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Re: T41 receive attenuator working?


 

On 2025-02-03 13:32, D Solt via groups.io wrote:
I wonder if my problem with the attenuator is related to software.
You can scope the control wires going to the attenuators. They're just DC levels.
For the receive attenuator, the signals are U21 pin 21 ( .5dB ) through U21 pin 26.
High = near 3.3V,
Low = near 0V.

- Jerry, KF6VB



All 3 of my boards behave the same. They receive well, but the levels
never change when I adjust the receive attenuator. Maybe I have an
earlier version of the software or the I2C addresses are not right.
My Bit Report shows:
0x21 Front Panel
0x24 BPF
0x27 FR MC23017 NOT FOUND
0x6F RF
0x25 LPF
0x29 LPT
Does this look correct? I'll download the latest version of the SW
tomorrow.
dave
On Fri, Jan 31, 2025 at 6:14?PM Oliver KI3P via groups.io [1]
<oliver@...> wrote:

Here's one way to test it.
Load the latest code onto the Teensy. It has an option under the RF
set menu to change the input attenuation.
Then, put a 10 MHz (or whatever) signal into the RF_in SMA connector
and hook an oscilloscope or spectrum analyzer to the output side of
the attenuator bypass jumper.
You should see the signal amplitude change when you adjust the RF
input attention setting in the RF menu.
-------- Original Message --------
On 1/31/25 9:46 AM, D Solt via groups.io [1] wrote:

How do I tell if the receive PE4302 attenuator is working. I
can't tell any difference in received signals at whatever settings
or when I jumper it out. I have two RF boards built up and they
behave the same. Before I swap the chips out, I wanted to get
some inputs. I haven't gotten to testing the transmitter circuits
yet.
dave, n3ds
Links:
------
[1]
[2] /g/SoftwareControlledHamRadio/message/32563
[3] /mt/110916510/243852
[4] /g/SoftwareControlledHamRadio/post
[5] /g/SoftwareControlledHamRadio/editsub/243852
[6]
/g/SoftwareControlledHamRadio/leave/10484476/243852/1943518115/xyzzy

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