE, CLK and DATA have a 1k ohm series resistor in them to prevent damage to the Pi. I am not 100% confident that this how this should be done but cannot see how else it would work with a resistor.

The PE43703 has been modified as per BATC instructions to switch it to series mode. The LED illuminates on power up and pads that were altered have been checked for continuity as expected. DIP switches 1&2 have been set to off and on and they seem to make no difference.

Can anybody shed some light on these issues please - I have been stuck on this problems for weeks and am at loss to what to do.

Thanks Paul G6MNJ
2019-09-08 13.32.40.jpg
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Re: PE43703 Attenuator & Lime o/p Issues

Post by G8GKQ » Sun Sep 08, 2019 5:21 pm


Issue 1: What video settings are you using? Please try Pi Camera 333KS FEC 7/8 DVB-S2. Alternatively try EasyCap (video in) 500 KS FEC 1/2 DVB-S.

Issue 2: All looks good to me. I have sent you a PM.

Dave, G8GKQ

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Re: PE43703 Attenuator & Lime o/p Issues

Post by g4hiz » Mon Sep 09, 2019 8:16 am


I recommend to double check that the Data, Clock and LE lines go to the correct functions on the Pi header. I initially had a similar problem with my attenuator board due to the Clock and Data lines being transposed.


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Re: PE43703 Attenuator & Lime o/p Issues

Post by M0PIT » Tue Sep 10, 2019 3:49 pm


Due to a self inflicted touch screen issue, I’ve been using Ethernet to control the Portsdown remotely.

My Lime Mini goes into a PE43703 enumerator being controlled from the Pi, and even though I’ve changed the attn level for the 2m band I was using, via the remote console, the signal level even after a reboot did not change.

I suspected it was the PE43703 or either my conf or my wiring, but after some investigation I found that if I disconnected the PE43703 interface and rebooted, I had about 32dB of attenuation, which is as it should be, however if I reconnected the interface and rebooted, I got about 5dB of attenuation, however I had configure Portsdown for 30dB of attenuation. To me this is saying that via the remote console, if you change the attn level, that change is not being passed on to the PE43703.

Phil, M0PIT

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