[hpsdr] Penny PTT unkeying spike - T/R sequencing?

[Phil Harman]

Hi Tom,

Thanks for the screen shots.  I suspect that the +2kHz tone is a result of
one of the registers in PowerSDR not being cleared when the PTT is
released.

For AM and FM the DSP code does not use a zero frequency IF so that would
be a good place to start looking.

Can you try the same tests with a 50 ohm load connected directly to the RF
output socket on Penny? I'd suggest a BNC plug with a 50 ohm resistor
inside - like the BNC Ethernet terminations we use to use.

I'll also see about getting you a version of KISS KONSOLE which will
enable you to run in full duplex so we can narrow the problem down a bit
more.

I've not seen the instability issues you have with Penelope before. 
Connect your 'scope to pin 3 of the DB25 connector on Penelope. This has
the I signal that is being set to Penelope by PowerSDR when you transmit.

If this is clean when the problem happens then it does indicate a problem
with your Penelope board.

Did the line-in version of initozy11. bat work OK?

73 Phil...VK6APH





> ***** High Performance Software Defined Radio Discussion List *****
>
> One of the guys suggested I post some screen shots of the spike problem
> and
> also pictures of the rig's layout. Hopefully someone might spot something
> that has been done before.. :-)
>
> Here's a thread I've been doing about the HPSDR project on another forum
> as
> a learning experience for newcomers.  On page 8,  my last two posts
> contain
> pictures of the spikes, images and rig layout.
>
> http://amfone.net/Amforum/index.php/topic,26512.msg201631.html#msg201631
>
>
> The Atlas is grounded on the Pandora via the posts. Should I add ground
> braid to various points?  I have the power supply about 6" away using
> twisted pairs for the 12, -12 and 5v leads. I expect to use linear
> supplies
> later, so did not mount the LHU piggyback. I have type 43 ferrite snap ons
> on most cabling, though maybe type 73 would be better.  The USB cable has
> a
> ferrite wound with 8 turns.
>
> The problems occur with all cables plugged in OR just the USB cable and PS
> connected ONLY - all other cables unplugged. Mox mouse or ext PTT key give
> the same results. The rig is barefoot with no linear. The screen shots are
> shown at 10mW AM carrier.  The spike tracks the drive control output in
> amplitude.
>
> Does anyone see a problem?
>
> Thanks.
>
> Tom, K1JJ
>
>
>
>
>
>
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