Re: Spectrum window crash / spot persistence

Patrick Herborn

On Tue, 23 Jul 2019 08:39:11 -0600
"Steve London" <n2ic@...> wrote:

Hiya Steve!

Many thanks for your response.

You have a few misconceptions.
Always happy to be corrected :)

See below.
Righty ho... answered below...

Steve, N2IC

On 07/22/2019 07:11 PM, Patrick Herborn wrote:
Evening All!

Some further updates on this, still using the 18Jul release.

So far I have not been able to replicate the crash with IC-7300, it
looks like the current release is OK for the moment. It does occasionally
reset the waterfall but that is not an issue - the spots stays.

I have had more time with the RSP1A and have more info on that :

With N1MM+ driving the RSP1A, the spectrum display will hang at
occasions around a transmit event. Sometimes it is at the start,
sometimes it is at the end, but it seems to be stable so long
as you don't TX.... if you do, and if it freezes, then it is not
possible to close and re-open the Spectrum window, nor is it
possible to open the SDRPlay ExtIO config window. The only way
to recover is to exit and re-start N1MM+ as a whole - sometimes
this might need Task Manager to kill hung processes. Other times
the frozen Spectrum window will cause a full N1MM+ crash.

Thinking this was a hardware issue I proceeded to add a ferrite
to the USB cable. Unfortunately that did not help, but it did lead
me down a different path. Thinking that the issue was a software
one rather than hardware, and that it was related to the magnitude
of the returned data from the SDR, I tried using Waterfall Bandmap
to provide a spectrum data source to N1MM+....

With WB running, the problem moved. N1MM+ faithfully reported what
WB was sending it, BUT WB itself would hang. It is possible (sometimes
with the help of Task Manager) to restart WB and get the spectrum
going again without having to restart N1MM+ - which is a step in
the right direction, but tedious when WB frequently hangs during TX.
I have both a RSP1 and RSP1A. In the IARU contest I used them both in a SO2R
configuration. I used two instances of WB, each driving it's own N1MM+ spectrum
display. Ran absolutely solid for the 24 hour contest.
That's great news because it means what we are trying to do is
definitely achievable - many thanks for confirming.

The antenna input for the RSP's is from each TS-590SG RX ant output.
Yes, that feature was added from the TS-590S -> TS590SG update. It's
a great rig and a great feature!

The level of RF going to the RSP while transmitting is quite low -
the RSP's are not overloading.
Yes, you are lucky with that. We don't have such an RX out, hence we
use a RX/TX switch in the antenna feedline. This connects the RSP1A
to the antenna during RX (with just over 3dB insertion loss, 3dB for
the power sharing, and a little more for the impedance mismatch).
During TX the RSP1A's output from the box is grounded, but a fair bit
of RF still comes through - as mentioned we see up to -21dBm but
only shortly, presumably because the ADC AGC loop targetting -30dBm
drops it back down.... that's in SDRCV3.

The fact that WB and N1MM+ both freeze is perhaps related to the
fact that WB was "merged" into N1MM+ and hence the source may be
very similar. That could help narrow things down a bit.
Fact ?
I based this assertion on an N1MM Logger+ Facebook post :

Apologies if I misconstrued that - no offence intended! I read it
as your code getting merged into N1MM+, but with hindsight perhaps
it was meant to mean that WB can now supply spectrum data to N1MM+.

I am the author of WB. I am also on the N1MM+ development team. There is
nothing "merged" about WB and N1MM+.
OK, many thanks for the clarification - and that information does help
point in the direction of the ExtIO dll...

WB is written in C#, while N1MM+ is in VB.Net.
Given that they display a *similar* freeze (N1MM+ shows nothing at all,
but WB spectrum freezes, stays visible and continually gets copied to
the waterfall), it suggests that the common item (assuming this is not
just a coincidence) is further upstream.

They communicate with each other over UDP.
WB acts as a Named Source to N1MM+....

The only commonality is that they both use the SDRPlay-supplied ExtIO.
That is definitely looking like the most likely culprit at the moment!

Doesn't explain the IC-7300 issue, but HOPING that was a USB oops.

If you like, I can send you the ExtIO that I am currently using with WB.
Yes, that would be a very good test! Also, if you happen to know, or can
find out, what settings you are using in the SDRPlay config window, that
would help a lot as well.

Furthermore I had two additional ideas to try, when near a rig and SDR
I can try it on....

1) Unplug the SDR from the RX/TX box and see if that helps. If it then
does not crash, then it is almost certainly related to the data coming
back from the SDR.

2) Try tuning the SDR far away from the TX frequency and see what
happens. The strong TX signal should not get past the IF filters and so
the SDR should not "see" the high ADC counts.

I'll try those, and any other suggestions others may have at the
earliest opportunity.

Steve, N2IC
Many thanks for your time, help and patience,

Pat. (M0MGO).

Patrick Herborn <pat@...>

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